Embed hiredis as it is broken literally everywhere

22 files changed, 5485 insertions, 4 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 99c1f56c9..f6830b64a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -666,10 +666,10 @@ IF(PCRE_LIBRARY)
 ELSE(PCRE_LIBRARY)
 	SET(CMAKE_REQUIRED_LIBRARIES "${CMAKE_REQUIRED_LIBRARIES};-lpcre")
 ENDIF(PCRE_LIBRARY)
-# Libhiredis pc file is so special
+
 IF(ENABLE_HIREDIS MATCHES "ON")
-	ProcessPackage(HIREDIS LIBRARY hiredis INCLUDE hiredis.h INCLUDE_SUFFIXES include/hiredis
-		ROOT ${HIREDIS_ROOT_DIR} MODULES hiredis libhiredis)
+	ADD_SUBDIRECTORY(contrib/hiredis)
+	INCLUDE_DIRECTORIES(BEFORE "${CMAKE_SOURCE_DIR}/contrib/hiredis")
 ENDIF(ENABLE_HIREDIS MATCHES "ON")
 
 
diff --git a/contrib/hiredis/CMakeLists.txt b/contrib/hiredis/CMakeLists.txt
new file mode 100644
index 000000000..c8896868c
--- /dev/null
+++ b/contrib/hiredis/CMakeLists.txt
@@ -0,0 +1,15 @@
+SET(HIREDISSRC	async.c
+				dict.c
+				hiredis.c
+				net.c
+				read.c
+				sds.c)
+
+SET(HIREDIS_CFLAGS "")
+IF("${CMAKE_C_COMPILER_ID}" STREQUAL "Clang" OR "${CMAKE_C_COMPILER_ID}" STREQUAL "GNU")
+	SET(HIREDIS_CFLAGS "${HIREDIS_CFLAGS} -O3")
+ENDIF()
+
+ADD_LIBRARY(rspamd-hiredis STATIC "${HIREDISSRC}")
+
+SET_TARGET_PROPERTIES(rspamd-hiredis PROPERTIES COMPILE_FLAGS "${HIREDIS_CFLAGS}")
\ No newline at end of file
diff --git a/contrib/hiredis/COPYING b/contrib/hiredis/COPYING
new file mode 100644
index 000000000..a5fc97395
--- /dev/null
+++ b/contrib/hiredis/COPYING
@@ -0,0 +1,29 @@
+Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice,
+  this list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of Redis nor the names of its contributors may be used
+  to endorse or promote products derived from this software without specific
+  prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/contrib/hiredis/README.md b/contrib/hiredis/README.md
new file mode 100644
index 000000000..4f1a58d2a
--- /dev/null
+++ b/contrib/hiredis/README.md
@@ -0,0 +1,392 @@
+[![Build Status](https://travis-ci.org/redis/hiredis.png)](https://travis-ci.org/redis/hiredis)
+
+# HIREDIS
+
+Hiredis is a minimalistic C client library for the [Redis](http://redis.io/) database.
+
+It is minimalistic because it just adds minimal support for the protocol, but
+at the same time it uses a high level printf-alike API in order to make it
+much higher level than otherwise suggested by its minimal code base and the
+lack of explicit bindings for every Redis command.
+
+Apart from supporting sending commands and receiving replies, it comes with
+a reply parser that is decoupled from the I/O layer. It
+is a stream parser designed for easy reusability, which can for instance be used
+in higher level language bindings for efficient reply parsing.
+
+Hiredis only supports the binary-safe Redis protocol, so you can use it with any
+Redis version >= 1.2.0.
+
+The library comes with multiple APIs. There is the
+*synchronous API*, the *asynchronous API* and the *reply parsing API*.
+
+## UPGRADING
+
+Version 0.9.0 is a major overhaul of hiredis in every aspect. However, upgrading existing
+code using hiredis should not be a big pain. The key thing to keep in mind when
+upgrading is that hiredis >= 0.9.0 uses a `redisContext*` to keep state, in contrast to
+the stateless 0.0.1 that only has a file descriptor to work with.
+
+## Synchronous API
+
+To consume the synchronous API, there are only a few function calls that need to be introduced:
+
+```c
+redisContext *redisConnect(const char *ip, int port);
+void *redisCommand(redisContext *c, const char *format, ...);
+void freeReplyObject(void *reply);
+```
+
+### Connecting
+
+The function `redisConnect` is used to create a so-called `redisContext`. The
+context is where Hiredis holds state for a connection. The `redisContext`
+struct has an integer `err` field that is non-zero when the connection is in
+an error state. The field `errstr` will contain a string with a description of
+the error. More information on errors can be found in the **Errors** section.
+After trying to connect to Redis using `redisConnect` you should
+check the `err` field to see if establishing the connection was successful:
+```c
+redisContext *c = redisConnect("127.0.0.1", 6379);
+if (c != NULL && c->err) {
+    printf("Error: %s\n", c->errstr);
+    // handle error
+}
+```
+
+### Sending commands
+
+There are several ways to issue commands to Redis. The first that will be introduced is
+`redisCommand`. This function takes a format similar to printf. In the simplest form,
+it is used like this:
+```c
+reply = redisCommand(context, "SET foo bar");
+```
+
+The specifier `%s` interpolates a string in the command, and uses `strlen` to
+determine the length of the string:
+```c
+reply = redisCommand(context, "SET foo %s", value);
+```
+When you need to pass binary safe strings in a command, the `%b` specifier can be
+used. Together with a pointer to the string, it requires a `size_t` length argument
+of the string:
+```c
+reply = redisCommand(context, "SET foo %b", value, (size_t) valuelen);
+```
+Internally, Hiredis splits the command in different arguments and will
+convert it to the protocol used to communicate with Redis.
+One or more spaces separates arguments, so you can use the specifiers
+anywhere in an argument:
+```c
+reply = redisCommand(context, "SET key:%s %s", myid, value);
+```
+
+### Using replies
+
+The return value of `redisCommand` holds a reply when the command was
+successfully executed. When an error occurs, the return value is `NULL` and
+the `err` field in the context will be set (see section on **Errors**).
+Once an error is returned the context cannot be reused and you should set up
+a new connection.
+
+The standard replies that `redisCommand` are of the type `redisReply`. The
+`type` field in the `redisReply` should be used to test what kind of reply
+was received:
+
+* **`REDIS_REPLY_STATUS`**:
+    * The command replied with a status reply. The status string can be accessed using `reply->str`.
+      The length of this string can be accessed using `reply->len`.
+
+* **`REDIS_REPLY_ERROR`**:
+    *  The command replied with an error. The error string can be accessed identical to `REDIS_REPLY_STATUS`.
+
+* **`REDIS_REPLY_INTEGER`**:
+    * The command replied with an integer. The integer value can be accessed using the
+      `reply->integer` field of type `long long`.
+
+* **`REDIS_REPLY_NIL`**:
+    * The command replied with a **nil** object. There is no data to access.
+
+* **`REDIS_REPLY_STRING`**:
+    * A bulk (string) reply. The value of the reply can be accessed using `reply->str`.
+      The length of this string can be accessed using `reply->len`.
+
+* **`REDIS_REPLY_ARRAY`**:
+    * A multi bulk reply. The number of elements in the multi bulk reply is stored in
+      `reply->elements`. Every element in the multi bulk reply is a `redisReply` object as well
+      and can be accessed via `reply->element[..index..]`.
+      Redis may reply with nested arrays but this is fully supported.
+
+Replies should be freed using the `freeReplyObject()` function.
+Note that this function will take care of freeing sub-reply objects
+contained in arrays and nested arrays, so there is no need for the user to
+free the sub replies (it is actually harmful and will corrupt the memory).
+
+**Important:** the current version of hiredis (0.10.0) frees replies when the
+asynchronous API is used. This means you should not call `freeReplyObject` when
+you use this API. The reply is cleaned up by hiredis _after_ the callback
+returns. This behavior will probably change in future releases, so make sure to
+keep an eye on the changelog when upgrading (see issue #39).
+
+### Cleaning up
+
+To disconnect and free the context the following function can be used:
+```c
+void redisFree(redisContext *c);
+```
+This function immediately closes the socket and then frees the allocations done in
+creating the context.
+
+### Sending commands (cont'd)
+
+Together with `redisCommand`, the function `redisCommandArgv` can be used to issue commands.
+It has the following prototype:
+```c
+void *redisCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
+```
+It takes the number of arguments `argc`, an array of strings `argv` and the lengths of the
+arguments `argvlen`. For convenience, `argvlen` may be set to `NULL` and the function will
+use `strlen(3)` on every argument to determine its length. Obviously, when any of the arguments
+need to be binary safe, the entire array of lengths `argvlen` should be provided.
+
+The return value has the same semantic as `redisCommand`.
+
+### Pipelining
+
+To explain how Hiredis supports pipelining in a blocking connection, there needs to be
+understanding of the internal execution flow.
+
+When any of the functions in the `redisCommand` family is called, Hiredis first formats the
+command according to the Redis protocol. The formatted command is then put in the output buffer
+of the context. This output buffer is dynamic, so it can hold any number of commands.
+After the command is put in the output buffer, `redisGetReply` is called. This function has the
+following two execution paths:
+
+1. The input buffer is non-empty:
+    * Try to parse a single reply from the input buffer and return it
+    * If no reply could be parsed, continue at *2*
+2. The input buffer is empty:
+    * Write the **entire** output buffer to the socket
+    * Read from the socket until a single reply could be parsed
+
+The function `redisGetReply` is exported as part of the Hiredis API and can be used when a reply
+is expected on the socket. To pipeline commands, the only things that needs to be done is
+filling up the output buffer. For this cause, two commands can be used that are identical
+to the `redisCommand` family, apart from not returning a reply:
+```c
+void redisAppendCommand(redisContext *c, const char *format, ...);
+void redisAppendCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
+```
+After calling either function one or more times, `redisGetReply` can be used to receive the
+subsequent replies. The return value for this function is either `REDIS_OK` or `REDIS_ERR`, where
+the latter means an error occurred while reading a reply. Just as with the other commands,
+the `err` field in the context can be used to find out what the cause of this error is.
+
+The following examples shows a simple pipeline (resulting in only a single call to `write(2)` and
+a single call to `read(2)`):
+```c
+redisReply *reply;
+redisAppendCommand(context,"SET foo bar");
+redisAppendCommand(context,"GET foo");
+redisGetReply(context,&reply); // reply for SET
+freeReplyObject(reply);
+redisGetReply(context,&reply); // reply for GET
+freeReplyObject(reply);
+```
+This API can also be used to implement a blocking subscriber:
+```c
+reply = redisCommand(context,"SUBSCRIBE foo");
+freeReplyObject(reply);
+while(redisGetReply(context,&reply) == REDIS_OK) {
+    // consume message
+    freeReplyObject(reply);
+}
+```
+### Errors
+
+When a function call is not successful, depending on the function either `NULL` or `REDIS_ERR` is
+returned. The `err` field inside the context will be non-zero and set to one of the
+following constants:
+
+* **`REDIS_ERR_IO`**:
+    There was an I/O error while creating the connection, trying to write
+    to the socket or read from the socket. If you included `errno.h` in your
+    application, you can use the global `errno` variable to find out what is
+    wrong.
+
+* **`REDIS_ERR_EOF`**:
+    The server closed the connection which resulted in an empty read.
+
+* **`REDIS_ERR_PROTOCOL`**:
+    There was an error while parsing the protocol.
+
+* **`REDIS_ERR_OTHER`**:
+    Any other error. Currently, it is only used when a specified hostname to connect
+    to cannot be resolved.
+
+In every case, the `errstr` field in the context will be set to hold a string representation
+of the error.
+
+## Asynchronous API
+
+Hiredis comes with an asynchronous API that works easily with any event library.
+Examples are bundled that show using Hiredis with [libev](http://software.schmorp.de/pkg/libev.html)
+and [libevent](http://monkey.org/~provos/libevent/).
+
+### Connecting
+
+The function `redisAsyncConnect` can be used to establish a non-blocking connection to
+Redis. It returns a pointer to the newly created `redisAsyncContext` struct. The `err` field
+should be checked after creation to see if there were errors creating the connection.
+Because the connection that will be created is non-blocking, the kernel is not able to
+instantly return if the specified host and port is able to accept a connection.
+```c
+redisAsyncContext *c = redisAsyncConnect("127.0.0.1", 6379);
+if (c->err) {
+    printf("Error: %s\n", c->errstr);
+    // handle error
+}
+```
+
+The asynchronous context can hold a disconnect callback function that is called when the
+connection is disconnected (either because of an error or per user request). This function should
+have the following prototype:
+```c
+void(const redisAsyncContext *c, int status);
+```
+On a disconnect, the `status` argument is set to `REDIS_OK` when disconnection was initiated by the
+user, or `REDIS_ERR` when the disconnection was caused by an error. When it is `REDIS_ERR`, the `err`
+field in the context can be accessed to find out the cause of the error.
+
+The context object is always freed after the disconnect callback fired. When a reconnect is needed,
+the disconnect callback is a good point to do so.
+
+Setting the disconnect callback can only be done once per context. For subsequent calls it will
+return `REDIS_ERR`. The function to set the disconnect callback has the following prototype:
+```c
+int redisAsyncSetDisconnectCallback(redisAsyncContext *ac, redisDisconnectCallback *fn);
+```
+### Sending commands and their callbacks
+
+In an asynchronous context, commands are automatically pipelined due to the nature of an event loop.
+Therefore, unlike the synchronous API, there is only a single way to send commands.
+Because commands are sent to Redis asynchronously, issuing a command requires a callback function
+that is called when the reply is received. Reply callbacks should have the following prototype:
+```c
+void(redisAsyncContext *c, void *reply, void *privdata);
+```
+The `privdata` argument can be used to curry arbitrary data to the callback from the point where
+the command is initially queued for execution.
+
+The functions that can be used to issue commands in an asynchronous context are:
+```c
+int redisAsyncCommand(
+  redisAsyncContext *ac, redisCallbackFn *fn, void *privdata,
+  const char *format, ...);
+int redisAsyncCommandArgv(
+  redisAsyncContext *ac, redisCallbackFn *fn, void *privdata,
+  int argc, const char **argv, const size_t *argvlen);
+```
+Both functions work like their blocking counterparts. The return value is `REDIS_OK` when the command
+was successfully added to the output buffer and `REDIS_ERR` otherwise. Example: when the connection
+is being disconnected per user-request, no new commands may be added to the output buffer and `REDIS_ERR` is
+returned on calls to the `redisAsyncCommand` family.
+
+If the reply for a command with a `NULL` callback is read, it is immediately freed. When the callback
+for a command is non-`NULL`, the memory is freed immediately following the callback: the reply is only
+valid for the duration of the callback.
+
+All pending callbacks are called with a `NULL` reply when the context encountered an error.
+
+### Disconnecting
+
+An asynchronous connection can be terminated using:
+```c
+void redisAsyncDisconnect(redisAsyncContext *ac);
+```
+When this function is called, the connection is **not** immediately terminated. Instead, new
+commands are no longer accepted and the connection is only terminated when all pending commands
+have been written to the socket, their respective replies have been read and their respective
+callbacks have been executed. After this, the disconnection callback is executed with the
+`REDIS_OK` status and the context object is freed.
+
+### Hooking it up to event library *X*
+
+There are a few hooks that need to be set on the context object after it is created.
+See the `adapters/` directory for bindings to *libev* and *libevent*.
+
+## Reply parsing API
+
+Hiredis comes with a reply parsing API that makes it easy for writing higher
+level language bindings.
+
+The reply parsing API consists of the following functions:
+```c
+redisReader *redisReaderCreate(void);
+void redisReaderFree(redisReader *reader);
+int redisReaderFeed(redisReader *reader, const char *buf, size_t len);
+int redisReaderGetReply(redisReader *reader, void **reply);
+```
+The same set of functions are used internally by hiredis when creating a
+normal Redis context, the above API just exposes it to the user for a direct
+usage.
+
+### Usage
+
+The function `redisReaderCreate` creates a `redisReader` structure that holds a
+buffer with unparsed data and state for the protocol parser.
+
+Incoming data -- most likely from a socket -- can be placed in the internal
+buffer of the `redisReader` using `redisReaderFeed`. This function will make a
+copy of the buffer pointed to by `buf` for `len` bytes. This data is parsed
+when `redisReaderGetReply` is called. This function returns an integer status
+and a reply object (as described above) via `void **reply`. The returned status
+can be either `REDIS_OK` or `REDIS_ERR`, where the latter means something went
+wrong (either a protocol error, or an out of memory error).
+
+The parser limits the level of nesting for multi bulk payloads to 7. If the
+multi bulk nesting level is higher than this, the parser returns an error.
+
+### Customizing replies
+
+The function `redisReaderGetReply` creates `redisReply` and makes the function
+argument `reply` point to the created `redisReply` variable. For instance, if
+the response of type `REDIS_REPLY_STATUS` then the `str` field of `redisReply`
+will hold the status as a vanilla C string. However, the functions that are
+responsible for creating instances of the `redisReply` can be customized by
+setting the `fn` field on the `redisReader` struct. This should be done
+immediately after creating the `redisReader`.
+
+For example, [hiredis-rb](https://github.com/pietern/hiredis-rb/blob/master/ext/hiredis_ext/reader.c)
+uses customized reply object functions to create Ruby objects.
+
+### Reader max buffer
+
+Both when using the Reader API directly or when using it indirectly via a
+normal Redis context, the redisReader structure uses a buffer in order to
+accumulate data from the server.
+Usually this buffer is destroyed when it is empty and is larger than 16
+KiB in order to avoid wasting memory in unused buffers
+
+However when working with very big payloads destroying the buffer may slow
+down performances considerably, so it is possible to modify the max size of
+an idle buffer changing the value of the `maxbuf` field of the reader structure
+to the desired value. The special value of 0 means that there is no maximum
+value for an idle buffer, so the buffer will never get freed.
+
+For instance if you have a normal Redis context you can set the maximum idle
+buffer to zero (unlimited) just with:
+```c
+context->reader->maxbuf = 0;
+```
+This should be done only in order to maximize performances when working with
+large payloads. The context should be set back to `REDIS_READER_MAX_BUF` again
+as soon as possible in order to prevent allocation of useless memory.
+
+## AUTHORS
+
+Hiredis was written by Salvatore Sanfilippo (antirez at gmail) and
+Pieter Noordhuis (pcnoordhuis at gmail) and is released under the BSD license.  
+Hiredis is currently maintained by Matt Stancliff (matt at genges dot com) and
+Jan-Erik Rediger (janerik at fnordig dot com)
diff --git a/contrib/hiredis/adapters/libevent.h b/contrib/hiredis/adapters/libevent.h
new file mode 100644
index 000000000..1c2b271bb
--- /dev/null
+++ b/contrib/hiredis/adapters/libevent.h
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __HIREDIS_LIBEVENT_H__
+#define __HIREDIS_LIBEVENT_H__
+#include <event.h>
+#include "../hiredis.h"
+#include "../async.h"
+
+typedef struct redisLibeventEvents {
+    redisAsyncContext *context;
+    struct event rev, wev;
+} redisLibeventEvents;
+
+static void redisLibeventReadEvent(int fd, short event, void *arg) {
+    ((void)fd); ((void)event);
+    redisLibeventEvents *e = (redisLibeventEvents*)arg;
+    redisAsyncHandleRead(e->context);
+}
+
+static void redisLibeventWriteEvent(int fd, short event, void *arg) {
+    ((void)fd); ((void)event);
+    redisLibeventEvents *e = (redisLibeventEvents*)arg;
+    redisAsyncHandleWrite(e->context);
+}
+
+static void redisLibeventAddRead(void *privdata) {
+    redisLibeventEvents *e = (redisLibeventEvents*)privdata;
+    event_add(&e->rev,NULL);
+}
+
+static void redisLibeventDelRead(void *privdata) {
+    redisLibeventEvents *e = (redisLibeventEvents*)privdata;
+    event_del(&e->rev);
+}
+
+static void redisLibeventAddWrite(void *privdata) {
+    redisLibeventEvents *e = (redisLibeventEvents*)privdata;
+    event_add(&e->wev,NULL);
+}
+
+static void redisLibeventDelWrite(void *privdata) {
+    redisLibeventEvents *e = (redisLibeventEvents*)privdata;
+    event_del(&e->wev);
+}
+
+static void redisLibeventCleanup(void *privdata) {
+    redisLibeventEvents *e = (redisLibeventEvents*)privdata;
+    event_del(&e->rev);
+    event_del(&e->wev);
+    free(e);
+}
+
+static int redisLibeventAttach(redisAsyncContext *ac, struct event_base *base) {
+    redisContext *c = &(ac->c);
+    redisLibeventEvents *e;
+
+    /* Nothing should be attached when something is already attached */
+    if (ac->ev.data != NULL)
+        return REDIS_ERR;
+
+    /* Create container for context and r/w events */
+    e = (redisLibeventEvents*)malloc(sizeof(*e));
+    e->context = ac;
+
+    /* Register functions to start/stop listening for events */
+    ac->ev.addRead = redisLibeventAddRead;
+    ac->ev.delRead = redisLibeventDelRead;
+    ac->ev.addWrite = redisLibeventAddWrite;
+    ac->ev.delWrite = redisLibeventDelWrite;
+    ac->ev.cleanup = redisLibeventCleanup;
+    ac->ev.data = e;
+
+    /* Initialize and install read/write events */
+    event_set(&e->rev,c->fd,EV_READ,redisLibeventReadEvent,e);
+    event_set(&e->wev,c->fd,EV_WRITE,redisLibeventWriteEvent,e);
+    event_base_set(base,&e->rev);
+    event_base_set(base,&e->wev);
+    return REDIS_OK;
+}
+#endif
diff --git a/contrib/hiredis/async.c b/contrib/hiredis/async.c
new file mode 100644
index 000000000..d955203f8
--- /dev/null
+++ b/contrib/hiredis/async.c
@@ -0,0 +1,687 @@
+/*
+ * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "fmacros.h"
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <assert.h>
+#include <ctype.h>
+#include <errno.h>
+#include "async.h"
+#include "net.h"
+#include "dict.c"
+#include "sds.h"
+
+#define _EL_ADD_READ(ctx) do { \
+        if ((ctx)->ev.addRead) (ctx)->ev.addRead((ctx)->ev.data); \
+    } while(0)
+#define _EL_DEL_READ(ctx) do { \
+        if ((ctx)->ev.delRead) (ctx)->ev.delRead((ctx)->ev.data); \
+    } while(0)
+#define _EL_ADD_WRITE(ctx) do { \
+        if ((ctx)->ev.addWrite) (ctx)->ev.addWrite((ctx)->ev.data); \
+    } while(0)
+#define _EL_DEL_WRITE(ctx) do { \
+        if ((ctx)->ev.delWrite) (ctx)->ev.delWrite((ctx)->ev.data); \
+    } while(0)
+#define _EL_CLEANUP(ctx) do { \
+        if ((ctx)->ev.cleanup) (ctx)->ev.cleanup((ctx)->ev.data); \
+    } while(0);
+
+/* Forward declaration of function in hiredis.c */
+int __redisAppendCommand(redisContext *c, const char *cmd, size_t len);
+
+/* Functions managing dictionary of callbacks for pub/sub. */
+static unsigned int callbackHash(const void *key) {
+    return dictGenHashFunction((const unsigned char *)key,
+                               sdslen((const sds)key));
+}
+
+static void *callbackValDup(void *privdata, const void *src) {
+    ((void) privdata);
+    redisCallback *dup = malloc(sizeof(*dup));
+    memcpy(dup,src,sizeof(*dup));
+    return dup;
+}
+
+static int callbackKeyCompare(void *privdata, const void *key1, const void *key2) {
+    int l1, l2;
+    ((void) privdata);
+
+    l1 = sdslen((const sds)key1);
+    l2 = sdslen((const sds)key2);
+    if (l1 != l2) return 0;
+    return memcmp(key1,key2,l1) == 0;
+}
+
+static void callbackKeyDestructor(void *privdata, void *key) {
+    ((void) privdata);
+    sdsfree((sds)key);
+}
+
+static void callbackValDestructor(void *privdata, void *val) {
+    ((void) privdata);
+    free(val);
+}
+
+static dictType callbackDict = {
+    callbackHash,
+    NULL,
+    callbackValDup,
+    callbackKeyCompare,
+    callbackKeyDestructor,
+    callbackValDestructor
+};
+
+static redisAsyncContext *redisAsyncInitialize(redisContext *c) {
+    redisAsyncContext *ac;
+
+    ac = realloc(c,sizeof(redisAsyncContext));
+    if (ac == NULL)
+        return NULL;
+
+    c = &(ac->c);
+
+    /* The regular connect functions will always set the flag REDIS_CONNECTED.
