Added all required dependencies

3 files changed, 982 insertions, 0 deletions

diff --git a/vendor/github.com/bradfitz/gomemcache/LICENSE b/vendor/github.com/bradfitz/gomemcache/LICENSE
new file mode 100644
index 0000000000..d645695673
--- /dev/null
+++ b/vendor/github.com/bradfitz/gomemcache/LICENSE
@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
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+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
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+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
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+   6. Trademarks. This License does not grant permission to use the trade
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diff --git a/vendor/github.com/bradfitz/gomemcache/memcache/memcache.go b/vendor/github.com/bradfitz/gomemcache/memcache/memcache.go
new file mode 100644
index 0000000000..7b5442d735
--- /dev/null
+++ b/vendor/github.com/bradfitz/gomemcache/memcache/memcache.go
@@ -0,0 +1,666 @@
+/*
+Copyright 2011 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package memcache provides a client for the memcached cache server.
+package memcache
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net"
+
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+// Similar to:
+// http://code.google.com/appengine/docs/go/memcache/reference.html
+
+var (
+	// ErrCacheMiss means that a Get failed because the item wasn't present.
+	ErrCacheMiss = errors.New("memcache: cache miss")
+
+	// ErrCASConflict means that a CompareAndSwap call failed due to the
+	// cached value being modified between the Get and the CompareAndSwap.
+	// If the cached value was simply evicted rather than replaced,
+	// ErrNotStored will be returned instead.
+	ErrCASConflict = errors.New("memcache: compare-and-swap conflict")
+
+	// ErrNotStored means that a conditional write operation (i.e. Add or
+	// CompareAndSwap) failed because the condition was not satisfied.
+	ErrNotStored = errors.New("memcache: item not stored")
+
+	// ErrServer means that a server error occurred.
+	ErrServerError = errors.New("memcache: server error")
+
+	// ErrNoStats means that no statistics were available.
+	ErrNoStats = errors.New("memcache: no statistics available")
+
+	// ErrMalformedKey is returned when an invalid key is used.
+	// Keys must be at maximum 250 bytes long, ASCII, and not
+	// contain whitespace or control characters.
+	ErrMalformedKey = errors.New("malformed: key is too long or contains invalid characters")
+
+	// ErrNoServers is returned when no servers are configured or available.
+	ErrNoServers = errors.New("memcache: no servers configured or available")
+)
+
+// DefaultTimeout is the default socket read/write timeout.
+const DefaultTimeout = 100 * time.Millisecond
+
+const (
+	buffered            = 8 // arbitrary buffered channel size, for readability
+	maxIdleConnsPerAddr = 2 // TODO(bradfitz): make this configurable?
+)
+
+// resumableError returns true if err is only a protocol-level cache error.
+// This is used to determine whether or not a server connection should
+// be re-used or not. If an error occurs, by default we don't reuse the
+// connection, unless it was just a cache error.
+func resumableError(err error) bool {
+	switch err {
+	case ErrCacheMiss, ErrCASConflict, ErrNotStored, ErrMalformedKey:
+		return true
+	}
+	return false
+}
+
+func legalKey(key string) bool {
+	if len(key) > 250 {
+		return false
+	}
+	for i := 0; i < len(key); i++ {
+		if key[i] <= ' ' || key[i] > 0x7e {
+			return false
+		}
+	}
+	return true
+}
+
+var (
+	crlf            = []byte("\r\n")
+	space           = []byte(" ")
+	resultOK        = []byte("OK\r\n")
+	resultStored    = []byte("STORED\r\n")
+	resultNotStored = []byte("NOT_STORED\r\n")
+	resultExists    = []byte("EXISTS\r\n")
+	resultNotFound  = []byte("NOT_FOUND\r\n")
+	resultDeleted   = []byte("DELETED\r\n")
+	resultEnd       = []byte("END\r\n")
+	resultOk        = []byte("OK\r\n")
+	resultTouched   = []byte("TOUCHED\r\n")
+
+	resultClientErrorPrefix = []byte("CLIENT_ERROR ")
+)
+
+// New returns a memcache client using the provided server(s)
+// with equal weight. If a server is listed multiple times,
+// it gets a proportional amount of weight.
+func New(server ...string) *Client {
+	ss := new(ServerList)
+	ss.SetServers(server...)
