Use a private memory context to store rule information in each relcache
authorTom Lane
Fri, 30 Jun 2000 07:04:23 +0000 (07:04 +0000)
committerTom Lane
Fri, 30 Jun 2000 07:04:23 +0000 (07:04 +0000)
entry that has rules.  This allows us to release the rule parsetrees
on relcache flush without needing a working freeObject() routine.
Formerly, the rule trees were leaked permanently at relcache flush.
Also, clean up handling of rule creation and deletion --- there was
not sufficient locking of the relation being modified, and there was
no reliable notification of other backends that a relcache reload
was needed.  Also, clean up relcache.c code so that scans of system
tables needed to load a relcache entry are done in the caller's
memory context, not in CacheMemoryContext.  This prevents any
un-pfreed memory from those scans from becoming a permanent memory
leak.

src/backend/catalog/index.c
src/backend/commands/trigger.c
src/backend/rewrite/rewriteDefine.c
src/backend/rewrite/rewriteHandler.c
src/backend/rewrite/rewriteRemove.c
src/backend/rewrite/rewriteSupport.c
src/backend/utils/cache/relcache.c
src/include/catalog/index.h
src/include/rewrite/rewriteSupport.h
src/include/utils/rel.h

index c73761899682d8d977fc2ebcb283bece1295cfe7..2c5ff64daba9d9d658d0cbeb56ed95d3e2ed399d 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.120 2000/06/28 03:31:23 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.121 2000/06/30 07:04:17 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -369,16 +369,21 @@ ConstructTupleDescriptor(Oid heapoid,
 
 /* ----------------------------------------------------------------
  * AccessMethodObjectIdGetForm
- *     Returns the formated access method tuple given its object identifier.
+ *     Returns an access method tuple given its object identifier,
+ *     or NULL if no such AM tuple can be found.
  *
- * XXX ADD INDEXING
+ * Scanning is done using CurrentMemoryContext as working storage,
+ * but the returned tuple will be allocated in resultCxt (which is
+ * typically CacheMemoryContext).
  *
- * Note:
- *     Assumes object identifier is valid.
+ * There was a note here about adding indexing, but I don't see a need
+ * for it.  There are so few tuples in pg_am that an indexscan would
+ * surely be slower.
  * ----------------------------------------------------------------
  */
 Form_pg_am
-AccessMethodObjectIdGetForm(Oid accessMethodObjectId)
+AccessMethodObjectIdGetForm(Oid accessMethodObjectId,
+                           MemoryContext resultCxt)
 {
    Relation    pg_am_desc;
    HeapScanDesc pg_am_scan;
@@ -415,10 +420,10 @@ AccessMethodObjectIdGetForm(Oid accessMethodObjectId)
    }
 
    /* ----------------
-    *  if found am tuple, then copy the form and return the copy
+    *  if found AM tuple, then copy it into resultCxt and return the copy
     * ----------------
     */
-   aform = (Form_pg_am) palloc(sizeof *aform);
+   aform = (Form_pg_am) MemoryContextAlloc(resultCxt, sizeof *aform);
    memcpy(aform, GETSTRUCT(pg_am_tuple), sizeof *aform);
 
    heap_endscan(pg_am_scan);
@@ -434,22 +439,8 @@ AccessMethodObjectIdGetForm(Oid accessMethodObjectId)
 static void
 ConstructIndexReldesc(Relation indexRelation, Oid amoid)
 {
-   MemoryContext oldcxt;
-
-   /* ----------------
-    *    here we make certain to allocate the access method
-    *    tuple within the cache context lest it vanish when the
-    *    context changes
-    * ----------------
-    */
-   if (!CacheMemoryContext)
-       CreateCacheMemoryContext();
-
-   oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
-
-   indexRelation->rd_am = AccessMethodObjectIdGetForm(amoid);
-
-   MemoryContextSwitchTo(oldcxt);
+   indexRelation->rd_am = AccessMethodObjectIdGetForm(amoid,
+                                                      CacheMemoryContext);
 
    /* ----------------
     *   XXX missing the initialization of some other fields
index fbb5a694b88572763c9176bb8c394f3fa47b8269..075f3a508b5520143ad4d9031dfa773b4e59ba48 100644 (file)
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.70 2000/06/28 03:31:28 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/commands/trigger.c,v 1.71 2000/06/30 07:04:17 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -431,10 +431,17 @@ RelationRemoveTriggers(Relation rel)
    heap_close(tgrel, RowExclusiveLock);
 }
 
+/*
+ * Build trigger data to attach to the given relcache entry.
+ *
+ * Note that trigger data must be allocated in CacheMemoryContext
+ * to ensure it survives as long as the relcache entry.  But we
+ * are probably running in a less long-lived working context.
+ */
 void
 RelationBuildTriggers(Relation relation)
 {
-   TriggerDesc *trigdesc = (TriggerDesc *) palloc(sizeof(TriggerDesc));
+   TriggerDesc *trigdesc;
    int         ntrigs = relation->rd_rel->reltriggers;
    Trigger    *triggers = NULL;
    Trigger    *build;
@@ -453,6 +460,8 @@ RelationBuildTriggers(Relation relation)
    int         found;
    bool        hasindex;
 
+   trigdesc = (TriggerDesc *) MemoryContextAlloc(CacheMemoryContext,
+                                                 sizeof(TriggerDesc));
    MemSet(trigdesc, 0, sizeof(TriggerDesc));
 
    ScanKeyEntryInitialize(&skey,
@@ -499,13 +508,16 @@ RelationBuildTriggers(Relation relation)
        pg_trigger = (Form_pg_trigger) GETSTRUCT(htup);
 
        if (triggers == NULL)
-           triggers = (Trigger *) palloc(sizeof(Trigger));
+           triggers = (Trigger *) MemoryContextAlloc(CacheMemoryContext,
+                                                     sizeof(Trigger));
        else
-           triggers = (Trigger *) repalloc(triggers, (found + 1) * sizeof(Trigger));
+           triggers = (Trigger *) repalloc(triggers,
+                                           (found + 1) * sizeof(Trigger));
        build = &(triggers[found]);
 
        build->tgoid = htup->t_data->t_oid;
-       build->tgname = nameout(&pg_trigger->tgname);
+       build->tgname = MemoryContextStrdup(CacheMemoryContext,
+                                           nameout(&pg_trigger->tgname));
        build->tgfoid = pg_trigger->tgfoid;
        build->tgfunc.fn_oid = InvalidOid; /* mark FmgrInfo as uninitialized */
        build->tgtype = pg_trigger->tgtype;
@@ -514,7 +526,8 @@ RelationBuildTriggers(Relation relation)
        build->tgdeferrable = pg_trigger->tgdeferrable;
        build->tginitdeferred = pg_trigger->tginitdeferred;
        build->tgnargs = pg_trigger->tgnargs;
-       memcpy(build->tgattr, &(pg_trigger->tgattr), FUNC_MAX_ARGS * sizeof(int16));
+       memcpy(build->tgattr, &(pg_trigger->tgattr),
+              FUNC_MAX_ARGS * sizeof(int16));
        val = (struct varlena *) fastgetattr(htup,
                                             Anum_pg_trigger_tgargs,
                                             tgrel->rd_att, &isnull);
@@ -533,10 +546,13 @@ RelationBuildTriggers(Relation relation)
                elog(ERROR, "RelationBuildTriggers: tgargs IS NULL for rel %s",
                     RelationGetRelationName(relation));
            p = (char *) VARDATA(val);
-           build->tgargs = (char **) palloc(build->tgnargs * sizeof(char *));
+           build->tgargs = (char **)
+               MemoryContextAlloc(CacheMemoryContext,
+                                  build->tgnargs * sizeof(char *));
            for (i = 0; i < build->tgnargs; i++)
            {
-               build->tgargs[i] = pstrdup(p);
+               build->tgargs[i] = MemoryContextStrdup(CacheMemoryContext,
+                                                      p);
                p += strlen(p) + 1;
            }
        }
@@ -611,7 +627,8 @@ DescribeTrigger(TriggerDesc *trigdesc, Trigger *trigger)
    {
        tp = &(t[TRIGGER_EVENT_INSERT]);
        if (*tp == NULL)
-           *tp = (Trigger **) palloc(sizeof(Trigger *));
+           *tp = (Trigger **) MemoryContextAlloc(CacheMemoryContext,
+                                                 sizeof(Trigger *));
        else
            *tp = (Trigger **) repalloc(*tp, (n[TRIGGER_EVENT_INSERT] + 1) *
                                        sizeof(Trigger *));
@@ -623,7 +640,8 @@ DescribeTrigger(TriggerDesc *trigdesc, Trigger *trigger)
    {
        tp = &(t[TRIGGER_EVENT_DELETE]);
        if (*tp == NULL)
-           *tp = (Trigger **) palloc(sizeof(Trigger *));
+           *tp = (Trigger **) MemoryContextAlloc(CacheMemoryContext,
+                                                 sizeof(Trigger *));
        else
            *tp = (Trigger **) repalloc(*tp, (n[TRIGGER_EVENT_DELETE] + 1) *
                                        sizeof(Trigger *));
@@ -635,7 +653,8 @@ DescribeTrigger(TriggerDesc *trigdesc, Trigger *trigger)
    {
        tp = &(t[TRIGGER_EVENT_UPDATE]);
        if (*tp == NULL)
-           *tp = (Trigger **) palloc(sizeof(Trigger *));
+           *tp = (Trigger **) MemoryContextAlloc(CacheMemoryContext,
+                                                 sizeof(Trigger *));
        else
            *tp = (Trigger **) repalloc(*tp, (n[TRIGGER_EVENT_UPDATE] + 1) *
                                        sizeof(Trigger *));
@@ -1023,10 +1042,9 @@ ltrmark:;
 
