From 88ef7067f7e74a80f83accac8afc49bed4b6268b Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 29 Apr 2002 22:14:34 +0000
Subject: [PATCH] Add cache invalidation callback hooks.
---
src/backend/utils/cache/inval.c | 102 ++++++++++++++++++++++++++++++--
src/include/utils/inval.h | 12 +++-
2 files changed, 109 insertions(+), 5 deletions(-)
diff --git a/src/backend/utils/cache/inval.c b/src/backend/utils/cache/inval.c
index 483c06bd6ac..f572f0864e1 100644
--- a/src/backend/utils/cache/inval.c
+++ b/src/backend/utils/cache/inval.c
@@ -74,7 +74,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/cache/inval.c,v 1.50 2002/04/12 20:38:28 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/cache/inval.c,v 1.51 2002/04/29 22:14:34 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -109,8 +109,7 @@ typedef struct InvalidationListHeader
InvalidationChunk *rclist; /* list of chunks holding relcache msgs */
} InvalidationListHeader;
-/*
- * ----------------
+/*----------------
* Invalidation info is divided into two lists:
* 1) events so far in current command, not yet reflected to caches.
* 2) events in previous commands of current transaction; these have
@@ -121,7 +120,7 @@ typedef struct InvalidationListHeader
* The relcache-file-invalidated flag can just be a simple boolean,
* since we only act on it at transaction commit; we don't care which
* command of the transaction set it.
- * ----------------
+ *----------------
*/
/* head of current-command event list */
@@ -132,6 +131,22 @@ static InvalidationListHeader PriorCmdInvalidMsgs;
static bool RelcacheInitFileInval; /* init file must be invalidated? */
+/*
+ * Dynamically-registered callback functions. Current implementation
+ * assumes there won't be very many of these at once; could improve if needed.
+ */
+
+#define MAX_CACHE_CALLBACKS 20
+
+static struct CACHECALLBACK
+{
+ int16 id; /* cache number or SHAREDINVALRELCACHE_ID */
+ CacheCallbackFunction function;
+ Datum arg;
+} cache_callback_list[MAX_CACHE_CALLBACKS];
+
+static int cache_callback_count = 0;
+
/* ----------------------------------------------------------------
* Invalidation list support functions
@@ -398,17 +413,39 @@ RegisterRelcacheInvalidation(Oid dbId, Oid relId)
static void
LocalExecuteInvalidationMessage(SharedInvalidationMessage *msg)
{
+ int i;
+
if (msg->id >= 0)
{
if (msg->cc.dbId == MyDatabaseId || msg->cc.dbId == 0)
+ {
CatalogCacheIdInvalidate(msg->cc.id,
msg->cc.hashValue,
&msg->cc.tuplePtr);
+
+ for (i = 0; i < cache_callback_count; i++)
+ {
+ struct CACHECALLBACK *ccitem = cache_callback_list + i;
+
+ if (ccitem->id == msg->cc.id)
+ (*ccitem->function) (ccitem->arg, InvalidOid);
+ }
+ }
}
else if (msg->id == SHAREDINVALRELCACHE_ID)
{
if (msg->rc.dbId == MyDatabaseId || msg->rc.dbId == 0)
+ {
RelationIdInvalidateRelationCacheByRelationId(msg->rc.relId);
+
+ for (i = 0; i < cache_callback_count; i++)
+ {
+ struct CACHECALLBACK *ccitem = cache_callback_list + i;
+
+ if (ccitem->id == SHAREDINVALRELCACHE_ID)
+ (*ccitem->function) (ccitem->arg, msg->rc.relId);
+ }
+ }
}
else
{
@@ -431,8 +468,17 @@ LocalExecuteInvalidationMessage(SharedInvalidationMessage *msg)
static void
InvalidateSystemCaches(void)
{
+ int i;
+
ResetCatalogCaches();
RelationCacheInvalidate();
+
+ for (i = 0; i < cache_callback_count; i++)
+ {
+ struct CACHECALLBACK *ccitem = cache_callback_list + i;
+
+ (*ccitem->function) (ccitem->arg, InvalidOid);
+ }
}
/*
@@ -640,3 +686,51 @@ CacheInvalidateRelcache(Oid relationId)
/* See KLUGE ALERT in PrepareForTupleInvalidation */
RegisterRelcacheInvalidation(MyDatabaseId, relationId);
}
+
+/*
+ * CacheRegisterSyscacheCallback
+ * Register the specified function to be called for all future
+ * invalidation events in the specified cache.
+ *
+ * NOTE: currently, the OID argument to the callback routine is not
+ * provided for syscache callbacks; the routine doesn't really get any
+ * useful info as to exactly what changed. It should treat every call
+ * as a "cache flush" request.
+ */
+void
+CacheRegisterSyscacheCallback(int cacheid,
+ CacheCallbackFunction func,
+ Datum arg)
+{
+ if (cache_callback_count >= MAX_CACHE_CALLBACKS)
+ elog(FATAL, "Out of cache_callback_list slots");
+
+ cache_callback_list[cache_callback_count].id = cacheid;
+ cache_callback_list[cache_callback_count].function = func;
+ cache_callback_list[cache_callback_count].arg = arg;
+
+ ++cache_callback_count;
+}
+
+/*
+ * CacheRegisterRelcacheCallback
+ * Register the specified function to be called for all future
+ * relcache invalidation events. The OID of the relation being
+ * invalidated will be passed to the function.
+ *
+ * NOTE: InvalidOid will be passed if a cache reset request is received.
+ * In this case the called routines should flush all cached state.
+ */
+void
+CacheRegisterRelcacheCallback(CacheCallbackFunction func,
+ Datum arg)
+{
+ if (cache_callback_count >= MAX_CACHE_CALLBACKS)
+ elog(FATAL, "Out of cache_callback_list slots");
+
+ cache_callback_list[cache_callback_count].id = SHAREDINVALRELCACHE_ID;
+ cache_callback_list[cache_callback_count].function = func;
+ cache_callback_list[cache_callback_count].arg = arg;
+
+ ++cache_callback_count;
+}
diff --git a/src/include/utils/inval.h b/src/include/utils/inval.h
index d2286ed54ef..2d5153ef1d0 100644
--- a/src/include/utils/inval.h
+++ b/src/include/utils/inval.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: inval.h,v 1.24 2002/03/03 17:47:56 tgl Exp $
+ * $Id: inval.h,v 1.25 2002/04/29 22:14:34 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -17,6 +17,9 @@
#include "access/htup.h"
+typedef void (*CacheCallbackFunction) (Datum arg, Oid relid);
+
+
extern void AcceptInvalidationMessages(void);
extern void AtEOXactInvalidationMessages(bool isCommit);
@@ -27,4 +30,11 @@ extern void CacheInvalidateHeapTuple(Relation relation, HeapTuple tuple);
extern void CacheInvalidateRelcache(Oid relationId);
+extern void CacheRegisterSyscacheCallback(int cacheid,
+ CacheCallbackFunction func,
+ Datum arg);
+
+extern void CacheRegisterRelcacheCallback(CacheCallbackFunction func,
+ Datum arg);
+
#endif /* INVAL_H */
--
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