postgres/src/backend/utils/adt/array_userfuncs.c

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/*-------------------------------------------------------------------------
*
* array_userfuncs.c
* Misc user-visible array support functions
*
* Copyright (c) 2003-2015, PostgreSQL Global Development Group
*
* IDENTIFICATION
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* src/backend/utils/adt/array_userfuncs.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "catalog/pg_type.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/typcache.h"
static Datum array_offset_common(FunctionCallInfo fcinfo);
/*
* fetch_array_arg_replace_nulls
*
* Fetch an array-valued argument; if it's null, construct an empty array
* value of the proper data type. Also cache basic element type information
* in fn_extra.
*/
static ArrayType *
fetch_array_arg_replace_nulls(FunctionCallInfo fcinfo, int argno)
{
ArrayType *v;
Oid element_type;
ArrayMetaState *my_extra;
/* First collect the array value */
if (!PG_ARGISNULL(argno))
{
v = PG_GETARG_ARRAYTYPE_P(argno);
element_type = ARR_ELEMTYPE(v);
}
else
{
/* We have to look up the array type and element type */
Oid arr_typeid = get_fn_expr_argtype(fcinfo->flinfo, argno);
if (!OidIsValid(arr_typeid))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine input data type")));
element_type = get_element_type(arr_typeid);
if (!OidIsValid(element_type))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("input data type is not an array")));
v = construct_empty_array(element_type);
}
/* Now cache required info, which might change from call to call */
my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
if (my_extra == NULL)
{
my_extra = (ArrayMetaState *)
MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
sizeof(ArrayMetaState));
my_extra->element_type = InvalidOid;
fcinfo->flinfo->fn_extra = my_extra;
}
if (my_extra->element_type != element_type)
{
get_typlenbyvalalign(element_type,
&my_extra->typlen,
&my_extra->typbyval,
&my_extra->typalign);
my_extra->element_type = element_type;
}
return v;
}
/*-----------------------------------------------------------------------------
* array_append :
* push an element onto the end of a one-dimensional array
*----------------------------------------------------------------------------
*/
Datum
array_append(PG_FUNCTION_ARGS)
{
ArrayType *v;
Datum newelem;
bool isNull;
ArrayType *result;
int *dimv,
*lb;
int indx;
ArrayMetaState *my_extra;
v = fetch_array_arg_replace_nulls(fcinfo, 0);
isNull = PG_ARGISNULL(1);
if (isNull)
newelem = (Datum) 0;
else
newelem = PG_GETARG_DATUM(1);
if (ARR_NDIM(v) == 1)
{
/* append newelem */
int ub;
lb = ARR_LBOUND(v);
dimv = ARR_DIMS(v);
ub = dimv[0] + lb[0] - 1;
indx = ub + 1;
/* overflow? */
if (indx < ub)
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
}
else if (ARR_NDIM(v) == 0)
indx = 1;
else
ereport(ERROR,
(errcode(ERRCODE_DATA_EXCEPTION),
errmsg("argument must be empty or one-dimensional array")));
/* Perform element insertion */
my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
result = array_set(v, 1, &indx, newelem, isNull,
-1, my_extra->typlen, my_extra->typbyval, my_extra->typalign);
PG_RETURN_ARRAYTYPE_P(result);
}
/*-----------------------------------------------------------------------------
* array_prepend :
* push an element onto the front of a one-dimensional array
*----------------------------------------------------------------------------
*/
Datum
array_prepend(PG_FUNCTION_ARGS)
{
ArrayType *v;
Datum newelem;
bool isNull;
ArrayType *result;
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int *lb;
int indx;
ArrayMetaState *my_extra;
isNull = PG_ARGISNULL(0);
if (isNull)
newelem = (Datum) 0;
else
newelem = PG_GETARG_DATUM(0);
v = fetch_array_arg_replace_nulls(fcinfo, 1);
if (ARR_NDIM(v) == 1)
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{
/* prepend newelem */
lb = ARR_LBOUND(v);
indx = lb[0] - 1;
/* overflow? */
if (indx > lb[0])
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
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}
else if (ARR_NDIM(v) == 0)
indx = 1;