 /* ----------
  * Internal data to the deferred trigger mechanism is held
- * during entire session in a global memor created at startup and
- * over statements/commands in a separate global memory which
- * is created at transaction start and destroyed at transaction
- * end.
+ * during entire session in a global context created at startup and
+ * over statements/commands in a separate context which
+ * is created at transaction start and destroyed at transaction end.
  * ----------
  */
 static MemoryContext deftrig_gcxt = NULL;
index 08351fe66969fc03ed9751270e679c74381248af..d92190f652419a060afddf75c95b09a14a39841c 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.47 2000/06/28 03:31:56 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.48 2000/06/30 07:04:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
  * InsertRule -
  *   takes the arguments and inserts them as attributes into the system
  *   relation "pg_rewrite"
- *
- *     ARGS :  rulname         -       name of the rule
- *             evtype          -       one of RETRIEVE,REPLACE,DELETE,APPEND
- *             evobj           -       name of relation
- *             evslot          -       comma delimited list of slots
- *                                     if null => multi-attr rule
- *             evinstead       -       is an instead rule
- *             actiontree      -       parsetree(s) of rule action
  */
 static Oid
 InsertRule(char *rulname,
           int evtype,
-          char *evobj,
-          char *evslot,
-          char *evqual,
+          Oid eventrel_oid,
+          AttrNumber evslot_index,
           bool evinstead,
+          char *evqual,
           char *actiontree)
 {
-   Relation    eventrel;
-   Oid         eventrel_oid;
-   AttrNumber  evslot_index;
    int         i;
    Datum       values[Natts_pg_rewrite];
    char        nulls[Natts_pg_rewrite];
@@ -59,21 +48,6 @@ InsertRule(char *rulname,
    HeapTuple   tup;
    Oid         rewriteObjectId;
 
-   eventrel = heap_openr(evobj, AccessShareLock);
-   eventrel_oid = RelationGetRelid(eventrel);
-
-   /*
-    * if the slotname is null, we know that this is a multi-attr rule
-    */
-   if (evslot == NULL)
-       evslot_index = -1;
-   else
-       evslot_index = attnameAttNum(eventrel, evslot);
-   heap_close(eventrel, AccessShareLock);
-
-   if (evqual == NULL)
-       evqual = "<>";
-
    if (IsDefinedRewriteRule(rulname))
        elog(ERROR, "Attempt to insert rule '%s' failed: already exists",
             rulname);
@@ -177,17 +151,27 @@ DefineQueryRewrite(RuleStmt *stmt)
    Node       *event_qual = stmt->whereClause;
    bool        is_instead = stmt->instead;
    List       *action = stmt->actions;
-   Relation    event_relation = NULL;
+   Relation    event_relation;
+   Oid         ev_relid;
    Oid         ruleId;
-   Oid         ev_relid = 0;
    char       *eslot_string = NULL;
-   int         event_attno = 0;
-   Oid         event_attype = 0;
+   int         event_attno;
+   Oid         event_attype;
    char       *actionP,
               *event_qualP;
    List       *l;
    Query      *query;
 
+   /*
+    * If we are installing an ON SELECT rule, we had better grab
+    * AccessExclusiveLock to ensure no SELECTs are currently running on
+    * the event relation.  For other types of rules, it might be sufficient
+    * to grab ShareLock to lock out insert/update/delete actions.  But
+    * for now, let's just grab AccessExclusiveLock all the time.
+    */
+   event_relation = heap_openr(event_obj->relname, AccessExclusiveLock);
+   ev_relid = RelationGetRelid(event_relation);
+
    /* ----------
     * The current rewrite handler is known to work on relation level
     * rules only. And for SELECT events, it expects one non-nothing
@@ -209,19 +193,18 @@ DefineQueryRewrite(RuleStmt *stmt)
    /*
     * No rule actions that modify OLD or NEW
     */
-   if (action != NIL)
-       foreach(l, action)
+   foreach(l, action)
    {
        query = (Query *) lfirst(l);
        if (query->resultRelation == 1)
        {
-           elog(NOTICE, "rule actions on OLD currently not supported");
-           elog(ERROR, " use views or triggers instead");
+           elog(ERROR, "rule actions on OLD currently not supported"
+                "\n\tuse views or triggers instead");
        }
        if (query->resultRelation == 2)
        {
-           elog(NOTICE, "rule actions on NEW currently not supported");
-           elog(ERROR, " use triggers instead");
+           elog(ERROR, "rule actions on NEW currently not supported"
+                "\n\tuse triggers instead");
        }
    }
 
@@ -242,8 +225,8 @@ DefineQueryRewrite(RuleStmt *stmt)
         */
        if (length(action) == 0)
        {
-           elog(NOTICE, "instead nothing rules on select currently not supported");
-           elog(ERROR, " use views instead");
+           elog(ERROR, "instead nothing rules on select currently not supported"
+                "\n\tuse views instead");
        }
 
        /*
@@ -265,8 +248,6 @@ DefineQueryRewrite(RuleStmt *stmt)
         * ... the targetlist of the SELECT action must exactly match the
         * event relation, ...
         */
-       event_relation = heap_openr(event_obj->relname, AccessShareLock);
-
        if (event_relation->rd_att->natts != length(query->targetList))
            elog(ERROR, "select rules target list must match event relations structure");
 
@@ -275,7 +256,7 @@ DefineQueryRewrite(RuleStmt *stmt)
            tle = (TargetEntry *) nth(i - 1, query->targetList);
            resdom = tle->resdom;
            attr = event_relation->rd_att->attrs[i - 1];
-           attname = pstrdup(NameStr(attr->attname));
+           attname = NameStr(attr->attname);
 
            if (strcmp(resdom->resname, attname) != 0)
                elog(ERROR, "select rules target entry %d has different column name from %s", i, attname);
@@ -303,8 +284,6 @@ DefineQueryRewrite(RuleStmt *stmt)
            }
        }
 
-       heap_close(event_relation, AccessShareLock);
-
        /*
         * LIMIT in view is not supported
         */
@@ -337,62 +316,46 @@ DefineQueryRewrite(RuleStmt *stmt)
    /*
     * This rule is allowed - install it.
     */
-
-   event_relation = heap_openr(event_obj->relname, AccessShareLock);
-   ev_relid = RelationGetRelid(event_relation);
-
    if (eslot_string == NULL)
    {
        event_attno = -1;
-       event_attype = -1;      /* XXX - don't care */
+       event_attype = InvalidOid;
    }
    else
    {
        event_attno = attnameAttNum(event_relation, eslot_string);
        event_attype = attnumTypeId(event_relation, event_attno);
    }
-   heap_close(event_relation, AccessShareLock);
 
    /* fix bug about instead nothing */
    ValidateRule(event_type, event_obj->relname,
                 eslot_string, event_qual, &action,
                 is_instead, event_attype);
 
-   if (action == NULL)
-   {
-       if (!is_instead)
-           return;             /* doesn't do anything */
-
-       event_qualP = nodeToString(event_qual);
-
-       ruleId = InsertRule(stmt->rulename,
-                           event_type,
-                           event_obj->relname,
-                           eslot_string,
-                           event_qualP,
-                           true,
-                           "<>");
-       prs2_addToRelation(ev_relid, ruleId, event_type, event_attno, TRUE,
-                          event_qual, NIL);
-
-   }
-   else
+   /* discard rule if it's null action and not INSTEAD; it's a no-op */
+   if (action != NULL || is_instead)
    {
        event_qualP = nodeToString(event_qual);
        actionP = nodeToString(action);
 
        ruleId = InsertRule(stmt->rulename,
                            event_type,
-                           event_obj->relname,
-                           eslot_string,
-                           event_qualP,
+                           ev_relid,
+                           event_attno,
                            is_instead,
+                           event_qualP,
                            actionP);
 