+     * For the async API, we want to wait until the first write event is
+     * received up before setting this flag, so reset it here. */
+    c->flags &= ~REDIS_CONNECTED;
+
+    ac->err = 0;
+    ac->errstr = NULL;
+    ac->data = NULL;
+
+    ac->ev.data = NULL;
+    ac->ev.addRead = NULL;
+    ac->ev.delRead = NULL;
+    ac->ev.addWrite = NULL;
+    ac->ev.delWrite = NULL;
+    ac->ev.cleanup = NULL;
+
+    ac->onConnect = NULL;
+    ac->onDisconnect = NULL;
+
+    ac->replies.head = NULL;
+    ac->replies.tail = NULL;
+    ac->sub.invalid.head = NULL;
+    ac->sub.invalid.tail = NULL;
+    ac->sub.channels = dictCreate(&callbackDict,NULL);
+    ac->sub.patterns = dictCreate(&callbackDict,NULL);
+    return ac;
+}
+
+/* We want the error field to be accessible directly instead of requiring
+ * an indirection to the redisContext struct. */
+static void __redisAsyncCopyError(redisAsyncContext *ac) {
+    if (!ac)
+        return;
+
+    redisContext *c = &(ac->c);
+    ac->err = c->err;
+    ac->errstr = c->errstr;
+}
+
+redisAsyncContext *redisAsyncConnect(const char *ip, int port) {
+    redisContext *c;
+    redisAsyncContext *ac;
+
+    c = redisConnectNonBlock(ip,port);
+    if (c == NULL)
+        return NULL;
+
+    ac = redisAsyncInitialize(c);
+    if (ac == NULL) {
+        redisFree(c);
+        return NULL;
+    }
+
+    __redisAsyncCopyError(ac);
+    return ac;
+}
+
+redisAsyncContext *redisAsyncConnectBind(const char *ip, int port,
+                                         const char *source_addr) {
+    redisContext *c = redisConnectBindNonBlock(ip,port,source_addr);
+    redisAsyncContext *ac = redisAsyncInitialize(c);
+    __redisAsyncCopyError(ac);
+    return ac;
+}
+
+redisAsyncContext *redisAsyncConnectBindWithReuse(const char *ip, int port,
+                                                  const char *source_addr) {
+    redisContext *c = redisConnectBindNonBlockWithReuse(ip,port,source_addr);
+    redisAsyncContext *ac = redisAsyncInitialize(c);
+    __redisAsyncCopyError(ac);
+    return ac;
+}
+
+redisAsyncContext *redisAsyncConnectUnix(const char *path) {
+    redisContext *c;
+    redisAsyncContext *ac;
+
+    c = redisConnectUnixNonBlock(path);
+    if (c == NULL)
+        return NULL;
+
+    ac = redisAsyncInitialize(c);
+    if (ac == NULL) {
+        redisFree(c);
+        return NULL;
+    }
+
+    __redisAsyncCopyError(ac);
+    return ac;
+}
+
+int redisAsyncSetConnectCallback(redisAsyncContext *ac, redisConnectCallback *fn) {
+    if (ac->onConnect == NULL) {
+        ac->onConnect = fn;
+
+        /* The common way to detect an established connection is to wait for
+         * the first write event to be fired. This assumes the related event
+         * library functions are already set. */
+        _EL_ADD_WRITE(ac);
+        return REDIS_OK;
+    }
+    return REDIS_ERR;
+}
+
+int redisAsyncSetDisconnectCallback(redisAsyncContext *ac, redisDisconnectCallback *fn) {
+    if (ac->onDisconnect == NULL) {
+        ac->onDisconnect = fn;
+        return REDIS_OK;
+    }
+    return REDIS_ERR;
+}
+
+/* Helper functions to push/shift callbacks */
+static int __redisPushCallback(redisCallbackList *list, redisCallback *source) {
+    redisCallback *cb;
+
+    /* Copy callback from stack to heap */
+    cb = malloc(sizeof(*cb));
+    if (cb == NULL)
+        return REDIS_ERR_OOM;
+
+    if (source != NULL) {
+        memcpy(cb,source,sizeof(*cb));
+        cb->next = NULL;
+    }
+
+    /* Store callback in list */
+    if (list->head == NULL)
+        list->head = cb;
+    if (list->tail != NULL)
+        list->tail->next = cb;
+    list->tail = cb;
+    return REDIS_OK;
+}
+
+static int __redisShiftCallback(redisCallbackList *list, redisCallback *target) {
+    redisCallback *cb = list->head;
+    if (cb != NULL) {
+        list->head = cb->next;
+        if (cb == list->tail)
+            list->tail = NULL;
+
+        /* Copy callback from heap to stack */
+        if (target != NULL)
+            memcpy(target,cb,sizeof(*cb));
+        free(cb);
+        return REDIS_OK;
+    }
+    return REDIS_ERR;
+}
+
+static void __redisRunCallback(redisAsyncContext *ac, redisCallback *cb, redisReply *reply) {
+    redisContext *c = &(ac->c);
+    if (cb->fn != NULL) {
+        c->flags |= REDIS_IN_CALLBACK;
+        cb->fn(ac,reply,cb->privdata);
+        c->flags &= ~REDIS_IN_CALLBACK;
+    }
+}
+
+/* Helper function to free the context. */
+static void __redisAsyncFree(redisAsyncContext *ac) {
+    redisContext *c = &(ac->c);
+    redisCallback cb;
+    dictIterator *it;
+    dictEntry *de;
+
+    /* Execute pending callbacks with NULL reply. */
+    while (__redisShiftCallback(&ac->replies,&cb) == REDIS_OK)
+        __redisRunCallback(ac,&cb,NULL);
+
+    /* Execute callbacks for invalid commands */
+    while (__redisShiftCallback(&ac->sub.invalid,&cb) == REDIS_OK)
+        __redisRunCallback(ac,&cb,NULL);
+
+    /* Run subscription callbacks callbacks with NULL reply */
+    it = dictGetIterator(ac->sub.channels);
+    while ((de = dictNext(it)) != NULL)
+        __redisRunCallback(ac,dictGetEntryVal(de),NULL);
+    dictReleaseIterator(it);
+    dictRelease(ac->sub.channels);
+
+    it = dictGetIterator(ac->sub.patterns);
+    while ((de = dictNext(it)) != NULL)
+        __redisRunCallback(ac,dictGetEntryVal(de),NULL);
+    dictReleaseIterator(it);
+    dictRelease(ac->sub.patterns);
+
+    /* Signal event lib to clean up */
+    _EL_CLEANUP(ac);
+
+    /* Execute disconnect callback. When redisAsyncFree() initiated destroying
+     * this context, the status will always be REDIS_OK. */
+    if (ac->onDisconnect && (c->flags & REDIS_CONNECTED)) {
+        if (c->flags & REDIS_FREEING) {
+            ac->onDisconnect(ac,REDIS_OK);
+        } else {
+            ac->onDisconnect(ac,(ac->err == 0) ? REDIS_OK : REDIS_ERR);
+        }
+    }
+
+    /* Cleanup self */
+    redisFree(c);
+}
+
+/* Free the async context. When this function is called from a callback,
+ * control needs to be returned to redisProcessCallbacks() before actual
+ * free'ing. To do so, a flag is set on the context which is picked up by
+ * redisProcessCallbacks(). Otherwise, the context is immediately free'd. */
+void redisAsyncFree(redisAsyncContext *ac) {
+    redisContext *c = &(ac->c);
+    c->flags |= REDIS_FREEING;
+    if (!(c->flags & REDIS_IN_CALLBACK))
+        __redisAsyncFree(ac);
+}
+
+/* Helper function to make the disconnect happen and clean up. */
+static void __redisAsyncDisconnect(redisAsyncContext *ac) {
+    redisContext *c = &(ac->c);
+
+    /* Make sure error is accessible if there is any */
+    __redisAsyncCopyError(ac);
+
+    if (ac->err == 0) {
+        /* For clean disconnects, there should be no pending callbacks. */
+        assert(__redisShiftCallback(&ac->replies,NULL) == REDIS_ERR);
+    } else {
+        /* Disconnection is caused by an error, make sure that pending
+         * callbacks cannot call new commands. */
+        c->flags |= REDIS_DISCONNECTING;
+    }
+
+    /* For non-clean disconnects, __redisAsyncFree() will execute pending
+     * callbacks with a NULL-reply. */
+    __redisAsyncFree(ac);
+}
+
+/* Tries to do a clean disconnect from Redis, meaning it stops new commands
+ * from being issued, but tries to flush the output buffer and execute
+ * callbacks for all remaining replies. When this function is called from a
+ * callback, there might be more replies and we can safely defer disconnecting
+ * to redisProcessCallbacks(). Otherwise, we can only disconnect immediately
+ * when there are no pending callbacks. */
+void redisAsyncDisconnect(redisAsyncContext *ac) {
+    redisContext *c = &(ac->c);
+    c->flags |= REDIS_DISCONNECTING;
+    if (!(c->flags & REDIS_IN_CALLBACK) && ac->replies.head == NULL)
+        __redisAsyncDisconnect(ac);
+}
+
+static int __redisGetSubscribeCallback(redisAsyncContext *ac, redisReply *reply, redisCallback *dstcb) {
+    redisContext *c = &(ac->c);
+    dict *callbacks;
+    dictEntry *de;
+    int pvariant;
+    char *stype;
+    sds sname;
+
+    /* Custom reply functions are not supported for pub/sub. This will fail
+     * very hard when they are used... */
+    if (reply->type == REDIS_REPLY_ARRAY) {
+        assert(reply->elements >= 2);
+        assert(reply->element[0]->type == REDIS_REPLY_STRING);
+        stype = reply->element[0]->str;
+        pvariant = (tolower(stype[0]) == 'p') ? 1 : 0;
+
+        if (pvariant)
+            callbacks = ac->sub.patterns;
+        else
+            callbacks = ac->sub.channels;
+
+        /* Locate the right callback */
+        assert(reply->element[1]->type == REDIS_REPLY_STRING);
+        sname = sdsnewlen(reply->element[1]->str,reply->element[1]->len);
+        de = dictFind(callbacks,sname);
+        if (de != NULL) {
+            memcpy(dstcb,dictGetEntryVal(de),sizeof(*dstcb));
+
+            /* If this is an unsubscribe message, remove it. */
+            if (strcasecmp(stype+pvariant,"unsubscribe") == 0) {
+                dictDelete(callbacks,sname);
+
+                /* If this was the last unsubscribe message, revert to
+                 * non-subscribe mode. */
+                assert(reply->element[2]->type == REDIS_REPLY_INTEGER);
+                if (reply->element[2]->integer == 0)
+                    c->flags &= ~REDIS_SUBSCRIBED;
+            }
+        }
+        sdsfree(sname);
+    } else {
+        /* Shift callback for invalid commands. */
+        __redisShiftCallback(&ac->sub.invalid,dstcb);
+    }
+    return REDIS_OK;
+}
+
+void redisProcessCallbacks(redisAsyncContext *ac) {
+    redisContext *c = &(ac->c);
+    redisCallback cb = {NULL, NULL, NULL};
+    void *reply = NULL;
+    int status;
+
+    while((status = redisGetReply(c,&reply)) == REDIS_OK) {
+        if (reply == NULL) {
+            /* When the connection is being disconnected and there are
+             * no more replies, this is the cue to really disconnect. */
+            if (c->flags & REDIS_DISCONNECTING && sdslen(c->obuf) == 0
+                && ac->replies.head == NULL) {
+                __redisAsyncDisconnect(ac);
+                return;
+            }
+
+            /* If monitor mode, repush callback */
+            if(c->flags & REDIS_MONITORING) {
+                __redisPushCallback(&ac->replies,&cb);
+            }
+
+            /* When the connection is not being disconnected, simply stop
+             * trying to get replies and wait for the next loop tick. */
+            break;
+        }
+
+        /* Even if the context is subscribed, pending regular callbacks will
+         * get a reply before pub/sub messages arrive. */
+        if (__redisShiftCallback(&ac->replies,&cb) != REDIS_OK) {
+            /*
+             * A spontaneous reply in a not-subscribed context can be the error
+             * reply that is sent when a new connection exceeds the maximum
+             * number of allowed connections on the server side.
+             *
+             * This is seen as an error instead of a regular reply because the
+             * server closes the connection after sending it.
+             *
+             * To prevent the error from being overwritten by an EOF error the
+             * connection is closed here. See issue #43.
+             *
+             * Another possibility is that the server is loading its dataset.
+             * In this case we also want to close the connection, and have the
+             * user wait until the server is ready to take our request.
+             */
+            if (((redisReply*)reply)->type == REDIS_REPLY_ERROR) {
+                c->err = REDIS_ERR_OTHER;
+                snprintf(c->errstr,sizeof(c->errstr),"%s",((redisReply*)reply)->str);
+                c->reader->fn->freeObject(reply);
+                __redisAsyncDisconnect(ac);
+                return;
+            }
+            /* No more regular callbacks and no errors, the context *must* be subscribed or monitoring. */
+            assert((c->flags & REDIS_SUBSCRIBED || c->flags & REDIS_MONITORING));
+            if(c->flags & REDIS_SUBSCRIBED)
+                __redisGetSubscribeCallback(ac,reply,&cb);
+        }
+
+        if (cb.fn != NULL) {
+            __redisRunCallback(ac,&cb,reply);
+            c->reader->fn->freeObject(reply);
+
+            /* Proceed with free'ing when redisAsyncFree() was called. */
+            if (c->flags & REDIS_FREEING) {
+                __redisAsyncFree(ac);
+                return;
+            }
+        } else {
+            /* No callback for this reply. This can either be a NULL callback,
+             * or there were no callbacks to begin with. Either way, don't
+             * abort with an error, but simply ignore it because the client
+             * doesn't know what the server will spit out over the wire. */
+            c->reader->fn->freeObject(reply);
+        }
+    }
+
+    /* Disconnect when there was an error reading the reply */
+    if (status != REDIS_OK)
+        __redisAsyncDisconnect(ac);
+}
+
+/* Internal helper function to detect socket status the first time a read or
+ * write event fires. When connecting was not successful, the connect callback
+ * is called with a REDIS_ERR status and the context is free'd. */
+static int __redisAsyncHandleConnect(redisAsyncContext *ac) {
+    redisContext *c = &(ac->c);
+
+    if (redisCheckSocketError(c) == REDIS_ERR) {
+        /* Try again later when connect(2) is still in progress. */
+        if (errno == EINPROGRESS)
+            return REDIS_OK;
+
+        if (ac->onConnect) ac->onConnect(ac,REDIS_ERR);
+        __redisAsyncDisconnect(ac);
+        return REDIS_ERR;
+    }
+
+    /* Mark context as connected. */
+    c->flags |= REDIS_CONNECTED;
+    if (ac->onConnect) ac->onConnect(ac,REDIS_OK);
+    return REDIS_OK;
+}
+
+/* This function should be called when the socket is readable.
+ * It processes all replies that can be read and executes their callbacks.
+ */
+void redisAsyncHandleRead(redisAsyncContext *ac) {
+    redisContext *c = &(ac->c);
+
+    if (!(c->flags & REDIS_CONNECTED)) {
+        /* Abort connect was not successful. */
+        if (__redisAsyncHandleConnect(ac) != REDIS_OK)
+            return;
+        /* Try again later when the context is still not connected. */
+        if (!(c->flags & REDIS_CONNECTED))
+            return;
+    }
+
+    if (redisBufferRead(c) == REDIS_ERR) {
+        __redisAsyncDisconnect(ac);
+    } else {
+        /* Always re-schedule reads */
+        _EL_ADD_READ(ac);
+        redisProcessCallbacks(ac);
+    }
+}
+
+void redisAsyncHandleWrite(redisAsyncContext *ac) {
+    redisContext *c = &(ac->c);
+    int done = 0;
+
+    if (!(c->flags & REDIS_CONNECTED)) {
+        /* Abort connect was not successful. */
+        if (__redisAsyncHandleConnect(ac) != REDIS_OK)
+            return;
+        /* Try again later when the context is still not connected. */
+        if (!(c->flags & REDIS_CONNECTED))
+            return;
+    }
+
+    if (redisBufferWrite(c,&done) == REDIS_ERR) {
+        __redisAsyncDisconnect(ac);
+    } else {
+        /* Continue writing when not done, stop writing otherwise */
+        if (!done)
+            _EL_ADD_WRITE(ac);
+        else
+            _EL_DEL_WRITE(ac);
+
+        /* Always schedule reads after writes */
+        _EL_ADD_READ(ac);
+    }
+}
+
+/* Sets a pointer to the first argument and its length starting at p. Returns
+ * the number of bytes to skip to get to the following argument. */
+static const char *nextArgument(const char *start, const char **str, size_t *len) {
+    const char *p = start;
+    if (p[0] != '$') {
+        p = strchr(p,'$');
+        if (p == NULL) return NULL;
+    }
+
+    *len = (int)strtol(p+1,NULL,10);
+    p = strchr(p,'\r');
+    assert(p);
+    *str = p+2;
+    return p+2+(*len)+2;
+}
+
+/* Helper function for the redisAsyncCommand* family of functions. Writes a
+ * formatted command to the output buffer and registers the provided callback
+ * function with the context. */
+static int __redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *cmd, size_t len) {
+    redisContext *c = &(ac->c);
+    redisCallback cb;
+    int pvariant, hasnext;
+    const char *cstr, *astr;
+    size_t clen, alen;
+    const char *p;
+    sds sname;
+    int ret;
+
+    /* Don't accept new commands when the connection is about to be closed. */
+    if (c->flags & (REDIS_DISCONNECTING | REDIS_FREEING)) return REDIS_ERR;
+
+    /* Setup callback */
+    cb.fn = fn;
+    cb.privdata = privdata;
+
+    /* Find out which command will be appended. */
+    p = nextArgument(cmd,&cstr,&clen);
+    assert(p != NULL);
+    hasnext = (p[0] == '$');
+    pvariant = (tolower(cstr[0]) == 'p') ? 1 : 0;
+    cstr += pvariant;
+    clen -= pvariant;
+
+    if (hasnext && strncasecmp(cstr,"subscribe\r\n",11) == 0) {
+        c->flags |= REDIS_SUBSCRIBED;
+
+        /* Add every channel/pattern to the list of subscription callbacks. */
+        while ((p = nextArgument(p,&astr,&alen)) != NULL) {
+            sname = sdsnewlen(astr,alen);
+            if (pvariant)
+                ret = dictReplace(ac->sub.patterns,sname,&cb);
+            else
+                ret = dictReplace(ac->sub.channels,sname,&cb);
+
+            if (ret == 0) sdsfree(sname);
+        }
+    } else if (strncasecmp(cstr,"unsubscribe\r\n",13) == 0) {
+        /* It is only useful to call (P)UNSUBSCRIBE when the context is
+         * subscribed to one or more channels or patterns. */
+        if (!(c->flags & REDIS_SUBSCRIBED)) return REDIS_ERR;
+
+        /* (P)UNSUBSCRIBE does not have its own response: every channel or
+         * pattern that is unsubscribed will receive a message. This means we
+         * should not append a callback function for this command. */
+     } else if(strncasecmp(cstr,"monitor\r\n",9) == 0) {
+         /* Set monitor flag and push callback */
+         c->flags |= REDIS_MONITORING;
+         __redisPushCallback(&ac->replies,&cb);
+    } else {
+        if (c->flags & REDIS_SUBSCRIBED)
+            /* This will likely result in an error reply, but it needs to be
+             * received and passed to the callback. */
+            __redisPushCallback(&ac->sub.invalid,&cb);
+        else
+            __redisPushCallback(&ac->replies,&cb);
+    }
+
+    __redisAppendCommand(c,cmd,len);
+
+    /* Always schedule a write when the write buffer is non-empty */
+    _EL_ADD_WRITE(ac);
+
+    return REDIS_OK;
+}
+
+int redisvAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *format, va_list ap) {
+    char *cmd;
+    int len;
+    int status;
+    len = redisvFormatCommand(&cmd,format,ap);
+
+    /* We don't want to pass -1 or -2 to future functions as a length. */
+    if (len < 0)
+        return REDIS_ERR;
+
+    status = __redisAsyncCommand(ac,fn,privdata,cmd,len);
+    free(cmd);
+    return status;
+}
+
+int redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *format, ...) {
+    va_list ap;
+    int status;
+    va_start(ap,format);
+    status = redisvAsyncCommand(ac,fn,privdata,format,ap);
+    va_end(ap);
+    return status;
+}
+
+int redisAsyncCommandArgv(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, int argc, const char **argv, const size_t *argvlen) {
+    sds cmd;
+    int len;
+    int status;
+    len = redisFormatSdsCommandArgv(&cmd,argc,argv,argvlen);
+    status = __redisAsyncCommand(ac,fn,privdata,cmd,len);
+    sdsfree(cmd);
+    return status;
+}
+
+int redisAsyncFormattedCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *cmd, size_t len) {
+    int status = __redisAsyncCommand(ac,fn,privdata,cmd,len);
+    return status;
+}
diff --git a/contrib/hiredis/async.h b/contrib/hiredis/async.h
new file mode 100644
index 000000000..59cbf469b
--- /dev/null
+++ b/contrib/hiredis/async.h
@@ -0,0 +1,129 @@
+/*
+ * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __HIREDIS_ASYNC_H
+#define __HIREDIS_ASYNC_H
+#include "hiredis.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct redisAsyncContext; /* need forward declaration of redisAsyncContext */
+struct dict; /* dictionary header is included in async.c */
+
+/* Reply callback prototype and container */
+typedef void (redisCallbackFn)(struct redisAsyncContext*, void*, void*);
+typedef struct redisCallback {
+    struct redisCallback *next; /* simple singly linked list */
+    redisCallbackFn *fn;
+    void *privdata;
+} redisCallback;
+
+/* List of callbacks for either regular replies or pub/sub */
+typedef struct redisCallbackList {
+    redisCallback *head, *tail;
+} redisCallbackList;
+
+/* Connection callback prototypes */
+typedef void (redisDisconnectCallback)(const struct redisAsyncContext*, int status);
+typedef void (redisConnectCallback)(const struct redisAsyncContext*, int status);
+
+/* Context for an async connection to Redis */
+typedef struct redisAsyncContext {
+    /* Hold the regular context, so it can be realloc'ed. */
+    redisContext c;
+
+    /* Setup error flags so they can be used directly. */
+    int err;
+    char *errstr;
+
+    /* Not used by hiredis */
+    void *data;
+
+    /* Event library data and hooks */
+    struct {
+        void *data;
+
+        /* Hooks that are called when the library expects to start
+         * reading/writing. These functions should be idempotent. */
+        void (*addRead)(void *privdata);
+        void (*delRead)(void *privdata);
+        void (*addWrite)(void *privdata);
+        void (*delWrite)(void *privdata);
+        void (*cleanup)(void *privdata);
+    } ev;
+
+    /* Called when either the connection is terminated due to an error or per
+     * user request. The status is set accordingly (REDIS_OK, REDIS_ERR). */
+    redisDisconnectCallback *onDisconnect;
+
+    /* Called when the first write event was received. */
+    redisConnectCallback *onConnect;
+
+    /* Regular command callbacks */
+    redisCallbackList replies;
+
+    /* Subscription callbacks */
+    struct {
+        redisCallbackList invalid;
+        struct dict *channels;
+        struct dict *patterns;
+    } sub;
+} redisAsyncContext;
+
+/* Functions that proxy to hiredis */
+redisAsyncContext *redisAsyncConnect(const char *ip, int port);
+redisAsyncContext *redisAsyncConnectBind(const char *ip, int port, const char *source_addr);
+redisAsyncContext *redisAsyncConnectBindWithReuse(const char *ip, int port,
+                                                  const char *source_addr);
+redisAsyncContext *redisAsyncConnectUnix(const char *path);
+int redisAsyncSetConnectCallback(redisAsyncContext *ac, redisConnectCallback *fn);
+int redisAsyncSetDisconnectCallback(redisAsyncContext *ac, redisDisconnectCallback *fn);
+void redisAsyncDisconnect(redisAsyncContext *ac);
+void redisAsyncFree(redisAsyncContext *ac);
+
+/* Handle read/write events */
+void redisAsyncHandleRead(redisAsyncContext *ac);
+void redisAsyncHandleWrite(redisAsyncContext *ac);
+
+/* Command functions for an async context. Write the command to the
+ * output buffer and register the provided callback. */
+int redisvAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *format, va_list ap);
+int redisAsyncCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *format, ...);
+int redisAsyncCommandArgv(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, int argc, const char **argv, const size_t *argvlen);
+int redisAsyncFormattedCommand(redisAsyncContext *ac, redisCallbackFn *fn, void *privdata, const char *cmd, size_t len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/contrib/hiredis/dict.c b/contrib/hiredis/dict.c
new file mode 100644
index 000000000..e17a62546
--- /dev/null
+++ b/contrib/hiredis/dict.c
@@ -0,0 +1,338 @@
+/* Hash table implementation.
