/* ----------------------------------------------------------------
* caql_endscan()
* free all resources associated with the scan, including tuples,
* tables and locks.
* NOTE: this function is *not* a "drop-in" replacement for
* ReleaseSysCache. ReleaseSysCache is only called for valid tuples,
* but you must always call endscan, even if getnext never returned a
* valid tuple.
* ----------------------------------------------------------------
*/
void caql_endscan(cqContext *pCtx)
{
if (pCtx->cq_indstate) /* close the indexes if they were open */
CatalogCloseIndexes(pCtx->cq_indstate);
pCtx->cq_indstate = NULL;
pCtx->cq_bScanBlock = false; /* scan block has ended */
if (pCtx->cq_freeScan)
{
if (!pCtx->cq_usesyscache)
systable_endscan(pCtx->cq_sysScan);
else
{
/* XXX XXX: no need to release if never fetched a valid tuple */
if (HeapTupleIsValid(pCtx->cq_lasttup))
ReleaseSysCache(pCtx->cq_lasttup);
}
}
caql_heapclose(pCtx);
if (pCtx->cq_free) /* free dynamic context */
pfree(pCtx);
pCtx->cq_freeScan = false;
pCtx->cq_free = false;
}
/* ----------------------------------------------------------------
* caql_begin_CacheList()
* Return a catclist
*
* In general, catquery will choose the syscache when the cql
* statement contains an equality predicate on *all* of the syscache
* primary key index columns, eg:
*
* cql("SELECT * FROM pg_amop WHERE amopopr = :1 and amopclaid = :2 ")
*
* will use the AMOPOPID syscache with index
* AccessMethodOperatorIndexId. However, the cql statement for a
* list-search requires an equality predicate on a subset of the
* initial columns of the index, with *all* of the index columns
* specified in an ORDER BY clause, eg:
*
* cql("SELECT * FROM pg_amop WHERE amopopr = :1 "
* " ORDER BY amopopr, amopclaid ")
*
* will use a syscache list-search if this cql statement is an
* argument to caql_begin_CacheList(). However, the syscache will
* *not* be used for this statement if it is supplied for
* caql_beginscan(), since SearchSysCache() can only return (at most)
* a single tuple.
*
* NOTE: caql_begin_CacheList() will assert (Insist!) at runtime if
* the cql statement does not map to a syscache lookup.
* NOTE: it may be possible to "collapse" this API into the existing
* beginscan/getnext/endscan.
* ----------------------------------------------------------------
*/
struct catclist *
caql_begin_CacheList(cqContext *pCtx0,
cq_list *pcql)
{
const char* caql_str = pcql->caqlStr;
const char* filenam = pcql->filename;
int lineno = pcql->lineno;
struct caql_hash_cookie *pchn = cq_lookup(caql_str, strlen(caql_str), pcql);
cqContext *pCtx;
cqContext cqc;
if (NULL == pchn)
elog(ERROR, "invalid caql string: %s\nfile: %s, line %d",
caql_str, filenam, lineno);
Assert(!pchn->bInsert); /* INSERT not allowed */
Assert(!pchn->bUpdate); /* UPDATE not allowed */
Assert(!pchn->bDelete); /* DELETE not allowed */
/* use the provided context, or provide a clean local ctx */
if (pCtx0)
pCtx = pCtx0;
else
pCtx = cqclr(&cqc);
/* NOTE: for case of cache list search, we must use syscache */
pCtx->cq_bCacheList = true;
pCtx = caql_switch(pchn, pCtx, pcql);
/* NOTE: caql_switch frees the pcql */
/* NOTE: must use the SysCache */
Insist (pCtx->cq_usesyscache);
caql_heapclose(pCtx);
return SearchSysCacheKeyArrayList(pCtx->cq_cacheId,
pCtx->cq_NumKeys,
pCtx->cq_cacheKeys);
}
/* ----------------------------------------------------------------
* caql_getfirst_only()
* Return a copy the first tuple, pallocd in the current memory context,
* and end the scan. Clients should heap_freetuple() as necessary.