-       /* what is the max size of type text? XXX -- glass */
-       if (length(action) > 15)
-           elog(ERROR, "max # of actions exceeded");
-       prs2_addToRelation(ev_relid, ruleId, event_type, event_attno,
-                          is_instead, event_qual, action);
+       /*
+        * Set pg_class 'relhasrules' field TRUE for event relation.
+        *
+        * Important side effect: an SI notice is broadcast to force all
+        * backends (including me!) to update relcache entries with the new
+        * rule.
+        */
+       setRelhasrulesInRelation(ev_relid, true);
    }
+
+   /* Close rel, but keep lock till commit... */
+   heap_close(event_relation, NoLock);
 }
index 255190ebf529ce5ce01255e6fd9190f2324a0107..acd62c9c70e9082065b795b5c11418a5e9d2c455 100644 (file)
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.76 2000/06/15 03:32:22 momjian Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.77 2000/06/30 07:04:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1332,11 +1332,11 @@ RewriteQuery(Query *parsetree, bool *instead_flag, List **qual_products)
    rt_entry = rt_fetch(result_relation, parsetree->rtable);
    rt_entry_relation = heap_openr(rt_entry->relname, AccessShareLock);
    rt_entry_locks = rt_entry_relation->rd_rules;
-   heap_close(rt_entry_relation, AccessShareLock);
 
    if (rt_entry_locks != NULL)
    {
-       List       *locks = matchLocks(event, rt_entry_locks, result_relation, parsetree);
+       List       *locks = matchLocks(event, rt_entry_locks,
+                                      result_relation, parsetree);
 
        product_queries = fireRules(parsetree,
                                    result_relation,
@@ -1346,13 +1346,15 @@ RewriteQuery(Query *parsetree, bool *instead_flag, List **qual_products)
                                    qual_products);
    }
 
+   heap_close(rt_entry_relation, AccessShareLock);
+
    return product_queries;
 }
 
 
 /*
  * to avoid infinite recursion, we restrict the number of times a query
- * can be rewritten. Detecting cycles is left for the reader as an excercise.
+ * can be rewritten. Detecting cycles is left for the reader as an exercise.
  */
 #ifndef REWRITE_INVOKE_MAX
 #define REWRITE_INVOKE_MAX     10
@@ -1373,8 +1375,6 @@ deepRewriteQuery(Query *parsetree)
    bool        instead;
    List       *qual_products = NIL;
 
-
-
    if (++numQueryRewriteInvoked > REWRITE_INVOKE_MAX)
    {
        elog(ERROR, "query rewritten %d times, may contain cycles",
index 13a07adbd8c864974d8220cc5bfbceab706433de..d50e1049097bbe006df356f111b38e0dd71214eb 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteRemove.c,v 1.37 2000/05/28 17:56:02 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteRemove.c,v 1.38 2000/06/30 07:04:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -52,30 +52,20 @@ RewriteGetRuleEventRel(char *rulename)
    return NameStr(((Form_pg_class) GETSTRUCT(htup))->relname);
 }
 
-/* ----------------------------------------------------------------
- *
+/*
  * RemoveRewriteRule
  *
  * Delete a rule given its rulename.
- *
- * There are three steps.
- *  1) Find the corresponding tuple in 'pg_rewrite' relation.
- *     Find the rule Id (i.e. the Oid of the tuple) and finally delete
- *     the tuple.
- *  3) Delete the locks from the 'pg_class' relation.
- *
- *
- * ----------------------------------------------------------------
  */
 void
 RemoveRewriteRule(char *ruleName)
 {
-   Relation    RewriteRelation = NULL;
-   HeapTuple   tuple = NULL;
-   Oid         ruleId = (Oid) 0;
-   Oid         eventRelationOid = (Oid) NULL;
-   Datum       eventRelationOidDatum = (Datum) NULL;
-   bool        isNull = false;
+   Relation    RewriteRelation;
+   Relation    event_relation;
+   HeapTuple   tuple;
+   Oid         ruleId;
+   Oid         eventRelationOid;
+   bool        hasMoreRules;
 
    /*
     * Open the pg_rewrite relation.
@@ -83,7 +73,7 @@ RemoveRewriteRule(char *ruleName)
    RewriteRelation = heap_openr(RewriteRelationName, RowExclusiveLock);
 
    /*
-    * Scan the RuleRelation ('pg_rewrite') until we find a tuple
+    * Find the tuple for the target rule.
     */
    tuple = SearchSysCacheTupleCopy(RULENAME,
                                    PointerGetDatum(ruleName),
@@ -99,44 +89,49 @@ RemoveRewriteRule(char *ruleName)
    }
 
    /*
-    * Store the OID of the rule (i.e. the tuple's OID) and the event
+    * Save the OID of the rule (i.e. the tuple's OID) and the event
     * relation's OID
     */
    ruleId = tuple->t_data->t_oid;
-   eventRelationOidDatum = heap_getattr(tuple,
-                                        Anum_pg_rewrite_ev_class,
-                                      RelationGetDescr(RewriteRelation),
-                                        &isNull);
-   if (isNull)
-   {
-       /* XXX strange!!! */
-       heap_freetuple(tuple);
-       elog(ERROR, "RemoveRewriteRule: internal error; null event target relation!");
-   }
-   eventRelationOid = DatumGetObjectId(eventRelationOidDatum);
+   eventRelationOid = ((Form_pg_rewrite) GETSTRUCT(tuple))->ev_class;
 
    /*
-    * Now delete the relation level locks from the updated relation.
-    * (Make sure we do this before we remove the rule from pg_rewrite.
-    * Otherwise, heap_openr on eventRelationOid which reads pg_rwrite for
-    * the rules will fail.)
+    * We had better grab AccessExclusiveLock so that we know no other
+    * rule additions/deletions are going on for this relation.  Else
+    * we cannot set relhasrules correctly.  Besides, we don't want to
+    * be changing the ruleset while queries are executing on the rel.
     */
-   prs2_deleteFromRelation(eventRelationOid, ruleId);
+   event_relation = heap_open(eventRelationOid, AccessExclusiveLock);
+
+   hasMoreRules = event_relation->rd_rules != NULL &&
+       event_relation->rd_rules->numLocks > 1;
 
    /*
     * Delete any comments associated with this rule
-    *
     */
-
    DeleteComments(ruleId);
 
    /*
-    * Now delete the tuple...
+    * Now delete the pg_rewrite tuple for the rule
     */
    heap_delete(RewriteRelation, &tuple->t_self, NULL);
 
    heap_freetuple(tuple);
+
    heap_close(RewriteRelation, RowExclusiveLock);
+
+   /*
+    * Set pg_class 'relhasrules' field correctly for event relation.
+    *
+    * Important side effect: an SI notice is broadcast to force all
+    * backends (including me!) to update relcache entries with the
+    * new rule set.  Therefore, must do this even if relhasrules is
+    * still true!
+    */
+   setRelhasrulesInRelation(eventRelationOid, hasMoreRules);
+
+   /* Close rel, but keep lock till commit... */
+   heap_close(event_relation, NoLock);
 }
 
 /*
index 113e0b73c596a0121f99e5e4ae2e96ede0ff5770..fe87f5693878536edbd3b636b2aca0bd77e6913a 100644 (file)
@@ -8,13 +8,12 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteSupport.c,v 1.42 2000/06/28 03:31:56 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteSupport.c,v 1.43 2000/06/30 07:04:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 
-
 #include "access/heapam.h"
 #include "catalog/catname.h"
 #include "catalog/indexing.h"
 #include "utils/catcache.h"
 #include "utils/syscache.h"
 
-/*
- * RuleIdGetActionInfo -
- *    given a rule oid, look it up and return the rule-event-qual and
- *    list of parsetrees for the rule (in parseTrees)
- */
-#ifdef NOT_USED
-static Node *
-RuleIdGetActionInfo(Oid ruleoid, bool *instead_flag, Query **parseTrees)
-{
-   HeapTuple   ruletuple;
-   char       *ruleaction = NULL;
-   bool        action_is_null = false;
-   bool        instead_is_null = false;
-   Relation    ruleRelation = NULL;
-   TupleDesc   ruleTupdesc = NULL;
-   Query      *ruleparse = NULL;
-   char       *rule_evqual_string = NULL;
-   Node       *rule_evqual = NULL;
-
-   ruleRelation = heap_openr(RewriteRelationName, AccessShareLock);
-   ruleTupdesc = RelationGetDescr(ruleRelation);
-   ruletuple = SearchSysCacheTuple(RULEOID,
-                                   ObjectIdGetDatum(ruleoid),
-                                   0, 0, 0);
-   if (ruletuple == NULL)
-       elog(ERROR, "rule %u isn't in rewrite system relation", ruleoid);
-
-   ruleaction = (char *) heap_getattr(ruletuple,
-                                      Anum_pg_rewrite_ev_action,
-                                      ruleTupdesc,
-                                      &action_is_null);
-   rule_evqual_string = (char *) heap_getattr(ruletuple,
-                                              Anum_pg_rewrite_ev_qual,
-                                          ruleTupdesc, &action_is_null);
-   *instead_flag = !!heap_getattr(ruletuple,
-                                  Anum_pg_rewrite_is_instead,
-                                  ruleTupdesc, &instead_is_null);
-
-   if (action_is_null || instead_is_null)
-       elog(ERROR, "internal error: rewrite rule not properly set up");
-
-   ruleaction = textout((struct varlena *) ruleaction);
-   rule_evqual_string = textout((struct varlena *) rule_evqual_string);
-
-   ruleparse = (Query *) stringToNode(ruleaction);
-   rule_evqual = (Node *) stringToNode(rule_evqual_string);
-
-   heap_close(ruleRelation, AccessShareLock);
-
-   *parseTrees = ruleparse;
-   return rule_evqual;
-}
-
-#endif
 
 int
 IsDefinedRewriteRule(char *ruleName)
@@ -88,7 +33,20 @@ IsDefinedRewriteRule(char *ruleName)
    return HeapTupleIsValid(tuple);
 }
 