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else
ereport(ERROR,
(errcode(ERRCODE_DATA_EXCEPTION),
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errmsg("argument must be empty or one-dimensional array")));
/* Perform element insertion */
my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
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result = array_set(v, 1, &indx, newelem, isNull,
-1, my_extra->typlen, my_extra->typbyval, my_extra->typalign);
/* Readjust result's LB to match the input's, as expected for prepend */
if (ARR_NDIM(v) == 1)
ARR_LBOUND(result)[0] = ARR_LBOUND(v)[0];
PG_RETURN_ARRAYTYPE_P(result);
}
/*-----------------------------------------------------------------------------
* array_cat :
* concatenate two nD arrays to form an nD array, or
* push an (n-1)D array onto the end of an nD array
*----------------------------------------------------------------------------
*/
Datum
array_cat(PG_FUNCTION_ARGS)
{
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ArrayType *v1,
*v2;
ArrayType *result;
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int *dims,
*lbs,
ndims,
nitems,
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ndatabytes,
nbytes;
int *dims1,
*lbs1,
ndims1,
nitems1,
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ndatabytes1;
int *dims2,
*lbs2,
ndims2,
nitems2,
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ndatabytes2;
int i;
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char *dat1,
*dat2;
bits8 *bitmap1,
*bitmap2;
Oid element_type;
Oid element_type1;
Oid element_type2;
int32 dataoffset;
/* Concatenating a null array is a no-op, just return the other input */
if (PG_ARGISNULL(0))
{
if (PG_ARGISNULL(1))
PG_RETURN_NULL();
result = PG_GETARG_ARRAYTYPE_P(1);
PG_RETURN_ARRAYTYPE_P(result);
}
if (PG_ARGISNULL(1))
{
result = PG_GETARG_ARRAYTYPE_P(0);
PG_RETURN_ARRAYTYPE_P(result);
}
v1 = PG_GETARG_ARRAYTYPE_P(0);
v2 = PG_GETARG_ARRAYTYPE_P(1);
element_type1 = ARR_ELEMTYPE(v1);
element_type2 = ARR_ELEMTYPE(v2);
/* Check we have matching element types */
if (element_type1 != element_type2)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("cannot concatenate incompatible arrays"),
errdetail("Arrays with element types %s and %s are not "
"compatible for concatenation.",
format_type_be(element_type1),
format_type_be(element_type2))));
/* OK, use it */
element_type = element_type1;
/*----------
* We must have one of the following combinations of inputs:
* 1) one empty array, and one non-empty array
* 2) both arrays empty
* 3) two arrays with ndims1 == ndims2
* 4) ndims1 == ndims2 - 1
* 5) ndims1 == ndims2 + 1
*----------
*/
ndims1 = ARR_NDIM(v1);
ndims2 = ARR_NDIM(v2);
/*
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* short circuit - if one input array is empty, and the other is not, we
* return the non-empty one as the result
*
* if both are empty, return the first one
*/
if (ndims1 == 0 && ndims2 > 0)
PG_RETURN_ARRAYTYPE_P(v2);
if (ndims2 == 0)
PG_RETURN_ARRAYTYPE_P(v1);
/* the rest fall under rule 3, 4, or 5 */
if (ndims1 != ndims2 &&
ndims1 != ndims2 - 1 &&
ndims1 != ndims2 + 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("cannot concatenate incompatible arrays"),
errdetail("Arrays of %d and %d dimensions are not "
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"compatible for concatenation.",
ndims1, ndims2)));
/* get argument array details */
lbs1 = ARR_LBOUND(v1);
lbs2 = ARR_LBOUND(v2);
dims1 = ARR_DIMS(v1);
dims2 = ARR_DIMS(v2);
dat1 = ARR_DATA_PTR(v1);
dat2 = ARR_DATA_PTR(v2);
bitmap1 = ARR_NULLBITMAP(v1);
bitmap2 = ARR_NULLBITMAP(v2);
nitems1 = ArrayGetNItems(ndims1, dims1);
nitems2 = ArrayGetNItems(ndims2, dims2);
ndatabytes1 = ARR_SIZE(v1) - ARR_DATA_OFFSET(v1);
ndatabytes2 = ARR_SIZE(v2) - ARR_DATA_OFFSET(v2);
if (ndims1 == ndims2)
{
/*
* resulting array is made up of the elements (possibly arrays
* themselves) of the input argument arrays
*/
ndims = ndims1;
dims = (int *) palloc(ndims * sizeof(int));
lbs = (int *) palloc(ndims * sizeof(int));
dims[0] = dims1[0] + dims2[0];
lbs[0] = lbs1[0];
for (i = 1; i < ndims; i++)
{
if (dims1[i] != dims2[i] || lbs1[i] != lbs2[i])