* If pbOnly is not NULL, return TRUE if a second tuple is not found,
* else return FALSE
* NOTE: this function will return NULL if no tuples satisfy the
* caql predicate -- use HeapTupleIsValid() to detect this condition.
* ----------------------------------------------------------------
*/
HeapTuple caql_getfirst_only(cqContext *pCtx0, bool *pbOnly, cq_list *pcql)
{
const char* caql_str = pcql->caqlStr;
const char* filenam = pcql->filename;
int lineno = pcql->lineno;
struct caql_hash_cookie *pchn = cq_lookup(caql_str, strlen(caql_str), pcql);
cqContext *pCtx;
cqContext cqc;
HeapTuple tuple, newTup = NULL;
if (NULL == pchn)
elog(ERROR, "invalid caql string: %s\nfile: %s, line %d",
caql_str, filenam, lineno);
Assert(!pchn->bInsert); /* INSERT not allowed */
/* use the provided context, or provide a clean local ctx */
if (pCtx0)
pCtx = pCtx0;
else
pCtx = cqclr(&cqc);
pCtx = caql_switch(pchn, pCtx, pcql);
/* NOTE: caql_switch frees the pcql */
if (pbOnly) *pbOnly = true;
/* use the SysCache */
if (pCtx->cq_usesyscache)
{
tuple = SearchSysCacheKeyArray(pCtx->cq_cacheId,
pCtx->cq_NumKeys,
pCtx->cq_cacheKeys);
if (HeapTupleIsValid(tuple))
{
newTup = heap_copytuple(tuple);
ReleaseSysCache(tuple);
/* only one */
}
caql_heapclose(pCtx);
pCtx->cq_lasttup = newTup; /* need this for update/delete */
return (newTup);
}
if (HeapTupleIsValid(tuple = systable_getnext(pCtx->cq_sysScan)))
{
/* always copy the tuple, because the endscan releases tup memory */
newTup = heap_copytuple(tuple);
if (pbOnly)
{
*pbOnly =
!(HeapTupleIsValid(systable_getnext(pCtx->cq_sysScan)));
}
}
systable_endscan(pCtx->cq_sysScan);
caql_heapclose(pCtx);
pCtx->cq_lasttup = newTup; /* need this for update/delete */
return (newTup);
}
/* ----------------------------------------------------------------
* caql_getcount()
* Perform COUNT(*) or DELETE
* ----------------------------------------------------------------
*/
int caql_getcount(cqContext *pCtx0, cq_list *pcql)
{
const char* caql_str = pcql->caqlStr;
const char* filenam = pcql->filename;
int lineno = pcql->lineno;
struct caql_hash_cookie *pchn = cq_lookup(caql_str, strlen(caql_str), pcql);
cqContext *pCtx;
cqContext cqc;
HeapTuple tuple;
Relation rel;
int ii = 0;
if (NULL == pchn)
elog(ERROR, "invalid caql string: %s\nfile: %s, line %d",
caql_str, filenam, lineno);
Assert(!pchn->bInsert); /* INSERT not allowed */
/* use the provided context, or provide a clean local ctx */
if (pCtx0)
pCtx = pCtx0;
else
pCtx = cqclr(&cqc);
pCtx = caql_switch(pchn, pCtx, pcql);
/* NOTE: caql_switch frees the pcql */
rel = pCtx->cq_heap_rel;
/* use the SysCache */
if (pCtx->cq_usesyscache)
{
tuple = SearchSysCacheKeyArray(pCtx->cq_cacheId,
pCtx->cq_NumKeys,
pCtx->cq_cacheKeys);
if (HeapTupleIsValid(tuple))
{
ii++;
pCtx->cq_lasttup = tuple;
if (pchn->bDelete)
simple_heap_delete(rel, &tuple->t_self);
ReleaseSysCache(tuple);
/* only one */
}
caql_heapclose(pCtx);
return (ii);
}
while (HeapTupleIsValid(tuple = systable_getnext(pCtx->cq_sysScan)))
{
if (HeapTupleIsValid(tuple) && pchn->bDelete)
{
pCtx->cq_lasttup = tuple;
if (pchn->bDelete)
simple_heap_delete(rel, &tuple->t_self);
}
ii++;
}
systable_endscan(pCtx->cq_sysScan);
caql_heapclose(pCtx);
return (ii);
}
/* ----------------------------------------------------------------
* caql_getcstring_plus()
* Return a cstring column from the first tuple and end the scan.
