ProcessUtility_hook:

Add ProcessUtility_hook() to handle all DDL to contrib/pg_stat_statements.

Itagaki Takahiro

2 files changed, 32 insertions, 2 deletions

diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 42071bfb6c1..67333b1796a 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.318 2009/11/20 20:38:11 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.319 2009/12/01 01:08:46 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -58,6 +58,9 @@
 #include "utils/syscache.h"
 
 
+/* Hooks for plugins to get control in ProcessUtility() */
+ProcessUtility_hook_type ProcessUtility_hook = NULL;
+
 /*
  * Verify user has ownership of specified relation, else ereport.
  *
@@ -244,6 +247,10 @@ check_xact_readonly(Node *parsetree)
  * completionTag is only set nonempty if we want to return a nondefault status.
  *
  * completionTag may be NULL if caller doesn't want a status string.
+ *
+ * We provide a function hook variable that lets loadable plugins
+ * get control when ProcessUtility is called.  Such a plugin would
+ * normally call standard_ProcessUtility().
  */
 void
 ProcessUtility(Node *parsetree,
@@ -260,6 +267,20 @@ ProcessUtility(Node *parsetree,
 	if (completionTag)
 		completionTag[0] = '\0';
 
+	if (ProcessUtility_hook)
+		(*ProcessUtility_hook) (parsetree, queryString, params, isTopLevel, dest, completionTag);
+	else
+		standard_ProcessUtility(parsetree, queryString, params, isTopLevel, dest, completionTag);
+}
+
+void
+standard_ProcessUtility(Node *parsetree,
+			   const char *queryString,
+			   ParamListInfo params,
+			   bool isTopLevel,
+			   DestReceiver *dest,
+			   char *completionTag)
+{
 	switch (nodeTag(parsetree))
 	{
 			/*
diff --git a/src/include/tcop/utility.h b/src/include/tcop/utility.h
index d609b0ac4e9..ce3ee1fb055 100644
--- a/src/include/tcop/utility.h
+++ b/src/include/tcop/utility.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/tcop/utility.h,v 1.35 2009/01/01 17:24:01 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/tcop/utility.h,v 1.36 2009/12/01 01:08:46 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,9 +17,18 @@
 #include "tcop/tcopprot.h"
 
 
+/* Hook for plugins to get control in ProcessUtility() */
+typedef void (*ProcessUtility_hook_type) (Node *parsetree,
+			   const char *queryString, ParamListInfo params, bool isTopLevel,
+			   DestReceiver *dest, char *completionTag);
+extern PGDLLIMPORT ProcessUtility_hook_type ProcessUtility_hook;
+
 extern void ProcessUtility(Node *parsetree, const char *queryString,
 			   ParamListInfo params, bool isTopLevel,
 			   DestReceiver *dest, char *completionTag);
+extern void standard_ProcessUtility(Node *parsetree, const char *queryString,
+			   ParamListInfo params, bool isTopLevel,
+			   DestReceiver *dest, char *completionTag);
 
 extern bool UtilityReturnsTuples(Node *parsetree);