+	return NewFromSelector(ss)
+}
+
+// NewFromSelector returns a new Client using the provided ServerSelector.
+func NewFromSelector(ss ServerSelector) *Client {
+	return &Client{selector: ss}
+}
+
+// Client is a memcache client.
+// It is safe for unlocked use by multiple concurrent goroutines.
+type Client struct {
+	// Timeout specifies the socket read/write timeout.
+	// If zero, DefaultTimeout is used.
+	Timeout time.Duration
+
+	selector ServerSelector
+
+	lk       sync.Mutex
+	freeconn map[string][]*conn
+}
+
+// Item is an item to be got or stored in a memcached server.
+type Item struct {
+	// Key is the Item's key (250 bytes maximum).
+	Key string
+
+	// Value is the Item's value.
+	Value []byte
+
+	// Flags are server-opaque flags whose semantics are entirely
+	// up to the app.
+	Flags uint32
+
+	// Expiration is the cache expiration time, in seconds: either a relative
+	// time from now (up to 1 month), or an absolute Unix epoch time.
+	// Zero means the Item has no expiration time.
+	Expiration int32
+
+	// Compare and swap ID.
+	casid uint64
+}
+
+// conn is a connection to a server.
+type conn struct {
+	nc   net.Conn
+	rw   *bufio.ReadWriter
+	addr net.Addr
+	c    *Client
+}
+
+// release returns this connection back to the client's free pool
+func (cn *conn) release() {
+	cn.c.putFreeConn(cn.addr, cn)
+}
+
+func (cn *conn) extendDeadline() {
+	cn.nc.SetDeadline(time.Now().Add(cn.c.netTimeout()))
+}
+
+// condRelease releases this connection if the error pointed to by err
+// is nil (not an error) or is only a protocol level error (e.g. a
+// cache miss).  The purpose is to not recycle TCP connections that
+// are bad.
+func (cn *conn) condRelease(err *error) {
+	if *err == nil || resumableError(*err) {
+		cn.release()
+	} else {
+		cn.nc.Close()
+	}
+}
+
+func (c *Client) putFreeConn(addr net.Addr, cn *conn) {
+	c.lk.Lock()
+	defer c.lk.Unlock()
+	if c.freeconn == nil {
+		c.freeconn = make(map[string][]*conn)
+	}
+	freelist := c.freeconn[addr.String()]
+	if len(freelist) >= maxIdleConnsPerAddr {
+		cn.nc.Close()
+		return
+	}
+	c.freeconn[addr.String()] = append(freelist, cn)
+}
+
+func (c *Client) getFreeConn(addr net.Addr) (cn *conn, ok bool) {
+	c.lk.Lock()
+	defer c.lk.Unlock()
+	if c.freeconn == nil {
+		return nil, false
+	}
+	freelist, ok := c.freeconn[addr.String()]
+	if !ok || len(freelist) == 0 {
+		return nil, false
+	}
+	cn = freelist[len(freelist)-1]
+	c.freeconn[addr.String()] = freelist[:len(freelist)-1]
+	return cn, true
+}
+
+func (c *Client) netTimeout() time.Duration {
+	if c.Timeout != 0 {
+		return c.Timeout
+	}
+	return DefaultTimeout
+}
+
+// ConnectTimeoutError is the error type used when it takes
+// too long to connect to the desired host. This level of
+// detail can generally be ignored.
+type ConnectTimeoutError struct {
+	Addr net.Addr
+}
+
+func (cte *ConnectTimeoutError) Error() string {
+	return "memcache: connect timeout to " + cte.Addr.String()
+}
+
+func (c *Client) dial(addr net.Addr) (net.Conn, error) {
+	type connError struct {
+		cn  net.Conn
+		err error
+	}
+
+	nc, err := net.DialTimeout(addr.Network(), addr.String(), c.netTimeout())
+	if err == nil {
+		return nc, nil
+	}
+
+	if ne, ok := err.(net.Error); ok && ne.Timeout() {
+		return nil, &ConnectTimeoutError{addr}
+	}
+
+	return nil, err
+}
+
+func (c *Client) getConn(addr net.Addr) (*conn, error) {
+	cn, ok := c.getFreeConn(addr)
+	if ok {
+		cn.extendDeadline()
+		return cn, nil
+	}
+	nc, err := c.dial(addr)
+	if err != nil {
+		return nil, err
+	}
+	cn = &conn{
+		nc:   nc,
+		addr: addr,
+		rw:   bufio.NewReadWriter(bufio.NewReader(nc), bufio.NewWriter(nc)),
+		c:    c,
+	}
+	cn.extendDeadline()
+	return cn, nil
+}
+
+func (c *Client) onItem(item *Item, fn func(*Client, *bufio.ReadWriter, *Item) error) error {
+	addr, err := c.selector.PickServer(item.Key)
+	if err != nil {
+		return err
+	}
+	cn, err := c.getConn(addr)
+	if err != nil {
+		return err
+	}
+	defer cn.condRelease(&err)
+	if err = fn(c, cn.rw, item); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (c *Client) FlushAll() error {
+	return c.selector.Each(c.flushAllFromAddr)
+}
+
+// Get gets the item for the given key. ErrCacheMiss is returned for a
+// memcache cache miss. The key must be at most 250 bytes in length.
