Changes related to canonical query format implementation.

query_classifier.cc: Now query can be parsed outside query_classifier_get_type by calling function parse_query. It creates parsing_info_t struct which is then added to the GWBUF which also includes the query. Parsing information follows the buffered query and it is freed at the same time with query buffer, in gwbuf_free.
buffer.c: additions of parsing information to gwbuf struct.
modutil.c: added function which returns query from GWBUF in plain text string.
readwritesplit.c:routeQuery now only calls query_classifier_get_type to get the query type instead of extracting plain text query from the GWBUF buffer.

server/core/modutil.c

@@ -29,6 +29,7 @@
  */
 #include <buffer.h>
 #include <string.h>
+#include <mysql_client_server_protocol.h>
 
 /**
  * Check if a GWBUF structure is a MySQL COM_QUERY packet
@@ -171,3 +172,57 @@ GWBUF	*addition;
 
 	return orig;
 }
+
+/**
+ * Copy query string from GWBUF buffer to separate memory area.
+ * 
+ * @param buf   GWBUF buffer including the query
+ * 
+ * @return Plaint text query if the packet type is COM_QUERY. Otherwise return 
+ * a string including the packet type.
+ */
+char* modutil_get_query(
+        GWBUF* buf)
+{
+        uint8_t*           packet;
+        mysql_server_cmd_t packet_type;
+        size_t             len;
+        char*              query_str;
+        
+        packet = GWBUF_DATA(buf);
+        packet_type = packet[4];
+        
+        switch (packet_type) {
+                case MYSQL_COM_QUIT:
+                        len = strlen("[Quit msg]")+1;
+                        if ((query_str = (char *)malloc(len+1)) == NULL)
+                        {
+                                goto retblock;
+                        }
+                        memcpy(query_str, "[Quit msg]", len);
+                        memset(&query_str[len], 0, 1);
+                        break;
+                        
+                case MYSQL_COM_QUERY:
+                        len = MYSQL_GET_PACKET_LEN(packet)-1; /*< distract 1 for packet type byte */        
+                        if ((query_str = (char *)malloc(len+1)) == NULL)
+                        {
+                                goto retblock;
+                        }
+                        memcpy(query_str, &packet[5], len);
+                        memset(&query_str[len], 0, 1);
+                        break;
+                        
+                default:
+                        len = strlen(STRPACKETTYPE(packet_type))+1;
+                        if ((query_str = (char *)malloc(len+1)) == NULL)
+                        {
+                                goto retblock;
+                        }
+                        memcpy(query_str, STRPACKETTYPE(packet_type), len);
+                        memset(&query_str[len], 0, 1);
+                        break;
+        } /*< switch */
+retblock:
+        return query_str;
+}