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Change SearchSysCache coding conventions so that a reference count is

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maintained for each cache entry.  A cache entry will not be freed until
the matching ReleaseSysCache call has been executed.  This eliminates
worries about cache entries getting dropped while still in use.  See
my posting to pg-hackers of even date for more info.
This commit is contained in:
Tom Lane
2000-11-16 22:30:52 +00:00
parent cff23842a4
commit a933ee38bb
95 changed files with 2672 additions and 2314 deletions
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105
src/backend/commands/comment.c
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@ -276,7 +276,6 @@ DeleteComments(Oid oid)
static void
CommentRelation(int reltype, char *relname, char *comment)
{
HeapTuple reltuple;
Oid oid;
char relkind;
@ -288,17 +287,20 @@ CommentRelation(int reltype, char *relname, char *comment)
/*** Now, attempt to find the oid in the cached version of pg_class ***/
reltuple = SearchSysCacheTuple(RELNAME, PointerGetDatum(relname),
0, 0, 0);
reltuple = SearchSysCache(RELNAME,
PointerGetDatum(relname),
0, 0, 0);
if (!HeapTupleIsValid(reltuple))
elog(ERROR, "relation '%s' does not exist", relname);
oid = reltuple->t_data->t_oid;
/*** Next, verify that the relation type matches the intent ***/
relkind = ((Form_pg_class) GETSTRUCT(reltuple))->relkind;
ReleaseSysCache(reltuple);
/*** Next, verify that the relation type matches the intent ***/
switch (reltype)
{
case (INDEX):
@ -322,7 +324,6 @@ CommentRelation(int reltype, char *relname, char *comment)
/*** Create the comments using the tuple's oid ***/
CreateComments(oid, comment);
}
/*------------------------------------------------------------------
@ -340,9 +341,7 @@ CommentRelation(int reltype, char *relname, char *comment)
static void
CommentAttribute(char *relname, char *attrname, char *comment)
{
Relation relation;
HeapTuple attrtuple;
Oid oid;
/*** First, check object security ***/
@ -350,15 +349,19 @@ CommentAttribute(char *relname, char *attrname, char *comment)
if (!pg_ownercheck(GetUserId(), relname, RELNAME))
elog(ERROR, "you are not permitted to comment on class '%s\'", relname);
/*** Now, fetch the attribute oid from the system cache ***/
/* Open the containing relation to ensure it won't go away meanwhile */
relation = heap_openr(relname, AccessShareLock);
attrtuple = SearchSysCacheTuple(ATTNAME, ObjectIdGetDatum(relation->rd_id),
PointerGetDatum(attrname), 0, 0);
if (!HeapTupleIsValid(attrtuple))
/*** Now, fetch the attribute oid from the system cache ***/
oid = GetSysCacheOid(ATTNAME,
ObjectIdGetDatum(relation->rd_id),
PointerGetDatum(attrname),
0, 0);
if (!OidIsValid(oid))
elog(ERROR, "'%s' is not an attribute of class '%s'",
attrname, relname);
oid = attrtuple->t_data->t_oid;
/*** Call CreateComments() to create/drop the comments ***/
@ -412,11 +415,13 @@ CommentDatabase(char *database, char *comment)
/*** Now, fetch user information ***/
userid = GetUserId();
usertuple = SearchSysCacheTuple(SHADOWSYSID, ObjectIdGetDatum(userid),
0, 0, 0);
usertuple = SearchSysCache(SHADOWSYSID,
ObjectIdGetDatum(userid),
0, 0, 0);
if (!HeapTupleIsValid(usertuple))
elog(ERROR, "invalid user id %u", (unsigned) userid);
superuser = ((Form_pg_shadow) GETSTRUCT(usertuple))->usesuper;
ReleaseSysCache(usertuple);
/*** Allow if the userid matches the database dba or is a superuser ***/
@ -452,8 +457,6 @@ CommentDatabase(char *database, char *comment)
static void
CommentRewrite(char *rule, char *comment)
{
HeapTuple rewritetuple;
Oid oid;
char *relation;
int aclcheck;
@ -472,17 +475,15 @@ CommentRewrite(char *rule, char *comment)
/*** Next, find the rule's oid ***/
rewritetuple = SearchSysCacheTuple(RULENAME, PointerGetDatum(rule),
0, 0, 0);
if (!HeapTupleIsValid(rewritetuple))
oid = GetSysCacheOid(RULENAME,
PointerGetDatum(rule),
0, 0, 0);
if (!OidIsValid(oid))
elog(ERROR, "rule '%s' does not exist", rule);