+func (c *Client) Get(key string) (item *Item, err error) {
+	err = c.withKeyAddr(key, func(addr net.Addr) error {
+		return c.getFromAddr(addr, []string{key}, func(it *Item) { item = it })
+	})
+	if err == nil && item == nil {
+		err = ErrCacheMiss
+	}
+	return
+}
+
+// Touch updates the expiry for the given key. The seconds parameter is either
+// a Unix timestamp or, if seconds is less than 1 month, the number of seconds
+// into the future at which time the item will expire. ErrCacheMiss is returned if the
+// key is not in the cache. The key must be at most 250 bytes in length.
+func (c *Client) Touch(key string, seconds int32) (err error) {
+	return c.withKeyAddr(key, func(addr net.Addr) error {
+		return c.touchFromAddr(addr, []string{key}, seconds)
+	})
+}
+
+func (c *Client) withKeyAddr(key string, fn func(net.Addr) error) (err error) {
+	if !legalKey(key) {
+		return ErrMalformedKey
+	}
+	addr, err := c.selector.PickServer(key)
+	if err != nil {
+		return err
+	}
+	return fn(addr)
+}
+
+func (c *Client) withAddrRw(addr net.Addr, fn func(*bufio.ReadWriter) error) (err error) {
+	cn, err := c.getConn(addr)
+	if err != nil {
+		return err
+	}
+	defer cn.condRelease(&err)
+	return fn(cn.rw)
+}
+
+func (c *Client) withKeyRw(key string, fn func(*bufio.ReadWriter) error) error {
+	return c.withKeyAddr(key, func(addr net.Addr) error {
+		return c.withAddrRw(addr, fn)
+	})
+}
+
+func (c *Client) getFromAddr(addr net.Addr, keys []string, cb func(*Item)) error {
+	return c.withAddrRw(addr, func(rw *bufio.ReadWriter) error {
+		if _, err := fmt.Fprintf(rw, "gets %s\r\n", strings.Join(keys, " ")); err != nil {
+			return err
+		}
+		if err := rw.Flush(); err != nil {
+			return err
+		}
+		if err := parseGetResponse(rw.Reader, cb); err != nil {
+			return err
+		}
+		return nil
+	})
+}
+
+// flushAllFromAddr send the flush_all command to the given addr
+func (c *Client) flushAllFromAddr(addr net.Addr) error {
+	return c.withAddrRw(addr, func(rw *bufio.ReadWriter) error {
+		if _, err := fmt.Fprintf(rw, "flush_all\r\n"); err != nil {
+			return err
+		}
+		if err := rw.Flush(); err != nil {
+			return err
+		}
+		line, err := rw.ReadSlice('\n')
+		if err != nil {
+			return err
+		}
+		switch {
+		case bytes.Equal(line, resultOk):
+			break
+		default:
+			return fmt.Errorf("memcache: unexpected response line from flush_all: %q", string(line))
+		}
+		return nil
+	})
+}
+
+func (c *Client) touchFromAddr(addr net.Addr, keys []string, expiration int32) error {
+	return c.withAddrRw(addr, func(rw *bufio.ReadWriter) error {
+		for _, key := range keys {
+			if _, err := fmt.Fprintf(rw, "touch %s %d\r\n", key, expiration); err != nil {
+				return err
+			}
+			if err := rw.Flush(); err != nil {
+				return err
+			}
+			line, err := rw.ReadSlice('\n')
+			if err != nil {
+				return err
+			}
+			switch {
+			case bytes.Equal(line, resultTouched):
+				break
+			case bytes.Equal(line, resultNotFound):
+				return ErrCacheMiss
+			default:
+				return fmt.Errorf("memcache: unexpected response line from touch: %q", string(line))
+			}
+		}
+		return nil
+	})
+}
+
+// GetMulti is a batch version of Get. The returned map from keys to
+// items may have fewer elements than the input slice, due to memcache
+// cache misses. Each key must be at most 250 bytes in length.
