postgresql/contrib/ltree/_ltree_op.c
Tom Lane 29d2f86a31 Allow zero-dimensional (ie, empty) arrays in contrib/ltree operations.
The main motivation for changing this is bug #4921, in which it's pointed out
that it's no longer safe to apply ltree operations to the result of
ARRAY(SELECT ...) if the sub-select might return no rows.  Before 8.3,
the ARRAY() construct would return NULL, which might or might not be helpful
but at least it wouldn't result in an error.  Now it returns an empty array
which results in a failure for no good reason, since the ltree operations
are all perfectly capable of dealing with zero-element arrays.

As far as I can find, these ltree functions are the only places where zero
array dimensionality is rejected unnecessarily.

Back-patch to 8.3 to prevent behavioral regression of queries that worked
in older releases.
2010-02-24 18:02:24 +00:00

335 lines
7.2 KiB
C

/*
* $PostgreSQL: pgsql/contrib/ltree/_ltree_op.c,v 1.14 2010/02/24 18:02:24 tgl Exp $
*
*
* op function for ltree[]
* Teodor Sigaev <teodor@stack.net>
*/
#include "postgres.h"
#include <ctype.h>
#include "utils/array.h"
#include "ltree.h"
PG_FUNCTION_INFO_V1(_ltree_isparent);
PG_FUNCTION_INFO_V1(_ltree_r_isparent);
PG_FUNCTION_INFO_V1(_ltree_risparent);
PG_FUNCTION_INFO_V1(_ltree_r_risparent);
PG_FUNCTION_INFO_V1(_ltq_regex);
PG_FUNCTION_INFO_V1(_ltq_rregex);
PG_FUNCTION_INFO_V1(_lt_q_regex);
PG_FUNCTION_INFO_V1(_lt_q_rregex);
PG_FUNCTION_INFO_V1(_ltxtq_exec);
PG_FUNCTION_INFO_V1(_ltxtq_rexec);
Datum _ltree_r_isparent(PG_FUNCTION_ARGS);
Datum _ltree_r_risparent(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(_ltree_extract_isparent);
PG_FUNCTION_INFO_V1(_ltree_extract_risparent);
PG_FUNCTION_INFO_V1(_ltq_extract_regex);
PG_FUNCTION_INFO_V1(_ltxtq_extract_exec);
Datum _ltree_extract_isparent(PG_FUNCTION_ARGS);
Datum _ltree_extract_risparent(PG_FUNCTION_ARGS);
Datum _ltq_extract_regex(PG_FUNCTION_ARGS);
Datum _ltxtq_extract_exec(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(_lca);
Datum _lca(PG_FUNCTION_ARGS);
typedef Datum (*PGCALL2) (PG_FUNCTION_ARGS);
#define NEXTVAL(x) ( (ltree*)( (char*)(x) + INTALIGN( VARSIZE(x) ) ) )
static bool
array_iterator(ArrayType *la, PGCALL2 callback, void *param, ltree **found)
{
int num = ArrayGetNItems(ARR_NDIM(la), ARR_DIMS(la));
ltree *item = (ltree *) ARR_DATA_PTR(la);
if (ARR_NDIM(la) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));
if (ARR_HASNULL(la))
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("array must not contain nulls")));
if (found)
*found = NULL;
while (num > 0)
{
if (DatumGetBool(DirectFunctionCall2(callback,
PointerGetDatum(item), PointerGetDatum(param))))
{
if (found)
*found = item;
return true;
}
num--;
item = NEXTVAL(item);
}
return false;
}
Datum
_ltree_isparent(PG_FUNCTION_ARGS)
{
ArrayType *la = PG_GETARG_ARRAYTYPE_P(0);
ltree *query = PG_GETARG_LTREE(1);
bool res = array_iterator(la, ltree_isparent, (void *) query, NULL);
PG_FREE_IF_COPY(la, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_BOOL(res);
}
Datum
_ltree_r_isparent(PG_FUNCTION_ARGS)
{
PG_RETURN_DATUM(DirectFunctionCall2(_ltree_isparent,
PG_GETARG_DATUM(1),
PG_GETARG_DATUM(0)
));
}
Datum
_ltree_risparent(PG_FUNCTION_ARGS)
{
ArrayType *la = PG_GETARG_ARRAYTYPE_P(0);
ltree *query = PG_GETARG_LTREE(1);
bool res = array_iterator(la, ltree_risparent, (void *) query, NULL);
PG_FREE_IF_COPY(la, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_BOOL(res);
}
Datum
_ltree_r_risparent(PG_FUNCTION_ARGS)
{
PG_RETURN_DATUM(DirectFunctionCall2(_ltree_risparent,
PG_GETARG_DATUM(1),
PG_GETARG_DATUM(0)
));
}
Datum
_ltq_regex(PG_FUNCTION_ARGS)
{
ArrayType *la = PG_GETARG_ARRAYTYPE_P(0);
lquery *query = PG_GETARG_LQUERY(1);
bool res = array_iterator(la, ltq_regex, (void *) query, NULL);
PG_FREE_IF_COPY(la, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_BOOL(res);
