Add cache invalidation callback hooks.

This commit is contained in:
Tom Lane 2002-04-29 22:14:34 +00:00
parent 8d615763da
commit 88ef7067f7
2 changed files with 109 additions and 5 deletions

View File

@ -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;
}

View File

@ -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 */