Add btree_gist support for enum types.

This will allow enums to be used in exclusion constraints.

The code uses the new CallerFInfoFunctionCall infrastructure in fmgr,
and the support for it added to btree_gist in commit 393bb504d7.

Reviewed by Tom Lane and Anastasia Lubennikova

Discussion:  http://postgr.es/m/56EA8A71.8060107@dunslane.net

contrib/btree_gist/Makefile

@@ -5,18 +5,19 @@ MODULE_big = btree_gist
 OBJS =  btree_gist.o btree_utils_num.o btree_utils_var.o btree_int2.o \
         btree_int4.o btree_int8.o btree_float4.o btree_float8.o btree_cash.o \
         btree_oid.o btree_ts.o btree_time.o btree_date.o btree_interval.o \
-        btree_macaddr.o btree_macaddr8.o btree_inet.o btree_text.o btree_bytea.o \
-        btree_bit.o btree_numeric.o btree_uuid.o $(WIN32RES)
+        btree_macaddr.o btree_macaddr8.o btree_inet.o btree_text.o \
+		btree_bytea.o btree_bit.o btree_numeric.o btree_uuid.o \
+		btree_enum.o $(WIN32RES)
 
 EXTENSION = btree_gist
 DATA = btree_gist--unpackaged--1.0.sql btree_gist--1.0--1.1.sql \
        btree_gist--1.1--1.2.sql btree_gist--1.2.sql btree_gist--1.2--1.3.sql \
-       btree_gist--1.3--1.4.sql
+       btree_gist--1.3--1.4.sql btree_gist--1.4--1.5.sql
 PGFILEDESC = "btree_gist - B-tree equivalent GiST operator classes"
 
 REGRESS = init int2 int4 int8 float4 float8 cash oid timestamp timestamptz \
         time timetz date interval macaddr macaddr8 inet cidr text varchar char \
-        bytea bit varbit numeric uuid not_equal
+        bytea bit varbit numeric uuid not_equal enum
 
 SHLIB_LINK += $(filter -lm, $(LIBS))
 