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("cannot concatenate incompatible arrays"),
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errdetail("Arrays with differing element dimensions are "
"not compatible for concatenation.")));
dims[i] = dims1[i];
lbs[i] = lbs1[i];
}
}
else if (ndims1 == ndims2 - 1)
{
/*
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* resulting array has the second argument as the outer array, with
* the first argument inserted at the front of the outer dimension
*/
ndims = ndims2;
dims = (int *) palloc(ndims * sizeof(int));
lbs = (int *) palloc(ndims * sizeof(int));
memcpy(dims, dims2, ndims * sizeof(int));
memcpy(lbs, lbs2, ndims * sizeof(int));
/* increment number of elements in outer array */
dims[0] += 1;
/* make sure the added element matches our existing elements */
for (i = 0; i < ndims1; i++)
{
if (dims1[i] != dims[i + 1] || lbs1[i] != lbs[i + 1])
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("cannot concatenate incompatible arrays"),
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errdetail("Arrays with differing dimensions are not "
"compatible for concatenation.")));
}
}
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else
{
/*
* (ndims1 == ndims2 + 1)
*
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* resulting array has the first argument as the outer array, with the
* second argument appended to the end of the outer dimension
*/
ndims = ndims1;
dims = (int *) palloc(ndims * sizeof(int));
lbs = (int *) palloc(ndims * sizeof(int));
memcpy(dims, dims1, ndims * sizeof(int));
memcpy(lbs, lbs1, ndims * sizeof(int));
/* increment number of elements in outer array */
dims[0] += 1;
/* make sure the added element matches our existing elements */
for (i = 0; i < ndims2; i++)
{
if (dims2[i] != dims[i + 1] || lbs2[i] != lbs[i + 1])
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("cannot concatenate incompatible arrays"),
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errdetail("Arrays with differing dimensions are not "
"compatible for concatenation.")));
}
}
/* Do this mainly for overflow checking */
nitems = ArrayGetNItems(ndims, dims);
/* build the result array */
ndatabytes = ndatabytes1 + ndatabytes2;
if (ARR_HASNULL(v1) || ARR_HASNULL(v2))
{
dataoffset = ARR_OVERHEAD_WITHNULLS(ndims, nitems);
nbytes = ndatabytes + dataoffset;
}
else
{
dataoffset = 0; /* marker for no null bitmap */
nbytes = ndatabytes + ARR_OVERHEAD_NONULLS(ndims);
}
result = (ArrayType *) palloc0(nbytes);
SET_VARSIZE(result, nbytes);
result->ndim = ndims;
result->dataoffset = dataoffset;
result->elemtype = element_type;
memcpy(ARR_DIMS(result), dims, ndims * sizeof(int));
memcpy(ARR_LBOUND(result), lbs, ndims * sizeof(int));
/* data area is arg1 then arg2 */
memcpy(ARR_DATA_PTR(result), dat1, ndatabytes1);
memcpy(ARR_DATA_PTR(result) + ndatabytes1, dat2, ndatabytes2);
/* handle the null bitmap if needed */
if (ARR_HASNULL(result))
{
array_bitmap_copy(ARR_NULLBITMAP(result), 0,
bitmap1, 0,
nitems1);
array_bitmap_copy(ARR_NULLBITMAP(result), nitems1,
bitmap2, 0,
nitems2);
}
PG_RETURN_ARRAYTYPE_P(result);
}
/*
* used by text_to_array() in varlena.c
*/
ArrayType *
create_singleton_array(FunctionCallInfo fcinfo,
Oid element_type,
Datum element,
bool isNull,
int ndims)
{
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Datum dvalues[1];
bool nulls[1];
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int16 typlen;
bool typbyval;
char typalign;
int dims[MAXDIM];
int lbs[MAXDIM];
int i;
ArrayMetaState *my_extra;
if (ndims < 1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("invalid number of dimensions: %d", ndims)));
if (ndims > MAXDIM)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("number of array dimensions (%d) exceeds the maximum allowed (%d)",
ndims, MAXDIM)));
dvalues[0] = element;
nulls[0] = isNull;
for (i = 0; i < ndims; i++)
{
dims[i] = 1;
lbs[i] = 1;
}
/*
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* We arrange to look up info about element type only once per series of
* calls, assuming the element type doesn't change underneath us.