* ----------------------------------------------------------------
*/
char *caql_getcstring_plus(cqContext *pCtx0, int *pFetchcount,
bool *pbIsNull, cq_list *pcql)
{
const char *caql_str = pcql->caqlStr;
const char *filenam = pcql->filename;
int lineno = pcql->lineno;
struct caql_hash_cookie *pchn = cq_lookup(caql_str, strlen(caql_str), pcql);
cqContext *pCtx;
cqContext cqc;
HeapTuple tuple;
char *result = NULL;
if (NULL == pchn)
elog(ERROR, "invalid caql string: %s\nfile: %s, line %d",
caql_str, filenam, lineno);
Assert(!pchn->bInsert); /* INSERT not allowed */
/* use the provided context, or provide a clean local ctx */
if (pCtx0)
pCtx = pCtx0;
else
pCtx = cqclr(&cqc);
pCtx = caql_switch(pchn, pCtx, pcql);
/* NOTE: caql_switch frees the pcql */
if (pFetchcount)
*pFetchcount = 0;
if (pbIsNull)
*pbIsNull = true;
/* use the SysCache */
if (pCtx->cq_usesyscache)
{
tuple = SearchSysCacheKeyArray(pCtx->cq_cacheId,
pCtx->cq_NumKeys,
pCtx->cq_cacheKeys);
}
else
{
tuple = systable_getnext(pCtx->cq_sysScan);
}
if (HeapTupleIsValid(tuple))
{
bool isnull;
Datum d;
if (pFetchcount)
*pFetchcount = 1;
d = caql_getattr_internal(pCtx, tuple, pchn->attnum, &isnull);
if (!isnull)
{
switch (pchn->atttype)
{
case NAMEOID:
result = DatumGetCString(DirectFunctionCall1(nameout, d));
break;
case TEXTOID:
result = DatumGetCString(DirectFunctionCall1(textout, d));
break;
default:
elog(ERROR, "column not a cstring: %s\nfile: %s, line %d",
caql_str, filenam, lineno);
}
}
if (pbIsNull)
*pbIsNull = isnull;
} /* end HeapTupleIsValid */
if (pCtx->cq_usesyscache)
{
if (HeapTupleIsValid(tuple))
ReleaseSysCache(tuple);
}
else
{
if (pFetchcount && HeapTupleIsValid(tuple))
{
if (HeapTupleIsValid(systable_getnext(pCtx->cq_sysScan)))
{
*pFetchcount = 2;
}
}
systable_endscan(pCtx->cq_sysScan);
}
caql_heapclose(pCtx);
return (result);
} /* end caql_getcstring_plus */
/* ----------------------------------------------------------------
* caql_getoid_only()
* Return the oid of the first tuple and end the scan
* If pbOnly is not NULL, return TRUE if a second tuple is not found,
* else return FALSE
* ----------------------------------------------------------------
*/
Oid caql_getoid_only(cqContext *pCtx0, bool *pbOnly, cq_list *pcql)
{
const char *caql_str = pcql->caqlStr;
const char *filenam = pcql->filename;
int lineno = pcql->lineno;
struct caql_hash_cookie *pchn = cq_lookup(caql_str, strlen(caql_str), pcql);
cqContext *pCtx;
cqContext cqc;
HeapTuple tuple;
Oid result = InvalidOid;
if (NULL == pchn)
elog(ERROR, "invalid caql string: %s\nfile: %s, line %d",
caql_str, filenam, lineno);
Assert(!pchn->bInsert); /* INSERT not allowed */
/* use the provided context, or provide a clean local ctx */
if (pCtx0)
pCtx = pCtx0;
else
pCtx = cqclr(&cqc);
pCtx = caql_switch(pchn, pCtx, pcql);
/* NOTE: caql_switch frees the pcql */
if (pbOnly)
*pbOnly = true;
/* use the SysCache */
if (pCtx->cq_usesyscache)
{
tuple = SearchSysCacheKeyArray(pCtx->cq_cacheId,
pCtx->cq_NumKeys,
pCtx->cq_cacheKeys);
if (HeapTupleIsValid(tuple))
{
result = HeapTupleGetOid(tuple);
ReleaseSysCache(tuple);
/* only one */
}
caql_heapclose(pCtx);
return (result);
}
if (HeapTupleIsValid(tuple = systable_getnext(pCtx->cq_sysScan)))
{
result = HeapTupleGetOid(tuple);
if (pbOnly)
{
*pbOnly =
!(HeapTupleIsValid(tuple =
systable_getnext(pCtx->cq_sysScan)));
}
}
systable_endscan(pCtx->cq_sysScan);
caql_heapclose(pCtx);
return (result);
}
/* ----------------------------------------------------------------
* caql_getoid_plus()
* Return an oid column from the first tuple and end the scan.
