bring xact events back

Author: kelvich

src/backend/access/transam/twophase.c

@@ -1510,6 +1510,12 @@ FinishPreparedTransaction(const char *gid, bool isCommit)
 	LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
 	RemoveGXact(gxact);
 	LWLockRelease(TwoPhaseStateLock);
+
+	if (isCommit)
+		CallXactCallbacks(XACT_EVENT_COMMIT_PREPARED);
+	else
+		CallXactCallbacks(XACT_EVENT_ABORT_PREPARED);
+
 	MyLockedGxact = NULL;
 
 	pfree(buf);
@@ -2408,3 +2414,13 @@ PrepareRedoRemove(TransactionId xid, bool giveWarning)
 
 	return;
 }
+
+
+/*
+ * Return identified of current global transaction
+ */
+const char*
+GetLockedGlobalTransactionId(void)
+{
+	return MyLockedGxact ? MyLockedGxact->gid : NULL;
+}

src/backend/access/transam/xact.c

@@ -306,7 +306,6 @@ static void AtCommit_Memory(void);
 static void AtStart_Cache(void);
 static void AtStart_Memory(void);
 static void AtStart_ResourceOwner(void);
-static void CallXactCallbacks(XactEvent event);
 static void CallSubXactCallbacks(SubXactEvent event,
 					 SubTransactionId mySubid,
 					 SubTransactionId parentSubid);
@@ -1922,6 +1921,7 @@ StartTransaction(void)
 	 */
 	s->state = TRANS_INPROGRESS;
 
+	CallXactCallbacks(XACT_EVENT_START);
 	ShowTransactionState("StartTransaction");
 }
 
@@ -3335,7 +3335,7 @@ UnregisterXactCallback(XactCallback callback, void *arg)
 	}
 }
 
-static void
+void
 CallXactCallbacks(XactEvent event)
 {
 	XactCallbackItem *item;

src/include/access/twophase.h

@@ -57,4 +57,7 @@ extern void PrepareRedoAdd(char *buf, XLogRecPtr start_lsn,
 			   XLogRecPtr end_lsn);
 extern void PrepareRedoRemove(TransactionId xid, bool giveWarning);
 extern void restoreTwoPhaseData(void);
+
+extern const char *GetLockedGlobalTransactionId(void);
+
 #endif							/* TWOPHASE_H */

src/include/access/xact.h

@@ -97,14 +97,17 @@ extern int	MyXactFlags;
  */
 typedef enum
 {
+	XACT_EVENT_START,
 	XACT_EVENT_COMMIT,
 	XACT_EVENT_PARALLEL_COMMIT,
 	XACT_EVENT_ABORT,
 	XACT_EVENT_PARALLEL_ABORT,
 	XACT_EVENT_PREPARE,
 	XACT_EVENT_PRE_COMMIT,
 	XACT_EVENT_PARALLEL_PRE_COMMIT,
-	XACT_EVENT_PRE_PREPARE
+	XACT_EVENT_PRE_PREPARE,
+	XACT_EVENT_COMMIT_PREPARED,
+	XACT_EVENT_ABORT_PREPARED
 } XactEvent;
 
 typedef void (*XactCallback) (XactEvent event, void *arg);
@@ -405,5 +408,6 @@ extern void ParseAbortRecord(uint8 info, xl_xact_abort *xlrec, xl_xact_parsed_ab
 extern void EnterParallelMode(void);
 extern void ExitParallelMode(void);
 extern bool IsInParallelMode(void);
+extern void CallXactCallbacks(XactEvent event);
 
 #endif							/* XACT_H */