*/
my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
if (my_extra == NULL)
{
fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
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sizeof(ArrayMetaState));
my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
my_extra->element_type = ~element_type;
}
if (my_extra->element_type != element_type)
{
/* Get info about element type */
get_typlenbyvalalign(element_type,
&my_extra->typlen,
&my_extra->typbyval,
&my_extra->typalign);
my_extra->element_type = element_type;
}
typlen = my_extra->typlen;
typbyval = my_extra->typbyval;
typalign = my_extra->typalign;
return construct_md_array(dvalues, nulls, ndims, dims, lbs, element_type,
typlen, typbyval, typalign);
}
/*
* ARRAY_AGG(anynonarray) aggregate function
*/
Datum
array_agg_transfn(PG_FUNCTION_ARGS)
{
Oid arg1_typeid = get_fn_expr_argtype(fcinfo->flinfo, 1);
MemoryContext aggcontext;
ArrayBuildState *state;
Datum elem;
if (arg1_typeid == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine input data type")));
/*
* Note: we do not need a run-time check about whether arg1_typeid is a
* valid array element type, because the parser would have verified that
* while resolving the input/result types of this polymorphic aggregate.
*/
if (!AggCheckCallContext(fcinfo, &aggcontext))
{
/* cannot be called directly because of internal-type argument */
elog(ERROR, "array_agg_transfn called in non-aggregate context");
}
if (PG_ARGISNULL(0))
state = initArrayResult(arg1_typeid, aggcontext, false);
else
state = (ArrayBuildState *) PG_GETARG_POINTER(0);
elem = PG_ARGISNULL(1) ? (Datum) 0 : PG_GETARG_DATUM(1);
state = accumArrayResult(state,
elem,
PG_ARGISNULL(1),
arg1_typeid,
aggcontext);
/*
* The transition type for array_agg() is declared to be "internal", which
* is a pass-by-value type the same size as a pointer. So we can safely
* pass the ArrayBuildState pointer through nodeAgg.c's machinations.
*/
PG_RETURN_POINTER(state);
}
Datum
array_agg_finalfn(PG_FUNCTION_ARGS)
{
Datum result;
ArrayBuildState *state;
int dims[1];
int lbs[1];
/* cannot be called directly because of internal-type argument */
Assert(AggCheckCallContext(fcinfo, NULL));
state = PG_ARGISNULL(0) ? NULL : (ArrayBuildState *) PG_GETARG_POINTER(0);
if (state == NULL)
PG_RETURN_NULL(); /* returns null iff no input values */
dims[0] = state->nelems;
lbs[0] = 1;
/*
* Make the result. We cannot release the ArrayBuildState because
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* sometimes aggregate final functions are re-executed. Rather, it is
* nodeAgg.c's responsibility to reset the aggcontext when it's safe to do
* so.
*/
result = makeMdArrayResult(state, 1, dims, lbs,
CurrentMemoryContext,
false);
PG_RETURN_DATUM(result);
}
/*
* ARRAY_AGG(anyarray) aggregate function
*/
Datum
array_agg_array_transfn(PG_FUNCTION_ARGS)
{
Oid arg1_typeid = get_fn_expr_argtype(fcinfo->flinfo, 1);
MemoryContext aggcontext;
ArrayBuildStateArr *state;
if (arg1_typeid == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine input data type")));
/*
* Note: we do not need a run-time check about whether arg1_typeid is a
* valid array type, because the parser would have verified that while
* resolving the input/result types of this polymorphic aggregate.