-static void
+/*
+ * setRelhasrulesInRelation
+ *     Set the value of the relation's relhasrules field in pg_class.
+ *
+ * NOTE: caller should be holding an appropriate lock on the relation.
+ *
+ * NOTE: an important side-effect of this operation is that an SI invalidation
+ * message is sent out to all backends --- including me --- causing relcache
+ * entries to be flushed or updated with the new set of rules for the table.
+ * Therefore, we execute the update even if relhasrules has the right value
+ * already.  Possible future improvement: skip the disk update and just send
+ * an SI message in that case.
+ */
+void
 setRelhasrulesInRelation(Oid relationId, bool relhasrules)
 {
    Relation    relationRelation;
@@ -96,9 +54,7 @@ setRelhasrulesInRelation(Oid relationId, bool relhasrules)
    Relation    idescs[Num_pg_class_indices];
 
    /*
-    * Lock a relation given its Oid. Go to the RelationRelation (i.e.
-    * pg_relation), find the appropriate tuple, and add the specified
-    * lock to it.
+    * Find the tuple to update in pg_class, using syscache for the lookup.
     */
    relationRelation = heap_openr(RelationRelationName, RowExclusiveLock);
    tuple = SearchSysCacheTupleCopy(RELOID,
@@ -106,10 +62,11 @@ setRelhasrulesInRelation(Oid relationId, bool relhasrules)
                                    0, 0, 0);
    Assert(HeapTupleIsValid(tuple));
 
+   /* Do the update */
    ((Form_pg_class) GETSTRUCT(tuple))->relhasrules = relhasrules;
    heap_update(relationRelation, &tuple->t_self, tuple, NULL);
 
-   /* keep the catalog indices up to date */
+   /* Keep the catalog indices up to date */
    CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, idescs);
    CatalogIndexInsert(idescs, Num_pg_class_indices, relationRelation, tuple);
    CatalogCloseIndices(Num_pg_class_indices, idescs);
@@ -117,120 +74,3 @@ setRelhasrulesInRelation(Oid relationId, bool relhasrules)
    heap_freetuple(tuple);
    heap_close(relationRelation, RowExclusiveLock);
 }
-
-void
-prs2_addToRelation(Oid relid,
-                  Oid ruleId,
-                  CmdType event_type,
-                  AttrNumber attno,
-                  bool isInstead,
-                  Node *qual,
-                  List *actions)
-{
-   Relation    relation;
-   RewriteRule *thisRule;
-   RuleLock   *rulelock;
-   MemoryContext oldcxt;
-
-   /*
-    * create an in memory RewriteRule data structure which is cached by
-    * every Relation descriptor. (see utils/cache/relcache.c)
-    */
-   oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
-   thisRule = (RewriteRule *) palloc(sizeof(RewriteRule));
-   if (qual != NULL)
-       qual = copyObject(qual);
-   if (actions != NIL)
-       actions = copyObject(actions);
-   MemoryContextSwitchTo(oldcxt);
-
-   thisRule->ruleId = ruleId;
-   thisRule->event = event_type;
-   thisRule->attrno = attno;
-   thisRule->qual = qual;
-   thisRule->actions = actions;
-   thisRule->isInstead = isInstead;
-
-   relation = heap_open(relid, AccessShareLock);
-
-   /*
-    * modify or create a RuleLock cached by Relation
-    */
-   if (relation->rd_rules == NULL)
-   {
-
-       oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
-       rulelock = (RuleLock *) palloc(sizeof(RuleLock));
-       rulelock->numLocks = 1;
-       rulelock->rules = (RewriteRule **) palloc(sizeof(RewriteRule *));
-       rulelock->rules[0] = thisRule;
-       relation->rd_rules = rulelock;
-       MemoryContextSwitchTo(oldcxt);
-
-       /*
-        * the fact that relation->rd_rules is NULL means the relhasrules
-        * attribute of the tuple of this relation in pg_class is false.
-        * We need to set it to true.
-        */
-       setRelhasrulesInRelation(relid, TRUE);
-   }
-   else
-   {
-       int         numlock;
-
-       rulelock = relation->rd_rules;
-       numlock = rulelock->numLocks;
-       /* expand, for safety reasons */
-       oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
-       rulelock->rules = (RewriteRule **) repalloc(rulelock->rules,
-                                 sizeof(RewriteRule *) * (numlock + 1));
-       MemoryContextSwitchTo(oldcxt);
-       rulelock->rules[numlock] = thisRule;
-       rulelock->numLocks++;
-   }
-
-   heap_close(relation, AccessShareLock);
-}
-
-void
-prs2_deleteFromRelation(Oid relid, Oid ruleId)
-{
-   RuleLock   *rulelock;
-   Relation    relation;
-   int         numlock;
-   int         i;
-   MemoryContext oldcxt;
-
-   relation = heap_open(relid, AccessShareLock);
-   rulelock = relation->rd_rules;
-   Assert(rulelock != NULL);
-
-   numlock = rulelock->numLocks;
-   for (i = 0; i < numlock; i++)
-   {
-       if (rulelock->rules[i]->ruleId == ruleId)
-           break;
-   }
-   Assert(i < numlock);
-   oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
-   pfree(rulelock->rules[i]);
-   MemoryContextSwitchTo(oldcxt);
-   if (numlock == 1)
-   {
-       relation->rd_rules = NULL;
-
-       /*
-        * we don't have rules any more, flag the relhasrules attribute of
-        * the tuple of this relation in pg_class false.
-        */
-       setRelhasrulesInRelation(relid, FALSE);
-   }
-   else
-   {
-       rulelock->rules[i] = rulelock->rules[numlock - 1];
-       rulelock->rules[numlock - 1] = NULL;
-       rulelock->numLocks--;
-   }
-
-   heap_close(relation, AccessShareLock);
-}
index b0ee20fce986f810cf90b4b61833166b4a068e79..dc69a0e508fc42a5c9b634d5f93cc144b8a37a72 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.104 2000/06/28 03:32:24 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/utils/cache/relcache.c,v 1.105 2000/06/30 07:04:10 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,9 +22,6 @@
  *     RelationClose                   - close an open relation
  *
  * NOTES
- *     This file is in the process of being cleaned up
- *     before I add system attribute indexing.  -cim 1/13/91
- *
  *     The following code contains many undocumented hacks.  Please be
  *     careful....
  *
@@ -59,6 +56,7 @@
 #include "storage/smgr.h"
 #include "utils/catcache.h"
 #include "utils/fmgroids.h"
+#include "utils/memutils.h"
 #include "utils/relcache.h"
 #include "utils/temprel.h"
 
@@ -77,7 +75,7 @@ static FormData_pg_attribute Desc_pg_log[Natts_pg_log] = {Schema_pg_log};
 /* ----------------
  *     Hash tables that index the relation cache
  *
- *     Relations are cached two ways, by name and by id,
+ *     Relations are looked up two ways, by name and by id,
  *     thus there are two hash tables for referencing them.
  * ----------------
  */
@@ -91,6 +89,12 @@ static HTAB *RelationIdCache;
  */
 static List *newlyCreatedRelns = NULL;
 
+/*
+ * This flag is false until we have prepared the critical relcache entries
+ * that are needed to do indexscans on the tables read by relcache building.
+ */
+static bool criticalRelcachesBuilt = false;
+
 
 /* ----------------
  *     RelationBuildDescInfo exists so code can be shared
@@ -211,20 +215,19 @@ static void RelationCacheAbortWalker(Relation *relationPtr, int dummy);
 static void init_irels(void);
 static void write_irels(void);
 
