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SELECT FOR UPDATE is implemented...

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This commit is contained in:
Vadim B. Mikheev
1999-01-25 12:01:19 +00:00
parent 443e24beb7
commit 247b3f9054
7 changed files with 715 additions and 581 deletions
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109
src/backend/executor/execMain.c
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@ -26,7 +26,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.62 1998/12/18 09:10:21 vadim Exp $
* $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.63 1999/01/25 12:01:03 vadim Exp $
*
*-------------------------------------------------------------------------
*/
@ -363,6 +363,32 @@ ExecCheckPerms(CmdType operation,
}
if (!ok)
elog(ERROR, "%s: %s", rname.data, aclcheck_error_strings[aclcheck_result]);
if (parseTree->rowMark != NULL)
{
foreach(lp, parseTree->rowMark)
{
RowMark *rm = lfirst(lp);
if (!(rm->info & ROW_ACL_FOR_UPDATE))
continue;
relid = ((RangeTblEntry *)nth(rm->rti - 1, rangeTable))->relid;
htup = SearchSysCacheTuple(RELOID,
ObjectIdGetDatum(relid),
0, 0, 0);
if (!HeapTupleIsValid(htup))
elog(ERROR, "ExecCheckPerms: bogus RT relid: %d",
relid);
StrNCpy(rname.data,
((Form_pg_class) GETSTRUCT(htup))->relname.data,
NAMEDATALEN);
ok = ((aclcheck_result = CHECK(ACL_WR)) == ACLCHECK_OK);
opstr = "write";
if (!ok)
elog(ERROR, "%s: %s", rname.data, aclcheck_error_strings[aclcheck_result]);
}
}
}
/* ===============================================================
@ -372,6 +398,11 @@ ExecCheckPerms(CmdType operation,
* ===============================================================
*/
typedef struct execRowMark
{
Relation relation;
char resname[32];
} execRowMark;
/* ----------------------------------------------------------------
* InitPlan
@ -398,6 +429,10 @@ InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate)
rangeTable = parseTree->rtable;
resultRelation = parseTree->resultRelation;
#ifndef NO_SECURITY
ExecCheckPerms(operation, resultRelation, rangeTable, parseTree);
#endif
/******************
* initialize the node's execution state
******************
@ -468,9 +503,32 @@ InitPlan(CmdType operation, Query *parseTree, Plan *plan, EState *estate)
estate->es_result_relation_info = NULL;
}
#ifndef NO_SECURITY
ExecCheckPerms(operation, resultRelation, rangeTable, parseTree);
#endif
/*
* Have to lock relations selected for update
*/
estate->es_rowMark = NULL;
if (parseTree->rowMark != NULL)
{
Relation relation;
Oid relid;
RowMark *rm;
List *l;
execRowMark *erm;
foreach(l, parseTree->rowMark)
{
rm = lfirst(l);
relid = ((RangeTblEntry *)nth(rm->rti - 1, rangeTable))->relid;
relation = heap_open(relid);
LockRelation(relation, RowShareLock);
if (!(rm->info & ROW_MARK_FOR_UPDATE))
continue;
erm = (execRowMark*) palloc(sizeof(execRowMark));
erm->relation = relation;
sprintf(erm->resname, "ctid%u", rm->rti);
estate->es_rowMark = lappend(estate->es_rowMark, erm);
}
}
/******************
* initialize the executor "tuple" table.
@ -777,6 +835,49 @@ ExecutePlan(EState *estate,
* ctid!! */
tupleid = &tuple_ctid;
}
else if (estate->es_rowMark != NULL)
{
List *l;
execRowMark *erm;
Buffer buffer;
HeapTupleData tuple;
int test;
foreach (l, estate->es_rowMark)
{
erm = lfirst(l);
if (!ExecGetJunkAttribute(junkfilter,
slot,
erm->resname,
&datum,
&isNull))
elog(ERROR, "ExecutePlan: NO (junk) `%s' was found!", erm->resname);
if (isNull)
elog(ERROR, "ExecutePlan: (junk) `%s' is NULL!", erm->resname);
tuple.t_self = *((ItemPointer) DatumGetPointer(datum));
test = heap_mark4update(erm->relation, &tuple, &buffer);
ReleaseBuffer(buffer);
switch (test)
{
case HeapTupleSelfUpdated:
case HeapTupleMayBeUpdated:
break;
case HeapTupleUpdated:
if (XactIsoLevel == XACT_SERIALIZABLE)
elog(ERROR, "Can't serialize access due to concurrent update");
else
elog(ERROR, "Isolation level %u is not supported", XactIsoLevel);
return(NULL);
default:
elog(ERROR, "Unknown status %u from heap_mark4update", test);
return(NULL);
}
}
}
/******************
* Finally create a new "clean" tuple with all junk attributes