+ *
+ * This file implements in memory hash tables with insert/del/replace/find/
+ * get-random-element operations. Hash tables will auto resize if needed
+ * tables of power of two in size are used, collisions are handled by
+ * chaining. See the source code for more information... :)
+ *
+ * Copyright (c) 2006-2010, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "fmacros.h"
+#include <stdlib.h>
+#include <assert.h>
+#include <limits.h>
+#include "dict.h"
+
+/* -------------------------- private prototypes ---------------------------- */
+
+static int _dictExpandIfNeeded(dict *ht);
+static unsigned long _dictNextPower(unsigned long size);
+static int _dictKeyIndex(dict *ht, const void *key);
+static int _dictInit(dict *ht, dictType *type, void *privDataPtr);
+
+/* -------------------------- hash functions -------------------------------- */
+
+/* Generic hash function (a popular one from Bernstein).
+ * I tested a few and this was the best. */
+static unsigned int dictGenHashFunction(const unsigned char *buf, int len) {
+    unsigned int hash = 5381;
+
+    while (len--)
+        hash = ((hash << 5) + hash) + (*buf++); /* hash * 33 + c */
+    return hash;
+}
+
+/* ----------------------------- API implementation ------------------------- */
+
+/* Reset an hashtable already initialized with ht_init().
+ * NOTE: This function should only called by ht_destroy(). */
+static void _dictReset(dict *ht) {
+    ht->table = NULL;
+    ht->size = 0;
+    ht->sizemask = 0;
+    ht->used = 0;
+}
+
+/* Create a new hash table */
+static dict *dictCreate(dictType *type, void *privDataPtr) {
+    dict *ht = malloc(sizeof(*ht));
+    _dictInit(ht,type,privDataPtr);
+    return ht;
+}
+
+/* Initialize the hash table */
+static int _dictInit(dict *ht, dictType *type, void *privDataPtr) {
+    _dictReset(ht);
+    ht->type = type;
+    ht->privdata = privDataPtr;
+    return DICT_OK;
+}
+
+/* Expand or create the hashtable */
+static int dictExpand(dict *ht, unsigned long size) {
+    dict n; /* the new hashtable */
+    unsigned long realsize = _dictNextPower(size), i;
+
+    /* the size is invalid if it is smaller than the number of
+     * elements already inside the hashtable */
+    if (ht->used > size)
+        return DICT_ERR;
+
+    _dictInit(&n, ht->type, ht->privdata);
+    n.size = realsize;
+    n.sizemask = realsize-1;
+    n.table = calloc(realsize,sizeof(dictEntry*));
+
+    /* Copy all the elements from the old to the new table:
+     * note that if the old hash table is empty ht->size is zero,
+     * so dictExpand just creates an hash table. */
+    n.used = ht->used;
+    for (i = 0; i < ht->size && ht->used > 0; i++) {
+        dictEntry *he, *nextHe;
+
+        if (ht->table[i] == NULL) continue;
+
+        /* For each hash entry on this slot... */
+        he = ht->table[i];
+        while(he) {
+            unsigned int h;
+
+            nextHe = he->next;
+            /* Get the new element index */
+            h = dictHashKey(ht, he->key) & n.sizemask;
+            he->next = n.table[h];
+            n.table[h] = he;
+            ht->used--;
+            /* Pass to the next element */
+            he = nextHe;
+        }
+    }
+    assert(ht->used == 0);
+    free(ht->table);
+
+    /* Remap the new hashtable in the old */
+    *ht = n;
+    return DICT_OK;
+}
+
+/* Add an element to the target hash table */
+static int dictAdd(dict *ht, void *key, void *val) {
+    int index;
+    dictEntry *entry;
+
+    /* Get the index of the new element, or -1 if
+     * the element already exists. */
+    if ((index = _dictKeyIndex(ht, key)) == -1)
+        return DICT_ERR;
+
+    /* Allocates the memory and stores key */
+    entry = malloc(sizeof(*entry));
+    entry->next = ht->table[index];
+    ht->table[index] = entry;
+
+    /* Set the hash entry fields. */
+    dictSetHashKey(ht, entry, key);
+    dictSetHashVal(ht, entry, val);
+    ht->used++;
+    return DICT_OK;
+}
+
+/* Add an element, discarding the old if the key already exists.
+ * Return 1 if the key was added from scratch, 0 if there was already an
+ * element with such key and dictReplace() just performed a value update
+ * operation. */
+static int dictReplace(dict *ht, void *key, void *val) {
+    dictEntry *entry, auxentry;
+
+    /* Try to add the element. If the key
+     * does not exists dictAdd will succeed. */
+    if (dictAdd(ht, key, val) == DICT_OK)
+        return 1;
+    /* It already exists, get the entry */
+    entry = dictFind(ht, key);
+    /* Free the old value and set the new one */
+    /* Set the new value and free the old one. Note that it is important
+     * to do that in this order, as the value may just be exactly the same
+     * as the previous one. In this context, think to reference counting,
+     * you want to increment (set), and then decrement (free), and not the
+     * reverse. */
+    auxentry = *entry;
+    dictSetHashVal(ht, entry, val);
+    dictFreeEntryVal(ht, &auxentry);
+    return 0;
+}
+
+/* Search and remove an element */
+static int dictDelete(dict *ht, const void *key) {
+    unsigned int h;
+    dictEntry *de, *prevde;
+
+    if (ht->size == 0)
+        return DICT_ERR;
+    h = dictHashKey(ht, key) & ht->sizemask;
+    de = ht->table[h];
+
+    prevde = NULL;
+    while(de) {
+        if (dictCompareHashKeys(ht,key,de->key)) {
+            /* Unlink the element from the list */
+            if (prevde)
+                prevde->next = de->next;
+            else
+                ht->table[h] = de->next;
+
+            dictFreeEntryKey(ht,de);
+            dictFreeEntryVal(ht,de);
+            free(de);
+            ht->used--;
+            return DICT_OK;
+        }
+        prevde = de;
+        de = de->next;
+    }
+    return DICT_ERR; /* not found */
+}
+
+/* Destroy an entire hash table */
+static int _dictClear(dict *ht) {
+    unsigned long i;
+
+    /* Free all the elements */
+    for (i = 0; i < ht->size && ht->used > 0; i++) {
+        dictEntry *he, *nextHe;
+
+        if ((he = ht->table[i]) == NULL) continue;
+        while(he) {
+            nextHe = he->next;
+            dictFreeEntryKey(ht, he);
+            dictFreeEntryVal(ht, he);
+            free(he);
+            ht->used--;
+            he = nextHe;
+        }
+    }
+    /* Free the table and the allocated cache structure */
+    free(ht->table);
+    /* Re-initialize the table */
+    _dictReset(ht);
+    return DICT_OK; /* never fails */
+}
+
+/* Clear & Release the hash table */
+static void dictRelease(dict *ht) {
+    _dictClear(ht);
+    free(ht);
+}
+
+static dictEntry *dictFind(dict *ht, const void *key) {
+    dictEntry *he;
+    unsigned int h;
+
+    if (ht->size == 0) return NULL;
+    h = dictHashKey(ht, key) & ht->sizemask;
+    he = ht->table[h];
+    while(he) {
+        if (dictCompareHashKeys(ht, key, he->key))
+            return he;
+        he = he->next;
+    }
+    return NULL;
+}
+
+static dictIterator *dictGetIterator(dict *ht) {
+    dictIterator *iter = malloc(sizeof(*iter));
+
+    iter->ht = ht;
+    iter->index = -1;
+    iter->entry = NULL;
+    iter->nextEntry = NULL;
+    return iter;
+}
+
+static dictEntry *dictNext(dictIterator *iter) {
+    while (1) {
+        if (iter->entry == NULL) {
+            iter->index++;
+            if (iter->index >=
+                    (signed)iter->ht->size) break;
+            iter->entry = iter->ht->table[iter->index];
+        } else {
+            iter->entry = iter->nextEntry;
+        }
+        if (iter->entry) {
+            /* We need to save the 'next' here, the iterator user
+             * may delete the entry we are returning. */
+            iter->nextEntry = iter->entry->next;
+            return iter->entry;
+        }
+    }
+    return NULL;
+}
+
+static void dictReleaseIterator(dictIterator *iter) {
+    free(iter);
+}
+
+/* ------------------------- private functions ------------------------------ */
+
+/* Expand the hash table if needed */
+static int _dictExpandIfNeeded(dict *ht) {
+    /* If the hash table is empty expand it to the initial size,
+     * if the table is "full" dobule its size. */
+    if (ht->size == 0)
+        return dictExpand(ht, DICT_HT_INITIAL_SIZE);
+    if (ht->used == ht->size)
+        return dictExpand(ht, ht->size*2);
+    return DICT_OK;
+}
+
+/* Our hash table capability is a power of two */
+static unsigned long _dictNextPower(unsigned long size) {
+    unsigned long i = DICT_HT_INITIAL_SIZE;
+
+    if (size >= LONG_MAX) return LONG_MAX;
+    while(1) {
+        if (i >= size)
+            return i;
+        i *= 2;
+    }
+}
+
+/* Returns the index of a free slot that can be populated with
+ * an hash entry for the given 'key'.
+ * If the key already exists, -1 is returned. */
+static int _dictKeyIndex(dict *ht, const void *key) {
+    unsigned int h;
+    dictEntry *he;
+
+    /* Expand the hashtable if needed */
+    if (_dictExpandIfNeeded(ht) == DICT_ERR)
+        return -1;
+    /* Compute the key hash value */
+    h = dictHashKey(ht, key) & ht->sizemask;
+    /* Search if this slot does not already contain the given key */
+    he = ht->table[h];
+    while(he) {
+        if (dictCompareHashKeys(ht, key, he->key))
+            return -1;
+        he = he->next;
+    }
+    return h;
+}
+
diff --git a/contrib/hiredis/dict.h b/contrib/hiredis/dict.h
new file mode 100644
index 000000000..95fcd280e
--- /dev/null
+++ b/contrib/hiredis/dict.h
@@ -0,0 +1,126 @@
+/* Hash table implementation.
+ *
+ * This file implements in memory hash tables with insert/del/replace/find/
+ * get-random-element operations. Hash tables will auto resize if needed
+ * tables of power of two in size are used, collisions are handled by
+ * chaining. See the source code for more information... :)
+ *
+ * Copyright (c) 2006-2010, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __DICT_H
+#define __DICT_H
+
+#define DICT_OK 0
+#define DICT_ERR 1
+
+/* Unused arguments generate annoying warnings... */
+#define DICT_NOTUSED(V) ((void) V)
+
+typedef struct dictEntry {
+    void *key;
+    void *val;
+    struct dictEntry *next;
+} dictEntry;
+
+typedef struct dictType {
+    unsigned int (*hashFunction)(const void *key);
+    void *(*keyDup)(void *privdata, const void *key);
+    void *(*valDup)(void *privdata, const void *obj);
+    int (*keyCompare)(void *privdata, const void *key1, const void *key2);
+    void (*keyDestructor)(void *privdata, void *key);
+    void (*valDestructor)(void *privdata, void *obj);
+} dictType;
+
+typedef struct dict {
+    dictEntry **table;
+    dictType *type;
+    unsigned long size;
+    unsigned long sizemask;
+    unsigned long used;
+    void *privdata;
+} dict;
+
+typedef struct dictIterator {
+    dict *ht;
+    int index;
+    dictEntry *entry, *nextEntry;
+} dictIterator;
+
+/* This is the initial size of every hash table */
+#define DICT_HT_INITIAL_SIZE     4
+
+/* ------------------------------- Macros ------------------------------------*/
+#define dictFreeEntryVal(ht, entry) \
+    if ((ht)->type->valDestructor) \
+        (ht)->type->valDestructor((ht)->privdata, (entry)->val)
+
+#define dictSetHashVal(ht, entry, _val_) do { \
+    if ((ht)->type->valDup) \
+        entry->val = (ht)->type->valDup((ht)->privdata, _val_); \
+    else \
+        entry->val = (_val_); \
+} while(0)
+
+#define dictFreeEntryKey(ht, entry) \
+    if ((ht)->type->keyDestructor) \
+        (ht)->type->keyDestructor((ht)->privdata, (entry)->key)
+
+#define dictSetHashKey(ht, entry, _key_) do { \
+    if ((ht)->type->keyDup) \
+        entry->key = (ht)->type->keyDup((ht)->privdata, _key_); \
+    else \
+        entry->key = (_key_); \
+} while(0)
+
+#define dictCompareHashKeys(ht, key1, key2) \
+    (((ht)->type->keyCompare) ? \
+        (ht)->type->keyCompare((ht)->privdata, key1, key2) : \
+        (key1) == (key2))
+
+#define dictHashKey(ht, key) (ht)->type->hashFunction(key)
+
+#define dictGetEntryKey(he) ((he)->key)
+#define dictGetEntryVal(he) ((he)->val)
+#define dictSlots(ht) ((ht)->size)
+#define dictSize(ht) ((ht)->used)
+
+/* API */
+static unsigned int dictGenHashFunction(const unsigned char *buf, int len);
+static dict *dictCreate(dictType *type, void *privDataPtr);
+static int dictExpand(dict *ht, unsigned long size);
+static int dictAdd(dict *ht, void *key, void *val);
+static int dictReplace(dict *ht, void *key, void *val);
+static int dictDelete(dict *ht, const void *key);
+static void dictRelease(dict *ht);
+static dictEntry * dictFind(dict *ht, const void *key);
+static dictIterator *dictGetIterator(dict *ht);
+static dictEntry *dictNext(dictIterator *iter);
+static void dictReleaseIterator(dictIterator *iter);
+
+#endif /* __DICT_H */
diff --git a/contrib/hiredis/fmacros.h b/contrib/hiredis/fmacros.h
new file mode 100644
index 000000000..19d7b2193
--- /dev/null
+++ b/contrib/hiredis/fmacros.h
@@ -0,0 +1,21 @@
+#ifndef __HIREDIS_FMACRO_H
+#define __HIREDIS_FMACRO_H
+
+#if defined(__linux__)
+#define _BSD_SOURCE
+#define _DEFAULT_SOURCE
+#endif
+
+#if defined(__sun__)
+#define _POSIX_C_SOURCE 200112L
+#elif defined(__linux__) || defined(__OpenBSD__) || defined(__NetBSD__)
+#define _XOPEN_SOURCE 600
+#else
+#define _XOPEN_SOURCE
+#endif
+
+#if __APPLE__ && __MACH__
+#define _OSX
+#endif
+
+#endif
diff --git a/contrib/hiredis/hiredis.c b/contrib/hiredis/hiredis.c
new file mode 100644
index 000000000..2b876d913
--- /dev/null
+++ b/contrib/hiredis/hiredis.c
@@ -0,0 +1,1021 @@
+/*
+ * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2014, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2015, Matt Stancliff <matt at genges dot com>,
+ *                     Jan-Erik Rediger <janerik at fnordig dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "fmacros.h"
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <assert.h>
+#include <errno.h>
+#include <ctype.h>
+
+#include "hiredis.h"
+#include "net.h"
+#include "sds.h"
+
+static redisReply *createReplyObject(int type);
+static void *createStringObject(const redisReadTask *task, char *str, size_t len);
+static void *createArrayObject(const redisReadTask *task, int elements);
+static void *createIntegerObject(const redisReadTask *task, long long value);
+static void *createNilObject(const redisReadTask *task);
+
+/* Default set of functions to build the reply. Keep in mind that such a
+ * function returning NULL is interpreted as OOM. */
+static redisReplyObjectFunctions defaultFunctions = {
+    createStringObject,
+    createArrayObject,
+    createIntegerObject,
+    createNilObject,
+    freeReplyObject
+};
+
+/* Create a reply object */
+static redisReply *createReplyObject(int type) {
+    redisReply *r = calloc(1,sizeof(*r));
+
+    if (r == NULL)
+        return NULL;
+
+    r->type = type;
+    return r;
+}
+
+/* Free a reply object */
+void freeReplyObject(void *reply) {
+    redisReply *r = reply;
+    size_t j;
+
+    if (r == NULL)
+        return;
+
+    switch(r->type) {
+    case REDIS_REPLY_INTEGER:
+        break; /* Nothing to free */
+    case REDIS_REPLY_ARRAY:
+        if (r->element != NULL) {
+            for (j = 0; j < r->elements; j++)
+                if (r->element[j] != NULL)
+                    freeReplyObject(r->element[j]);
+            free(r->element);
+        }
+        break;
+    case REDIS_REPLY_ERROR:
+    case REDIS_REPLY_STATUS:
+    case REDIS_REPLY_STRING:
+        if (r->str != NULL)
+            free(r->str);
+        break;
+    }
+    free(r);
+}
+
+static void *createStringObject(const redisReadTask *task, char *str, size_t len) {
+    redisReply *r, *parent;
+    char *buf;
+
+    r = createReplyObject(task->type);
+    if (r == NULL)
+        return NULL;
+
+    buf = malloc(len+1);
+    if (buf == NULL) {
+        freeReplyObject(r);
+        return NULL;
+    }
+
+    assert(task->type == REDIS_REPLY_ERROR  ||
+           task->type == REDIS_REPLY_STATUS ||
+           task->type == REDIS_REPLY_STRING);
+
+    /* Copy string value */
+    memcpy(buf,str,len);
+    buf[len] = '\0';
+    r->str = buf;
+    r->len = len;
+
+    if (task->parent) {
+        parent = task->parent->obj;
+        assert(parent->type == REDIS_REPLY_ARRAY);
+        parent->element[task->idx] = r;
+    }
+    return r;
+}
+
+static void *createArrayObject(const redisReadTask *task, int elements) {
+    redisReply *r, *parent;
+
+    r = createReplyObject(REDIS_REPLY_ARRAY);
+    if (r == NULL)
+        return NULL;
+
+    if (elements > 0) {
+        r->element = calloc(elements,sizeof(redisReply*));
+        if (r->element == NULL) {
+            freeReplyObject(r);
+            return NULL;
+        }
+    }
+
+    r->elements = elements;
+
+    if (task->parent) {
+        parent = task->parent->obj;
+        assert(parent->type == REDIS_REPLY_ARRAY);
+        parent->element[task->idx] = r;
+    }
+    return r;
+}
+
+static void *createIntegerObject(const redisReadTask *task, long long value) {
+    redisReply *r, *parent;
+
+    r = createReplyObject(REDIS_REPLY_INTEGER);
+    if (r == NULL)
+        return NULL;
+
+    r->integer = value;
+
+    if (task->parent) {
+        parent = task->parent->obj;
+        assert(parent->type == REDIS_REPLY_ARRAY);
+        parent->element[task->idx] = r;
+    }
+    return r;
+}
+
+static void *createNilObject(const redisReadTask *task) {
+    redisReply *r, *parent;
+
+    r = createReplyObject(REDIS_REPLY_NIL);
+    if (r == NULL)
+        return NULL;
+
+    if (task->parent) {
+        parent = task->parent->obj;
+        assert(parent->type == REDIS_REPLY_ARRAY);
+        parent->element[task->idx] = r;
+    }
+    return r;
+}
+
+/* Return the number of digits of 'v' when converted to string in radix 10.