-static void formrdesc(char *relationName, u_int natts,
+static void formrdesc(char *relationName, int natts,
          FormData_pg_attribute *att);
 
 static HeapTuple ScanPgRelation(RelationBuildDescInfo buildinfo);
 static HeapTuple scan_pg_rel_seq(RelationBuildDescInfo buildinfo);
 static HeapTuple scan_pg_rel_ind(RelationBuildDescInfo buildinfo);
-static Relation AllocateRelationDesc(Relation relation, u_int natts,
-                    Form_pg_class relp);
+static Relation AllocateRelationDesc(Relation relation, Form_pg_class relp);
 static void RelationBuildTupleDesc(RelationBuildDescInfo buildinfo,
-                      Relation relation, u_int natts);
+                      Relation relation);
 static void build_tupdesc_seq(RelationBuildDescInfo buildinfo,
-                 Relation relation, u_int natts);
+                 Relation relation);
 static void build_tupdesc_ind(RelationBuildDescInfo buildinfo,
-                 Relation relation, u_int natts);
+                 Relation relation);
 static Relation RelationBuildDesc(RelationBuildDescInfo buildinfo,
                  Relation oldrelation);
 static void IndexedAccessMethodInitialize(Relation relation);
@@ -232,7 +235,6 @@ static void AttrDefaultFetch(Relation relation);
 static void RelCheckFetch(Relation relation);
 static List *insert_ordered_oid(List *list, Oid datum);
 
-static bool criticalRelcacheBuild = false;
 
 /* ----------------------------------------------------------------
  *     RelationIdGetRelation() and RelationNameGetRelation()
@@ -262,7 +264,7 @@ ScanPgRelation(RelationBuildDescInfo buildinfo)
     * can, and do.
     */
 
-   if (IsIgnoringSystemIndexes() || !criticalRelcacheBuild)
+   if (IsIgnoringSystemIndexes() || !criticalRelcachesBuilt)
        return scan_pg_rel_seq(buildinfo);
    else
        return scan_pg_rel_ind(buildinfo);
@@ -379,34 +381,23 @@ scan_pg_rel_ind(RelationBuildDescInfo buildinfo)
  * ----------------
  */
 static Relation
-AllocateRelationDesc(Relation relation, u_int natts,
-                    Form_pg_class relp)
+AllocateRelationDesc(Relation relation, Form_pg_class relp)
 {
+   MemoryContext oldcxt;
    Form_pg_class relationForm;
 
-   /* ----------------
-    *  Copy the relation tuple form
-    *
-    *  We only allocate space for the fixed fields, ie, CLASS_TUPLE_SIZE.
-    *  relacl is NOT stored in the relcache --- there'd be little point
-    *  in it, since we don't copy the tuple's nullvalues bitmap and hence
-    *  wouldn't know if the value is valid ... bottom line is that relacl
-    *  *cannot* be retrieved from the relcache.  Get it from the syscache
-    *  if you need it.
-    * ----------------
-    */
-   relationForm = (Form_pg_class) palloc(CLASS_TUPLE_SIZE);
-
-   memcpy((char *) relationForm, (char *) relp, CLASS_TUPLE_SIZE);
+   /* Relcache entries must live in CacheMemoryContext */
+   oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
 
    /* ----------------
     *  allocate space for new relation descriptor, if needed
+    * ----------------
     */
    if (relation == NULL)
        relation = (Relation) palloc(sizeof(RelationData));
 
    /* ----------------
-    *  clear new reldesc
+    *  clear all fields of reldesc
     * ----------------
     */
    MemSet((char *) relation, 0, sizeof(RelationData));
@@ -414,12 +405,29 @@ AllocateRelationDesc(Relation relation, u_int natts,
    /* make sure relation is marked as having no open file yet */
    relation->rd_fd = -1;
 
-   /* initialize attribute tuple form */
-   relation->rd_att = CreateTemplateTupleDesc(natts);
+   /* ----------------
+    *  Copy the relation tuple form
+    *
+    *  We only allocate space for the fixed fields, ie, CLASS_TUPLE_SIZE.
+    *  relacl is NOT stored in the relcache --- there'd be little point
+    *  in it, since we don't copy the tuple's nullvalues bitmap and hence
+    *  wouldn't know if the value is valid ... bottom line is that relacl
+    *  *cannot* be retrieved from the relcache.  Get it from the syscache
+    *  if you need it.
+    * ----------------
+    */
+   relationForm = (Form_pg_class) palloc(CLASS_TUPLE_SIZE);
 
-   /* and initialize relation tuple form */
+   memcpy((char *) relationForm, (char *) relp, CLASS_TUPLE_SIZE);
+
+   /* initialize relation tuple form */
    relation->rd_rel = relationForm;
 
+   /* and allocate attribute tuple form storage */
+   relation->rd_att = CreateTemplateTupleDesc(relationForm->relnatts);
+
+   MemoryContextSwitchTo(oldcxt);
+
    return relation;
 }
 
@@ -432,8 +440,7 @@ AllocateRelationDesc(Relation relation, u_int natts,
  */
 static void
 RelationBuildTupleDesc(RelationBuildDescInfo buildinfo,
-                      Relation relation,
-                      u_int natts)
+                      Relation relation)
 {
 
    /*
@@ -442,14 +449,17 @@ RelationBuildTupleDesc(RelationBuildDescInfo buildinfo,
     * can, and do.
     */
 
-   if (IsIgnoringSystemIndexes() || !criticalRelcacheBuild)
-       build_tupdesc_seq(buildinfo, relation, natts);
+   if (IsIgnoringSystemIndexes() || !criticalRelcachesBuilt)
+       build_tupdesc_seq(buildinfo, relation);
    else
-       build_tupdesc_ind(buildinfo, relation, natts);
+       build_tupdesc_ind(buildinfo, relation);
 }
 
 static void
-SetConstrOfRelation(Relation relation, TupleConstr *constr, int ndef, AttrDefault *attrdef)
+SetConstrOfRelation(Relation relation,
+                   TupleConstr *constr,
+                   int ndef,
+                   AttrDefault *attrdef)
 {
    if (constr->has_not_null || ndef > 0 || relation->rd_rel->relchecks)
    {
@@ -471,8 +481,9 @@ SetConstrOfRelation(Relation relation, TupleConstr *constr, int ndef, AttrDefaul
        if (relation->rd_rel->relchecks > 0)    /* CHECKs */
        {
            constr->num_check = relation->rd_rel->relchecks;
-           constr->check = (ConstrCheck *) palloc(constr->num_check *
-                                                  sizeof(ConstrCheck));
+           constr->check = (ConstrCheck *)
+               MemoryContextAlloc(CacheMemoryContext,
+                                  constr->num_check * sizeof(ConstrCheck));
            MemSet(constr->check, 0, constr->num_check * sizeof(ConstrCheck));
            RelCheckFetch(relation);
        }
@@ -488,8 +499,7 @@ SetConstrOfRelation(Relation relation, TupleConstr *constr, int ndef, AttrDefaul
 
 static void
 build_tupdesc_seq(RelationBuildDescInfo buildinfo,
-                 Relation relation,
-                 u_int natts)
+                 Relation relation)
 {
    HeapTuple   pg_attribute_tuple;
    Relation    pg_attribute_desc;
@@ -497,11 +507,14 @@ build_tupdesc_seq(RelationBuildDescInfo buildinfo,
    Form_pg_attribute attp;
    ScanKeyData key;
    int         need;
-   TupleConstr *constr = (TupleConstr *) palloc(sizeof(TupleConstr));
+   TupleConstr *constr;
    AttrDefault *attrdef = NULL;
    int         ndef = 0;
 
+   constr = (TupleConstr *) MemoryContextAlloc(CacheMemoryContext,
+                                               sizeof(TupleConstr));
    constr->has_not_null = false;
+
    /* ----------------
     *  form a scan key
     * ----------------
@@ -522,7 +535,7 @@ build_tupdesc_seq(RelationBuildDescInfo buildinfo,
     *  add attribute data to relation->rd_att
     * ----------------
     */
-   need = natts;
+   need = relation->rd_rel->relnatts;
 
    pg_attribute_tuple = heap_getnext(pg_attribute_scan, 0);
    while (HeapTupleIsValid(pg_attribute_tuple) && need > 0)
@@ -532,12 +545,14 @@ build_tupdesc_seq(RelationBuildDescInfo buildinfo,
        if (attp->attnum > 0)
        {
            relation->rd_att->attrs[attp->attnum - 1] =
-               (Form_pg_attribute) palloc(ATTRIBUTE_TUPLE_SIZE);
+               (Form_pg_attribute) MemoryContextAlloc(CacheMemoryContext,
+                                                      ATTRIBUTE_TUPLE_SIZE);
 