contrib/btree_gist/btree_enum.c

@@ -0,0 +1,187 @@
+/*
+ * contrib/btree_gist/btree_enum.c
+ */
+#include "postgres.h"
+#include "fmgr.h"
+#include "utils/builtins.h"
+
+#include "btree_gist.h"
+#include "btree_utils_num.h"
+
+/* enums are really Oids, so we just use the same structure */
+
+typedef struct
+{
+	Oid			lower;
+	Oid			upper;
+} oidKEY;
+
+/*
+** enum ops
+*/
+PG_FUNCTION_INFO_V1(gbt_enum_compress);
+PG_FUNCTION_INFO_V1(gbt_enum_fetch);
+PG_FUNCTION_INFO_V1(gbt_enum_union);
+PG_FUNCTION_INFO_V1(gbt_enum_picksplit);
+PG_FUNCTION_INFO_V1(gbt_enum_consistent);
+PG_FUNCTION_INFO_V1(gbt_enum_penalty);
+PG_FUNCTION_INFO_V1(gbt_enum_same);
+
+
+static bool
+gbt_enumgt(const void *a, const void *b, FmgrInfo *flinfo)
+{
+	return DatumGetBool(
+		CallerFInfoFunctionCall2(enum_gt, flinfo, InvalidOid, ObjectIdGetDatum(*((const Oid *) a)), ObjectIdGetDatum(*((const Oid *) b)))
+		);
+}
+static bool
+gbt_enumge(const void *a, const void *b, FmgrInfo *flinfo)
+{
+	return DatumGetBool(
+		CallerFInfoFunctionCall2(enum_ge, flinfo, InvalidOid, ObjectIdGetDatum(*((const Oid *) a)), ObjectIdGetDatum(*((const Oid *) b)))
+		);
+}
+static bool
+gbt_enumeq(const void *a, const void *b, FmgrInfo *flinfo)
+{
+	return (*((const Oid *) a) == *((const Oid *) b));
+}
+static bool
+gbt_enumle(const void *a, const void *b, FmgrInfo *flinfo)
+{
+	return DatumGetBool(
+						CallerFInfoFunctionCall2(enum_le, flinfo, InvalidOid, ObjectIdGetDatum(*((const Oid *) a)), ObjectIdGetDatum(*((const Oid *) b)))
+		);
+}
+static bool
+gbt_enumlt(const void *a, const void *b, FmgrInfo *flinfo)
+{
+	return DatumGetBool(
+						CallerFInfoFunctionCall2(enum_lt, flinfo, InvalidOid, ObjectIdGetDatum(*((const Oid *) a)), ObjectIdGetDatum(*((const Oid *) b)))
+		);
+}
+
+static int
+gbt_enumkey_cmp(const void *a, const void *b, FmgrInfo *flinfo)
+{
+	oidKEY	   *ia = (oidKEY *) (((const Nsrt *) a)->t);
+	oidKEY	   *ib = (oidKEY *) (((const Nsrt *) b)->t);
+
+	if (ia->lower == ib->lower)
+	{
+		if (ia->upper == ib->upper)
+			return 0;
+
+		return DatumGetInt32(
+			CallerFInfoFunctionCall2(enum_cmp, flinfo, InvalidOid, ObjectIdGetDatum(ia->upper), ObjectIdGetDatum(ib->upper))
+			);
+	}
+
+	return DatumGetInt32(
+		CallerFInfoFunctionCall2(enum_cmp, flinfo, InvalidOid, ObjectIdGetDatum(ia->lower), ObjectIdGetDatum(ib->lower))
+		);
+}
+
+static const gbtree_ninfo tinfo =
+{
+	gbt_t_enum,
+	sizeof(Oid),
+	8,							/* sizeof(gbtreekey8) */
+	gbt_enumgt,
+	gbt_enumge,
+	gbt_enumeq,
+	gbt_enumle,
+	gbt_enumlt,
+	gbt_enumkey_cmp,
+	NULL /* no KNN support at least for now */
+};
+
+
+/**************************************************
+ * Enum ops
+ **************************************************/
+
+
+Datum
+gbt_enum_compress(PG_FUNCTION_ARGS)
+{
+	GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
+
+	PG_RETURN_POINTER(gbt_num_compress(entry, &tinfo));
+}
+
+Datum
+gbt_enum_fetch(PG_FUNCTION_ARGS)
+{
+	GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
+
+	PG_RETURN_POINTER(gbt_num_fetch(entry, &tinfo));
+}
+
+Datum
+gbt_enum_consistent(PG_FUNCTION_ARGS)
+{
+	GISTENTRY  *entry = (GISTENTRY *) PG_GETARG_POINTER(0);
+	Oid			query = PG_GETARG_OID(1);
+	StrategyNumber strategy = (StrategyNumber) PG_GETARG_UINT16(2);
+
+	/* Oid		subtype = PG_GETARG_OID(3); */
+	bool	   *recheck = (bool *) PG_GETARG_POINTER(4);
+	oidKEY	   *kkk = (oidKEY *) DatumGetPointer(entry->key);
+	GBT_NUMKEY_R key;
+
+	/* All cases served by this function are exact */
+	*recheck = false;
+
+	key.lower = (GBT_NUMKEY *) &kkk->lower;
+	key.upper = (GBT_NUMKEY *) &kkk->upper;
+
+	PG_RETURN_BOOL(
+				   gbt_num_consistent(&key, (void *) &query, &strategy, GIST_LEAF(entry), &tinfo, fcinfo->flinfo)
+		);
+}
+
+Datum
+gbt_enum_union(PG_FUNCTION_ARGS)
+{
+	GistEntryVector *entryvec = (GistEntryVector *) PG_GETARG_POINTER(0);
+	void	   *out = palloc(sizeof(oidKEY));
+
+	*(int *) PG_GETARG_POINTER(1) = sizeof(oidKEY);
+	PG_RETURN_POINTER(gbt_num_union((void *) out, entryvec, &tinfo, fcinfo->flinfo));
+}
+
+
+Datum
+gbt_enum_penalty(PG_FUNCTION_ARGS)
+{
+	oidKEY	   *origentry = (oidKEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(0))->key);
+	oidKEY	   *newentry = (oidKEY *) DatumGetPointer(((GISTENTRY *) PG_GETARG_POINTER(1))->key);
+	float	   *result = (float *) PG_GETARG_POINTER(2);
+
+	penalty_num(result, origentry->lower, origentry->upper, newentry->lower, newentry->upper);
+
+	PG_RETURN_POINTER(result);
+}
+
+Datum
+gbt_enum_picksplit(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_POINTER(gbt_num_picksplit(
+									(GistEntryVector *) PG_GETARG_POINTER(0),
+									  (GIST_SPLITVEC *) PG_GETARG_POINTER(1),
+										&tinfo, fcinfo->flinfo
+										));
+}
+
+Datum
+gbt_enum_same(PG_FUNCTION_ARGS)
+{
+	oidKEY	   *b1 = (oidKEY *) PG_GETARG_POINTER(0);
+	oidKEY	   *b2 = (oidKEY *) PG_GETARG_POINTER(1);
+	bool	   *result = (bool *) PG_GETARG_POINTER(2);
+
+	*result = gbt_num_same((void *) b1, (void *) b2, &tinfo, fcinfo->flinfo);
+	PG_RETURN_POINTER(result);
+}