+ * Implementation borrowed from link in redis/src/util.c:string2ll(). */
+static uint32_t countDigits(uint64_t v) {
+  uint32_t result = 1;
+  for (;;) {
+    if (v < 10) return result;
+    if (v < 100) return result + 1;
+    if (v < 1000) return result + 2;
+    if (v < 10000) return result + 3;
+    v /= 10000U;
+    result += 4;
+  }
+}
+
+/* Helper that calculates the bulk length given a certain string length. */
+static size_t bulklen(size_t len) {
+    return 1+countDigits(len)+2+len+2;
+}
+
+int redisvFormatCommand(char **target, const char *format, va_list ap) {
+    const char *c = format;
+    char *cmd = NULL; /* final command */
+    int pos; /* position in final command */
+    sds curarg, newarg; /* current argument */
+    int touched = 0; /* was the current argument touched? */
+    char **curargv = NULL, **newargv = NULL;
+    int argc = 0;
+    int totlen = 0;
+    int error_type = 0; /* 0 = no error; -1 = memory error; -2 = format error */
+    int j;
+
+    /* Abort if there is not target to set */
+    if (target == NULL)
+        return -1;
+
+    /* Build the command string accordingly to protocol */
+    curarg = sdsempty();
+    if (curarg == NULL)
+        return -1;
+
+    while(*c != '\0') {
+        if (*c != '%' || c[1] == '\0') {
+            if (*c == ' ') {
+                if (touched) {
+                    newargv = realloc(curargv,sizeof(char*)*(argc+1));
+                    if (newargv == NULL) goto memory_err;
+                    curargv = newargv;
+                    curargv[argc++] = curarg;
+                    totlen += bulklen(sdslen(curarg));
+
+                    /* curarg is put in argv so it can be overwritten. */
+                    curarg = sdsempty();
+                    if (curarg == NULL) goto memory_err;
+                    touched = 0;
+                }
+            } else {
+                newarg = sdscatlen(curarg,c,1);
+                if (newarg == NULL) goto memory_err;
+                curarg = newarg;
+                touched = 1;
+            }
+        } else {
+            char *arg;
+            size_t size;
+
+            /* Set newarg so it can be checked even if it is not touched. */
+            newarg = curarg;
+
+            switch(c[1]) {
+            case 's':
+                arg = va_arg(ap,char*);
+                size = strlen(arg);
+                if (size > 0)
+                    newarg = sdscatlen(curarg,arg,size);
+                break;
+            case 'b':
+                arg = va_arg(ap,char*);
+                size = va_arg(ap,size_t);
+                if (size > 0)
+                    newarg = sdscatlen(curarg,arg,size);
+                break;
+            case '%':
+                newarg = sdscat(curarg,"%");
+                break;
+            default:
+                /* Try to detect printf format */
+                {
+                    static const char intfmts[] = "diouxX";
+                    static const char flags[] = "#0-+ ";
+                    char _format[16];
+                    const char *_p = c+1;
+                    size_t _l = 0;
+                    va_list _cpy;
+
+                    /* Flags */
+                    while (*_p != '\0' && strchr(flags,*_p) != NULL) _p++;
+
+                    /* Field width */
+                    while (*_p != '\0' && isdigit(*_p)) _p++;
+
+                    /* Precision */
+                    if (*_p == '.') {
+                        _p++;
+                        while (*_p != '\0' && isdigit(*_p)) _p++;
+                    }
+
+                    /* Copy va_list before consuming with va_arg */
+                    va_copy(_cpy,ap);
+
+                    /* Integer conversion (without modifiers) */
+                    if (strchr(intfmts,*_p) != NULL) {
+                        va_arg(ap,int);
+                        goto fmt_valid;
+                    }
+
+                    /* Double conversion (without modifiers) */
+                    if (strchr("eEfFgGaA",*_p) != NULL) {
+                        va_arg(ap,double);
+                        goto fmt_valid;
+                    }
+
+                    /* Size: char */
+                    if (_p[0] == 'h' && _p[1] == 'h') {
+                        _p += 2;
+                        if (*_p != '\0' && strchr(intfmts,*_p) != NULL) {
+                            va_arg(ap,int); /* char gets promoted to int */
+                            goto fmt_valid;
+                        }
+                        goto fmt_invalid;
+                    }
+
+                    /* Size: short */
+                    if (_p[0] == 'h') {
+                        _p += 1;
+                        if (*_p != '\0' && strchr(intfmts,*_p) != NULL) {
+                            va_arg(ap,int); /* short gets promoted to int */
+                            goto fmt_valid;
+                        }
+                        goto fmt_invalid;
+                    }
+
+                    /* Size: long long */
+                    if (_p[0] == 'l' && _p[1] == 'l') {
+                        _p += 2;
+                        if (*_p != '\0' && strchr(intfmts,*_p) != NULL) {
+                            va_arg(ap,long long);
+                            goto fmt_valid;
+                        }
+                        goto fmt_invalid;
+                    }
+
+                    /* Size: long */
+                    if (_p[0] == 'l') {
+                        _p += 1;
+                        if (*_p != '\0' && strchr(intfmts,*_p) != NULL) {
+                            va_arg(ap,long);
+                            goto fmt_valid;
+                        }
+                        goto fmt_invalid;
+                    }
+
+                fmt_invalid:
+                    va_end(_cpy);
+                    goto format_err;
+
+                fmt_valid:
+                    _l = (_p+1)-c;
+                    if (_l < sizeof(_format)-2) {
+                        memcpy(_format,c,_l);
+                        _format[_l] = '\0';
+                        newarg = sdscatvprintf(curarg,_format,_cpy);
+
+                        /* Update current position (note: outer blocks
+                         * increment c twice so compensate here) */
+                        c = _p-1;
+                    }
+
+                    va_end(_cpy);
+                    break;
+                }
+            }
+
+            if (newarg == NULL) goto memory_err;
+            curarg = newarg;
+
+            touched = 1;
+            c++;
+        }
+        c++;
+    }
+
+    /* Add the last argument if needed */
+    if (touched) {
+        newargv = realloc(curargv,sizeof(char*)*(argc+1));
+        if (newargv == NULL) goto memory_err;
+        curargv = newargv;
+        curargv[argc++] = curarg;
+        totlen += bulklen(sdslen(curarg));
+    } else {
+        sdsfree(curarg);
+    }
+
+    /* Clear curarg because it was put in curargv or was free'd. */
+    curarg = NULL;
+
+    /* Add bytes needed to hold multi bulk count */
+    totlen += 1+countDigits(argc)+2;
+
+    /* Build the command at protocol level */
+    cmd = malloc(totlen+1);
+    if (cmd == NULL) goto memory_err;
+
+    pos = sprintf(cmd,"*%d\r\n",argc);
+    for (j = 0; j < argc; j++) {
+        pos += sprintf(cmd+pos,"$%zu\r\n",sdslen(curargv[j]));
+        memcpy(cmd+pos,curargv[j],sdslen(curargv[j]));
+        pos += sdslen(curargv[j]);
+        sdsfree(curargv[j]);
+        cmd[pos++] = '\r';
+        cmd[pos++] = '\n';
+    }
+    assert(pos == totlen);
+    cmd[pos] = '\0';
+
+    free(curargv);
+    *target = cmd;
+    return totlen;
+
+format_err:
+    error_type = -2;
+    goto cleanup;
+
+memory_err:
+    error_type = -1;
+    goto cleanup;
+
+cleanup:
+    if (curargv) {
+        while(argc--)
+            sdsfree(curargv[argc]);
+        free(curargv);
+    }
+
+    sdsfree(curarg);
+
+    /* No need to check cmd since it is the last statement that can fail,
+     * but do it anyway to be as defensive as possible. */
+    if (cmd != NULL)
+        free(cmd);
+
+    return error_type;
+}
+
+/* Format a command according to the Redis protocol. This function
+ * takes a format similar to printf:
+ *
+ * %s represents a C null terminated string you want to interpolate
+ * %b represents a binary safe string
+ *
+ * When using %b you need to provide both the pointer to the string
+ * and the length in bytes as a size_t. Examples:
+ *
+ * len = redisFormatCommand(target, "GET %s", mykey);
+ * len = redisFormatCommand(target, "SET %s %b", mykey, myval, myvallen);
+ */
+int redisFormatCommand(char **target, const char *format, ...) {
+    va_list ap;
+    int len;
+    va_start(ap,format);
+    len = redisvFormatCommand(target,format,ap);
+    va_end(ap);
+
+    /* The API says "-1" means bad result, but we now also return "-2" in some
+     * cases.  Force the return value to always be -1. */
+    if (len < 0)
+        len = -1;
+
+    return len;
+}
+
+/* Format a command according to the Redis protocol using an sds string and
+ * sdscatfmt for the processing of arguments. This function takes the
+ * number of arguments, an array with arguments and an array with their
+ * lengths. If the latter is set to NULL, strlen will be used to compute the
+ * argument lengths.
+ */
+int redisFormatSdsCommandArgv(sds *target, int argc, const char **argv,
+                              const size_t *argvlen)
+{
+    sds cmd;
+    unsigned long long totlen;
+    int j;
+    size_t len;
+
+    /* Abort on a NULL target */
+    if (target == NULL)
+        return -1;
+
+    /* Calculate our total size */
+    totlen = 1+countDigits(argc)+2;
+    for (j = 0; j < argc; j++) {
+        len = argvlen ? argvlen[j] : strlen(argv[j]);
+        totlen += bulklen(len);
+    }
+
+    /* Use an SDS string for command construction */
+    cmd = sdsempty();
+    if (cmd == NULL)
+        return -1;
+
+    /* We already know how much storage we need */
+    cmd = sdsMakeRoomFor(cmd, totlen);
+    if (cmd == NULL)
+        return -1;
+
+    /* Construct command */
+    cmd = sdscatfmt(cmd, "*%i\r\n", argc);
+    for (j=0; j < argc; j++) {
+        len = argvlen ? argvlen[j] : strlen(argv[j]);
+        cmd = sdscatfmt(cmd, "$%T\r\n", len);
+        cmd = sdscatlen(cmd, argv[j], len);
+        cmd = sdscatlen(cmd, "\r\n", sizeof("\r\n")-1);
+    }
+
+    assert(sdslen(cmd)==totlen);
+
+    *target = cmd;
+    return totlen;
+}
+
+void redisFreeSdsCommand(sds cmd) {
+    sdsfree(cmd);
+}
+
+/* Format a command according to the Redis protocol. This function takes the
+ * number of arguments, an array with arguments and an array with their
+ * lengths. If the latter is set to NULL, strlen will be used to compute the
+ * argument lengths.
+ */
+int redisFormatCommandArgv(char **target, int argc, const char **argv, const size_t *argvlen) {
+    char *cmd = NULL; /* final command */
+    int pos; /* position in final command */
+    size_t len;
+    int totlen, j;
+
+    /* Abort on a NULL target */
+    if (target == NULL)
+        return -1;
+
+    /* Calculate number of bytes needed for the command */
+    totlen = 1+countDigits(argc)+2;
+    for (j = 0; j < argc; j++) {
+        len = argvlen ? argvlen[j] : strlen(argv[j]);
+        totlen += bulklen(len);
+    }
+
+    /* Build the command at protocol level */
+    cmd = malloc(totlen+1);
+    if (cmd == NULL)
+        return -1;
+
+    pos = sprintf(cmd,"*%d\r\n",argc);
+    for (j = 0; j < argc; j++) {
+        len = argvlen ? argvlen[j] : strlen(argv[j]);
+        pos += sprintf(cmd+pos,"$%zu\r\n",len);
+        memcpy(cmd+pos,argv[j],len);
+        pos += len;
+        cmd[pos++] = '\r';
+        cmd[pos++] = '\n';
+    }
+    assert(pos == totlen);
+    cmd[pos] = '\0';
+
+    *target = cmd;
+    return totlen;
+}
+
+void redisFreeCommand(char *cmd) {
+    free(cmd);
+}
+
+void __redisSetError(redisContext *c, int type, const char *str) {
+    size_t len;
+
+    c->err = type;
+    if (str != NULL) {
+        len = strlen(str);
+        len = len < (sizeof(c->errstr)-1) ? len : (sizeof(c->errstr)-1);
+        memcpy(c->errstr,str,len);
+        c->errstr[len] = '\0';
+    } else {
+        /* Only REDIS_ERR_IO may lack a description! */
+        assert(type == REDIS_ERR_IO);
+        __redis_strerror_r(errno, c->errstr, sizeof(c->errstr));
+    }
+}
+
+redisReader *redisReaderCreate(void) {
+    return redisReaderCreateWithFunctions(&defaultFunctions);
+}
+
+static redisContext *redisContextInit(void) {
+    redisContext *c;
+
+    c = calloc(1,sizeof(redisContext));
+    if (c == NULL)
+        return NULL;
+
+    c->err = 0;
+    c->errstr[0] = '\0';
+    c->obuf = sdsempty();
+    c->reader = redisReaderCreate();
+    c->tcp.host = NULL;
+    c->tcp.source_addr = NULL;
+    c->unix_sock.path = NULL;
+    c->timeout = NULL;
+
+    if (c->obuf == NULL || c->reader == NULL) {
+        redisFree(c);
+        return NULL;
+    }
+
+    return c;
+}
+
+void redisFree(redisContext *c) {
+    if (c == NULL)
+        return;
+    if (c->fd > 0)
+        close(c->fd);
+    if (c->obuf != NULL)
+        sdsfree(c->obuf);
+    if (c->reader != NULL)
+        redisReaderFree(c->reader);
+    if (c->tcp.host)
+        free(c->tcp.host);
+    if (c->tcp.source_addr)
+        free(c->tcp.source_addr);
+    if (c->unix_sock.path)
+        free(c->unix_sock.path);
+    if (c->timeout)
+        free(c->timeout);
+    free(c);
+}
+
+int redisFreeKeepFd(redisContext *c) {
+    int fd = c->fd;
+    c->fd = -1;
+    redisFree(c);
+    return fd;
+}
+
+int redisReconnect(redisContext *c) {
+    c->err = 0;
+    memset(c->errstr, '\0', strlen(c->errstr));
+
+    if (c->fd > 0) {
+        close(c->fd);
+    }
+
+    sdsfree(c->obuf);
+    redisReaderFree(c->reader);
+
+    c->obuf = sdsempty();
+    c->reader = redisReaderCreate();
+
+    if (c->connection_type == REDIS_CONN_TCP) {
+        return redisContextConnectBindTcp(c, c->tcp.host, c->tcp.port,
+                c->timeout, c->tcp.source_addr);
+    } else if (c->connection_type == REDIS_CONN_UNIX) {
+        return redisContextConnectUnix(c, c->unix_sock.path, c->timeout);
+    } else {
+        /* Something bad happened here and shouldn't have. There isn't
+           enough information in the context to reconnect. */
+        __redisSetError(c,REDIS_ERR_OTHER,"Not enough information to reconnect");
+    }
+
+    return REDIS_ERR;
+}
+
+/* Connect to a Redis instance. On error the field error in the returned
+ * context will be set to the return value of the error function.
+ * When no set of reply functions is given, the default set will be used. */
+redisContext *redisConnect(const char *ip, int port) {
+    redisContext *c;
+
+    c = redisContextInit();
+    if (c == NULL)
+        return NULL;
+
+    c->flags |= REDIS_BLOCK;
+    redisContextConnectTcp(c,ip,port,NULL);
+    return c;
+}
+
+redisContext *redisConnectWithTimeout(const char *ip, int port, const struct timeval tv) {
+    redisContext *c;
+
+    c = redisContextInit();
+    if (c == NULL)
+        return NULL;
+
+    c->flags |= REDIS_BLOCK;
+    redisContextConnectTcp(c,ip,port,&tv);
+    return c;
+}
+
+redisContext *redisConnectNonBlock(const char *ip, int port) {
+    redisContext *c;
+
+    c = redisContextInit();
+    if (c == NULL)
+        return NULL;
+
+    c->flags &= ~REDIS_BLOCK;
+    redisContextConnectTcp(c,ip,port,NULL);
+    return c;
+}
+
+redisContext *redisConnectBindNonBlock(const char *ip, int port,
+                                       const char *source_addr) {
+    redisContext *c = redisContextInit();
+    c->flags &= ~REDIS_BLOCK;
+    redisContextConnectBindTcp(c,ip,port,NULL,source_addr);
+    return c;
+}
+
+redisContext *redisConnectBindNonBlockWithReuse(const char *ip, int port,
+                                                const char *source_addr) {
+    redisContext *c = redisContextInit();
+    c->flags &= ~REDIS_BLOCK;
+    c->flags |= REDIS_REUSEADDR;
+    redisContextConnectBindTcp(c,ip,port,NULL,source_addr);
+    return c;
+}
+
+redisContext *redisConnectUnix(const char *path) {
+    redisContext *c;
+
+    c = redisContextInit();
+    if (c == NULL)
+        return NULL;
+
+    c->flags |= REDIS_BLOCK;
+    redisContextConnectUnix(c,path,NULL);
+    return c;
+}
+
+redisContext *redisConnectUnixWithTimeout(const char *path, const struct timeval tv) {
+    redisContext *c;
+
+    c = redisContextInit();
+    if (c == NULL)
+        return NULL;
+
+    c->flags |= REDIS_BLOCK;
+    redisContextConnectUnix(c,path,&tv);
+    return c;
+}
+
+redisContext *redisConnectUnixNonBlock(const char *path) {
+    redisContext *c;
+
+    c = redisContextInit();
+    if (c == NULL)
+        return NULL;
+
+    c->flags &= ~REDIS_BLOCK;
+    redisContextConnectUnix(c,path,NULL);
+    return c;
+}
+
+redisContext *redisConnectFd(int fd) {
+    redisContext *c;
+
+    c = redisContextInit();
+    if (c == NULL)
+        return NULL;
+
+    c->fd = fd;
+    c->flags |= REDIS_BLOCK | REDIS_CONNECTED;
+    return c;
+}
+
+/* Set read/write timeout on a blocking socket. */
+int redisSetTimeout(redisContext *c, const struct timeval tv) {
+    if (c->flags & REDIS_BLOCK)
+        return redisContextSetTimeout(c,tv);
+    return REDIS_ERR;
+}
+
+/* Enable connection KeepAlive. */
+int redisEnableKeepAlive(redisContext *c) {
+    if (redisKeepAlive(c, REDIS_KEEPALIVE_INTERVAL) != REDIS_OK)
+        return REDIS_ERR;
+    return REDIS_OK;
+}
+
+/* Use this function to handle a read event on the descriptor. It will try
+ * and read some bytes from the socket and feed them to the reply parser.
+ *
+ * After this function is called, you may use redisContextReadReply to
+ * see if there is a reply available. */
+int redisBufferRead(redisContext *c) {
+    char buf[1024*16];
+    int nread;
+
+    /* Return early when the context has seen an error. */
+    if (c->err)
+        return REDIS_ERR;
+
+    nread = read(c->fd,buf,sizeof(buf));
+    if (nread == -1) {
+        if ((errno == EAGAIN && !(c->flags & REDIS_BLOCK)) || (errno == EINTR)) {
+            /* Try again later */
+        } else {
+            __redisSetError(c,REDIS_ERR_IO,NULL);
+            return REDIS_ERR;
+        }
+    } else if (nread == 0) {
+        __redisSetError(c,REDIS_ERR_EOF,"Server closed the connection");
+        return REDIS_ERR;
+    } else {
+        if (redisReaderFeed(c->reader,buf,nread) != REDIS_OK) {
+            __redisSetError(c,c->reader->err,c->reader->errstr);
+            return REDIS_ERR;
+        }
+    }
+    return REDIS_OK;
+}
+
+/* Write the output buffer to the socket.
+ *
+ * Returns REDIS_OK when the buffer is empty, or (a part of) the buffer was
+ * successfully written to the socket. When the buffer is empty after the
+ * write operation, "done" is set to 1 (if given).
+ *
+ * Returns REDIS_ERR if an error occurred trying to write and sets
+ * c->errstr to hold the appropriate error string.
+ */
+int redisBufferWrite(redisContext *c, int *done) {
+    int nwritten;
+
+    /* Return early when the context has seen an error. */
+    if (c->err)
+        return REDIS_ERR;
+
+    if (sdslen(c->obuf) > 0) {
+        nwritten = write(c->fd,c->obuf,sdslen(c->obuf));
+        if (nwritten == -1) {
+            if ((errno == EAGAIN && !(c->flags & REDIS_BLOCK)) || (errno == EINTR)) {
+                /* Try again later */
+            } else {
+                __redisSetError(c,REDIS_ERR_IO,NULL);
+                return REDIS_ERR;
+            }
+        } else if (nwritten > 0) {
+            if (nwritten == (signed)sdslen(c->obuf)) {
+                sdsfree(c->obuf);
+                c->obuf = sdsempty();
+            } else {
+                sdsrange(c->obuf,nwritten,-1);
+            }
+        }
+    }
+    if (done != NULL) *done = (sdslen(c->obuf) == 0);
+    return REDIS_OK;
+}
+
+/* Internal helper function to try and get a reply from the reader,
+ * or set an error in the context otherwise. */
+int redisGetReplyFromReader(redisContext *c, void **reply) {
+    if (redisReaderGetReply(c->reader,reply) == REDIS_ERR) {
+        __redisSetError(c,c->reader->err,c->reader->errstr);
+        return REDIS_ERR;
+    }
+    return REDIS_OK;
+}
+
+int redisGetReply(redisContext *c, void **reply) {
+    int wdone = 0;
+    void *aux = NULL;
+
+    /* Try to read pending replies */
+    if (redisGetReplyFromReader(c,&aux) == REDIS_ERR)
+        return REDIS_ERR;
+
+    /* For the blocking context, flush output buffer and read reply */
+    if (aux == NULL && c->flags & REDIS_BLOCK) {
+        /* Write until done */
+        do {
+            if (redisBufferWrite(c,&wdone) == REDIS_ERR)
+                return REDIS_ERR;
+        } while (!wdone);
+
+        /* Read until there is a reply */
+        do {
+            if (redisBufferRead(c) == REDIS_ERR)
+                return REDIS_ERR;
+            if (redisGetReplyFromReader(c,&aux) == REDIS_ERR)
+                return REDIS_ERR;
+        } while (aux == NULL);
+    }
+
+    /* Set reply object */
+    if (reply != NULL) *reply = aux;
+    return REDIS_OK;
+}
+
+
+/* Helper function for the redisAppendCommand* family of functions.
