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-rw-r--r--src/backend/utils/adt/arrayfuncs.c86
-rw-r--r--src/include/catalog/pg_proc.h7
-rw-r--r--src/include/utils/array.h4
-rw-r--r--src/test/regress/expected/arrays.out30
-rw-r--r--src/test/regress/sql/arrays.sql17
5 files changed, 141 insertions, 3 deletions
diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c
index b9e9aa8fd79..68676bd28c8 100644
--- a/src/backend/utils/adt/arrayfuncs.c
+++ b/src/backend/utils/adt/arrayfuncs.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.143 2008/04/11 22:52:05 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.144 2008/04/28 14:48:57 alvherre Exp $
*
*-------------------------------------------------------------------------
*/
@@ -17,6 +17,7 @@
#include <ctype.h>
#include "access/tupmacs.h"
+#include "funcapi.h"
#include "libpq/pqformat.h"
#include "parser/parse_coerce.h"
#include "utils/array.h"
@@ -4231,3 +4232,86 @@ array_smaller(PG_FUNCTION_ARGS)
PG_RETURN_ARRAYTYPE_P(result);
}
+
+
+typedef struct generate_subscripts_fctx
+{
+ int4 lower;
+ int4 upper;
+ bool reverse;
+} generate_subscripts_fctx;
+
+/*
+ * generate_subscripts(array anyarray, dim int [, reverse bool])
+ * Returns all subscripts of the array for any dimension
+ */
+Datum
+generate_subscripts(PG_FUNCTION_ARGS)
+{
+ FuncCallContext *funcctx;
+ MemoryContext oldcontext;
+ generate_subscripts_fctx *fctx;
+
+ /* stuff done only on the first call of the function */
+ if (SRF_IS_FIRSTCALL())
+ {
+ ArrayType *v = PG_GETARG_ARRAYTYPE_P(0);
+ int reqdim = PG_GETARG_INT32(1);
+ int *lb,
+ *dimv;
+
+ /* create a function context for cross-call persistence */
+ funcctx = SRF_FIRSTCALL_INIT();
+
+ /* Sanity check: does it look like an array at all? */
+ if (ARR_NDIM(v) <= 0 || ARR_NDIM(v) > MAXDIM)
+ SRF_RETURN_DONE(funcctx);
+
+ /* Sanity check: was the requested dim valid */
+ if (reqdim <= 0 || reqdim > ARR_NDIM(v))
+ SRF_RETURN_DONE(funcctx);
+
+ /*
+ * switch to memory context appropriate for multiple function calls
+ */
+ oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+ fctx = (generate_subscripts_fctx *) palloc(sizeof(generate_subscripts_fctx));
+
+ lb = ARR_LBOUND(v);
+ dimv = ARR_DIMS(v);
+
+ fctx->lower = lb[reqdim - 1];
+ fctx->upper = dimv[reqdim - 1] + lb[reqdim - 1] - 1;
+ fctx->reverse = (PG_NARGS() < 3) ? false : PG_GETARG_BOOL(2);
+
+ funcctx->user_fctx = fctx;
+
+ MemoryContextSwitchTo(oldcontext);
+ }
+
+ funcctx = SRF_PERCALL_SETUP();
+
+ fctx = funcctx->user_fctx;
+
+ if (fctx->lower <= fctx->upper)
+ {
+ if (!fctx->reverse)
+ SRF_RETURN_NEXT(funcctx, Int32GetDatum(fctx->lower++));
+ else
+ SRF_RETURN_NEXT(funcctx, Int32GetDatum(fctx->upper--));
+ }
+ else
+ /* done when there are no more elements left */
+ SRF_RETURN_DONE(funcctx);
+}
+
+/*
+ * generate_subscripts_nodir
+ * Implements the 2-argument version of generate_subscripts
+ */
+Datum
+generate_subscripts_nodir(PG_FUNCTION_ARGS)
+{
+ /* just call the other one -- it can handle both cases */
+ return generate_subscripts(fcinfo);
+}
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 90b55034135..2f0809bca36 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.492 2008/04/17 20:56:41 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.493 2008/04/28 14:48:57 alvherre Exp $
*
* NOTES
* The script catalog/genbki.sh reads this file and generates .bki
@@ -1010,6 +1010,11 @@ DATA(insert OID = 515 ( array_larger PGNSP PGUID 12 1 0 f f t f i 2 2277 "22
