MXS-1266: saving GTID components into gtid_maps storage. part1

Saving GTID components into gtid_maps storage will allow to create a
hiearchical binlog cache dir.

Empty GTID  for master registration can be specified with SET
@@global.gtid_slave_pos = ‘’

server/modules/routing/binlogrouter/blr.h

@@ -546,24 +546,6 @@ typedef enum
     BLRM_XID_EVENT_SEEN        /*< Received XID event of current transaction */
 } master_transaction_t;
 
-/** Transaction Details */
-typedef struct pending_transaction
-{
-    char gtid[GTID_MAX_LEN + 1];   /** MariaDB 10.x GTID */
-    master_transaction_t state;    /** Transaction state */
-    uint64_t start_pos;            /** The BEGIN pos */
-    uint64_t end_pos;              /** The next_pos in COMMIT event*/
-} PENDING_TRANSACTION;
-
-/** MariaDB GTID info */
-typedef struct mariadb_gtid_info
-{
-    char *gtid;        /** MariaDB 10.x GTID */
-    char *file;        /** The binlog file */
-    uint64_t start;    /** The BEGIN pos */
-    uint64_t end;      /** The next_pos in COMMIT event*/
-} MARIADB_GTID_INFO;
-
 /** MariaDB GTID elements */
 typedef struct mariadb_gtid_elems
 {
@@ -572,6 +554,25 @@ typedef struct mariadb_gtid_elems
     uint64_t seq_no;      /*< The sequence number */
 } MARIADB_GTID_ELEMS;
 
+/** Transaction Details */
+typedef struct pending_transaction
+{
+    char gtid[GTID_MAX_LEN + 1];     /** MariaDB 10.x GTID */
+    master_transaction_t state;      /** Transaction state */
+    uint64_t start_pos;              /** The BEGIN pos */
+    uint64_t end_pos;                /** The next_pos in COMMIT event*/
+    MARIADB_GTID_ELEMS gtid_elms;    /* MariaDB 10.x GTID components */
+} PENDING_TRANSACTION;
+
+/** MariaDB GTID info */
+typedef struct mariadb_gtid_info
+{
+    char *gtid;        /** MariaDB 10.x GTID, string value */
+    char *file;        /** The binlog file */
+    uint64_t start;    /** The BEGIN pos: i.e the GTID event */
+    uint64_t end;      /** The next_pos in COMMIT event*/
+} MARIADB_GTID_INFO;
+
 /**
  * The per instance data for the router.
  */