+ *
+ * Write a formatted command to the output buffer. When this family
+ * is used, you need to call redisGetReply yourself to retrieve
+ * the reply (or replies in pub/sub).
+ */
+int __redisAppendCommand(redisContext *c, const char *cmd, size_t len) {
+    sds newbuf;
+
+    newbuf = sdscatlen(c->obuf,cmd,len);
+    if (newbuf == NULL) {
+        __redisSetError(c,REDIS_ERR_OOM,"Out of memory");
+        return REDIS_ERR;
+    }
+
+    c->obuf = newbuf;
+    return REDIS_OK;
+}
+
+int redisAppendFormattedCommand(redisContext *c, const char *cmd, size_t len) {
+
+    if (__redisAppendCommand(c, cmd, len) != REDIS_OK) {
+        return REDIS_ERR;
+    }
+
+    return REDIS_OK;
+}
+
+int redisvAppendCommand(redisContext *c, const char *format, va_list ap) {
+    char *cmd;
+    int len;
+
+    len = redisvFormatCommand(&cmd,format,ap);
+    if (len == -1) {
+        __redisSetError(c,REDIS_ERR_OOM,"Out of memory");
+        return REDIS_ERR;
+    } else if (len == -2) {
+        __redisSetError(c,REDIS_ERR_OTHER,"Invalid format string");
+        return REDIS_ERR;
+    }
+
+    if (__redisAppendCommand(c,cmd,len) != REDIS_OK) {
+        free(cmd);
+        return REDIS_ERR;
+    }
+
+    free(cmd);
+    return REDIS_OK;
+}
+
+int redisAppendCommand(redisContext *c, const char *format, ...) {
+    va_list ap;
+    int ret;
+
+    va_start(ap,format);
+    ret = redisvAppendCommand(c,format,ap);
+    va_end(ap);
+    return ret;
+}
+
+int redisAppendCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen) {
+    sds cmd;
+    int len;
+
+    len = redisFormatSdsCommandArgv(&cmd,argc,argv,argvlen);
+    if (len == -1) {
+        __redisSetError(c,REDIS_ERR_OOM,"Out of memory");
+        return REDIS_ERR;
+    }
+
+    if (__redisAppendCommand(c,cmd,len) != REDIS_OK) {
+        sdsfree(cmd);
+        return REDIS_ERR;
+    }
+
+    sdsfree(cmd);
+    return REDIS_OK;
+}
+
+/* Helper function for the redisCommand* family of functions.
+ *
+ * Write a formatted command to the output buffer. If the given context is
+ * blocking, immediately read the reply into the "reply" pointer. When the
+ * context is non-blocking, the "reply" pointer will not be used and the
+ * command is simply appended to the write buffer.
+ *
+ * Returns the reply when a reply was successfully retrieved. Returns NULL
+ * otherwise. When NULL is returned in a blocking context, the error field
+ * in the context will be set.
+ */
+static void *__redisBlockForReply(redisContext *c) {
+    void *reply;
+
+    if (c->flags & REDIS_BLOCK) {
+        if (redisGetReply(c,&reply) != REDIS_OK)
+            return NULL;
+        return reply;
+    }
+    return NULL;
+}
+
+void *redisvCommand(redisContext *c, const char *format, va_list ap) {
+    if (redisvAppendCommand(c,format,ap) != REDIS_OK)
+        return NULL;
+    return __redisBlockForReply(c);
+}
+
+void *redisCommand(redisContext *c, const char *format, ...) {
+    va_list ap;
+    void *reply = NULL;
+    va_start(ap,format);
+    reply = redisvCommand(c,format,ap);
+    va_end(ap);
+    return reply;
+}
+
+void *redisCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen) {
+    if (redisAppendCommandArgv(c,argc,argv,argvlen) != REDIS_OK)
+        return NULL;
+    return __redisBlockForReply(c);
+}
diff --git a/contrib/hiredis/hiredis.h b/contrib/hiredis/hiredis.h
new file mode 100644
index 000000000..edba65886
--- /dev/null
+++ b/contrib/hiredis/hiredis.h
@@ -0,0 +1,223 @@
+/*
+ * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2014, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2015, Matt Stancliff <matt at genges dot com>,
+ *                     Jan-Erik Rediger <janerik at fnordig dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __HIREDIS_H
+#define __HIREDIS_H
+#include "read.h"
+#include <stdarg.h> /* for va_list */
+#include <sys/time.h> /* for struct timeval */
+#include <stdint.h> /* uintXX_t, etc */
+#include "sds.h" /* for sds */
+
+#define HIREDIS_MAJOR 0
+#define HIREDIS_MINOR 13
+#define HIREDIS_PATCH 3
+#define HIREDIS_SONAME 0.13
+
+/* Connection type can be blocking or non-blocking and is set in the
+ * least significant bit of the flags field in redisContext. */
+#define REDIS_BLOCK 0x1
+
+/* Connection may be disconnected before being free'd. The second bit
+ * in the flags field is set when the context is connected. */
+#define REDIS_CONNECTED 0x2
+
+/* The async API might try to disconnect cleanly and flush the output
+ * buffer and read all subsequent replies before disconnecting.
+ * This flag means no new commands can come in and the connection
+ * should be terminated once all replies have been read. */
+#define REDIS_DISCONNECTING 0x4
+
+/* Flag specific to the async API which means that the context should be clean
+ * up as soon as possible. */
+#define REDIS_FREEING 0x8
+
+/* Flag that is set when an async callback is executed. */
+#define REDIS_IN_CALLBACK 0x10
+
+/* Flag that is set when the async context has one or more subscriptions. */
+#define REDIS_SUBSCRIBED 0x20
+
+/* Flag that is set when monitor mode is active */
+#define REDIS_MONITORING 0x40
+
+/* Flag that is set when we should set SO_REUSEADDR before calling bind() */
+#define REDIS_REUSEADDR 0x80
+
+#define REDIS_KEEPALIVE_INTERVAL 15 /* seconds */
+
+/* number of times we retry to connect in the case of EADDRNOTAVAIL and
+ * SO_REUSEADDR is being used. */
+#define REDIS_CONNECT_RETRIES  10
+
+/* strerror_r has two completely different prototypes and behaviors
+ * depending on system issues, so we need to operate on the error buffer
+ * differently depending on which strerror_r we're using. */
+#ifndef _GNU_SOURCE
+/* "regular" POSIX strerror_r that does the right thing. */
+#define __redis_strerror_r(errno, buf, len)                                    \
+    do {                                                                       \
+        strerror_r((errno), (buf), (len));                                     \
+    } while (0)
+#else
+/* "bad" GNU strerror_r we need to clean up after. */
+#define __redis_strerror_r(errno, buf, len)                                    \
+    do {                                                                       \
+        char *err_str = strerror_r((errno), (buf), (len));                     \
+        /* If return value _isn't_ the start of the buffer we passed in,       \
+         * then GNU strerror_r returned an internal static buffer and we       \
+         * need to copy the result into our private buffer. */                 \
+        if (err_str != (buf)) {                                                \
+            buf[(len)] = '\0';                                                 \
+            strncat((buf), err_str, ((len) - 1));                              \
+        }                                                                      \
+    } while (0)
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* This is the reply object returned by redisCommand() */
+typedef struct redisReply {
+    int type; /* REDIS_REPLY_* */
+    long long integer; /* The integer when type is REDIS_REPLY_INTEGER */
+    int len; /* Length of string */
+    char *str; /* Used for both REDIS_REPLY_ERROR and REDIS_REPLY_STRING */
+    size_t elements; /* number of elements, for REDIS_REPLY_ARRAY */
+    struct redisReply **element; /* elements vector for REDIS_REPLY_ARRAY */
+} redisReply;
+
+redisReader *redisReaderCreate(void);
+
+/* Function to free the reply objects hiredis returns by default. */
+void freeReplyObject(void *reply);
+
+/* Functions to format a command according to the protocol. */
+int redisvFormatCommand(char **target, const char *format, va_list ap);
+int redisFormatCommand(char **target, const char *format, ...);
+int redisFormatCommandArgv(char **target, int argc, const char **argv, const size_t *argvlen);
+int redisFormatSdsCommandArgv(sds *target, int argc, const char ** argv, const size_t *argvlen);
+void redisFreeCommand(char *cmd);
+void redisFreeSdsCommand(sds cmd);
+
+enum redisConnectionType {
+    REDIS_CONN_TCP,
+    REDIS_CONN_UNIX,
+};
+
+/* Context for a connection to Redis */
+typedef struct redisContext {
+    int err; /* Error flags, 0 when there is no error */
+    char errstr[128]; /* String representation of error when applicable */
+    int fd;
+    int flags;
+    char *obuf; /* Write buffer */
+    redisReader *reader; /* Protocol reader */
+
+    enum redisConnectionType connection_type;
+    struct timeval *timeout;
+
+    struct {
+        char *host;
+        char *source_addr;
+        int port;
+    } tcp;
+
+    struct {
+        char *path;
+    } unix_sock;
+
+} redisContext;
+
+redisContext *redisConnect(const char *ip, int port);
+redisContext *redisConnectWithTimeout(const char *ip, int port, const struct timeval tv);
+redisContext *redisConnectNonBlock(const char *ip, int port);
+redisContext *redisConnectBindNonBlock(const char *ip, int port,
+                                       const char *source_addr);
+redisContext *redisConnectBindNonBlockWithReuse(const char *ip, int port,
+                                                const char *source_addr);
+redisContext *redisConnectUnix(const char *path);
+redisContext *redisConnectUnixWithTimeout(const char *path, const struct timeval tv);
+redisContext *redisConnectUnixNonBlock(const char *path);
+redisContext *redisConnectFd(int fd);
+
+/**
+ * Reconnect the given context using the saved information.
+ *
+ * This re-uses the exact same connect options as in the initial connection.
+ * host, ip (or path), timeout and bind address are reused,
+ * flags are used unmodified from the existing context.
+ *
+ * Returns REDIS_OK on successful connect or REDIS_ERR otherwise.
+ */
+int redisReconnect(redisContext *c);
+
+int redisSetTimeout(redisContext *c, const struct timeval tv);
+int redisEnableKeepAlive(redisContext *c);
+void redisFree(redisContext *c);
+int redisFreeKeepFd(redisContext *c);
+int redisBufferRead(redisContext *c);
+int redisBufferWrite(redisContext *c, int *done);
+
+/* In a blocking context, this function first checks if there are unconsumed
+ * replies to return and returns one if so. Otherwise, it flushes the output
+ * buffer to the socket and reads until it has a reply. In a non-blocking
+ * context, it will return unconsumed replies until there are no more. */
+int redisGetReply(redisContext *c, void **reply);
+int redisGetReplyFromReader(redisContext *c, void **reply);
+
+/* Write a formatted command to the output buffer. Use these functions in blocking mode
+ * to get a pipeline of commands. */
+int redisAppendFormattedCommand(redisContext *c, const char *cmd, size_t len);
+
+/* Write a command to the output buffer. Use these functions in blocking mode
+ * to get a pipeline of commands. */
+int redisvAppendCommand(redisContext *c, const char *format, va_list ap);
+int redisAppendCommand(redisContext *c, const char *format, ...);
+int redisAppendCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
+
+/* Issue a command to Redis. In a blocking context, it is identical to calling
+ * redisAppendCommand, followed by redisGetReply. The function will return
+ * NULL if there was an error in performing the request, otherwise it will
+ * return the reply. In a non-blocking context, it is identical to calling
+ * only redisAppendCommand and will always return NULL. */
+void *redisvCommand(redisContext *c, const char *format, va_list ap);
+void *redisCommand(redisContext *c, const char *format, ...);
+void *redisCommandArgv(redisContext *c, int argc, const char **argv, const size_t *argvlen);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/contrib/hiredis/net.c b/contrib/hiredis/net.c
new file mode 100644
index 000000000..60a2dc754
--- /dev/null
+++ b/contrib/hiredis/net.c
@@ -0,0 +1,458 @@
+/* Extracted from anet.c to work properly with Hiredis error reporting.
+ *
+ * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2014, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2015, Matt Stancliff <matt at genges dot com>,
+ *                     Jan-Erik Rediger <janerik at fnordig dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "fmacros.h"
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/select.h>
+#include <sys/un.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <string.h>
+#include <netdb.h>
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <poll.h>
+#include <limits.h>
+#include <stdlib.h>
+
+#include "net.h"
+#include "sds.h"
+
+/* Defined in hiredis.c */
+void __redisSetError(redisContext *c, int type, const char *str);
+
+static void redisContextCloseFd(redisContext *c) {
+    if (c && c->fd >= 0) {
+        close(c->fd);
+        c->fd = -1;
+    }
+}
+
+static void __redisSetErrorFromErrno(redisContext *c, int type, const char *prefix) {
+    char buf[128] = { 0 };
+    size_t len = 0;
+
+    if (prefix != NULL)
+        len = snprintf(buf,sizeof(buf),"%s: ",prefix);
+    __redis_strerror_r(errno, (char *)(buf + len), sizeof(buf) - len);
+    __redisSetError(c,type,buf);
+}
+
+static int redisSetReuseAddr(redisContext *c) {
+    int on = 1;
+    if (setsockopt(c->fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) {
+        __redisSetErrorFromErrno(c,REDIS_ERR_IO,NULL);
+        redisContextCloseFd(c);
+        return REDIS_ERR;
+    }
+    return REDIS_OK;
+}
+
+static int redisCreateSocket(redisContext *c, int type) {
+    int s;
+    if ((s = socket(type, SOCK_STREAM, 0)) == -1) {
+        __redisSetErrorFromErrno(c,REDIS_ERR_IO,NULL);
+        return REDIS_ERR;
+    }
+    c->fd = s;
+    if (type == AF_INET) {
+        if (redisSetReuseAddr(c) == REDIS_ERR) {
+            return REDIS_ERR;
+        }
+    }
+    return REDIS_OK;
+}
+
+static int redisSetBlocking(redisContext *c, int blocking) {
+    int flags;
+
+    /* Set the socket nonblocking.
+     * Note that fcntl(2) for F_GETFL and F_SETFL can't be
+     * interrupted by a signal. */
+    if ((flags = fcntl(c->fd, F_GETFL)) == -1) {
+        __redisSetErrorFromErrno(c,REDIS_ERR_IO,"fcntl(F_GETFL)");
+        redisContextCloseFd(c);
+        return REDIS_ERR;
+    }
+
+    if (blocking)
+        flags &= ~O_NONBLOCK;
+    else
+        flags |= O_NONBLOCK;
+
+    if (fcntl(c->fd, F_SETFL, flags) == -1) {
+        __redisSetErrorFromErrno(c,REDIS_ERR_IO,"fcntl(F_SETFL)");
+        redisContextCloseFd(c);
+        return REDIS_ERR;
+    }
+    return REDIS_OK;
+}
+
+int redisKeepAlive(redisContext *c, int interval) {
+    int val = 1;
+    int fd = c->fd;
+
+    if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &val, sizeof(val)) == -1){
+        __redisSetError(c,REDIS_ERR_OTHER,strerror(errno));
+        return REDIS_ERR;
+    }
+
+    val = interval;
+
+#ifdef _OSX
+    if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPALIVE, &val, sizeof(val)) < 0) {
+        __redisSetError(c,REDIS_ERR_OTHER,strerror(errno));
+        return REDIS_ERR;
+    }
+#else
+#if defined(__GLIBC__) && !defined(__FreeBSD_kernel__)
+    val = interval;
+    if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPIDLE, &val, sizeof(val)) < 0) {
+        __redisSetError(c,REDIS_ERR_OTHER,strerror(errno));
+        return REDIS_ERR;
+    }
+
+    val = interval/3;
+    if (val == 0) val = 1;
+    if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPINTVL, &val, sizeof(val)) < 0) {
+        __redisSetError(c,REDIS_ERR_OTHER,strerror(errno));
+        return REDIS_ERR;
+    }
+
+    val = 3;
+    if (setsockopt(fd, IPPROTO_TCP, TCP_KEEPCNT, &val, sizeof(val)) < 0) {
+        __redisSetError(c,REDIS_ERR_OTHER,strerror(errno));
+        return REDIS_ERR;
+    }
+#endif
+#endif
+
+    return REDIS_OK;
+}
+
+static int redisSetTcpNoDelay(redisContext *c) {
+    int yes = 1;
+    if (setsockopt(c->fd, IPPROTO_TCP, TCP_NODELAY, &yes, sizeof(yes)) == -1) {
+        __redisSetErrorFromErrno(c,REDIS_ERR_IO,"setsockopt(TCP_NODELAY)");
+        redisContextCloseFd(c);
+        return REDIS_ERR;
+    }
+    return REDIS_OK;
+}
+
+#define __MAX_MSEC (((LONG_MAX) - 999) / 1000)
+
+static int redisContextWaitReady(redisContext *c, const struct timeval *timeout) {
+    struct pollfd   wfd[1];
+    long msec;
+
+    msec          = -1;
+    wfd[0].fd     = c->fd;
+    wfd[0].events = POLLOUT;
+
+    /* Only use timeout when not NULL. */
+    if (timeout != NULL) {
+        if (timeout->tv_usec > 1000000 || timeout->tv_sec > __MAX_MSEC) {
+            __redisSetErrorFromErrno(c, REDIS_ERR_IO, NULL);
+            redisContextCloseFd(c);
+            return REDIS_ERR;
+        }
+
+        msec = (timeout->tv_sec * 1000) + ((timeout->tv_usec + 999) / 1000);
+
+        if (msec < 0 || msec > INT_MAX) {
+            msec = INT_MAX;
+        }
+    }
+
+    if (errno == EINPROGRESS) {
+        int res;
+
+        if ((res = poll(wfd, 1, msec)) == -1) {
+            __redisSetErrorFromErrno(c, REDIS_ERR_IO, "poll(2)");
+            redisContextCloseFd(c);
+            return REDIS_ERR;
+        } else if (res == 0) {
+            errno = ETIMEDOUT;
+            __redisSetErrorFromErrno(c,REDIS_ERR_IO,NULL);
+            redisContextCloseFd(c);
+            return REDIS_ERR;
+        }
+
+        if (redisCheckSocketError(c) != REDIS_OK)
+            return REDIS_ERR;
+
+        return REDIS_OK;
+    }
+
+    __redisSetErrorFromErrno(c,REDIS_ERR_IO,NULL);
+    redisContextCloseFd(c);
+    return REDIS_ERR;
+}
+
+int redisCheckSocketError(redisContext *c) {
+    int err = 0;
+    socklen_t errlen = sizeof(err);
+
+    if (getsockopt(c->fd, SOL_SOCKET, SO_ERROR, &err, &errlen) == -1) {
+        __redisSetErrorFromErrno(c,REDIS_ERR_IO,"getsockopt(SO_ERROR)");
+        return REDIS_ERR;
+    }
+
+    if (err) {
+        errno = err;
+        __redisSetErrorFromErrno(c,REDIS_ERR_IO,NULL);
+        return REDIS_ERR;
+    }
+
+    return REDIS_OK;
+}
+
+int redisContextSetTimeout(redisContext *c, const struct timeval tv) {
+    if (setsockopt(c->fd,SOL_SOCKET,SO_RCVTIMEO,&tv,sizeof(tv)) == -1) {
+        __redisSetErrorFromErrno(c,REDIS_ERR_IO,"setsockopt(SO_RCVTIMEO)");
+        return REDIS_ERR;
+    }
+    if (setsockopt(c->fd,SOL_SOCKET,SO_SNDTIMEO,&tv,sizeof(tv)) == -1) {
+        __redisSetErrorFromErrno(c,REDIS_ERR_IO,"setsockopt(SO_SNDTIMEO)");
+        return REDIS_ERR;
+    }
+    return REDIS_OK;
+}
+
+static int _redisContextConnectTcp(redisContext *c, const char *addr, int port,
+                                   const struct timeval *timeout,
+                                   const char *source_addr) {
+    int s, rv, n;
+    char _port[6];  /* strlen("65535"); */
+    struct addrinfo hints, *servinfo, *bservinfo, *p, *b;
+    int blocking = (c->flags & REDIS_BLOCK);
+    int reuseaddr = (c->flags & REDIS_REUSEADDR);
+    int reuses = 0;
+
+    c->connection_type = REDIS_CONN_TCP;
+    c->tcp.port = port;
+
+    /* We need to take possession of the passed parameters
+     * to make them reusable for a reconnect.
+     * We also carefully check we don't free data we already own,
+     * as in the case of the reconnect method.
+     *
+     * This is a bit ugly, but atleast it works and doesn't leak memory.