*/
if (!AggCheckCallContext(fcinfo, &aggcontext))
{
/* cannot be called directly because of internal-type argument */
elog(ERROR, "array_agg_array_transfn called in non-aggregate context");
}
if (PG_ARGISNULL(0))
state = initArrayResultArr(arg1_typeid, InvalidOid, aggcontext, false);
else
state = (ArrayBuildStateArr *) PG_GETARG_POINTER(0);
state = accumArrayResultArr(state,
PG_GETARG_DATUM(1),
PG_ARGISNULL(1),
arg1_typeid,
aggcontext);
/*
* The transition type for array_agg() is declared to be "internal", which
* is a pass-by-value type the same size as a pointer. So we can safely
* pass the ArrayBuildStateArr pointer through nodeAgg.c's machinations.
*/
PG_RETURN_POINTER(state);
}
Datum
array_agg_array_finalfn(PG_FUNCTION_ARGS)
{
Datum result;
ArrayBuildStateArr *state;
/* cannot be called directly because of internal-type argument */
Assert(AggCheckCallContext(fcinfo, NULL));
state = PG_ARGISNULL(0) ? NULL : (ArrayBuildStateArr *) PG_GETARG_POINTER(0);
if (state == NULL)
PG_RETURN_NULL(); /* returns null iff no input values */
/*
* Make the result. We cannot release the ArrayBuildStateArr because
* sometimes aggregate final functions are re-executed. Rather, it is
* nodeAgg.c's responsibility to reset the aggcontext when it's safe to do
* so.
*/
result = makeArrayResultArr(state, CurrentMemoryContext, false);
PG_RETURN_DATUM(result);
}
/*-----------------------------------------------------------------------------
* array_offset, array_offset_start :
* return the offset of a value in an array.
*
* IS NOT DISTINCT FROM semantics are used for comparisons. Return NULL when
* the value is not found.
*-----------------------------------------------------------------------------
*/
Datum
array_offset(PG_FUNCTION_ARGS)
{
return array_offset_common(fcinfo);
}
Datum
array_offset_start(PG_FUNCTION_ARGS)
{
return array_offset_common(fcinfo);
}
/*
* array_offset_common
* Common code for array_offset and array_offset_start
*
* These are separate wrappers for the sake of opr_sanity regression test.
* They are not strict so we have to test for null inputs explicitly.
*/
static Datum
array_offset_common(FunctionCallInfo fcinfo)
{
ArrayType *array;
Oid collation = PG_GET_COLLATION();
Oid element_type;
Datum searched_element,
value;
bool isnull;
int offset = 0,
offset_min;
bool found = false;
TypeCacheEntry *typentry;
ArrayMetaState *my_extra;
bool null_search;
ArrayIterator array_iterator;
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
array = PG_GETARG_ARRAYTYPE_P(0);
element_type = ARR_ELEMTYPE(array);
/*
* We refuse to search for elements in multi-dimensional arrays, since we
* have no good way to report the element's location in the array.
*/
if (ARR_NDIM(array) > 1)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("searching for elements in multidimensional arrays is not supported")));
if (PG_ARGISNULL(1))
{
/* fast return when the array doesn't have have nulls */
if (!array_contains_nulls(array))
PG_RETURN_NULL();
searched_element = (Datum) 0;
null_search = true;
}
else
{
searched_element = PG_GETARG_DATUM(1);
null_search = false;
}
/* figure out where to start */
if (PG_NARGS() == 3)
{
if (PG_ARGISNULL(2))
ereport(ERROR,
(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
errmsg("initial offset should not be NULL")));
offset_min = PG_GETARG_INT32(2);
}
else
offset_min = 1;
/*
* We arrange to look up type info for array_create_iterator only once per
* series of calls, assuming the element type doesn't change underneath us.
*/
my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
if (my_extra == NULL)
{
fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
sizeof(ArrayMetaState));
my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
my_extra->element_type = ~element_type;
}
if (my_extra->element_type != element_type)
{
get_typlenbyvalalign(element_type,
&my_extra->typlen,
&my_extra->typbyval,
&my_extra->typalign);
typentry = lookup_type_cache(element_type, TYPECACHE_EQ_OPR_FINFO);
if (!OidIsValid(typentry->eq_opr_finfo.fn_oid))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_FUNCTION),
errmsg("could not identify an equality operator for type %s",
format_type_be(element_type))));
my_extra->element_type = element_type;
fmgr_info(typentry->eq_opr_finfo.fn_oid, &my_extra->proc);
}
/* Examine each array element until we find a match. */
array_iterator = array_create_iterator(array, 0, my_extra);
while (array_iterate(array_iterator, &value, &isnull))
{
offset += 1;
/* skip initial elements if caller requested so */
if (offset < offset_min)
continue;
/*
* Can't look at the array element's value if it's null; but if we
* search for null, we have a hit and are done.