            memcpy((char *) (relation->rd_att->attrs[attp->attnum - 1]),
                   (char *) attp,
                   ATTRIBUTE_TUPLE_SIZE);
            need--;
+
            /* Update if this attribute have a constraint */
            if (attp->attnotnull)
                constr->has_not_null = true;
@@ -546,10 +561,12 @@ build_tupdesc_seq(RelationBuildDescInfo buildinfo,
            {
                if (attrdef == NULL)
                {
-                   attrdef = (AttrDefault *) palloc(relation->rd_rel->relnatts *
-                                                    sizeof(AttrDefault));
+                   attrdef = (AttrDefault *)
+                       MemoryContextAlloc(CacheMemoryContext,
+                                          relation->rd_rel->relnatts *
+                                          sizeof(AttrDefault));
                    MemSet(attrdef, 0,
-                      relation->rd_rel->relnatts * sizeof(AttrDefault));
+                          relation->rd_rel->relnatts * sizeof(AttrDefault));
                }
                attrdef[ndef].adnum = attp->attnum;
                attrdef[ndef].adbin = NULL;
@@ -575,17 +592,18 @@ build_tupdesc_seq(RelationBuildDescInfo buildinfo,
 
 static void
 build_tupdesc_ind(RelationBuildDescInfo buildinfo,
-                 Relation relation,
-                 u_int natts)
+                 Relation relation)
 {
    Relation    attrel;
    HeapTuple   atttup;
    Form_pg_attribute attp;
-   TupleConstr *constr = (TupleConstr *) palloc(sizeof(TupleConstr));
+   TupleConstr *constr;
    AttrDefault *attrdef = NULL;
    int         ndef = 0;
    int         i;
 
+   constr = (TupleConstr *) MemoryContextAlloc(CacheMemoryContext,
+                                               sizeof(TupleConstr));
    constr->has_not_null = false;
 
    attrel = heap_openr(AttributeRelationName, AccessShareLock);
@@ -616,7 +634,8 @@ build_tupdesc_ind(RelationBuildDescInfo buildinfo,
        }
 
        relation->rd_att->attrs[i - 1] = attp =
-           (Form_pg_attribute) palloc(ATTRIBUTE_TUPLE_SIZE);
+           (Form_pg_attribute) MemoryContextAlloc(CacheMemoryContext,
+                                                  ATTRIBUTE_TUPLE_SIZE);
 
        memcpy((char *) attp,
               (char *) (Form_pg_attribute) GETSTRUCT(atttup),
@@ -638,8 +657,10 @@ build_tupdesc_ind(RelationBuildDescInfo buildinfo,
        {
            if (attrdef == NULL)
            {
-               attrdef = (AttrDefault *) palloc(relation->rd_rel->relnatts *
-                                                sizeof(AttrDefault));
+               attrdef = (AttrDefault *)
+                   MemoryContextAlloc(CacheMemoryContext,
+                                      relation->rd_rel->relnatts *
+                                      sizeof(AttrDefault));
                MemSet(attrdef, 0,
                       relation->rd_rel->relnatts * sizeof(AttrDefault));
            }
@@ -652,7 +673,6 @@ build_tupdesc_ind(RelationBuildDescInfo buildinfo,
    heap_close(attrel, AccessShareLock);
 
    SetConstrOfRelation(relation, constr, ndef, attrdef);
-
 }
 
 /* --------------------------------
@@ -660,11 +680,22 @@ build_tupdesc_ind(RelationBuildDescInfo buildinfo,
  *
  *     Form the relation's rewrite rules from information in
  *     the pg_rewrite system catalog.
+ *
+ * Note: The rule parsetrees are potentially very complex node structures.
+ * To allow these trees to be freed when the relcache entry is flushed,
+ * we make a private memory context to hold the RuleLock information for
+ * each relcache entry that has associated rules.  The context is used
+ * just for rule info, not for any other subsidiary data of the relcache
+ * entry, because that keeps the update logic in RelationClearRelation()
+ * manageable.  The other subsidiary data structures are simple enough
+ * to be easy to free explicitly, anyway.
  * --------------------------------
  */
 static void
 RelationBuildRuleLock(Relation relation)
 {
+   MemoryContext rulescxt;
+   MemoryContext oldcxt;
    HeapTuple   pg_rewrite_tuple;
    Relation    pg_rewrite_desc;
    TupleDesc   pg_rewrite_tupdesc;
@@ -675,13 +706,25 @@ RelationBuildRuleLock(Relation relation)
    RewriteRule **rules;
    int         maxlocks;
 
+   /*
+    * Make the private context.  Parameters are set on the assumption
+    * that it'll probably not contain much data.
+    */
+   rulescxt = AllocSetContextCreate(CacheMemoryContext,
+                                    RelationGetRelationName(relation),
+                                    0, /* minsize */
+                                    1024, /* initsize */
+                                    1024); /* maxsize */
+   relation->rd_rulescxt = rulescxt;
+
    /* ----------------
     *  form an array to hold the rewrite rules (the array is extended if
     *  necessary)
     * ----------------
     */
    maxlocks = 4;
-   rules = (RewriteRule **) palloc(sizeof(RewriteRule *) * maxlocks);
+   rules = (RewriteRule **)
+       MemoryContextAlloc(rulescxt, sizeof(RewriteRule *) * maxlocks);
    numlocks = 0;
 
    /* ----------------
@@ -710,26 +753,32 @@ RelationBuildRuleLock(Relation relation)
        char       *rule_evqual_str;
        RewriteRule *rule;
 
-       rule = (RewriteRule *) palloc(sizeof(RewriteRule));
+       rule = (RewriteRule *) MemoryContextAlloc(rulescxt,
+                                                 sizeof(RewriteRule));
 
        rule->ruleId = pg_rewrite_tuple->t_data->t_oid;
 
-       rule->event = (int) heap_getattr(pg_rewrite_tuple,
-                            Anum_pg_rewrite_ev_type, pg_rewrite_tupdesc,
-                                        &isnull) - 48;
-       rule->attrno = (int) heap_getattr(pg_rewrite_tuple,
-                            Anum_pg_rewrite_ev_attr, pg_rewrite_tupdesc,
-                                         &isnull);
-       rule->isInstead = !!heap_getattr(pg_rewrite_tuple,
-                         Anum_pg_rewrite_is_instead, pg_rewrite_tupdesc,
-                                        &isnull);
+       rule->event = DatumGetInt32(heap_getattr(pg_rewrite_tuple,
+                                                Anum_pg_rewrite_ev_type,
+                                                pg_rewrite_tupdesc,
+                                                &isnull)) - 48;
+       rule->attrno = DatumGetInt16(heap_getattr(pg_rewrite_tuple,
+                                                 Anum_pg_rewrite_ev_attr,
+                                                 pg_rewrite_tupdesc,
+                                                 &isnull));
+       rule->isInstead = DatumGetBool(heap_getattr(pg_rewrite_tuple,
+                                                   Anum_pg_rewrite_is_instead,
+                                                   pg_rewrite_tupdesc,
+                                                   &isnull));
 
        ruleaction = heap_getattr(pg_rewrite_tuple,
                                  Anum_pg_rewrite_ev_action,
                                  pg_rewrite_tupdesc,
                                  &isnull);
        ruleaction_str = lztextout((lztext *) DatumGetPointer(ruleaction));
+       oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
        rule->actions = (List *) stringToNode(ruleaction_str);
+       MemoryContextSwitchTo(oldcxt);
        pfree(ruleaction_str);
 
        rule_evqual = heap_getattr(pg_rewrite_tuple,
@@ -737,13 +786,16 @@ RelationBuildRuleLock(Relation relation)
                                   pg_rewrite_tupdesc,
                                   &isnull);
        rule_evqual_str = lztextout((lztext *) DatumGetPointer(rule_evqual));
+       oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
        rule->qual = (Node *) stringToNode(rule_evqual_str);
+       MemoryContextSwitchTo(oldcxt);
        pfree(rule_evqual_str);
 
        if (numlocks >= maxlocks)
        {
            maxlocks *= 2;
-           rules = (RewriteRule **) repalloc(rules, sizeof(RewriteRule *) * maxlocks);
+           rules = (RewriteRule **)
+               repalloc(rules, sizeof(RewriteRule *) * maxlocks);
        }
        rules[numlocks++] = rule;
    }
@@ -759,42 +811,13 @@ RelationBuildRuleLock(Relation relation)
     *  form a RuleLock and insert into relation
     * ----------------
     */
-   rulelock = (RuleLock *) palloc(sizeof(RuleLock));
+   rulelock = (RuleLock *) MemoryContextAlloc(rulescxt, sizeof(RuleLock));
    rulelock->numLocks = numlocks;
    rulelock->rules = rules;
 
    relation->rd_rules = rulelock;
 }
 
-/* --------------------------------
- *     FreeRuleLock
- *
- *     Release the storage used for a set of rewrite rules.
- *
- *     Probably this should be in the rules code someplace...
- * --------------------------------
- */
-static void
-FreeRuleLock(RuleLock *rlock)
-{
-   int         i;
-
-   if (rlock == NULL)
-       return;
-   for (i = 0; i < rlock->numLocks; i++)
-   {
-       RewriteRule *rule = rlock->rules[i];
-
-#if 0                          /* does freefuncs.c still work?  Not sure */
-       freeObject(rule->actions);
-       freeObject(rule->qual);
-#endif
-       pfree(rule);
-   }
-   pfree(rlock->rules);
-   pfree(rlock);
-}
-
 /* --------------------------------
  *     equalRuleLocks
  *
@@ -886,7 +909,6 @@ RelationBuildDesc(RelationBuildDescInfo buildinfo,
 {
    File        fd;
    Relation    relation;
-   u_int       natts;
    Oid         relid;
    Oid         relam;
    HeapTuple   pg_class_tuple;
@@ -912,17 +934,19 @@ RelationBuildDesc(RelationBuildDescInfo buildinfo,
     */
    relid = pg_class_tuple->t_data->t_oid;
    relp = (Form_pg_class) GETSTRUCT(pg_class_tuple);
-   natts = relp->relnatts;
 
