* This file is the property of the Digital Music Network (DMN).
* It is being made available to users of the PostgreSQL system
* under the BSD license.
- *
- * NOTE: This module requires sizeof(void *) to be the same as sizeof(int)
*/
#include "postgres.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "executor/executor.h"
-#include "utils/fcache.h"
-#include "utils/sets.h"
#include "utils/syscache.h"
#include "access/tupmacs.h"
#include "access/xact.h"
#include "utils/lsyscache.h"
-/* Uncomment this define if you are compiling for postgres 7.2.x */
-/* #define PG_7_2 */
-
/* This is actually a postgres version of a one dimensional array */
typedef struct
} CTX;
#define TOASTED 1
-#define START_NUM 8
-#define PGARRAY_SIZE(n) (sizeof(PGARRAY) + ((n-1)*sizeof(int4)))
+#define START_NUM 8 /* initial size of arrays */
+#define PGARRAY_SIZE(n) (sizeof(PGARRAY) + (((n)-1)*sizeof(int4)))
-static PGARRAY *GetPGArray(int4 state, int fAdd);
-static PGARRAY *ShrinkPGArray(PGARRAY * p);
+static PGARRAY *GetPGArray(PGARRAY *p, int fAdd);
+static PGARRAY *ShrinkPGArray(PGARRAY *p);
Datum int_agg_state(PG_FUNCTION_ARGS);
-Datum int_agg_final_count(PG_FUNCTION_ARGS);
Datum int_agg_final_array(PG_FUNCTION_ARGS);
Datum int_enum(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(int_agg_state);
-PG_FUNCTION_INFO_V1(int_agg_final_count);
PG_FUNCTION_INFO_V1(int_agg_final_array);
PG_FUNCTION_INFO_V1(int_enum);
/*
* Manage the aggregation state of the array
- * You need to specify the correct memory context, or it will vanish!
+ *
+ * Need to specify a suitably long-lived memory context, or it will vanish!
+ * TopTransactionContext isn't really right, but it's close enough.
*/
static PGARRAY *
-GetPGArray(int4 state, int fAdd)
+GetPGArray(PGARRAY *p, int fAdd)
{
- PGARRAY *p = (PGARRAY *) state;
-
- if (!state)
+ if (!p)
{
/* New array */
int cb = PGARRAY_SIZE(START_NUM);
p = (PGARRAY *) MemoryContextAlloc(TopTransactionContext, cb);
-
- if (!p)
- {
- elog(ERROR, "Integer aggregator, cant allocate TopTransactionContext memory");
- return 0;
- }
-
p->a.size = cb;
p->a.ndim = 0;
p->a.flags = 0;
-#ifndef PG_7_2
p->a.elemtype = INT4OID;
-#endif
p->items = 0;
p->lower = START_NUM;
}
int cbNew = PGARRAY_SIZE(n);
pn = (PGARRAY *) repalloc(p, cbNew);
-
- if (!pn)
- { /* Realloc failed! Reallocate new block. */
- pn = (PGARRAY *) MemoryContextAlloc(TopTransactionContext, cbNew);
- if (!pn)
- {
- elog(ERROR, "Integer aggregator, REALLY REALLY can't alloc memory");
- return (PGARRAY *) NULL;
- }
- memcpy(pn, p, p->a.size);
- pfree(p);
- }
pn->a.size = cbNew;
pn->lower = n;
return pn;
}
/* Shrinks the array to its actual size and moves it into the standard
- * memory allocation context, frees working memory */
+ * memory allocation context, frees working memory
+ */
static PGARRAY *
ShrinkPGArray(PGARRAY * p)
{
/* use current transaction context */
pnew = palloc(cb);
- if (pnew)
- {
- /*
- * Fix up the fields in the new structure, so Postgres
- * understands
- */
- memcpy(pnew, p, cb);
- pnew->a.size = cb;
- pnew->a.ndim = 1;
- pnew->a.flags = 0;
-#ifndef PG_7_2
- pnew->a.elemtype = INT4OID;
-#endif
- pnew->lower = 0;
- }
- else
- elog(ERROR, "Integer aggregator, can't allocate memory");
+ /*
+ * Fix up the fields in the new structure, so Postgres understands
+ */
+ memcpy(pnew, p, cb);
+ pnew->a.size = cb;
+ pnew->a.ndim = 1;
+ pnew->a.flags = 0;
+ pnew->a.elemtype = INT4OID;
+ pnew->lower = 1;
+
pfree(p);
}
return pnew;
Datum
int_agg_state(PG_FUNCTION_ARGS)
{
- int4 state = PG_GETARG_INT32(0);
- int4 value = PG_GETARG_INT32(1);
-
- PGARRAY *p = GetPGArray(state, 1);
+ PGARRAY *state;
+ PGARRAY *p;
- if (!p)
- elog(ERROR, "No aggregate storage");
- else if (p->items >= p->lower)
- elog(ERROR, "aggregate storage too small");
+ if (PG_ARGISNULL(0))
+ state = NULL;
else
- p->array[p->items++] = value;