+     **/
+    if (c->tcp.host != addr) {
+        if (c->tcp.host)
+            free(c->tcp.host);
+
+        c->tcp.host = strdup(addr);
+    }
+
+    if (timeout) {
+        if (c->timeout != timeout) {
+            if (c->timeout == NULL)
+                c->timeout = malloc(sizeof(struct timeval));
+
+            memcpy(c->timeout, timeout, sizeof(struct timeval));
+        }
+    } else {
+        if (c->timeout)
+            free(c->timeout);
+        c->timeout = NULL;
+    }
+
+    if (source_addr == NULL) {
+        free(c->tcp.source_addr);
+        c->tcp.source_addr = NULL;
+    } else if (c->tcp.source_addr != source_addr) {
+        free(c->tcp.source_addr);
+        c->tcp.source_addr = strdup(source_addr);
+    }
+
+    snprintf(_port, 6, "%d", port);
+    memset(&hints,0,sizeof(hints));
+    hints.ai_family = AF_INET;
+    hints.ai_socktype = SOCK_STREAM;
+
+    /* Try with IPv6 if no IPv4 address was found. We do it in this order since
+     * in a Redis client you can't afford to test if you have IPv6 connectivity
+     * as this would add latency to every connect. Otherwise a more sensible
+     * route could be: Use IPv6 if both addresses are available and there is IPv6
+     * connectivity. */
+    if ((rv = getaddrinfo(c->tcp.host,_port,&hints,&servinfo)) != 0) {
+         hints.ai_family = AF_INET6;
+         if ((rv = getaddrinfo(addr,_port,&hints,&servinfo)) != 0) {
+            __redisSetError(c,REDIS_ERR_OTHER,gai_strerror(rv));
+            return REDIS_ERR;
+        }
+    }
+    for (p = servinfo; p != NULL; p = p->ai_next) {
+addrretry:
+        if ((s = socket(p->ai_family,p->ai_socktype,p->ai_protocol)) == -1)
+            continue;
+
+        c->fd = s;
+        if (redisSetBlocking(c,0) != REDIS_OK)
+            goto error;
+        if (c->tcp.source_addr) {
+            int bound = 0;
+            /* Using getaddrinfo saves us from self-determining IPv4 vs IPv6 */
+            if ((rv = getaddrinfo(c->tcp.source_addr, NULL, &hints, &bservinfo)) != 0) {
+                char buf[128];
+                snprintf(buf,sizeof(buf),"Can't get addr: %s",gai_strerror(rv));
+                __redisSetError(c,REDIS_ERR_OTHER,buf);
+                goto error;
+            }
+
+            if (reuseaddr) {
+                n = 1;
+                if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char*) &n,
+                               sizeof(n)) < 0) {
+                    goto error;
+                }
+            }
+
+            for (b = bservinfo; b != NULL; b = b->ai_next) {
+                if (bind(s,b->ai_addr,b->ai_addrlen) != -1) {
+                    bound = 1;
+                    break;
+                }
+            }
+            freeaddrinfo(bservinfo);
+            if (!bound) {
+                char buf[128];
+                snprintf(buf,sizeof(buf),"Can't bind socket: %s",strerror(errno));
+                __redisSetError(c,REDIS_ERR_OTHER,buf);
+                goto error;
+            }
+        }
+        if (connect(s,p->ai_addr,p->ai_addrlen) == -1) {
+            if (errno == EHOSTUNREACH) {
+                redisContextCloseFd(c);
+                continue;
+            } else if (errno == EINPROGRESS && !blocking) {
+                /* This is ok. */
+            } else if (errno == EADDRNOTAVAIL && reuseaddr) {
+                if (++reuses >= REDIS_CONNECT_RETRIES) {
+                    goto error;
+                } else {
+                    goto addrretry;
+                }
+            } else {
+                if (redisContextWaitReady(c,c->timeout) != REDIS_OK)
+                    goto error;
+            }
+        }
+        if (blocking && redisSetBlocking(c,1) != REDIS_OK)
+            goto error;
+        if (redisSetTcpNoDelay(c) != REDIS_OK)
+            goto error;
+
+        c->flags |= REDIS_CONNECTED;
+        rv = REDIS_OK;
+        goto end;
+    }
+    if (p == NULL) {
+        char buf[128];
+        snprintf(buf,sizeof(buf),"Can't create socket: %s",strerror(errno));
+        __redisSetError(c,REDIS_ERR_OTHER,buf);
+        goto error;
+    }
+
+error:
+    rv = REDIS_ERR;
+end:
+    freeaddrinfo(servinfo);
+    return rv;  // Need to return REDIS_OK if alright
+}
+
+int redisContextConnectTcp(redisContext *c, const char *addr, int port,
+                           const struct timeval *timeout) {
+    return _redisContextConnectTcp(c, addr, port, timeout, NULL);
+}
+
+int redisContextConnectBindTcp(redisContext *c, const char *addr, int port,
+                               const struct timeval *timeout,
+                               const char *source_addr) {
+    return _redisContextConnectTcp(c, addr, port, timeout, source_addr);
+}
+
+int redisContextConnectUnix(redisContext *c, const char *path, const struct timeval *timeout) {
+    int blocking = (c->flags & REDIS_BLOCK);
+    struct sockaddr_un sa;
+
+    if (redisCreateSocket(c,AF_LOCAL) < 0)
+        return REDIS_ERR;
+    if (redisSetBlocking(c,0) != REDIS_OK)
+        return REDIS_ERR;
+
+    c->connection_type = REDIS_CONN_UNIX;
+    if (c->unix_sock.path != path)
+        c->unix_sock.path = strdup(path);
+
+    if (timeout) {
+        if (c->timeout != timeout) {
+            if (c->timeout == NULL)
+                c->timeout = malloc(sizeof(struct timeval));
+
+            memcpy(c->timeout, timeout, sizeof(struct timeval));
+        }
+    } else {
+        if (c->timeout)
+            free(c->timeout);
+        c->timeout = NULL;
+    }
+
+    sa.sun_family = AF_LOCAL;
+    strncpy(sa.sun_path,path,sizeof(sa.sun_path)-1);
+    if (connect(c->fd, (struct sockaddr*)&sa, sizeof(sa)) == -1) {
+        if (errno == EINPROGRESS && !blocking) {
+            /* This is ok. */
+        } else {
+            if (redisContextWaitReady(c,c->timeout) != REDIS_OK)
+                return REDIS_ERR;
+        }
+    }
+
+    /* Reset socket to be blocking after connect(2). */
+    if (blocking && redisSetBlocking(c,1) != REDIS_OK)
+        return REDIS_ERR;
+
+    c->flags |= REDIS_CONNECTED;
+    return REDIS_OK;
+}
diff --git a/contrib/hiredis/net.h b/contrib/hiredis/net.h
new file mode 100644
index 000000000..2f1a0bf85
--- /dev/null
+++ b/contrib/hiredis/net.h
@@ -0,0 +1,53 @@
+/* Extracted from anet.c to work properly with Hiredis error reporting.
+ *
+ * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2014, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ * Copyright (c) 2015, Matt Stancliff <matt at genges dot com>,
+ *                     Jan-Erik Rediger <janerik at fnordig dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __NET_H
+#define __NET_H
+
+#include "hiredis.h"
+
+#if defined(__sun)
+#define AF_LOCAL AF_UNIX
+#endif
+
+int redisCheckSocketError(redisContext *c);
+int redisContextSetTimeout(redisContext *c, const struct timeval tv);
+int redisContextConnectTcp(redisContext *c, const char *addr, int port, const struct timeval *timeout);
+int redisContextConnectBindTcp(redisContext *c, const char *addr, int port,
+                               const struct timeval *timeout,
+                               const char *source_addr);
+int redisContextConnectUnix(redisContext *c, const char *path, const struct timeval *timeout);
+int redisKeepAlive(redisContext *c, int interval);
+
+#endif
diff --git a/contrib/hiredis/read.c b/contrib/hiredis/read.c
new file mode 100644
index 000000000..df1a467a9
--- /dev/null
+++ b/contrib/hiredis/read.c
@@ -0,0 +1,525 @@
+/*
+ * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#include "fmacros.h"
+#include <string.h>
+#include <stdlib.h>
+#ifndef _MSC_VER
+#include <unistd.h>
+#endif
+#include <assert.h>
+#include <errno.h>
+#include <ctype.h>
+
+#include "read.h"
+#include "sds.h"
+
+static void __redisReaderSetError(redisReader *r, int type, const char *str) {
+    size_t len;
+
+    if (r->reply != NULL && r->fn && r->fn->freeObject) {
+        r->fn->freeObject(r->reply);
+        r->reply = NULL;
+    }
+
+    /* Clear input buffer on errors. */
+    if (r->buf != NULL) {
+        sdsfree(r->buf);
+        r->buf = NULL;
+        r->pos = r->len = 0;
+    }
+
+    /* Reset task stack. */
+    r->ridx = -1;
+
+    /* Set error. */
+    r->err = type;
+    len = strlen(str);
+    len = len < (sizeof(r->errstr)-1) ? len : (sizeof(r->errstr)-1);
+    memcpy(r->errstr,str,len);
+    r->errstr[len] = '\0';
+}
+
+static size_t chrtos(char *buf, size_t size, char byte) {
+    size_t len = 0;
+
+    switch(byte) {
+    case '\\':
+    case '"':
+        len = snprintf(buf,size,"\"\\%c\"",byte);
+        break;
+    case '\n': len = snprintf(buf,size,"\"\\n\""); break;
+    case '\r': len = snprintf(buf,size,"\"\\r\""); break;
+    case '\t': len = snprintf(buf,size,"\"\\t\""); break;
+    case '\a': len = snprintf(buf,size,"\"\\a\""); break;
+    case '\b': len = snprintf(buf,size,"\"\\b\""); break;
+    default:
+        if (isprint(byte))
+            len = snprintf(buf,size,"\"%c\"",byte);
+        else
+            len = snprintf(buf,size,"\"\\x%02x\"",(unsigned char)byte);
+        break;
+    }
+
+    return len;
+}
+
+static void __redisReaderSetErrorProtocolByte(redisReader *r, char byte) {
+    char cbuf[8], sbuf[128];
+
+    chrtos(cbuf,sizeof(cbuf),byte);
+    snprintf(sbuf,sizeof(sbuf),
+        "Protocol error, got %s as reply type byte", cbuf);
+    __redisReaderSetError(r,REDIS_ERR_PROTOCOL,sbuf);
+}
+
+static void __redisReaderSetErrorOOM(redisReader *r) {
+    __redisReaderSetError(r,REDIS_ERR_OOM,"Out of memory");
+}
+
+static char *readBytes(redisReader *r, unsigned int bytes) {
+    char *p;
+    if (r->len-r->pos >= bytes) {
+        p = r->buf+r->pos;
+        r->pos += bytes;
+        return p;
+    }
+    return NULL;
+}
+
+/* Find pointer to \r\n. */
+static char *seekNewline(char *s, size_t len) {
+    int pos = 0;
+    int _len = len-1;
+
+    /* Position should be < len-1 because the character at "pos" should be
+     * followed by a \n. Note that strchr cannot be used because it doesn't
+     * allow to search a limited length and the buffer that is being searched
+     * might not have a trailing NULL character. */
+    while (pos < _len) {
+        while(pos < _len && s[pos] != '\r') pos++;
+        if (s[pos] != '\r') {
+            /* Not found. */
+            return NULL;
+        } else {
+            if (s[pos+1] == '\n') {
+                /* Found. */
+                return s+pos;
+            } else {
+                /* Continue searching. */
+                pos++;
+            }
+        }
+    }
+    return NULL;
+}
+
+/* Read a long long value starting at *s, under the assumption that it will be
+ * terminated by \r\n. Ambiguously returns -1 for unexpected input. */
+static long long readLongLong(char *s) {
+    long long v = 0;
+    int dec, mult = 1;
+    char c;
+
+    if (*s == '-') {
+        mult = -1;
+        s++;
+    } else if (*s == '+') {
+        mult = 1;
+        s++;
+    }
+
+    while ((c = *(s++)) != '\r') {
+        dec = c - '0';
+        if (dec >= 0 && dec < 10) {
+            v *= 10;
+            v += dec;
+        } else {
+            /* Should not happen... */
+            return -1;
+        }
+    }
+
+    return mult*v;
+}
+
+static char *readLine(redisReader *r, int *_len) {
+    char *p, *s;
+    int len;
+
+    p = r->buf+r->pos;
+    s = seekNewline(p,(r->len-r->pos));
+    if (s != NULL) {
+        len = s-(r->buf+r->pos);
+        r->pos += len+2; /* skip \r\n */
+        if (_len) *_len = len;
+        return p;
+    }
+    return NULL;
+}
+
+static void moveToNextTask(redisReader *r) {
+    redisReadTask *cur, *prv;
+    while (r->ridx >= 0) {
+        /* Return a.s.a.p. when the stack is now empty. */
+        if (r->ridx == 0) {
+            r->ridx--;
+            return;
+        }
+
+        cur = &(r->rstack[r->ridx]);
+        prv = &(r->rstack[r->ridx-1]);
+        assert(prv->type == REDIS_REPLY_ARRAY);
+        if (cur->idx == prv->elements-1) {
+            r->ridx--;
+        } else {
+            /* Reset the type because the next item can be anything */
+            assert(cur->idx < prv->elements);
+            cur->type = -1;
+            cur->elements = -1;
+            cur->idx++;
+            return;
+        }
+    }
+}
+
+static int processLineItem(redisReader *r) {
+    redisReadTask *cur = &(r->rstack[r->ridx]);
+    void *obj;
+    char *p;
+    int len;
+
+    if ((p = readLine(r,&len)) != NULL) {
+        if (cur->type == REDIS_REPLY_INTEGER) {
+            if (r->fn && r->fn->createInteger)
+                obj = r->fn->createInteger(cur,readLongLong(p));
+            else
+                obj = (void*)REDIS_REPLY_INTEGER;
+        } else {
+            /* Type will be error or status. */
+            if (r->fn && r->fn->createString)
+                obj = r->fn->createString(cur,p,len);
+            else
+                obj = (void*)(size_t)(cur->type);
+        }
+
+        if (obj == NULL) {
+            __redisReaderSetErrorOOM(r);
+            return REDIS_ERR;
+        }
+
+        /* Set reply if this is the root object. */
+        if (r->ridx == 0) r->reply = obj;
+        moveToNextTask(r);
+        return REDIS_OK;
+    }
+
+    return REDIS_ERR;
+}
+
+static int processBulkItem(redisReader *r) {
+    redisReadTask *cur = &(r->rstack[r->ridx]);
+    void *obj = NULL;
+    char *p, *s;
+    long len;
+    unsigned long bytelen;
+    int success = 0;
+
+    p = r->buf+r->pos;
+    s = seekNewline(p,r->len-r->pos);
+    if (s != NULL) {
+        p = r->buf+r->pos;
+        bytelen = s-(r->buf+r->pos)+2; /* include \r\n */
+        len = readLongLong(p);
+
+        if (len < 0) {
+            /* The nil object can always be created. */
+            if (r->fn && r->fn->createNil)
+                obj = r->fn->createNil(cur);
+            else
+                obj = (void*)REDIS_REPLY_NIL;
+            success = 1;
+        } else {
+            /* Only continue when the buffer contains the entire bulk item. */
+            bytelen += len+2; /* include \r\n */
+            if (r->pos+bytelen <= r->len) {
+                if (r->fn && r->fn->createString)
+                    obj = r->fn->createString(cur,s+2,len);
+                else
+                    obj = (void*)REDIS_REPLY_STRING;
+                success = 1;
+            }
+        }
+
+        /* Proceed when obj was created. */
+        if (success) {
+            if (obj == NULL) {
+                __redisReaderSetErrorOOM(r);
+                return REDIS_ERR;
+            }
+
+            r->pos += bytelen;
+
+            /* Set reply if this is the root object. */
+            if (r->ridx == 0) r->reply = obj;
+            moveToNextTask(r);
+            return REDIS_OK;
+        }
+    }
+
+    return REDIS_ERR;
+}
+
+static int processMultiBulkItem(redisReader *r) {
+    redisReadTask *cur = &(r->rstack[r->ridx]);
+    void *obj;
+    char *p;
+    long elements;
+    int root = 0;
+
+    /* Set error for nested multi bulks with depth > 7 */
+    if (r->ridx == 8) {
+        __redisReaderSetError(r,REDIS_ERR_PROTOCOL,
+            "No support for nested multi bulk replies with depth > 7");
+        return REDIS_ERR;
+    }
+
+    if ((p = readLine(r,NULL)) != NULL) {
+        elements = readLongLong(p);
+        root = (r->ridx == 0);
+
+        if (elements == -1) {
+            if (r->fn && r->fn->createNil)
+                obj = r->fn->createNil(cur);
+            else
+                obj = (void*)REDIS_REPLY_NIL;
+
+            if (obj == NULL) {
+                __redisReaderSetErrorOOM(r);
+                return REDIS_ERR;
+            }
+
+            moveToNextTask(r);
+        } else {
+            if (r->fn && r->fn->createArray)
+                obj = r->fn->createArray(cur,elements);
+            else
+                obj = (void*)REDIS_REPLY_ARRAY;
+
+            if (obj == NULL) {
+                __redisReaderSetErrorOOM(r);
+                return REDIS_ERR;
+            }
+
+            /* Modify task stack when there are more than 0 elements. */
+            if (elements > 0) {
+                cur->elements = elements;
+                cur->obj = obj;
+                r->ridx++;
+                r->rstack[r->ridx].type = -1;
+                r->rstack[r->ridx].elements = -1;
+                r->rstack[r->ridx].idx = 0;
+                r->rstack[r->ridx].obj = NULL;
+                r->rstack[r->ridx].parent = cur;
+                r->rstack[r->ridx].privdata = r->privdata;
+            } else {
+                moveToNextTask(r);
+            }
+        }
+
+        /* Set reply if this is the root object. */
+        if (root) r->reply = obj;
+        return REDIS_OK;
+    }
+
+    return REDIS_ERR;
+}
+
+static int processItem(redisReader *r) {
+    redisReadTask *cur = &(r->rstack[r->ridx]);
+    char *p;
+
+    /* check if we need to read type */
+    if (cur->type < 0) {
+        if ((p = readBytes(r,1)) != NULL) {
+            switch (p[0]) {
+            case '-':
+                cur->type = REDIS_REPLY_ERROR;
+                break;
+            case '+':
+                cur->type = REDIS_REPLY_STATUS;
+                break;
+            case ':':
+                cur->type = REDIS_REPLY_INTEGER;
+                break;
+            case '$':
+                cur->type = REDIS_REPLY_STRING;
+                break;
+            case '*':
+                cur->type = REDIS_REPLY_ARRAY;
+                break;
+            default:
+                __redisReaderSetErrorProtocolByte(r,*p);
+                return REDIS_ERR;
+            }
+        } else {
+            /* could not consume 1 byte */
+            return REDIS_ERR;
+        }
+    }
+
+    /* process typed item */
+    switch(cur->type) {
+    case REDIS_REPLY_ERROR:
+    case REDIS_REPLY_STATUS:
+    case REDIS_REPLY_INTEGER:
+        return processLineItem(r);
+    case REDIS_REPLY_STRING:
+        return processBulkItem(r);
+    case REDIS_REPLY_ARRAY:
+        return processMultiBulkItem(r);
+    default:
+        assert(NULL);
+        return REDIS_ERR; /* Avoid warning. */
+    }
+}
+
+redisReader *redisReaderCreateWithFunctions(redisReplyObjectFunctions *fn) {
+    redisReader *r;
+
+    r = calloc(sizeof(redisReader),1);
+    if (r == NULL)
+        return NULL;
+
+    r->err = 0;
+    r->errstr[0] = '\0';
+    r->fn = fn;
+    r->buf = sdsempty();
+    r->maxbuf = REDIS_READER_MAX_BUF;
+    if (r->buf == NULL) {
+        free(r);
+        return NULL;
+    }
+
+    r->ridx = -1;
+    return r;
+}
+
+void redisReaderFree(redisReader *r) {
+    if (r->reply != NULL && r->fn && r->fn->freeObject)
+        r->fn->freeObject(r->reply);
+    if (r->buf != NULL)
+        sdsfree(r->buf);
+    free(r);
+}
+
+int redisReaderFeed(redisReader *r, const char *buf, size_t len) {
+    sds newbuf;
+
+    /* Return early when this reader is in an erroneous state. */
+    if (r->err)
+        return REDIS_ERR;
+
+    /* Copy the provided buffer. */
+    if (buf != NULL && len >= 1) {
+        /* Destroy internal buffer when it is empty and is quite large. */
+        if (r->len == 0 && r->maxbuf != 0 && sdsavail(r->buf) > r->maxbuf) {
+            sdsfree(r->buf);
+            r->buf = sdsempty();
+            r->pos = 0;
+
+            /* r->buf should not be NULL since we just free'd a larger one. */
+            assert(r->buf != NULL);
+        }
+
+        newbuf = sdscatlen(r->buf,buf,len);
+        if (newbuf == NULL) {
+            __redisReaderSetErrorOOM(r);
+            return REDIS_ERR;
+        }
+
+        r->buf = newbuf;
+        r->len = sdslen(r->buf);
+    }
+
+    return REDIS_OK;
+}
+
+int redisReaderGetReply(redisReader *r, void **reply) {
+    /* Default target pointer to NULL. */
+    if (reply != NULL)
+        *reply = NULL;
+
+    /* Return early when this reader is in an erroneous state. */
+    if (r->err)
+        return REDIS_ERR;
+
+    /* When the buffer is empty, there will never be a reply. */
+    if (r->len == 0)
+        return REDIS_OK;
+
+    /* Set first item to process when the stack is empty. */
+    if (r->ridx == -1) {
+        r->rstack[0].type = -1;
+        r->rstack[0].elements = -1;
+        r->rstack[0].idx = -1;
+        r->rstack[0].obj = NULL;
+        r->rstack[0].parent = NULL;
+        r->rstack[0].privdata = r->privdata;
+        r->ridx = 0;
+    }
+
+    /* Process items in reply. */
+    while (r->ridx >= 0)
+        if (processItem(r) != REDIS_OK)
+            break;
+
+    /* Return ASAP when an error occurred. */
+    if (r->err)
+        return REDIS_ERR;
+
+    /* Discard part of the buffer when we've consumed at least 1k, to avoid
+     * doing unnecessary calls to memmove() in sds.c. */
+    if (r->pos >= 1024) {
+        sdsrange(r->buf,r->pos,-1);
+        r->pos = 0;
+        r->len = sdslen(r->buf);
+    }
+
+    /* Emit a reply when there is one. */
+    if (r->ridx == -1) {
+        if (reply != NULL)
+            *reply = r->reply;
+        r->reply = NULL;
+    }
+    return REDIS_OK;
+}
diff --git a/contrib/hiredis/read.h b/contrib/hiredis/read.h
new file mode 100644
index 000000000..180e6c6bf
--- /dev/null
+++ b/contrib/hiredis/read.h
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+#ifndef __HIREDIS_READ_H
+#define __HIREDIS_READ_H
+#include <stdio.h> /* for size_t */
+
+#define REDIS_ERR -1
+#define REDIS_OK 0
+
+/* When an error occurs, the err flag in a context is set to hold the type of
+ * error that occurred. REDIS_ERR_IO means there was an I/O error and you
+ * should use the "errno" variable to find out what is wrong.