oid = rewritetuple->t_data->t_oid;
/*** Call CreateComments() to create/drop the comments ***/
CreateComments(oid, comment);
}
/*------------------------------------------------------------------
@ -499,8 +500,6 @@ CommentRewrite(char *rule, char *comment)
static void
CommentType(char *type, char *comment)
{
HeapTuple typetuple;
Oid oid;
/*** First, validate user ***/
@ -515,17 +514,15 @@ CommentType(char *type, char *comment)
/*** Next, find the type's oid ***/
typetuple = SearchSysCacheTuple(TYPENAME, PointerGetDatum(type),
0, 0, 0);
if (!HeapTupleIsValid(typetuple))
oid = GetSysCacheOid(TYPENAME,
PointerGetDatum(type),
0, 0, 0);
if (!OidIsValid(oid))
elog(ERROR, "type '%s' does not exist", type);
oid = typetuple->t_data->t_oid;
/*** Call CreateComments() to create/drop the comments ***/
CreateComments(oid, comment);
}
/*------------------------------------------------------------------
@ -543,7 +540,6 @@ CommentAggregate(char *aggregate, List *arguments, char *comment)
{
TypeName *aggtype = (TypeName *) lfirst(arguments);
char *aggtypename = NULL;
HeapTuple aggtuple;
Oid baseoid,
oid;
bool defined;
@ -580,9 +576,11 @@ CommentAggregate(char *aggregate, List *arguments, char *comment)
/*** Now, attempt to find the actual tuple in pg_aggregate ***/
aggtuple = SearchSysCacheTuple(AGGNAME, PointerGetDatum(aggregate),
ObjectIdGetDatum(baseoid), 0, 0);
if (!HeapTupleIsValid(aggtuple))
oid = GetSysCacheOid(AGGNAME,
PointerGetDatum(aggregate),
ObjectIdGetDatum(baseoid),
0, 0);
if (!OidIsValid(oid))
{
if (aggtypename)
{
@ -593,12 +591,9 @@ CommentAggregate(char *aggregate, List *arguments, char *comment)
elog(ERROR, "aggregate '%s' does not exist", aggregate);
}
oid = aggtuple->t_data->t_oid;
/*** Call CreateComments() to create/drop the comments ***/
CreateComments(oid, comment);
}
/*------------------------------------------------------------------
@ -615,8 +610,6 @@ CommentAggregate(char *aggregate, List *arguments, char *comment)
static void
CommentProc(char *function, List *arguments, char *comment)
{
HeapTuple argtuple,
functuple;
Oid oid,
argoids[FUNC_MAX_ARGS];
int i,
@ -640,12 +633,11 @@ CommentProc(char *function, List *arguments, char *comment)
argoids[i] = InvalidOid;
else
{
argtuple = SearchSysCacheTuple(TYPENAME,
PointerGetDatum(typnam),
0, 0, 0);
if (!HeapTupleIsValid(argtuple))
argoids[i] = GetSysCacheOid(TYPENAME,
PointerGetDatum(typnam),
0, 0, 0);
if (!OidIsValid(argoids[i]))
elog(ERROR, "CommentProc: type '%s' not found", typnam);
argoids[i] = argtuple->t_data->t_oid;
}
}
@ -659,14 +651,14 @@ CommentProc(char *function, List *arguments, char *comment)
/*** Now, find the corresponding oid for this procedure ***/
functuple = SearchSysCacheTuple(PROCNAME, PointerGetDatum(function),
Int32GetDatum(argcount),
PointerGetDatum(argoids), 0);
if (!HeapTupleIsValid(functuple))
oid = GetSysCacheOid(PROCNAME,
PointerGetDatum(function),
Int32GetDatum(argcount),
PointerGetDatum(argoids),
0);
if (!OidIsValid(oid))
func_error("CommentProc", function, argcount, argoids, NULL);
oid = functuple->t_data->t_oid;
/*** Call CreateComments() to create/drop the comments ***/
CreateComments(oid, comment);
@ -738,10 +730,11 @@ CommentOperator(char *opername, List *arguments, char *comment)
/*** Attempt to fetch the operator oid ***/
optuple = SearchSysCacheTupleCopy(OPERNAME, PointerGetDatum(opername),
ObjectIdGetDatum(leftoid),
ObjectIdGetDatum(rightoid),
CharGetDatum(oprtype));
optuple = SearchSysCache(OPERNAME,
PointerGetDatum(opername),
ObjectIdGetDatum(leftoid),
ObjectIdGetDatum(rightoid),
CharGetDatum(oprtype));
if (!HeapTupleIsValid(optuple))
elog(ERROR, "operator '%s' does not exist", opername);
@ -764,6 +757,8 @@ CommentOperator(char *opername, List *arguments, char *comment)
if (oid == InvalidOid)
elog(ERROR, "operator '%s' does not have an underlying function", opername);
ReleaseSysCache(optuple);
/*** Call CreateComments() to create/drop the comments ***/
CreateComments(oid, comment);