+// If no error is returned, the returned map will also be non-nil.
+func (c *Client) GetMulti(keys []string) (map[string]*Item, error) {
+	var lk sync.Mutex
+	m := make(map[string]*Item)
+	addItemToMap := func(it *Item) {
+		lk.Lock()
+		defer lk.Unlock()
+		m[it.Key] = it
+	}
+
+	keyMap := make(map[net.Addr][]string)
+	for _, key := range keys {
+		if !legalKey(key) {
+			return nil, ErrMalformedKey
+		}
+		addr, err := c.selector.PickServer(key)
+		if err != nil {
+			return nil, err
+		}
+		keyMap[addr] = append(keyMap[addr], key)
+	}
+
+	ch := make(chan error, buffered)
+	for addr, keys := range keyMap {
+		go func(addr net.Addr, keys []string) {
+			ch <- c.getFromAddr(addr, keys, addItemToMap)
+		}(addr, keys)
+	}
+
+	var err error
+	for _ = range keyMap {
+		if ge := <-ch; ge != nil {
+			err = ge
+		}
+	}
+	return m, err
+}
+
+// parseGetResponse reads a GET response from r and calls cb for each
+// read and allocated Item
+func parseGetResponse(r *bufio.Reader, cb func(*Item)) error {
+	for {
+		line, err := r.ReadSlice('\n')
+		if err != nil {
+			return err
+		}
+		if bytes.Equal(line, resultEnd) {
+			return nil
+		}
+		it := new(Item)
+		size, err := scanGetResponseLine(line, it)
+		if err != nil {
+			return err
+		}
+		it.Value, err = ioutil.ReadAll(io.LimitReader(r, int64(size)+2))
+		if err != nil {
+			return err
+		}
+		if !bytes.HasSuffix(it.Value, crlf) {
+			return fmt.Errorf("memcache: corrupt get result read")
+		}
+		it.Value = it.Value[:size]
+		cb(it)
+	}
+}
+
+// scanGetResponseLine populates it and returns the declared size of the item.
+// It does not read the bytes of the item.
+func scanGetResponseLine(line []byte, it *Item) (size int, err error) {
+	pattern := "VALUE %s %d %d %d\r\n"
+	dest := []interface{}{&it.Key, &it.Flags, &size, &it.casid}
+	if bytes.Count(line, space) == 3 {
+		pattern = "VALUE %s %d %d\r\n"
+		dest = dest[:3]
+	}
+	n, err := fmt.Sscanf(string(line), pattern, dest...)
+	if err != nil || n != len(dest) {
+		return -1, fmt.Errorf("memcache: unexpected line in get response: %q", line)
+	}
+	return size, nil
+}
+
+// Set writes the given item, unconditionally.
+func (c *Client) Set(item *Item) error {
+	return c.onItem(item, (*Client).set)
+}
+
+func (c *Client) set(rw *bufio.ReadWriter, item *Item) error {
+	return c.populateOne(rw, "set", item)
+}
+
+// Add writes the given item, if no value already exists for its
+// key. ErrNotStored is returned if that condition is not met.
+func (c *Client) Add(item *Item) error {
+	return c.onItem(item, (*Client).add)
+}
+
+func (c *Client) add(rw *bufio.ReadWriter, item *Item) error {
+	return c.populateOne(rw, "add", item)
+}
+
+// Replace writes the given item, but only if the server *does*
+// already hold data for this key
+func (c *Client) Replace(item *Item) error {
+	return c.onItem(item, (*Client).replace)
+}
+
+func (c *Client) replace(rw *bufio.ReadWriter, item *Item) error {
+	return c.populateOne(rw, "replace", item)
+}
+
+// CompareAndSwap writes the given item that was previously returned
+// by Get, if the value was neither modified or evicted between the
+// Get and the CompareAndSwap calls. The item's Key should not change
+// between calls but all other item fields may differ. ErrCASConflict
+// is returned if the value was modified in between the
+// calls. ErrNotStored is returned if the value was evicted in between
+// the calls.