*/
if (isnull || null_search)
{
if (isnull && null_search)
{
found = true;
break;
}
else
continue;
}
/* not nulls, so run the operator */
if (DatumGetBool(FunctionCall2Coll(&my_extra->proc, collation,
searched_element, value)))
{
found = true;
break;
}
}
array_free_iterator(array_iterator);
/* Avoid leaking memory when handed toasted input */
PG_FREE_IF_COPY(array, 0);
if (!found)
PG_RETURN_NULL();
PG_RETURN_INT32(offset);
}
/*-----------------------------------------------------------------------------
* array_offsets :
* return an array of offsets of a value in an array.
*
* IS NOT DISTINCT FROM semantics are used for comparisons. Returns NULL when
* the input array is NULL. When the value is not found in the array, returns
* an empty array.
*
* This is not strict so we have to test for null inputs explicitly.
*-----------------------------------------------------------------------------
*/
Datum
array_offsets(PG_FUNCTION_ARGS)
{
ArrayType *array;
Oid collation = PG_GET_COLLATION();
Oid element_type;
Datum searched_element,
value;
bool isnull;
int offset = 0;
TypeCacheEntry *typentry;
ArrayMetaState *my_extra;
bool null_search;
ArrayIterator array_iterator;
ArrayBuildState *astate = NULL;
if (PG_ARGISNULL(0))
PG_RETURN_NULL();
array = PG_GETARG_ARRAYTYPE_P(0);
element_type = ARR_ELEMTYPE(array);
/*
* We refuse to search for elements in multi-dimensional arrays, since we
* have no good way to report the element's location in the array.
*/
if (ARR_NDIM(array) > 1)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("searching for elements in multidimensional arrays is not supported")));
astate = initArrayResult(INT4OID, CurrentMemoryContext, false);
if (PG_ARGISNULL(1))
{
/* fast return when the array doesn't have have nulls */
if (!array_contains_nulls(array))
PG_RETURN_DATUM(makeArrayResult(astate, CurrentMemoryContext));
searched_element = (Datum) 0;
null_search = true;
}
else
{
searched_element = PG_GETARG_DATUM(1);
null_search = false;
}
/*
* We arrange to look up type info for array_create_iterator only once per
* series of calls, assuming the element type doesn't change underneath us.
*/
my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
if (my_extra == NULL)
{
fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
sizeof(ArrayMetaState));
my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
my_extra->element_type = ~element_type;
}
if (my_extra->element_type != element_type)
{
get_typlenbyvalalign(element_type,
&my_extra->typlen,
&my_extra->typbyval,
&my_extra->typalign);
typentry = lookup_type_cache(element_type, TYPECACHE_EQ_OPR_FINFO);
if (!OidIsValid(typentry->eq_opr_finfo.fn_oid))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_FUNCTION),
errmsg("could not identify an equality operator for type %s",
format_type_be(element_type))));
my_extra->element_type = element_type;
fmgr_info(typentry->eq_opr_finfo.fn_oid, &my_extra->proc);
}
/*
* Accumulate each array offset iff the element matches the given element.
*/
array_iterator = array_create_iterator(array, 0, my_extra);
while (array_iterate(array_iterator, &value, &isnull))
{
offset += 1;
/*
* Can't look at the array element's value if it's null; but if we
* search for null, we have a hit.
*/
if (isnull || null_search)
{
if (isnull && null_search)
astate =
accumArrayResult(astate, Int32GetDatum(offset), false,
INT4OID, CurrentMemoryContext);
continue;
}
/* not nulls, so run the operator */
if (DatumGetBool(FunctionCall2Coll(&my_extra->proc, collation,
searched_element, value)))
astate =
accumArrayResult(astate, Int32GetDatum(offset), false,
INT4OID, CurrentMemoryContext);
}
array_free_iterator(array_iterator);
/* Avoid leaking memory when handed toasted input */
PG_FREE_IF_COPY(array, 0);
PG_RETURN_DATUM(makeArrayResult(astate, CurrentMemoryContext));
}