    /* ----------------
     *  allocate storage for the relation descriptor,
-    *  initialize relation->rd_rel and get the access method id.
-    *  The storage is allocated in memory context CacheMemoryContext.
+    *  and copy pg_class_tuple to relation->rd_rel.
     * ----------------
     */
-   oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
-   relation = AllocateRelationDesc(oldrelation, natts, relp);
-   relam = relation->rd_rel->relam;
+   relation = AllocateRelationDesc(oldrelation, relp);
+
+   /* -------------------
+    *  now we can free the memory allocated for pg_class_tuple
+    * -------------------
+    */
+   heap_freetuple(pg_class_tuple);
 
    /* ----------------
     *  initialize the relation's relation id (relation->rd_id)
@@ -946,26 +970,30 @@ RelationBuildDesc(RelationBuildDescInfo buildinfo,
     *  initialize the access method information (relation->rd_am)
     * ----------------
     */
+   relam = relation->rd_rel->relam;
    if (OidIsValid(relam))
-       relation->rd_am = AccessMethodObjectIdGetForm(relam);
+       relation->rd_am = AccessMethodObjectIdGetForm(relam,
+                                                     CacheMemoryContext);
 
    /* ----------------
     *  initialize the tuple descriptor (relation->rd_att).
     * ----------------
     */
-   RelationBuildTupleDesc(buildinfo, relation, natts);
+   RelationBuildTupleDesc(buildinfo, relation);
 
    /* ----------------
-    *  initialize rules that affect this relation
+    *  Fetch rules and triggers that affect this relation
     * ----------------
     */
-   if (relp->relhasrules)
+   if (relation->rd_rel->relhasrules)
        RelationBuildRuleLock(relation);
    else
+   {
        relation->rd_rules = NULL;
+       relation->rd_rulescxt = NULL;
+   }
 
-   /* Triggers */
-   if (relp->reltriggers > 0)
+   if (relation->rd_rel->reltriggers > 0)
        RelationBuildTriggers(relation);
    else
        relation->trigdesc = NULL;
@@ -993,7 +1021,7 @@ RelationBuildDesc(RelationBuildDescInfo buildinfo,
    Assert(fd >= -1);
    if (fd == -1)
        elog(NOTICE, "RelationIdBuildRelation: smgropen(%s): %m",
-            NameStr(relp->relname));
+            NameStr(relation->rd_rel->relname));
 
    relation->rd_fd = fd;
 
@@ -1002,17 +1030,10 @@ RelationBuildDesc(RelationBuildDescInfo buildinfo,
     *  restore memory context and return the new reldesc.
     * ----------------
     */
+   oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
    RelationCacheInsert(relation);
-
    MemoryContextSwitchTo(oldcxt);
 
-   /* -------------------
-    *  free the memory allocated for pg_class_tuple
-    *  and for lock data pointed to by pg_class_tuple
-    * -------------------
-    */
-   heap_freetuple(pg_class_tuple);
-
    return relation;
 }
 
@@ -1030,13 +1051,15 @@ IndexedAccessMethodInitialize(Relation relation)
    natts = relation->rd_rel->relnatts;
    relamstrategies = relation->rd_am->amstrategies;
    stratSize = AttributeNumberGetIndexStrategySize(natts, relamstrategies);
-   strategy = (IndexStrategy) palloc(stratSize);
-   relamsupport = relation->rd_am->amsupport;
+   strategy = (IndexStrategy) MemoryContextAlloc(CacheMemoryContext,
+                                                 stratSize);
 
+   relamsupport = relation->rd_am->amsupport;
    if (relamsupport > 0)
    {
        supportSize = natts * (relamsupport * sizeof(RegProcedure));
-       support = (RegProcedure *) palloc(supportSize);
+       support = (RegProcedure *) MemoryContextAlloc(CacheMemoryContext,
+                                                     supportSize);
    }
    else
        support = (RegProcedure *) NULL;
@@ -1052,20 +1075,20 @@ IndexedAccessMethodInitialize(Relation relation)
 /* --------------------------------
  *     formrdesc
  *
- *     This is a special version of RelationBuildDesc()
- *     used by RelationInitialize() in initializing the
- *     relcache.  The system relation descriptors built
- *     here are all nailed in the descriptor caches, for
- *     bootstrapping.
+ *     This is a special cut-down version of RelationBuildDesc()
+ *     used by RelationInitialize() in initializing the relcache.
+ *     The relation descriptor is built just from the supplied parameters.
+ *
+ * NOTE: we assume we are already switched into CacheMemoryContext.
  * --------------------------------
  */
 static void
 formrdesc(char *relationName,
-         u_int natts,
+         int natts,
          FormData_pg_attribute *att)
 {
    Relation    relation;
-   u_int       i;
+   int         i;
 
    /* ----------------
     *  allocate new relation desc
@@ -1095,8 +1118,9 @@ formrdesc(char *relationName,
    strcpy(RelationGetPhysicalRelationName(relation), relationName);
 
    /* ----------------
-      initialize attribute tuple form
-   */
+    *  initialize attribute tuple form
+    * ----------------
+    */
    relation->rd_att = CreateTemplateTupleDesc(natts);
 
    /*
@@ -1120,7 +1144,7 @@ formrdesc(char *relationName,
    relation->rd_rel->relpages = 1;     /* XXX */
    relation->rd_rel->reltuples = 1;    /* XXX */
    relation->rd_rel->relkind = RELKIND_RELATION;
-   relation->rd_rel->relnatts = (uint16) natts;
+   relation->rd_rel->relnatts = (int16) natts;
    relation->rd_isnailed = true;
 
    /* ----------------
@@ -1157,6 +1181,10 @@ formrdesc(char *relationName,
     * Determining this requires a scan on pg_class, but to do the scan
     * the rdesc for pg_class must already exist.  Therefore we must do
     * the check (and possible set) after cache insertion.
+    *
+    * XXX I believe the above comment is misguided; we should be
+    * running in bootstrap or init processing mode, and CatalogHasIndex
+    * relies on hard-wired info in those cases.
     */
    relation->rd_rel->relhasindex =
        CatalogHasIndex(relationName, RelationGetRelid(relation));
@@ -1171,8 +1199,9 @@ formrdesc(char *relationName,
 /* --------------------------------
  *     RelationIdCacheGetRelation
  *
- *     Lookup a reldesc by OID.
- *     Only try to get the reldesc by looking up the cache
+ *     Lookup an existing reldesc by OID.
+ *
+ *     Only try to get the reldesc by looking in the cache,
  *     do not go to the disk.
  *
  *     NB: relation ref count is incremented if successful.
@@ -1355,7 +1384,7 @@ RelationClose(Relation relation)
  *  (one with refcount > 0).  However, this routine just does whichever
  *  it's told to do; callers must determine which they want.
  *
- *  If we detect a change in the relation's TupleDesc or trigger data
+ *  If we detect a change in the relation's TupleDesc, rules, or triggers
  *  while rebuilding, we complain unless refcount is 0.
  * --------------------------------
  */
@@ -1383,8 +1412,6 @@ RelationClearRelation(Relation relation, bool rebuildIt)
    if (relation->rd_isnailed)
        return;
 
-   oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
-
    /*
     * Remove relation from hash tables
     *
@@ -1392,7 +1419,9 @@ RelationClearRelation(Relation relation, bool rebuildIt)
     * visible in the hash tables until it's valid again, so don't try to
     * optimize this away...
     */
+   oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
    RelationCacheDelete(relation);
+   MemoryContextSwitchTo(oldcxt);
 