+ * For other values, the "errstr" field will hold a description. */
+#define REDIS_ERR_IO 1 /* Error in read or write */
+#define REDIS_ERR_EOF 3 /* End of file */
+#define REDIS_ERR_PROTOCOL 4 /* Protocol error */
+#define REDIS_ERR_OOM 5 /* Out of memory */
+#define REDIS_ERR_OTHER 2 /* Everything else... */
+
+#define REDIS_REPLY_STRING 1
+#define REDIS_REPLY_ARRAY 2
+#define REDIS_REPLY_INTEGER 3
+#define REDIS_REPLY_NIL 4
+#define REDIS_REPLY_STATUS 5
+#define REDIS_REPLY_ERROR 6
+
+#define REDIS_READER_MAX_BUF (1024*16)  /* Default max unused reader buffer. */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct redisReadTask {
+    int type;
+    int elements; /* number of elements in multibulk container */
+    int idx; /* index in parent (array) object */
+    void *obj; /* holds user-generated value for a read task */
+    struct redisReadTask *parent; /* parent task */
+    void *privdata; /* user-settable arbitrary field */
+} redisReadTask;
+
+typedef struct redisReplyObjectFunctions {
+    void *(*createString)(const redisReadTask*, char*, size_t);
+    void *(*createArray)(const redisReadTask*, int);
+    void *(*createInteger)(const redisReadTask*, long long);
+    void *(*createNil)(const redisReadTask*);
+    void (*freeObject)(void*);
+} redisReplyObjectFunctions;
+
+typedef struct redisReader {
+    int err; /* Error flags, 0 when there is no error */
+    char errstr[128]; /* String representation of error when applicable */
+
+    char *buf; /* Read buffer */
+    size_t pos; /* Buffer cursor */
+    size_t len; /* Buffer length */
+    size_t maxbuf; /* Max length of unused buffer */
+
+    redisReadTask rstack[9];
+    int ridx; /* Index of current read task */
+    void *reply; /* Temporary reply pointer */
+
+    redisReplyObjectFunctions *fn;
+    void *privdata;
+} redisReader;
+
+/* Public API for the protocol parser. */
+redisReader *redisReaderCreateWithFunctions(redisReplyObjectFunctions *fn);
+void redisReaderFree(redisReader *r);
+int redisReaderFeed(redisReader *r, const char *buf, size_t len);
+int redisReaderGetReply(redisReader *r, void **reply);
+
+/* Backwards compatibility, can be removed on big version bump. */
+#define redisReplyReaderCreate redisReaderCreate
+#define redisReplyReaderFree redisReaderFree
+#define redisReplyReaderFeed redisReaderFeed
+#define redisReplyReaderGetReply redisReaderGetReply
+#define redisReplyReaderSetPrivdata(_r, _p) (int)(((redisReader*)(_r))->privdata = (_p))
+#define redisReplyReaderGetObject(_r) (((redisReader*)(_r))->reply)
+#define redisReplyReaderGetError(_r) (((redisReader*)(_r))->errstr)
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/contrib/hiredis/sds.c b/contrib/hiredis/sds.c
new file mode 100644
index 000000000..f01247de9
--- /dev/null
+++ b/contrib/hiredis/sds.c
@@ -0,0 +1,1095 @@
+/* SDS (Simple Dynamic Strings), A C dynamic strings library.
+ *
+ * Copyright (c) 2006-2014, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <assert.h>
+
+#include "sds.h"
+
+/* Create a new sds string with the content specified by the 'init' pointer
+ * and 'initlen'.
+ * If NULL is used for 'init' the string is initialized with zero bytes.
+ *
+ * The string is always null-termined (all the sds strings are, always) so
+ * even if you create an sds string with:
+ *
+ * mystring = sdsnewlen("abc",3");
+ *
+ * You can print the string with printf() as there is an implicit \0 at the
+ * end of the string. However the string is binary safe and can contain
+ * \0 characters in the middle, as the length is stored in the sds header. */
+sds sdsnewlen(const void *init, size_t initlen) {
+    struct sdshdr *sh;
+
+    if (init) {
+        sh = malloc(sizeof *sh+initlen+1);
+    } else {
+        sh = calloc(sizeof *sh+initlen+1,1);
+    }
+    if (sh == NULL) return NULL;
+    sh->len = initlen;
+    sh->free = 0;
+    if (initlen && init)
+        memcpy(sh->buf, init, initlen);
+    sh->buf[initlen] = '\0';
+    return (char*)sh->buf;
+}
+
+/* Create an empty (zero length) sds string. Even in this case the string
+ * always has an implicit null term. */
+sds sdsempty(void) {
+    return sdsnewlen("",0);
+}
+
+/* Create a new sds string starting from a null termined C string. */
+sds sdsnew(const char *init) {
+    size_t initlen = (init == NULL) ? 0 : strlen(init);
+    return sdsnewlen(init, initlen);
+}
+
+/* Duplicate an sds string. */
+sds sdsdup(const sds s) {
+    return sdsnewlen(s, sdslen(s));
+}
+
+/* Free an sds string. No operation is performed if 's' is NULL. */
+void sdsfree(sds s) {
+    if (s == NULL) return;
+    free(s-sizeof(struct sdshdr));
+}
+
+/* Set the sds string length to the length as obtained with strlen(), so
+ * considering as content only up to the first null term character.
+ *
+ * This function is useful when the sds string is hacked manually in some
+ * way, like in the following example:
+ *
+ * s = sdsnew("foobar");
+ * s[2] = '\0';
+ * sdsupdatelen(s);
+ * printf("%d\n", sdslen(s));
+ *
+ * The output will be "2", but if we comment out the call to sdsupdatelen()
+ * the output will be "6" as the string was modified but the logical length
+ * remains 6 bytes. */
+void sdsupdatelen(sds s) {
+    struct sdshdr *sh = (void*) (s-sizeof *sh);
+    int reallen = strlen(s);
+    sh->free += (sh->len-reallen);
+    sh->len = reallen;
+}
+
+/* Modify an sds string on-place to make it empty (zero length).
+ * However all the existing buffer is not discarded but set as free space
+ * so that next append operations will not require allocations up to the
+ * number of bytes previously available. */
+void sdsclear(sds s) {
+    struct sdshdr *sh = (void*) (s-sizeof *sh);
+    sh->free += sh->len;
+    sh->len = 0;
+    sh->buf[0] = '\0';
+}
+
+/* Enlarge the free space at the end of the sds string so that the caller
+ * is sure that after calling this function can overwrite up to addlen
+ * bytes after the end of the string, plus one more byte for nul term.
+ *
+ * Note: this does not change the *length* of the sds string as returned
+ * by sdslen(), but only the free buffer space we have. */
+sds sdsMakeRoomFor(sds s, size_t addlen) {
+    struct sdshdr *sh, *newsh;
+    size_t free = sdsavail(s);
+    size_t len, newlen;
+
+    if (free >= addlen) return s;
+    len = sdslen(s);
+    sh = (void*) (s-sizeof *sh);
+    newlen = (len+addlen);
+    if (newlen < SDS_MAX_PREALLOC)
+        newlen *= 2;
+    else
+        newlen += SDS_MAX_PREALLOC;
+    newsh = realloc(sh, sizeof *newsh+newlen+1);
+    if (newsh == NULL) return NULL;
+
+    newsh->free = newlen - len;
+    return newsh->buf;
+}
+
+/* Reallocate the sds string so that it has no free space at the end. The
+ * contained string remains not altered, but next concatenation operations
+ * will require a reallocation.
+ *
+ * After the call, the passed sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+sds sdsRemoveFreeSpace(sds s) {
+    struct sdshdr *sh;
+
+    sh = (void*) (s-sizeof *sh);
+    sh = realloc(sh, sizeof *sh+sh->len+1);
+    sh->free = 0;
+    return sh->buf;
+}
+
+/* Return the total size of the allocation of the specifed sds string,
+ * including:
+ * 1) The sds header before the pointer.
+ * 2) The string.
+ * 3) The free buffer at the end if any.
+ * 4) The implicit null term.
+ */
+size_t sdsAllocSize(sds s) {
+    struct sdshdr *sh = (void*) (s-sizeof *sh);
+
+    return sizeof(*sh)+sh->len+sh->free+1;
+}
+
+/* Increment the sds length and decrements the left free space at the
+ * end of the string according to 'incr'. Also set the null term
+ * in the new end of the string.
+ *
+ * This function is used in order to fix the string length after the
+ * user calls sdsMakeRoomFor(), writes something after the end of
+ * the current string, and finally needs to set the new length.
+ *
+ * Note: it is possible to use a negative increment in order to
+ * right-trim the string.
+ *
+ * Usage example:
+ *
+ * Using sdsIncrLen() and sdsMakeRoomFor() it is possible to mount the
+ * following schema, to cat bytes coming from the kernel to the end of an
+ * sds string without copying into an intermediate buffer:
+ *
+ * oldlen = sdslen(s);
+ * s = sdsMakeRoomFor(s, BUFFER_SIZE);
+ * nread = read(fd, s+oldlen, BUFFER_SIZE);
+ * ... check for nread <= 0 and handle it ...
+ * sdsIncrLen(s, nread);
+ */
+void sdsIncrLen(sds s, int incr) {
+    struct sdshdr *sh = (void*) (s-sizeof *sh);
+
+    assert(sh->free >= incr);
+    sh->len += incr;
+    sh->free -= incr;
+    assert(sh->free >= 0);
+    s[sh->len] = '\0';
+}
+
+/* Grow the sds to have the specified length. Bytes that were not part of
+ * the original length of the sds will be set to zero.
+ *
+ * if the specified length is smaller than the current length, no operation
+ * is performed. */
+sds sdsgrowzero(sds s, size_t len) {
+    struct sdshdr *sh = (void*) (s-sizeof *sh);
+    size_t totlen, curlen = sh->len;
+
+    if (len <= curlen) return s;
+    s = sdsMakeRoomFor(s,len-curlen);
+    if (s == NULL) return NULL;
+
+    /* Make sure added region doesn't contain garbage */
+    sh = (void*)(s-sizeof *sh);
+    memset(s+curlen,0,(len-curlen+1)); /* also set trailing \0 byte */
+    totlen = sh->len+sh->free;
+    sh->len = len;
+    sh->free = totlen-sh->len;
+    return s;
+}
+
+/* Append the specified binary-safe string pointed by 't' of 'len' bytes to the
+ * end of the specified sds string 's'.
+ *
+ * After the call, the passed sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+sds sdscatlen(sds s, const void *t, size_t len) {
+    struct sdshdr *sh;
+    size_t curlen = sdslen(s);
+
+    s = sdsMakeRoomFor(s,len);
+    if (s == NULL) return NULL;
+    sh = (void*) (s-sizeof *sh);
+    memcpy(s+curlen, t, len);
+    sh->len = curlen+len;
+    sh->free = sh->free-len;
+    s[curlen+len] = '\0';
+    return s;
+}
+
+/* Append the specified null termianted C string to the sds string 's'.
+ *
+ * After the call, the passed sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+sds sdscat(sds s, const char *t) {
+    return sdscatlen(s, t, strlen(t));
+}
+
+/* Append the specified sds 't' to the existing sds 's'.
+ *
+ * After the call, the modified sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+sds sdscatsds(sds s, const sds t) {
+    return sdscatlen(s, t, sdslen(t));
+}
+
+/* Destructively modify the sds string 's' to hold the specified binary
+ * safe string pointed by 't' of length 'len' bytes. */
+sds sdscpylen(sds s, const char *t, size_t len) {
+    struct sdshdr *sh = (void*) (s-sizeof *sh);
+    size_t totlen = sh->free+sh->len;
+
+    if (totlen < len) {
+        s = sdsMakeRoomFor(s,len-sh->len);
+        if (s == NULL) return NULL;
+        sh = (void*) (s-sizeof *sh);
+        totlen = sh->free+sh->len;
+    }
+    memcpy(s, t, len);
+    s[len] = '\0';
+    sh->len = len;
+    sh->free = totlen-len;
+    return s;
+}
+
+/* Like sdscpylen() but 't' must be a null-termined string so that the length
+ * of the string is obtained with strlen(). */
+sds sdscpy(sds s, const char *t) {
+    return sdscpylen(s, t, strlen(t));
+}
+
+/* Helper for sdscatlonglong() doing the actual number -> string
+ * conversion. 's' must point to a string with room for at least
+ * SDS_LLSTR_SIZE bytes.
+ *
+ * The function returns the length of the null-terminated string
+ * representation stored at 's'. */
+#define SDS_LLSTR_SIZE 21
+int sdsll2str(char *s, long long value) {
+    char *p, aux;
+    unsigned long long v;
+    size_t l;
+
+    /* Generate the string representation, this method produces
+     * an reversed string. */
+    v = (value < 0) ? -value : value;
+    p = s;
+    do {
+        *p++ = '0'+(v%10);
+        v /= 10;
+    } while(v);
+    if (value < 0) *p++ = '-';
+
+    /* Compute length and add null term. */
+    l = p-s;
+    *p = '\0';
+
+    /* Reverse the string. */
+    p--;
+    while(s < p) {
+        aux = *s;
+        *s = *p;
+        *p = aux;
+        s++;
+        p--;
+    }
+    return l;
+}
+
+/* Identical sdsll2str(), but for unsigned long long type. */
+int sdsull2str(char *s, unsigned long long v) {
+    char *p, aux;
+    size_t l;
+
+    /* Generate the string representation, this method produces
+     * an reversed string. */
+    p = s;
+    do {
+        *p++ = '0'+(v%10);
+        v /= 10;
+    } while(v);
+
+    /* Compute length and add null term. */
+    l = p-s;
+    *p = '\0';
+
+    /* Reverse the string. */
+    p--;
+    while(s < p) {
+        aux = *s;
+        *s = *p;
+        *p = aux;
+        s++;
+        p--;
+    }
+    return l;
+}
+
+/* Like sdscatpritf() but gets va_list instead of being variadic. */
+sds sdscatvprintf(sds s, const char *fmt, va_list ap) {
+    va_list cpy;
+    char *buf, *t;
+    size_t buflen = 16;
+
+    while(1) {
+        buf = malloc(buflen);
+        if (buf == NULL) return NULL;
+        buf[buflen-2] = '\0';
+        va_copy(cpy,ap);
+        vsnprintf(buf, buflen, fmt, cpy);
+        if (buf[buflen-2] != '\0') {
+            free(buf);
+            buflen *= 2;
+            continue;
+        }
+        break;
+    }
+    t = sdscat(s, buf);
+    free(buf);
+    return t;
+}
+
+/* Append to the sds string 's' a string obtained using printf-alike format
+ * specifier.
+ *
+ * After the call, the modified sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call.
+ *
+ * Example:
+ *
+ * s = sdsnew("Sum is: ");
+ * s = sdscatprintf(s,"%d+%d = %d",a,b,a+b);
+ *
+ * Often you need to create a string from scratch with the printf-alike
+ * format. When this is the need, just use sdsempty() as the target string:
+ *
+ * s = sdscatprintf(sdsempty(), "... your format ...", args);
+ */
+sds sdscatprintf(sds s, const char *fmt, ...) {
+    va_list ap;
+    char *t;
+    va_start(ap, fmt);
+    t = sdscatvprintf(s,fmt,ap);
+    va_end(ap);
+    return t;
+}
+
+/* This function is similar to sdscatprintf, but much faster as it does
+ * not rely on sprintf() family functions implemented by the libc that
+ * are often very slow. Moreover directly handling the sds string as
+ * new data is concatenated provides a performance improvement.
+ *
+ * However this function only handles an incompatible subset of printf-alike
+ * format specifiers:
+ *
+ * %s - C String
+ * %S - SDS string
+ * %i - signed int
+ * %I - 64 bit signed integer (long long, int64_t)
+ * %u - unsigned int
+ * %U - 64 bit unsigned integer (unsigned long long, uint64_t)
+ * %T - A size_t variable.
+ * %% - Verbatim "%" character.
+ */
+sds sdscatfmt(sds s, char const *fmt, ...) {
+    struct sdshdr *sh = (void*) (s-(sizeof(struct sdshdr)));
+    size_t initlen = sdslen(s);
+    const char *f = fmt;
+    int i;
+    va_list ap;
+
+    va_start(ap,fmt);
+    f = fmt;    /* Next format specifier byte to process. */
+    i = initlen; /* Position of the next byte to write to dest str. */
+    while(*f) {
+        char next, *str;
+        int l;
+        long long num;
+        unsigned long long unum;
+
+        /* Make sure there is always space for at least 1 char. */
+        if (sh->free == 0) {
+            s = sdsMakeRoomFor(s,1);
+            sh = (void*) (s-(sizeof(struct sdshdr)));
+        }
+
+        switch(*f) {
+        case '%':
+            next = *(f+1);
+            f++;
+            switch(next) {
+            case 's':
+            case 'S':
+                str = va_arg(ap,char*);
+                l = (next == 's') ? strlen(str) : sdslen(str);
+                if (sh->free < l) {
+                    s = sdsMakeRoomFor(s,l);
+                    sh = (void*) (s-(sizeof(struct sdshdr)));
+                }
+                memcpy(s+i,str,l);
+                sh->len += l;
+                sh->free -= l;
+                i += l;
+                break;
+            case 'i':
+            case 'I':
+                if (next == 'i')
+                    num = va_arg(ap,int);
+                else
+                    num = va_arg(ap,long long);
+                {
+                    char buf[SDS_LLSTR_SIZE];
+                    l = sdsll2str(buf,num);
+                    if (sh->free < l) {
+                        s = sdsMakeRoomFor(s,l);
+                        sh = (void*) (s-(sizeof(struct sdshdr)));
+                    }
+                    memcpy(s+i,buf,l);
+                    sh->len += l;
+                    sh->free -= l;
+                    i += l;
+                }
+                break;
+            case 'u':
+            case 'U':
+            case 'T':
+                if (next == 'u')
+                    unum = va_arg(ap,unsigned int);
+                else if(next == 'U')
+                    unum = va_arg(ap,unsigned long long);
+                else
+                    unum = (unsigned long long)va_arg(ap,size_t);
+                {
+                    char buf[SDS_LLSTR_SIZE];
+                    l = sdsull2str(buf,unum);
+                    if (sh->free < l) {
+                        s = sdsMakeRoomFor(s,l);
+                        sh = (void*) (s-(sizeof(struct sdshdr)));
+                    }
+                    memcpy(s+i,buf,l);
+                    sh->len += l;
+                    sh->free -= l;
+                    i += l;
+                }
+                break;
+            default: /* Handle %% and generally %<unknown>. */
+                s[i++] = next;
+                sh->len += 1;
+                sh->free -= 1;
+                break;
+            }
+            break;
+        default:
+            s[i++] = *f;
+            sh->len += 1;
+            sh->free -= 1;
+            break;
+        }
+        f++;
+    }
+    va_end(ap);
+
+    /* Add null-term */
+    s[i] = '\0';
+    return s;
+}
+
+
+/* Remove the part of the string from left and from right composed just of
+ * contiguous characters found in 'cset', that is a null terminted C string.
+ *
+ * After the call, the modified sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call.
+ *
+ * Example:
+ *
+ * s = sdsnew("AA...AA.a.aa.aHelloWorld     :::");
+ * s = sdstrim(s,"A. :");
+ * printf("%s\n", s);
+ *
+ * Output will be just "Hello World".
+ */
+void sdstrim(sds s, const char *cset) {
+    struct sdshdr *sh = (void*) (s-sizeof *sh);
+    char *start, *end, *sp, *ep;
+    size_t len;
+
+    sp = start = s;
+    ep = end = s+sdslen(s)-1;
+    while(sp <= end && strchr(cset, *sp)) sp++;
+    while(ep > start && strchr(cset, *ep)) ep--;
+    len = (sp > ep) ? 0 : ((ep-sp)+1);
+    if (sh->buf != sp) memmove(sh->buf, sp, len);
+    sh->buf[len] = '\0';
+    sh->free = sh->free+(sh->len-len);
+    sh->len = len;
+}
+
+/* Turn the string into a smaller (or equal) string containing only the
+ * substring specified by the 'start' and 'end' indexes.
+ *
+ * start and end can be negative, where -1 means the last character of the
+ * string, -2 the penultimate character, and so forth.
+ *
+ * The interval is inclusive, so the start and end characters will be part
+ * of the resulting string.
+ *
+ * The string is modified in-place.
+ *
+ * Example:
+ *
+ * s = sdsnew("Hello World");
+ * sdsrange(s,1,-1); => "ello World"
+ */
+void sdsrange(sds s, int start, int end) {
+    struct sdshdr *sh = (void*) (s-sizeof *sh);
+    size_t newlen, len = sdslen(s);
+
+    if (len == 0) return;
+    if (start < 0) {
+        start = len+start;
+        if (start < 0) start = 0;
+    }
+    if (end < 0) {
+        end = len+end;
+        if (end < 0) end = 0;
+    }
+    newlen = (start > end) ? 0 : (end-start)+1;
+    if (newlen != 0) {
+        if (start >= (signed)len) {
+            newlen = 0;
+        } else if (end >= (signed)len) {
+            end = len-1;
+            newlen = (start > end) ? 0 : (end-start)+1;
+        }
+    } else {
+        start = 0;
+    }
+    if (start && newlen) memmove(sh->buf, sh->buf+start, newlen);
+    sh->buf[newlen] = 0;
+    sh->free = sh->free+(sh->len-newlen);
+    sh->len = newlen;
+}
+
+/* Apply tolower() to every character of the sds string 's'. */
+void sdstolower(sds s) {
+    int len = sdslen(s), j;
+
+    for (j = 0; j < len; j++) s[j] = tolower(s[j]);
+}
+
+/* Apply toupper() to every character of the sds string 's'. */
+void sdstoupper(sds s) {
+    int len = sdslen(s), j;
+
+    for (j = 0; j < len; j++) s[j] = toupper(s[j]);
+}
+
+/* Compare two sds strings s1 and s2 with memcmp().
+ *
+ * Return value:
+ *
+ *     1 if s1 > s2.
+ *    -1 if s1 < s2.
+ *     0 if s1 and s2 are exactly the same binary string.
+ *
+ * If two strings share exactly the same prefix, but one of the two has
+ * additional characters, the longer string is considered to be greater than
+ * the smaller one. */
+int sdscmp(const sds s1, const sds s2) {
+    size_t l1, l2, minlen;
+    int cmp;
+
+    l1 = sdslen(s1);
+    l2 = sdslen(s2);
+    minlen = (l1 < l2) ? l1 : l2;
+    cmp = memcmp(s1,s2,minlen);
+    if (cmp == 0) return l1-l2;
+    return cmp;
+}
+
+/* Split 's' with separator in 'sep'. An array
+ * of sds strings is returned. *count will be set
+ * by reference to the number of tokens returned.