}
Datum
_ltq_rregex(PG_FUNCTION_ARGS)
{
PG_RETURN_DATUM(DirectFunctionCall2(_ltq_regex,
PG_GETARG_DATUM(1),
PG_GETARG_DATUM(0)
));
}
Datum
_lt_q_regex(PG_FUNCTION_ARGS)
{
ArrayType *_tree = PG_GETARG_ARRAYTYPE_P(0);
ArrayType *_query = PG_GETARG_ARRAYTYPE_P(1);
lquery *query = (lquery *) ARR_DATA_PTR(_query);
bool res = false;
int num = ArrayGetNItems(ARR_NDIM(_query), ARR_DIMS(_query));
if (ARR_NDIM(_query) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));
if (ARR_HASNULL(_query))
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("array must not contain nulls")));
while (num > 0)
{
if (array_iterator(_tree, ltq_regex, (void *) query, NULL))
{
res = true;
break;
}
num--;
query = (lquery *) NEXTVAL(query);
}
PG_FREE_IF_COPY(_tree, 0);
PG_FREE_IF_COPY(_query, 1);
PG_RETURN_BOOL(res);
}
Datum
_lt_q_rregex(PG_FUNCTION_ARGS)
{
PG_RETURN_DATUM(DirectFunctionCall2(_lt_q_regex,
PG_GETARG_DATUM(1),
PG_GETARG_DATUM(0)
));
}
Datum
_ltxtq_exec(PG_FUNCTION_ARGS)
{
ArrayType *la = PG_GETARG_ARRAYTYPE_P(0);
ltxtquery *query = PG_GETARG_LTXTQUERY(1);
bool res = array_iterator(la, ltxtq_exec, (void *) query, NULL);
PG_FREE_IF_COPY(la, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_BOOL(res);
}
Datum
_ltxtq_rexec(PG_FUNCTION_ARGS)
{
PG_RETURN_DATUM(DirectFunctionCall2(_ltxtq_exec,
PG_GETARG_DATUM(1),
PG_GETARG_DATUM(0)
));
}
Datum
_ltree_extract_isparent(PG_FUNCTION_ARGS)
{
ArrayType *la = PG_GETARG_ARRAYTYPE_P(0);
ltree *query = PG_GETARG_LTREE(1);
ltree *found,
*item;
if (!array_iterator(la, ltree_isparent, (void *) query, &found))
{
PG_FREE_IF_COPY(la, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_NULL();
}
item = (ltree *) palloc(VARSIZE(found));
memcpy(item, found, VARSIZE(found));
PG_FREE_IF_COPY(la, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_POINTER(item);
}
Datum
_ltree_extract_risparent(PG_FUNCTION_ARGS)
{
ArrayType *la = PG_GETARG_ARRAYTYPE_P(0);
ltree *query = PG_GETARG_LTREE(1);
ltree *found,
*item;
if (!array_iterator(la, ltree_risparent, (void *) query, &found))
{
PG_FREE_IF_COPY(la, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_NULL();
}
item = (ltree *) palloc(VARSIZE(found));
memcpy(item, found, VARSIZE(found));
PG_FREE_IF_COPY(la, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_POINTER(item);
}
Datum
_ltq_extract_regex(PG_FUNCTION_ARGS)
{
ArrayType *la = PG_GETARG_ARRAYTYPE_P(0);
lquery *query = PG_GETARG_LQUERY(1);
ltree *found,
*item;
if (!array_iterator(la, ltq_regex, (void *) query, &found))
{
PG_FREE_IF_COPY(la, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_NULL();
}
item = (ltree *) palloc(VARSIZE(found));
memcpy(item, found, VARSIZE(found));
PG_FREE_IF_COPY(la, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_POINTER(item);
}
Datum
_ltxtq_extract_exec(PG_FUNCTION_ARGS)
{
ArrayType *la = PG_GETARG_ARRAYTYPE_P(0);
ltxtquery *query = PG_GETARG_LTXTQUERY(1);
ltree *found,
*item;
if (!array_iterator(la, ltxtq_exec, (void *) query, &found))
{
PG_FREE_IF_COPY(la, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_NULL();
}
item = (ltree *) palloc(VARSIZE(found));
memcpy(item, found, VARSIZE(found));
PG_FREE_IF_COPY(la, 0);
PG_FREE_IF_COPY(query, 1);
PG_RETURN_POINTER(item);
}
Datum
_lca(PG_FUNCTION_ARGS)
{
ArrayType *la = PG_GETARG_ARRAYTYPE_P(0);
int num = ArrayGetNItems(ARR_NDIM(la), ARR_DIMS(la));
ltree *item = (ltree *) ARR_DATA_PTR(la);
ltree **a,
*res;
if (ARR_NDIM(la) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));
if (ARR_HASNULL(la))
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("array must not contain nulls")));
a = (ltree **) palloc(sizeof(ltree *) * num);
while (num > 0)
{
num--;
a[num] = item;
item = NEXTVAL(item);
}
res = lca_inner(a, ArrayGetNItems(ARR_NDIM(la), ARR_DIMS(la)));
pfree(a);
PG_FREE_IF_COPY(la, 0);
if (res)
PG_RETURN_POINTER(res);
else
PG_RETURN_NULL();
}