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Split array_push into separate array_append and array_prepend functions.

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There wasn't any good reason for a single C function to implement both
these SQL functions: it saved very little code overall, and it required
significant pushups to re-determine at runtime which case applied.  Redoing
it as two functions ends up with just slightly more lines of code, but it's
simpler to understand, and faster too because we need not repeat syscache
lookups on every call.

An important side benefit is that this eliminates the only case in which
different aliases of the same C function had both anyarray and anyelement
arguments at the same position, which would almost always be a mistake.
The opr_sanity regression test will now notice such mistakes since there's
no longer a valid case where it happens.
This commit is contained in:
Tom Lane
2015-02-18 20:53:14 -05:00
parent d30292b8c4
commit 56a79a869b
5 changed files with 135 additions and 112 deletions
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232
src/backend/utils/adt/array_userfuncs.c
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@ -17,101 +17,98 @@
#include "utils/lsyscache.h"
/*
* 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;
ArrayMetaState *my_extra;
my_extra = (ArrayMetaState *) fcinfo->flinfo->fn_extra;
if (my_extra == NULL)
{
/* First time through, so look up the array type and element type */
Oid arr_typeid = get_fn_expr_argtype(fcinfo->flinfo, argno);
Oid element_type;
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")));
my_extra = (ArrayMetaState *)
MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
sizeof(ArrayMetaState));
my_extra->element_type = element_type;
/* Cache info about element type */
get_typlenbyvalalign(element_type,
&my_extra->typlen,
&my_extra->typbyval,
&my_extra->typalign);
fcinfo->flinfo->fn_extra = my_extra;
}
/* Now we can collect the array value */
if (PG_ARGISNULL(argno))
v = construct_empty_array(my_extra->element_type);
else
v = PG_GETARG_ARRAYTYPE_P(argno);
return v;
}
/*-----------------------------------------------------------------------------
* array_push :
* push an element onto either end of a one-dimensional array
* array_append :
* push an element onto the end of a one-dimensional array
*----------------------------------------------------------------------------
*/
Datum
array_push(PG_FUNCTION_ARGS)
array_append(PG_FUNCTION_ARGS)
{
ArrayType *v;
Datum newelem;
bool isNull;
ArrayType *result;
int *dimv,
*lb;
ArrayType *result;
int indx;
Oid element_type;
int16 typlen;
bool typbyval;
char typalign;
Oid arg0_typeid = get_fn_expr_argtype(fcinfo->flinfo, 0);
Oid arg1_typeid = get_fn_expr_argtype(fcinfo->flinfo, 1);
Oid arg0_elemid;
Oid arg1_elemid;
ArrayMetaState *my_extra;
if (arg0_typeid == InvalidOid || arg1_typeid == InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("could not determine input data types")));
arg0_elemid = get_element_type(arg0_typeid);
arg1_elemid = get_element_type(arg1_typeid);
if (arg0_elemid != InvalidOid)
{
if (PG_ARGISNULL(0))
v = construct_empty_array(arg0_elemid);
else
v = PG_GETARG_ARRAYTYPE_P(0);
isNull = PG_ARGISNULL(1);
if (isNull)
newelem = (Datum) 0;
else
newelem = PG_GETARG_DATUM(1);
}
else if (arg1_elemid != InvalidOid)
{
if (PG_ARGISNULL(1))
v = construct_empty_array(arg1_elemid);
else
v = PG_GETARG_ARRAYTYPE_P(1);
isNull = PG_ARGISNULL(0);
if (isNull)
newelem = (Datum) 0;
else
newelem = PG_GETARG_DATUM(0);
}
v = fetch_array_arg_replace_nulls(fcinfo, 0);
isNull = PG_ARGISNULL(1);
if (isNull)
newelem = (Datum) 0;
else
{
/* Shouldn't get here given proper type checking in parser */
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("neither input type is an array")));
PG_RETURN_NULL(); /* keep compiler quiet */
}
element_type = ARR_ELEMTYPE(v);
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;
if (arg0_elemid != InvalidOid)
{
/* append newelem */
int 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
{
/* prepend newelem */
indx = lb[0] - 1;
/* overflow? */
if (indx > lb[0])
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
}
/* 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;
@ -120,39 +117,66 @@ array_push(PG_FUNCTION_ARGS)
(errcode(ERRCODE_DATA_EXCEPTION),
errmsg("argument must be empty or one-dimensional array")));
/*
* We arrange to look up info about element type only once per series of
* calls, assuming the element type doesn't change underneath us.
*/
/* Perform element insertion */
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 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;
result = array_set(v, 1, &indx, newelem, isNull,
-1, typlen, typbyval, typalign);
-1, my_extra->typlen, my_extra->typbyval, my_extra->typalign);
/*
* Readjust result's LB to match the input's. This does nothing in the
* append case, but it's the simplest way to implement the prepend case.
*/
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;
int *dimv,
*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)
{
/* prepend newelem */
lb = ARR_LBOUND(v);
dimv = ARR_DIMS(v);
indx = lb[0] - 1;
/* overflow? */
if (indx > lb[0])
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);
/* 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];