+ *
+ * On out of memory, zero length string, zero length
+ * separator, NULL is returned.
+ *
+ * Note that 'sep' is able to split a string using
+ * a multi-character separator. For example
+ * sdssplit("foo_-_bar","_-_"); will return two
+ * elements "foo" and "bar".
+ *
+ * This version of the function is binary-safe but
+ * requires length arguments. sdssplit() is just the
+ * same function but for zero-terminated strings.
+ */
+sds *sdssplitlen(const char *s, int len, const char *sep, int seplen, int *count) {
+    int elements = 0, slots = 5, start = 0, j;
+    sds *tokens;
+
+    if (seplen < 1 || len < 0) return NULL;
+
+    tokens = malloc(sizeof(sds)*slots);
+    if (tokens == NULL) return NULL;
+
+    if (len == 0) {
+        *count = 0;
+        return tokens;
+    }
+    for (j = 0; j < (len-(seplen-1)); j++) {
+        /* make sure there is room for the next element and the final one */
+        if (slots < elements+2) {
+            sds *newtokens;
+
+            slots *= 2;
+            newtokens = realloc(tokens,sizeof(sds)*slots);
+            if (newtokens == NULL) goto cleanup;
+            tokens = newtokens;
+        }
+        /* search the separator */
+        if ((seplen == 1 && *(s+j) == sep[0]) || (memcmp(s+j,sep,seplen) == 0)) {
+            tokens[elements] = sdsnewlen(s+start,j-start);
+            if (tokens[elements] == NULL) goto cleanup;
+            elements++;
+            start = j+seplen;
+            j = j+seplen-1; /* skip the separator */
+        }
+    }
+    /* Add the final element. We are sure there is room in the tokens array. */
+    tokens[elements] = sdsnewlen(s+start,len-start);
+    if (tokens[elements] == NULL) goto cleanup;
+    elements++;
+    *count = elements;
+    return tokens;
+
+cleanup:
+    {
+        int i;
+        for (i = 0; i < elements; i++) sdsfree(tokens[i]);
+        free(tokens);
+        *count = 0;
+        return NULL;
+    }
+}
+
+/* Free the result returned by sdssplitlen(), or do nothing if 'tokens' is NULL. */
+void sdsfreesplitres(sds *tokens, int count) {
+    if (!tokens) return;
+    while(count--)
+        sdsfree(tokens[count]);
+    free(tokens);
+}
+
+/* Create an sds string from a long long value. It is much faster than:
+ *
+ * sdscatprintf(sdsempty(),"%lld\n", value);
+ */
+sds sdsfromlonglong(long long value) {
+    char buf[32], *p;
+    unsigned long long v;
+
+    v = (value < 0) ? -value : value;
+    p = buf+31; /* point to the last character */
+    do {
+        *p-- = '0'+(v%10);
+        v /= 10;
+    } while(v);
+    if (value < 0) *p-- = '-';
+    p++;
+    return sdsnewlen(p,32-(p-buf));
+}
+
+/* Append to the sds string "s" an escaped string representation where
+ * all the non-printable characters (tested with isprint()) are turned into
+ * escapes in the form "\n\r\a...." or "\x<hex-number>".
+ *
+ * After the call, the modified sds string is no longer valid and all the
+ * references must be substituted with the new pointer returned by the call. */
+sds sdscatrepr(sds s, const char *p, size_t len) {
+    s = sdscatlen(s,"\"",1);
+    while(len--) {
+        switch(*p) {
+        case '\\':
+        case '"':
+            s = sdscatprintf(s,"\\%c",*p);
+            break;
+        case '\n': s = sdscatlen(s,"\\n",2); break;
+        case '\r': s = sdscatlen(s,"\\r",2); break;
+        case '\t': s = sdscatlen(s,"\\t",2); break;
+        case '\a': s = sdscatlen(s,"\\a",2); break;
+        case '\b': s = sdscatlen(s,"\\b",2); break;
+        default:
+            if (isprint(*p))
+                s = sdscatprintf(s,"%c",*p);
+            else
+                s = sdscatprintf(s,"\\x%02x",(unsigned char)*p);
+            break;
+        }
+        p++;
+    }
+    return sdscatlen(s,"\"",1);
+}
+
+/* Helper function for sdssplitargs() that returns non zero if 'c'
+ * is a valid hex digit. */
+int is_hex_digit(char c) {
+    return (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') ||
+           (c >= 'A' && c <= 'F');
+}
+
+/* Helper function for sdssplitargs() that converts a hex digit into an
+ * integer from 0 to 15 */
+int hex_digit_to_int(char c) {
+    switch(c) {
+    case '0': return 0;
+    case '1': return 1;
+    case '2': return 2;
+    case '3': return 3;
+    case '4': return 4;
+    case '5': return 5;
+    case '6': return 6;
+    case '7': return 7;
+    case '8': return 8;
+    case '9': return 9;
+    case 'a': case 'A': return 10;
+    case 'b': case 'B': return 11;
+    case 'c': case 'C': return 12;
+    case 'd': case 'D': return 13;
+    case 'e': case 'E': return 14;
+    case 'f': case 'F': return 15;
+    default: return 0;
+    }
+}
+
+/* Split a line into arguments, where every argument can be in the
+ * following programming-language REPL-alike form:
+ *
+ * foo bar "newline are supported\n" and "\xff\x00otherstuff"
+ *
+ * The number of arguments is stored into *argc, and an array
+ * of sds is returned.
+ *
+ * The caller should free the resulting array of sds strings with
+ * sdsfreesplitres().
+ *
+ * Note that sdscatrepr() is able to convert back a string into
+ * a quoted string in the same format sdssplitargs() is able to parse.
+ *
+ * The function returns the allocated tokens on success, even when the
+ * input string is empty, or NULL if the input contains unbalanced
+ * quotes or closed quotes followed by non space characters
+ * as in: "foo"bar or "foo'
+ */
+sds *sdssplitargs(const char *line, int *argc) {
+    const char *p = line;
+    char *current = NULL;
+    char **vector = NULL;
+
+    *argc = 0;
+    while(1) {
+        /* skip blanks */
+        while(*p && isspace(*p)) p++;
+        if (*p) {
+            /* get a token */
+            int inq=0;  /* set to 1 if we are in "quotes" */
+            int insq=0; /* set to 1 if we are in 'single quotes' */
+            int done=0;
+
+            if (current == NULL) current = sdsempty();
+            while(!done) {
+                if (inq) {
+                    if (*p == '\\' && *(p+1) == 'x' &&
+                                             is_hex_digit(*(p+2)) &&
+                                             is_hex_digit(*(p+3)))
+                    {
+                        unsigned char byte;
+
+                        byte = (hex_digit_to_int(*(p+2))*16)+
+                                hex_digit_to_int(*(p+3));
+                        current = sdscatlen(current,(char*)&byte,1);
+                        p += 3;
+                    } else if (*p == '\\' && *(p+1)) {
+                        char c;
+
+                        p++;
+                        switch(*p) {
+                        case 'n': c = '\n'; break;
+                        case 'r': c = '\r'; break;
+                        case 't': c = '\t'; break;
+                        case 'b': c = '\b'; break;
+                        case 'a': c = '\a'; break;
+                        default: c = *p; break;
+                        }
+                        current = sdscatlen(current,&c,1);
+                    } else if (*p == '"') {
+                        /* closing quote must be followed by a space or
+                         * nothing at all. */
+                        if (*(p+1) && !isspace(*(p+1))) goto err;
+                        done=1;
+                    } else if (!*p) {
+                        /* unterminated quotes */
+                        goto err;
+                    } else {
+                        current = sdscatlen(current,p,1);
+                    }
+                } else if (insq) {
+                    if (*p == '\\' && *(p+1) == '\'') {
+                        p++;
+                        current = sdscatlen(current,"'",1);
+                    } else if (*p == '\'') {
+                        /* closing quote must be followed by a space or
+                         * nothing at all. */
+                        if (*(p+1) && !isspace(*(p+1))) goto err;
+                        done=1;
+                    } else if (!*p) {
+                        /* unterminated quotes */
+                        goto err;
+                    } else {
+                        current = sdscatlen(current,p,1);
+                    }
+                } else {
+                    switch(*p) {
+                    case ' ':
+                    case '\n':
+                    case '\r':
+                    case '\t':
+                    case '\0':
+                        done=1;
+                        break;
+                    case '"':
+                        inq=1;
+                        break;
+                    case '\'':
+                        insq=1;
+                        break;
+                    default:
+                        current = sdscatlen(current,p,1);
+                        break;
+                    }
+                }
+                if (*p) p++;
+            }
+            /* add the token to the vector */
+            vector = realloc(vector,((*argc)+1)*sizeof(char*));
+            vector[*argc] = current;
+            (*argc)++;
+            current = NULL;
+        } else {
+            /* Even on empty input string return something not NULL. */
+            if (vector == NULL) vector = malloc(sizeof(void*));
+            return vector;
+        }
+    }
+
+err:
+    while((*argc)--)
+        sdsfree(vector[*argc]);
+    free(vector);
+    if (current) sdsfree(current);
+    *argc = 0;
+    return NULL;
+}
+
+/* Modify the string substituting all the occurrences of the set of
+ * characters specified in the 'from' string to the corresponding character
+ * in the 'to' array.
+ *
+ * For instance: sdsmapchars(mystring, "ho", "01", 2)
+ * will have the effect of turning the string "hello" into "0ell1".
+ *
+ * The function returns the sds string pointer, that is always the same
+ * as the input pointer since no resize is needed. */
+sds sdsmapchars(sds s, const char *from, const char *to, size_t setlen) {
+    size_t j, i, l = sdslen(s);
+
+    for (j = 0; j < l; j++) {
+        for (i = 0; i < setlen; i++) {
+            if (s[j] == from[i]) {
+                s[j] = to[i];
+                break;
+            }
+        }
+    }
+    return s;
+}
+
+/* Join an array of C strings using the specified separator (also a C string).
+ * Returns the result as an sds string. */
+sds sdsjoin(char **argv, int argc, char *sep, size_t seplen) {
+    sds join = sdsempty();
+    int j;
+
+    for (j = 0; j < argc; j++) {
+        join = sdscat(join, argv[j]);
+        if (j != argc-1) join = sdscatlen(join,sep,seplen);
+    }
+    return join;
+}
+
+/* Like sdsjoin, but joins an array of SDS strings. */
+sds sdsjoinsds(sds *argv, int argc, const char *sep, size_t seplen) {
+    sds join = sdsempty();
+    int j;
+
+    for (j = 0; j < argc; j++) {
+        join = sdscatsds(join, argv[j]);
+        if (j != argc-1) join = sdscatlen(join,sep,seplen);
+    }
+    return join;
+}
+
+#ifdef SDS_TEST_MAIN
+#include <stdio.h>
+#include "testhelp.h"
+
+int main(void) {
+    {
+        struct sdshdr *sh;
+        sds x = sdsnew("foo"), y;
+
+        test_cond("Create a string and obtain the length",
+            sdslen(x) == 3 && memcmp(x,"foo\0",4) == 0)
+
+        sdsfree(x);
+        x = sdsnewlen("foo",2);
+        test_cond("Create a string with specified length",
+            sdslen(x) == 2 && memcmp(x,"fo\0",3) == 0)
+
+        x = sdscat(x,"bar");
+        test_cond("Strings concatenation",
+            sdslen(x) == 5 && memcmp(x,"fobar\0",6) == 0);
+
+        x = sdscpy(x,"a");
+        test_cond("sdscpy() against an originally longer string",
+            sdslen(x) == 1 && memcmp(x,"a\0",2) == 0)
+
+        x = sdscpy(x,"xyzxxxxxxxxxxyyyyyyyyyykkkkkkkkkk");
+        test_cond("sdscpy() against an originally shorter string",
+            sdslen(x) == 33 &&
+            memcmp(x,"xyzxxxxxxxxxxyyyyyyyyyykkkkkkkkkk\0",33) == 0)
+
+        sdsfree(x);
+        x = sdscatprintf(sdsempty(),"%d",123);
+        test_cond("sdscatprintf() seems working in the base case",
+            sdslen(x) == 3 && memcmp(x,"123\0",4) ==0)
+
+        sdsfree(x);
+        x = sdsnew("xxciaoyyy");
+        sdstrim(x,"xy");
+        test_cond("sdstrim() correctly trims characters",
+            sdslen(x) == 4 && memcmp(x,"ciao\0",5) == 0)
+
+        y = sdsdup(x);
+        sdsrange(y,1,1);
+        test_cond("sdsrange(...,1,1)",
+            sdslen(y) == 1 && memcmp(y,"i\0",2) == 0)
+
+        sdsfree(y);
+        y = sdsdup(x);
+        sdsrange(y,1,-1);
+        test_cond("sdsrange(...,1,-1)",
+            sdslen(y) == 3 && memcmp(y,"iao\0",4) == 0)
+
+        sdsfree(y);
+        y = sdsdup(x);
+        sdsrange(y,-2,-1);
+        test_cond("sdsrange(...,-2,-1)",
+            sdslen(y) == 2 && memcmp(y,"ao\0",3) == 0)
+
+        sdsfree(y);
+        y = sdsdup(x);
+        sdsrange(y,2,1);
+        test_cond("sdsrange(...,2,1)",
+            sdslen(y) == 0 && memcmp(y,"\0",1) == 0)
+
+        sdsfree(y);
+        y = sdsdup(x);
+        sdsrange(y,1,100);
+        test_cond("sdsrange(...,1,100)",
+            sdslen(y) == 3 && memcmp(y,"iao\0",4) == 0)
+
+        sdsfree(y);
+        y = sdsdup(x);
+        sdsrange(y,100,100);
+        test_cond("sdsrange(...,100,100)",
+            sdslen(y) == 0 && memcmp(y,"\0",1) == 0)
+
+        sdsfree(y);
+        sdsfree(x);
+        x = sdsnew("foo");
+        y = sdsnew("foa");
+        test_cond("sdscmp(foo,foa)", sdscmp(x,y) > 0)
+
+        sdsfree(y);
+        sdsfree(x);
+        x = sdsnew("bar");
+        y = sdsnew("bar");
+        test_cond("sdscmp(bar,bar)", sdscmp(x,y) == 0)
+
+        sdsfree(y);
+        sdsfree(x);
+        x = sdsnew("aar");
+        y = sdsnew("bar");
+        test_cond("sdscmp(bar,bar)", sdscmp(x,y) < 0)
+
+        sdsfree(y);
+        sdsfree(x);
+        x = sdsnewlen("\a\n\0foo\r",7);
+        y = sdscatrepr(sdsempty(),x,sdslen(x));
+        test_cond("sdscatrepr(...data...)",
+            memcmp(y,"\"\\a\\n\\x00foo\\r\"",15) == 0)
+
+        {
+            int oldfree;
+
+            sdsfree(x);
+            x = sdsnew("0");
+            sh = (void*) (x-(sizeof(struct sdshdr)));
+            test_cond("sdsnew() free/len buffers", sh->len == 1 && sh->free == 0);
+            x = sdsMakeRoomFor(x,1);
+            sh = (void*) (x-(sizeof(struct sdshdr)));
+            test_cond("sdsMakeRoomFor()", sh->len == 1 && sh->free > 0);
+            oldfree = sh->free;
+            x[1] = '1';
+            sdsIncrLen(x,1);
+            test_cond("sdsIncrLen() -- content", x[0] == '0' && x[1] == '1');
+            test_cond("sdsIncrLen() -- len", sh->len == 2);
+            test_cond("sdsIncrLen() -- free", sh->free == oldfree-1);
+        }
+    }
+    test_report()
+    return 0;
+}
+#endif
diff --git a/contrib/hiredis/sds.h b/contrib/hiredis/sds.h
new file mode 100644
index 000000000..19a2abd31
--- /dev/null
+++ b/contrib/hiredis/sds.h
@@ -0,0 +1,105 @@
+/* SDS (Simple Dynamic Strings), A C dynamic strings library.
+ *
+ * Copyright (c) 2006-2014, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __SDS_H
+#define __SDS_H
+
+#define SDS_MAX_PREALLOC (1024*1024)
+
+#include <sys/types.h>
+#include <stdarg.h>
+#ifdef _MSC_VER
+#include "win32.h"
+#endif
+
+typedef char *sds;
+
+struct sdshdr {
+    int len;
+    int free;
+    char buf[];
+};
+
+static inline size_t sdslen(const sds s) {
+    struct sdshdr *sh = (struct sdshdr *)(s-sizeof *sh);
+    return sh->len;
+}
+
+static inline size_t sdsavail(const sds s) {
+    struct sdshdr *sh = (struct sdshdr *)(s-sizeof *sh);
+    return sh->free;
+}
+
+sds sdsnewlen(const void *init, size_t initlen);
+sds sdsnew(const char *init);
+sds sdsempty(void);
+size_t sdslen(const sds s);
+sds sdsdup(const sds s);
+void sdsfree(sds s);
+size_t sdsavail(const sds s);
+sds sdsgrowzero(sds s, size_t len);
+sds sdscatlen(sds s, const void *t, size_t len);
+sds sdscat(sds s, const char *t);
+sds sdscatsds(sds s, const sds t);
+sds sdscpylen(sds s, const char *t, size_t len);
+sds sdscpy(sds s, const char *t);
+
+sds sdscatvprintf(sds s, const char *fmt, va_list ap);
+#ifdef __GNUC__
+sds sdscatprintf(sds s, const char *fmt, ...)
+    __attribute__((format(printf, 2, 3)));
+#else
+sds sdscatprintf(sds s, const char *fmt, ...);
+#endif
+
+sds sdscatfmt(sds s, char const *fmt, ...);
+void sdstrim(sds s, const char *cset);
+void sdsrange(sds s, int start, int end);
+void sdsupdatelen(sds s);
+void sdsclear(sds s);
+int sdscmp(const sds s1, const sds s2);
+sds *sdssplitlen(const char *s, int len, const char *sep, int seplen, int *count);
+void sdsfreesplitres(sds *tokens, int count);
+void sdstolower(sds s);
+void sdstoupper(sds s);
+sds sdsfromlonglong(long long value);
+sds sdscatrepr(sds s, const char *p, size_t len);
+sds *sdssplitargs(const char *line, int *argc);
+sds sdsmapchars(sds s, const char *from, const char *to, size_t setlen);
+sds sdsjoin(char **argv, int argc, char *sep, size_t seplen);
+sds sdsjoinsds(sds *argv, int argc, const char *sep, size_t seplen);
+
+/* Low level functions exposed to the user API */
+sds sdsMakeRoomFor(sds s, size_t addlen);
+void sdsIncrLen(sds s, int incr);
+sds sdsRemoveFreeSpace(sds s);
+size_t sdsAllocSize(sds s);
+
+#endif
diff --git a/debian/copyright b/debian/copyright
index e8f675680..2acbb868e 100644
--- a/debian/copyright
+++ b/debian/copyright
@@ -69,6 +69,11 @@ Copyright: 2001-2015 Dr Martin Porter
            2002-2015 Richard Boulton
 License: BSD-2-Clause
 
+Files: contrib/hiredis/*
+Copyright: 2009-2011, Salvatore Sanfilippo <antirez at gmail dot com>
+           2010-2011, Pieter Noordhuis <pcnoordhuis at gmail dot com>
+License: BSD-3-Clause-Redis
+
 Files: src/libutil/diff.c
 Copyright: 2004 Michael B. Allen <mba2000 ioplex.com>
            2010-2014 Vsevolod Stakhov <vsevolod@highsecure.ru>
@@ -110,7 +115,7 @@ Comment:
  The exact meaning of "Public domain" mentioned in the file headers was taken from:
  http://www.corpit.ru/mjt/tinycdb.html
 
-Files: src/libcryptobox/curve25519/*
+Files: src/libcryptobox/curve25519/curve25519-donna*
 Copyright: 2008, Google Inc.
 License: BSD-3-Clause-Google
 
@@ -238,6 +243,32 @@ License: BSD-3-Clause-Google
  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+License: BSD-3-Clause-Redis
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+ .
+ Redistributions of source code must retain the above copyright notice,
+ this list of conditions and the following disclaimer.
+ .
+ Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+ .
+ Neither the name of Redis nor the names of its contributors may be used
+ to endorse or promote products derived from this software without specific
+ prior written permission.
+ .
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
 License: Expat
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index a37256c41..4eb83074c 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -125,6 +125,9 @@ TARGET_LINK_LIBRARIES(rspamd rspamd-server)
 IF (ENABLE_SNOWBALL MATCHES "ON")
 	TARGET_LINK_LIBRARIES(rspamd stemmer)
 ENDIF()
+IF(ENABLE_HIREDIS MATCHES "ON")
+	TARGET_LINK_LIBRARIES(rspamd rspamd-hiredis)
+ENDIF()
 TARGET_LINK_LIBRARIES(rspamd rspamd-actrie)
 
 IF (ENABLE_FANN MATCHES "ON")
diff --git a/src/rspamadm/CMakeLists.txt b/src/rspamadm/CMakeLists.txt
index 3f8a3d0c3..1fc801b46 100644
--- a/src/rspamadm/CMakeLists.txt
+++ b/src/rspamadm/CMakeLists.txt
@@ -36,6 +36,9 @@ TARGET_LINK_LIBRARIES(rspamadm ${RSPAMD_REQUIRED_LIBRARIES})
 IF (ENABLE_SNOWBALL MATCHES "ON")
     TARGET_LINK_LIBRARIES(rspamadm stemmer)
 ENDIF()
+IF(ENABLE_HIREDIS MATCHES "ON")
+	TARGET_LINK_LIBRARIES(rspamadm rspamd-hiredis)
+ENDIF()
 TARGET_LINK_LIBRARIES(rspamadm rspamd-actrie)
 
 IF (NOT DEBIAN_BUILD)
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index a2096c128..f21e604f7 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -28,6 +28,9 @@ TARGET_LINK_LIBRARIES(rspamd-test ${RSPAMD_REQUIRED_LIBRARIES})
 IF (ENABLE_SNOWBALL MATCHES "ON")
 	TARGET_LINK_LIBRARIES(rspamd-test stemmer)
 ENDIF()
+IF(ENABLE_HIREDIS MATCHES "ON")
+	TARGET_LINK_LIBRARIES(rspamd-test rspamd-hiredis)
+ENDIF()
 IF (ENABLE_HYPERSCAN MATCHES "ON")
 	TARGET_LINK_LIBRARIES(rspamd-test hs)
 	SET_TARGET_PROPERTIES(rspamd-test PROPERTIES LINKER_LANGUAGE CXX)