DESCR("larger of two");
DATA(insert OID = 516 ( array_smaller PGNSP PGUID 12 1 0 f f t f i 2 2277 "2277 2277" _null_ _null_ _null_ array_smaller - _null_ _null_ ));
DESCR("smaller of two");
+DATA(insert OID = 1191 ( generate_subscripts PGNSP PGUID 12 1 1000 f f t t v 3 23 "2277 23 16" _null_ _null_ _null_ generate_subscripts - _null_ _null_ ));
+DESCR("array subscripts generator");
+DATA(insert OID = 1192 ( generate_subscripts PGNSP PGUID 12 1 1000 f f t t v 2 23 "2277 23" _null_ _null_ _null_ generate_subscripts_nodir - _null_ _null_ ));
+DESCR("array subscripts generator");
+
DATA(insert OID = 760 ( smgrin PGNSP PGUID 12 1 0 f f t f s 1 210 "2275" _null_ _null_ _null_ smgrin - _null_ _null_ ));
DESCR("I/O");
diff --git a/src/include/utils/array.h b/src/include/utils/array.h
index 9f253879f94..f8595d908b1 100644
--- a/src/include/utils/array.h
+++ b/src/include/utils/array.h
@@ -49,7 +49,7 @@
* Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/utils/array.h,v 1.66 2008/01/01 19:45:59 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/utils/array.h,v 1.67 2008/04/28 14:48:57 alvherre Exp $
*
*-------------------------------------------------------------------------
*/
@@ -200,6 +200,8 @@ extern Datum array_lower(PG_FUNCTION_ARGS);
extern Datum array_upper(PG_FUNCTION_ARGS);
extern Datum array_larger(PG_FUNCTION_ARGS);
extern Datum array_smaller(PG_FUNCTION_ARGS);
+extern Datum generate_subscripts(PG_FUNCTION_ARGS);
+extern Datum generate_subscripts_nodir(PG_FUNCTION_ARGS);
extern Datum array_ref(ArrayType *array, int nSubscripts, int *indx,
int arraytyplen, int elmlen, bool elmbyval, char elmalign,
diff --git a/src/test/regress/expected/arrays.out b/src/test/regress/expected/arrays.out
index c82cd3919b9..9ab372d15a5 100644
--- a/src/test/regress/expected/arrays.out
+++ b/src/test/regress/expected/arrays.out
@@ -903,3 +903,33 @@ select c2[2].f2 from comptable;
drop type _comptype;
drop table comptable;
drop type comptype;
+create or replace function unnest1(anyarray)
+returns setof anyelement as $$
+select $1[s] from generate_subscripts($1,1) g(s);
+$$ language sql immutable;
+create or replace function unnest2(anyarray)
+returns setof anyelement as $$
+select $1[s1][s2] from generate_subscripts($1,1) g1(s1),
+ generate_subscripts($1,2) g2(s2);
+$$ language sql immutable;
+select * from unnest1(array[1,2,3]);
+ unnest1
+---------
+ 1
+ 2
+ 3
+(3 rows)
+
+select * from unnest2(array[[1,2,3],[4,5,6]]);
+ unnest2
+---------
+ 1
+ 2
+ 3
+ 4
+ 5
+ 6
+(6 rows)
+
+drop function unnest1(anyarray);
+drop function unnest2(anyarray);
diff --git a/src/test/regress/sql/arrays.sql b/src/test/regress/sql/arrays.sql
index 192648a39b6..6590cad36c4 100644
--- a/src/test/regress/sql/arrays.sql
+++ b/src/test/regress/sql/arrays.sql
@@ -340,3 +340,20 @@ select c2[2].f2 from comptable;
drop type _comptype;
drop table comptable;
drop type comptype;
+
+create or replace function unnest1(anyarray)
+returns setof anyelement as $$
+select $1[s] from generate_subscripts($1,1) g(s);
+$$ language sql immutable;
+
+create or replace function unnest2(anyarray)
+returns setof anyelement as $$
+select $1[s1][s2] from generate_subscripts($1,1) g1(s1),
+ generate_subscripts($1,2) g2(s2);
+$$ language sql immutable;
+
+select * from unnest1(array[1,2,3]);
+select * from unnest2(array[[1,2,3],[4,5,6]]);
+
+drop function unnest1(anyarray);
+drop function unnest2(anyarray);
generated by cgit v1.2.3 (git 2.25.1) at 2025-05-25 23:56:45 +0000