    /* Clear out catcache's entries for this relation */
    SystemCacheRelationFlushed(RelationGetRelid(relation));
@@ -1425,7 +1454,8 @@ RelationClearRelation(Relation relation, bool rebuildIt)
    {
        /* ok to zap remaining substructure */
        FreeTupleDesc(relation->rd_att);
-       FreeRuleLock(relation->rd_rules);
+       if (relation->rd_rulescxt)
+           MemoryContextDelete(relation->rd_rulescxt);
        FreeTriggerDesc(relation->trigdesc);
        pfree(relation);
    }
@@ -1443,6 +1473,7 @@ RelationClearRelation(Relation relation, bool rebuildIt)
        bool        old_myxactonly = relation->rd_myxactonly;
        TupleDesc   old_att = relation->rd_att;
        RuleLock   *old_rules = relation->rd_rules;
+       MemoryContext old_rulescxt = relation->rd_rulescxt;
        TriggerDesc *old_trigdesc = relation->trigdesc;
        int         old_nblocks = relation->rd_nblocks;
        bool        relDescChanged = false;
@@ -1455,7 +1486,8 @@ RelationClearRelation(Relation relation, bool rebuildIt)
        {
            /* Should only get here if relation was deleted */
            FreeTupleDesc(old_att);
-           FreeRuleLock(old_rules);
+           if (old_rulescxt)
+               MemoryContextDelete(old_rulescxt);
            FreeTriggerDesc(old_trigdesc);
            pfree(relation);
            elog(ERROR, "RelationClearRelation: relation %u deleted while still in use",
@@ -1475,12 +1507,15 @@ RelationClearRelation(Relation relation, bool rebuildIt)
        }
        if (equalRuleLocks(old_rules, relation->rd_rules))
        {
-           FreeRuleLock(relation->rd_rules);
+           if (relation->rd_rulescxt)
+               MemoryContextDelete(relation->rd_rulescxt);
            relation->rd_rules = old_rules;
+           relation->rd_rulescxt = old_rulescxt;
        }
        else
        {
-           FreeRuleLock(old_rules);
+           if (old_rulescxt)
+               MemoryContextDelete(old_rulescxt);
            relDescChanged = true;
        }
        if (equalTriggerDescs(old_trigdesc, relation->trigdesc))
@@ -1505,8 +1540,6 @@ RelationClearRelation(Relation relation, bool rebuildIt)
            elog(ERROR, "RelationClearRelation: relation %u modified while in use",
                 buildinfo.i.info_id);
    }
-
-   MemoryContextSwitchTo(oldcxt);
 }
 
 /* --------------------------------
@@ -1570,12 +1603,9 @@ RelationForgetRelation(Oid rid)
    {
        if (relation->rd_myxactonly)
        {
-           MemoryContext oldcxt;
            List       *curr;
            List       *prev = NIL;
 
-           oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
-
            foreach(curr, newlyCreatedRelns)
            {
                Relation    reln = lfirst(curr);
@@ -1593,7 +1623,6 @@ RelationForgetRelation(Oid rid)
            else
                lnext(prev) = lnext(curr);
            pfree(curr);
-           MemoryContextSwitchTo(oldcxt);
        }
 
        /* Unconditionally destroy the relcache entry */
@@ -1731,10 +1760,10 @@ RelationRegisterRelation(Relation relation)
 {
    MemoryContext oldcxt;
 
-   oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
-
    RelationInitLockInfo(relation);
 
+   oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
+
    RelationCacheInsert(relation);
 
    /*
@@ -1761,13 +1790,9 @@ RelationRegisterRelation(Relation relation)
 void
 RelationPurgeLocalRelation(bool xactCommitted)
 {
-   MemoryContext oldcxt;
-
    if (newlyCreatedRelns == NULL)
        return;
 
-   oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
-
    while (newlyCreatedRelns)
    {
        List       *l = newlyCreatedRelns;
@@ -1796,8 +1821,6 @@ RelationPurgeLocalRelation(bool xactCommitted)
        if (!IsBootstrapProcessingMode())
            RelationClearRelation(reln, false);
    }
-
-   MemoryContextSwitchTo(oldcxt);
 }
 
 /* --------------------------------
@@ -1943,7 +1966,9 @@ AttrDefaultFetch(Relation relation)
                elog(NOTICE, "AttrDefaultFetch: adbin IS NULL for attr %s in rel %s",
                     NameStr(relation->rd_att->attrs[adform->adnum - 1]->attname),
                     RelationGetRelationName(relation));
-           attrdef[i].adbin = textout(val);
+           else
+               attrdef[i].adbin = MemoryContextStrdup(CacheMemoryContext,
+                                                      textout(val));
            break;
        }
        if (hasindex)
@@ -2039,14 +2064,16 @@ RelCheckFetch(Relation relation)
        if (isnull)
            elog(ERROR, "RelCheckFetch: rcname IS NULL for rel %s",
                 RelationGetRelationName(relation));
-       check[found].ccname = pstrdup(NameStr(*rcname));
+       check[found].ccname = MemoryContextStrdup(CacheMemoryContext,
+                                                 NameStr(*rcname));
        val = (struct varlena *) fastgetattr(htup,
                                             Anum_pg_relcheck_rcbin,
                                             rcrel->rd_att, &isnull);
        if (isnull)
            elog(ERROR, "RelCheckFetch: rcbin IS NULL for rel %s",
                 RelationGetRelationName(relation));
-       check[found].ccbin = textout(val);
+       check[found].ccbin = MemoryContextStrdup(CacheMemoryContext,
+                                                textout(val));
        found++;
        if (hasindex)
            ReleaseBuffer(buffer);
@@ -2416,7 +2443,7 @@ init_irels(void)
 
        RelationCacheInsert(ird);
    }
-   criticalRelcacheBuild = true;
+   criticalRelcachesBuilt = true;
 }
 
 static void
@@ -2489,7 +2516,7 @@ write_irels(void)
    irel[2] = RelationBuildDesc(bi, NULL);
    irel[2]->rd_isnailed = true;
 
-   criticalRelcacheBuild = true;
+   criticalRelcachesBuilt = true;
 
    /*
     * Removed the following ProcessingMode -- inoue
index 15cfb21e21e83b35dea8ad8ad5147da6a156d316..6676265d66613dd7ad0bd4d51da5b9abae8c873a 100644 (file)
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: index.h,v 1.25 2000/06/17 23:41:51 tgl Exp $
+ * $Id: index.h,v 1.26 2000/06/30 07:04:06 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,7 +17,8 @@
 #include "access/itup.h"
 #include "nodes/execnodes.h"
 
-extern Form_pg_am AccessMethodObjectIdGetForm(Oid accessMethodObjectId);
+extern Form_pg_am AccessMethodObjectIdGetForm(Oid accessMethodObjectId,
+                                             MemoryContext resultCxt);
 
 extern void UpdateIndexPredicate(Oid indexoid, Node *oldPred, Node *predicate);
 
index 25541ed9b9566e64444bbae30b369f99b2350a1a..589f4245f740ff49abf4ce612f31a955da5307da 100644 (file)
@@ -7,22 +7,15 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: rewriteSupport.h,v 1.11 2000/01/26 05:58:30 momjian Exp $
+ * $Id: rewriteSupport.h,v 1.12 2000/06/30 07:04:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #ifndef REWRITESUPPORT_H
 #define REWRITESUPPORT_H
 
-#include "access/attnum.h"
-#include "nodes/pg_list.h"
-
 extern int IsDefinedRewriteRule(char *ruleName);
 
-extern void prs2_addToRelation(Oid relid, Oid ruleId, CmdType event_type,
-                  AttrNumber attno, bool isInstead, Node *qual,
-                  List *actions);
-extern void prs2_deleteFromRelation(Oid relid, Oid ruleId);
-
+extern void setRelhasrulesInRelation(Oid relationId, bool relhasrules);
 
 #endif  /* REWRITESUPPORT_H */
index 901020611aca5547708c18ca58c73668a1d5dffd..121012d7fd4984bf61683ec5fcfec04e9bd8a2f5 100644 (file)
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: rel.h,v 1.38 2000/06/18 22:44:34 tgl Exp $
+ * $Id: rel.h,v 1.39 2000/06/30 07:04:03 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -85,7 +85,7 @@ typedef struct TriggerDesc
 
 typedef struct RelationData
 {
-   File        rd_fd;          /* open file descriptor */
+   File        rd_fd;          /* open file descriptor, or -1 if none */
    int         rd_nblocks;     /* number of blocks in rel */
    uint16      rd_refcnt;      /* reference count */
    bool        rd_myxactonly;  /* rel uses the local buffer mgr */
@@ -99,6 +99,7 @@ typedef struct RelationData
    LockInfoData rd_lockInfo;   /* lock mgr's info for locking relation */
    TupleDesc   rd_att;         /* tuple descriptor */
    RuleLock   *rd_rules;       /* rewrite rules */
+   MemoryContext rd_rulescxt;  /* private memory cxt for rd_rules, if any */
    IndexStrategy rd_istrat;    /* info needed if rel is an index */
    RegProcedure *rd_support;
    TriggerDesc *trigdesc;      /* Trigger info, or NULL if rel has none */