- PG_RETURN_INT32(p);
+ state = (PGARRAY *) PG_GETARG_POINTER(0);
+ p = GetPGArray(state, 1);
+
+ if (!PG_ARGISNULL(1))
+ {
+ int4 value = PG_GETARG_INT32(1);
+
+ if (!p) /* internal error */
+ elog(ERROR, "no aggregate storage");
+ else if (p->items >= p->lower) /* internal error */
+ elog(ERROR, "aggregate storage too small");
+ else
+ p->array[p->items++] = value;
+ }
+ PG_RETURN_POINTER(p);
}
-/* This is the final function used for the integer aggregator. It returns all the integers
- * collected as a one dimentional integer array */
+/* This is the final function used for the integer aggregator. It returns all
+ * the integers collected as a one dimensional integer array
+ */
Datum
int_agg_final_array(PG_FUNCTION_ARGS)
{
- PGARRAY *pnew = ShrinkPGArray(GetPGArray(PG_GETARG_INT32(0), 0));
+ PGARRAY *state = (PGARRAY *) PG_GETARG_POINTER(0);
+ PGARRAY *pnew = ShrinkPGArray(GetPGArray(state, 0));
if (pnew)
PG_RETURN_POINTER(pnew);
ReturnSetInfo *rsi = (ReturnSetInfo *) fcinfo->resultinfo;
if (!rsi || !IsA(rsi, ReturnSetInfo))
- elog(ERROR, "No ReturnSetInfo sent! function must be declared returning a 'setof' integer");
+ elog(ERROR, "int_enum called in context that cannot accept a set");
if (!p)
{
- elog(WARNING, "No data sent");
+ elog(WARNING, "no data sent");
PG_RETURN_NULL();
}
/* Allocate a working context */
pc = (CTX *) palloc(sizeof(CTX));
- /* Don't copy atribute if you don't need too */
+ /* Don't copy attribute if you don't need to */
if (VARATT_IS_EXTENDED(p))
{
/* Toasted!!! */
pc->p = (PGARRAY *) PG_DETOAST_DATUM_COPY(p);
pc->flags = TOASTED;
- if (!pc->p)
- {
- elog(ERROR, "Error in toaster!!! no detoasting");
- PG_RETURN_NULL();
- }
}
else
{
pc->p = p;
pc->flags = 0;
}
- fcinfo->context = (Node *) pc;
pc->num = 0;
+ fcinfo->context = (Node *) pc;
}
- else
-/* use an existing one */
+ else /* use an existing one */
pc = (CTX *) fcinfo->context;
/* Are we done yet? */
if (pc->num >= pc->p->items)
rsi->isDone = ExprEndResult;
}
else
-/* nope, return the next value */
{
+ /* nope, return the next value */
int val = pc->p->array[pc->num++];
rsi->isDone = ExprMultipleResult;
-- Adjust this setting to control where the objects get created.
SET search_path = public;
-SET autocommit TO 'on';
-
-- Internal function for the aggregate
-- Is called for each item in an aggregation
-CREATE OR REPLACE FUNCTION int_agg_state (int4, int4)
-RETURNS int4
+CREATE OR REPLACE FUNCTION int_agg_state (int4[], int4)
+RETURNS int4[]
AS 'MODULE_PATHNAME','int_agg_state'
LANGUAGE 'C';
-- Internal function for the aggregate
-- Is called at the end of the aggregation, and returns an array.
-CREATE OR REPLACE FUNCTION int_agg_final_array (int4)
+CREATE OR REPLACE FUNCTION int_agg_final_array (int4[])
RETURNS int4[]
AS 'MODULE_PATHNAME','int_agg_final_array'
-LANGUAGE 'C';
+LANGUAGE 'C' STRICT;
--- The aggration funcion.
+-- The aggregate function itself
-- uses the above functions to create an array of integers from an aggregation.
-CREATE OR REPLACE AGGREGATE int_array_aggregate (
+CREATE AGGREGATE int_array_aggregate (
BASETYPE = int4,
SFUNC = int_agg_state,
- STYPE = int4,
- FINALFUNC = int_agg_final_array,
- INITCOND = 0
+ STYPE = int4[],
+ FINALFUNC = int_agg_final_array
);
+-- The aggregate component functions are not designed to be called
+-- independently, so disable public access to them
+REVOKE ALL ON FUNCTION int_agg_state (int4[], int4) FROM PUBLIC;
+REVOKE ALL ON FUNCTION int_agg_final_array (int4[]) FROM PUBLIC;
+
-- The enumeration function
--- returns each element in a one dimentional integer array
+-- returns each element in a one dimensional integer array
-- as a row.
CREATE OR REPLACE FUNCTION int_array_enum(int4[])
RETURNS setof integer
AS 'MODULE_PATHNAME','int_enum'
-LANGUAGE 'C';
+LANGUAGE 'C' IMMUTABLE STRICT;
projects / postgresql / commitdiff