* Note: this works for regproc columns as well, but you should cast
* the output as RegProcedure.
* ----------------------------------------------------------------
*/
Oid caql_getoid_plus(cqContext *pCtx0, int *pFetchcount,
bool *pbIsNull, cq_list *pcql)
{
const char *caql_str = pcql->caqlStr;
const char *filenam = pcql->filename;
int lineno = pcql->lineno;
struct caql_hash_cookie *pchn = cq_lookup(caql_str, strlen(caql_str), pcql);
cqContext *pCtx;
cqContext cqc;
HeapTuple tuple;
Oid result = InvalidOid;
if (NULL == pchn)
elog(ERROR, "invalid caql string: %s\nfile: %s, line %d",
caql_str, filenam, lineno);
Assert(!pchn->bInsert); /* INSERT not allowed */
/* use the provided context, or provide a clean local ctx */
if (pCtx0)
pCtx = pCtx0;
else
pCtx = cqclr(&cqc);
pCtx = caql_switch(pchn, pCtx, pcql);
/* NOTE: caql_switch frees the pcql */
if (pFetchcount)
*pFetchcount = 0;
if (pbIsNull)
*pbIsNull = true;
/* use the SysCache */
if (pCtx->cq_usesyscache)
{
tuple = SearchSysCacheKeyArray(pCtx->cq_cacheId,
pCtx->cq_NumKeys,
pCtx->cq_cacheKeys);
}
else
{
tuple = systable_getnext(pCtx->cq_sysScan);
}
if (HeapTupleIsValid(tuple))
{
if (pFetchcount)
*pFetchcount = 1;
/* if attnum not set, (InvalidAttrNumber == 0)
* use tuple oid, else extract oid from column
* (includes ObjectIdAttributeNumber == -2)
*/
if (pchn->attnum <= InvalidAttrNumber)
{
if (pbIsNull)
*pbIsNull = false;
result = HeapTupleGetOid(tuple);
}
else /* find oid column */
{
bool isnull;
Datum d = caql_getattr_internal(pCtx, tuple, pchn->attnum,
&isnull);
if (!isnull)
{
switch (pchn->atttype)
{
case OIDOID:
case REGPROCOID:
result = DatumGetObjectId(d);
break;
default:
elog(ERROR, "column not an oid: %s\nfile: %s, line %d",
caql_str, filenam, lineno);
}
}
if (pbIsNull)
*pbIsNull = isnull;
}
} /* end HeapTupleIsValid */
if (pCtx->cq_usesyscache)
{
if (HeapTupleIsValid(tuple))
ReleaseSysCache(tuple);
}
else
{
if (pFetchcount && HeapTupleIsValid(tuple))
{
if (HeapTupleIsValid(systable_getnext(pCtx->cq_sysScan)))
{
*pFetchcount = 2;
}
}
systable_endscan(pCtx->cq_sysScan);
}
caql_heapclose(pCtx);
return (result);
} /* end caql_getoid_plus */