+func (c *Client) CompareAndSwap(item *Item) error {
+	return c.onItem(item, (*Client).cas)
+}
+
+func (c *Client) cas(rw *bufio.ReadWriter, item *Item) error {
+	return c.populateOne(rw, "cas", item)
+}
+
+func (c *Client) populateOne(rw *bufio.ReadWriter, verb string, item *Item) error {
+	if !legalKey(item.Key) {
+		return ErrMalformedKey
+	}
+	var err error
+	if verb == "cas" {
+		_, err = fmt.Fprintf(rw, "%s %s %d %d %d %d\r\n",
+			verb, item.Key, item.Flags, item.Expiration, len(item.Value), item.casid)
+	} else {
+		_, err = fmt.Fprintf(rw, "%s %s %d %d %d\r\n",
+			verb, item.Key, item.Flags, item.Expiration, len(item.Value))
+	}
+	if err != nil {
+		return err
+	}
+	if _, err = rw.Write(item.Value); err != nil {
+		return err
+	}
+	if _, err := rw.Write(crlf); err != nil {
+		return err
+	}
+	if err := rw.Flush(); err != nil {
+		return err
+	}
+	line, err := rw.ReadSlice('\n')
+	if err != nil {
+		return err
+	}
+	switch {
+	case bytes.Equal(line, resultStored):
+		return nil
+	case bytes.Equal(line, resultNotStored):
+		return ErrNotStored
+	case bytes.Equal(line, resultExists):
+		return ErrCASConflict
+	case bytes.Equal(line, resultNotFound):
+		return ErrCacheMiss
+	}
+	return fmt.Errorf("memcache: unexpected response line from %q: %q", verb, string(line))
+}
+
+func writeReadLine(rw *bufio.ReadWriter, format string, args ...interface{}) ([]byte, error) {
+	_, err := fmt.Fprintf(rw, format, args...)
+	if err != nil {
+		return nil, err
+	}
+	if err := rw.Flush(); err != nil {
+		return nil, err
+	}
+	line, err := rw.ReadSlice('\n')
+	return line, err
+}
+
+func writeExpectf(rw *bufio.ReadWriter, expect []byte, format string, args ...interface{}) error {
+	line, err := writeReadLine(rw, format, args...)
+	if err != nil {
+		return err
+	}
+	switch {
+	case bytes.Equal(line, resultOK):
+		return nil
+	case bytes.Equal(line, expect):
+		return nil
+	case bytes.Equal(line, resultNotStored):
+		return ErrNotStored
+	case bytes.Equal(line, resultExists):
+		return ErrCASConflict
+	case bytes.Equal(line, resultNotFound):
+		return ErrCacheMiss
+	}
+	return fmt.Errorf("memcache: unexpected response line: %q", string(line))
+}
+
+// Delete deletes the item with the provided key. The error ErrCacheMiss is
+// returned if the item didn't already exist in the cache.
+func (c *Client) Delete(key string) error {
+	return c.withKeyRw(key, func(rw *bufio.ReadWriter) error {
+		return writeExpectf(rw, resultDeleted, "delete %s\r\n", key)
+	})
+}
+
+// DeleteAll deletes all items in the cache.
+func (c *Client) DeleteAll() error {
+	return c.withKeyRw("", func(rw *bufio.ReadWriter) error {
+		return writeExpectf(rw, resultDeleted, "flush_all\r\n")
+	})
+}
+
+// Increment atomically increments key by delta. The return value is
+// the new value after being incremented or an error. If the value
+// didn't exist in memcached the error is ErrCacheMiss. The value in
+// memcached must be an decimal number, or an error will be returned.
+// On 64-bit overflow, the new value wraps around.
+func (c *Client) Increment(key string, delta uint64) (newValue uint64, err error) {
+	return c.incrDecr("incr", key, delta)
+}
+
+// Decrement atomically decrements key by delta. The return value is
+// the new value after being decremented or an error. If the value
+// didn't exist in memcached the error is ErrCacheMiss. The value in
+// memcached must be an decimal number, or an error will be returned.
+// On underflow, the new value is capped at zero and does not wrap
+// around.
