[Feature] Add gzip compression support for rspamd controller

CMakeLists.txt

 	LIST(APPEND CMAKE_REQUIRED_LIBRARIES resolv)
 	LIST(APPEND CMAKE_REQUIRED_LIBRARIES nsl)
 	MESSAGE(STATUS "Configuring for Linux")
-	IF(ENABLE_STATIC MATCHES "ON")
-		LIST(APPEND CMAKE_REQUIRED_LIBRARIES z)
-	ENDIF()
 	IF(EXISTS "/etc/debian_version")
 		SET(LINUX_START_SCRIPT "rspamd_debian.in")
 	ELSE(EXISTS "/etc/debian_version")
 	ROOT ${OPENSSL_ROOT_DIR} MODULES openssl libssl)
 ProcessPackage(MAGIC LIBRARY magic INCLUDE magic.h INCLUDE_SUFFIXES include/libmagic
 	ROOT ${LIBMAGIC_ROOT_DIR} MODULES magic)
+ProcessPackage(LIBZ LIBRARY z INCLUDE zlib.h INCLUDE_SUFFIXES include/zlib
+		ROOT ${LIBZ_ROOT_DIR} MODULES z)
 
 IF(ENABLE_HYPERSCAN MATCHES "ON")
 	ProcessPackage(HYPERSCAN LIBRARY hs INCLUDE hs.h INCLUDE_SUFFIXES

src/libserver/worker_util.c

 #ifdef HAVE_LIBUTIL_H
 #include <libutil.h>
 #endif
+#include "zlib.h"
 
 static void rspamd_worker_ignore_signal (int signo);
 /**
 {
 	GList *cur;
 	struct event *events;
-	GHashTableIter it;
-	struct rspamd_worker_signal_handler *sigh;
-	gpointer k, v;
 	struct rspamd_map *map;
 
 	/* Remove all events */
 	}
 }
 
+static rspamd_fstring_t *
+rspamd_controller_maybe_compress (struct rspamd_http_connection_entry *entry,
+		rspamd_fstring_t *buf, struct rspamd_http_message *msg)
+{
+	z_stream strm;
+	gint rc;
+	rspamd_fstring_t *comp;
+	gchar *p;
+	gsize remain;
+
+	if (entry->support_gzip) {
+		memset (&strm, 0, sizeof (strm));
+		rc = deflateInit2 (&strm, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
+			MAX_WBITS + 16, MAX_MEM_LEVEL - 1, Z_DEFAULT_STRATEGY);
+
+		if (rc != Z_OK) {
+			return buf;
+		}
+
+		comp = rspamd_fstring_sized_new (MIN (buf->len, 32768));
+
+		strm.avail_in = buf->len;
+		strm.next_in = (guchar *)buf->str;
+		p = comp->str;
+		remain = comp->allocated;
+
+		while (strm.avail_in != 0) {
+			strm.avail_out = remain;
+			strm.next_out = p;
+
+			rc = deflate (&strm, Z_FINISH);
+
+			if (rc != Z_OK) {
+				if (rc == Z_STREAM_END) {
+					break;
+				}
+				else {
+					rspamd_fstring_free (comp);
+					deflateEnd (&strm);
+
+					return buf;
+				}
+			}
+
+			comp->len = strm.total_out;
+
+			if (strm.avail_out == 0 && strm.avail_in != 0) {
+				/* Need to allocate more */
+				remain = comp->len;
+				comp = rspamd_fstring_grow (comp, comp->allocated +
+						strm.avail_in + 10);
+				p = comp->str + remain;
+				remain = comp->allocated - remain;
+			}
+		}
+
+		deflateEnd (&strm);
+		comp->len = strm.total_out;
+		rspamd_fstring_free (buf); /* We replace buf with its compressed version */
+		rspamd_http_message_add_header (msg, "Content-Encoding", "gzip");
+
+		return comp;
+	}
+
+	return buf;
+}
+
 void
 rspamd_controller_send_error (struct rspamd_http_connection_entry *entry,
 	gint code, const gchar *error_msg, ...)
 	msg->code = code;
 	reply = rspamd_fstring_sized_new (msg->status->len + 16);
 	rspamd_printf_fstring (&reply, "{\"error\":\"%V\"}", msg->status);
-	rspamd_http_message_set_body_from_fstring_steal (msg, reply);
+	rspamd_http_message_set_body_from_fstring_steal (msg,
+			rspamd_controller_maybe_compress (entry, reply, msg));
 	rspamd_http_connection_reset (entry->conn);
 	rspamd_http_router_insert_headers (entry->rt, msg);
 	rspamd_http_connection_write_message (entry->conn,
 	msg->code = 200;
 	msg->status = rspamd_fstring_new_init ("OK", 2);
 	reply = rspamd_fstring_new_init (str, strlen (str));
-	rspamd_http_message_set_body_from_fstring_steal (msg, reply);
+	rspamd_http_message_set_body_from_fstring_steal (msg,
+			rspamd_controller_maybe_compress (entry, reply, msg));
 	rspamd_http_connection_reset (entry->conn);
 	rspamd_http_router_insert_headers (entry->rt, msg);
 	rspamd_http_connection_write_message (entry->conn,
 	msg->status = rspamd_fstring_new_init ("OK", 2);
 	reply = rspamd_fstring_sized_new (BUFSIZ);
 	rspamd_ucl_emit_fstring (obj, UCL_EMIT_JSON_COMPACT, &reply);
-	rspamd_http_message_set_body_from_fstring_steal (msg, reply);
+	rspamd_http_message_set_body_from_fstring_steal (msg,
+			rspamd_controller_maybe_compress (entry, reply, msg));
 	rspamd_http_connection_reset (entry->conn);
 	rspamd_http_router_insert_headers (entry->rt, msg);
 	rspamd_http_connection_write_message (entry->conn,

src/libutil/http.c

 
 	GError *err;
 	rspamd_ftok_t lookup;
+	const rspamd_ftok_t *encoding;
 	struct http_parser_url u;
 	guint i;
 	rspamd_regexp_t *re;
 
 		entry->is_reply = TRUE;
 
+		encoding = rspamd_http_message_find_header (msg, "Accept-Encoding");
+
+		if (encoding && rspamd_substring_search (encoding->begin, encoding->len,
+				"gzip", 4) != -1) {
+			entry->support_gzip = TRUE;
+		}
+
 		if (handler != NULL) {
 			return handler (entry, msg);
 		}

src/libutil/http.h

 	struct rspamd_http_connection *conn;
 	gpointer ud;
 	gboolean is_reply;
+	gboolean support_gzip;
 	struct rspamd_http_connection_entry *prev, *next;
 };