+func (c *Client) Decrement(key string, delta uint64) (newValue uint64, err error) {
+	return c.incrDecr("decr", key, delta)
+}
+
+func (c *Client) incrDecr(verb, key string, delta uint64) (uint64, error) {
+	var val uint64
+	err := c.withKeyRw(key, func(rw *bufio.ReadWriter) error {
+		line, err := writeReadLine(rw, "%s %s %d\r\n", verb, key, delta)
+		if err != nil {
+			return err
+		}
+		switch {
+		case bytes.Equal(line, resultNotFound):
+			return ErrCacheMiss
+		case bytes.HasPrefix(line, resultClientErrorPrefix):
+			errMsg := line[len(resultClientErrorPrefix) : len(line)-2]
+			return errors.New("memcache: client error: " + string(errMsg))
+		}
+		val, err = strconv.ParseUint(string(line[:len(line)-2]), 10, 64)
+		if err != nil {
+			return err
+		}
+		return nil
+	})
+	return val, err
+}
diff --git a/vendor/github.com/bradfitz/gomemcache/memcache/selector.go b/vendor/github.com/bradfitz/gomemcache/memcache/selector.go
new file mode 100644
index 0000000000..10b04d349f
--- /dev/null
+++ b/vendor/github.com/bradfitz/gomemcache/memcache/selector.go
@@ -0,0 +1,114 @@
+/*
+Copyright 2011 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package memcache
+
+import (
+	"hash/crc32"
+	"net"
+	"strings"
+	"sync"
+)
+
+// ServerSelector is the interface that selects a memcache server
+// as a function of the item's key.
+//
+// All ServerSelector implementations must be safe for concurrent use
+// by multiple goroutines.
+type ServerSelector interface {
+	// PickServer returns the server address that a given item
+	// should be shared onto.
+	PickServer(key string) (net.Addr, error)
+	Each(func(net.Addr) error) error
+}
+
+// ServerList is a simple ServerSelector. Its zero value is usable.
+type ServerList struct {
+	mu    sync.RWMutex
+	addrs []net.Addr
+}
+
+// SetServers changes a ServerList's set of servers at runtime and is
+// safe for concurrent use by multiple goroutines.
+//
+// Each server is given equal weight. A server is given more weight
+// if it's listed multiple times.
+//
+// SetServers returns an error if any of the server names fail to
+// resolve. No attempt is made to connect to the server. If any error
+// is returned, no changes are made to the ServerList.
+func (ss *ServerList) SetServers(servers ...string) error {
+	naddr := make([]net.Addr, len(servers))
+	for i, server := range servers {
+		if strings.Contains(server, "/") {
+			addr, err := net.ResolveUnixAddr("unix", server)
+			if err != nil {
+				return err
+			}
+			naddr[i] = addr
+		} else {
+			tcpaddr, err := net.ResolveTCPAddr("tcp", server)
+			if err != nil {
+				return err
+			}
+			naddr[i] = tcpaddr
+		}
+	}
+
+	ss.mu.Lock()
+	defer ss.mu.Unlock()
+	ss.addrs = naddr
+	return nil
+}
+
+// Each iterates over each server calling the given function
+func (ss *ServerList) Each(f func(net.Addr) error) error {
+	ss.mu.RLock()
+	defer ss.mu.RUnlock()
+	for _, a := range ss.addrs {
+		if err := f(a); nil != err {
+			return err
+		}
+	}
+	return nil
+}
+
+// keyBufPool returns []byte buffers for use by PickServer's call to
+// crc32.ChecksumIEEE to avoid allocations. (but doesn't avoid the
+// copies, which at least are bounded in size and small)
+var keyBufPool = sync.Pool{
+	New: func() interface{} {
+		b := make([]byte, 256)
+		return &b
+	},
+}
+
+func (ss *ServerList) PickServer(key string) (net.Addr, error) {
+	ss.mu.RLock()
+	defer ss.mu.RUnlock()
+	if len(ss.addrs) == 0 {
+		return nil, ErrNoServers
+	}
+	if len(ss.addrs) == 1 {
+		return ss.addrs[0], nil
+	}
+	bufp := keyBufPool.Get().(*[]byte)
+	n := copy(*bufp, key)
+	cs := crc32.ChecksumIEEE((*bufp)[:n])
+	keyBufPool.Put(bufp)
+
+	return ss.addrs[cs%uint32(len(ss.addrs))], nil
+}