contrib/btree_gist/btree_gist--1.4--1.5.sql

@@ -0,0 +1,69 @@
+/* contrib/btree_gist/btree_gist--1.4--1.5.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "ALTER EXTENSION btree_gist UPDATE TO '1.5'" to load this file. \quit
+
+--
+--
+--
+-- enum ops
+--
+--
+--
+-- define the GiST support methods
+CREATE FUNCTION gbt_enum_consistent(internal,anyenum,int2,oid,internal)
+RETURNS bool
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION gbt_enum_compress(internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION gbt_enum_fetch(internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION gbt_enum_penalty(internal,internal,internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION gbt_enum_picksplit(internal, internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION gbt_enum_union(internal, internal)
+RETURNS gbtreekey8
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+CREATE FUNCTION gbt_enum_same(gbtreekey8, gbtreekey8, internal)
+RETURNS internal
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE STRICT;
+
+-- Create the operator class
+CREATE OPERATOR CLASS gist_enum_ops
+DEFAULT FOR TYPE anyenum USING gist
+AS
+	OPERATOR	1	<  ,
+	OPERATOR	2	<= ,
+	OPERATOR	3	=  ,
+	OPERATOR	4	>= ,
+	OPERATOR	5	>  ,
+	FUNCTION	1	gbt_enum_consistent (internal, anyenum, int2, oid, internal),
+	FUNCTION	2	gbt_enum_union (internal, internal),
+	FUNCTION	3	gbt_enum_compress (internal),
+	FUNCTION	4	gbt_decompress (internal),
+	FUNCTION	5	gbt_enum_penalty (internal, internal, internal),
+	FUNCTION	6	gbt_enum_picksplit (internal, internal),
+	FUNCTION	7	gbt_enum_same (gbtreekey8, gbtreekey8, internal),
+	STORAGE		gbtreekey8;
+
+ALTER OPERATOR FAMILY gist_enum_ops USING gist ADD
+	OPERATOR	6	<> (anyenum, anyenum) ,
+	FUNCTION	9 (anyenum, anyenum) gbt_enum_fetch (internal) ;

contrib/btree_gist/btree_gist.control

@@ -1,5 +1,5 @@
 # btree_gist extension
 comment = 'support for indexing common datatypes in GiST'
-default_version = '1.4'
+default_version = '1.5'
 module_pathname = '$libdir/btree_gist'
 relocatable = true

contrib/btree_gist/btree_gist.h

@@ -33,7 +33,8 @@ enum gbtree_type
 	gbt_t_bytea,
 	gbt_t_bit,
 	gbt_t_inet,
-	gbt_t_uuid
+	gbt_t_uuid,
+	gbt_t_enum
 };
 
 #endif

contrib/btree_gist/btree_utils_num.c

@@ -48,6 +48,7 @@ gbt_num_compress(GISTENTRY *entry, const gbtree_ninfo *tinfo)
 				leaf = &v.i8;
 				break;
 			case gbt_t_oid:
+			case gbt_t_enum:
 				v.i4 = DatumGetObjectId(entry->key);
 				leaf = &v.i4;
 				break;
@@ -122,6 +123,7 @@ gbt_num_fetch(GISTENTRY *entry, const gbtree_ninfo *tinfo)
 			datum = Int64GetDatum(*(int64 *) entry->key);
 			break;
 		case gbt_t_oid:
+		case gbt_t_enum:
 			datum = ObjectIdGetDatum(*(Oid *) entry->key);
 			break;
 		case gbt_t_float4:

contrib/btree_gist/data/enum.data

@@ -0,0 +1,595 @@
+r
+v
+i
+b
+r
+\N
+y
+v
+g
+o
+y
+b
+o
+o
+o
+o
+v
+r
+i
+o
+b
+r
+g
+b
+i
+o
+r
+r
+r
+\N
+o
+b
+v
+y
+o
+\N
+i
+o
+o
+g
+g
+b
+y
+v
+g
+g
+\N
+v
+g
+i
+i
+\N
+v
+y
+i
+r
+\N
+r
+\N
+g
+\N
+g
+\N
+v
+g
+y
+v
+r
+v
+r
+v
+y
+i
+i
+v
+y
+v
+i
+b
+i
+i
+r
+r
+\N
+\N
+y
+r
+g
+i
+y
+i
+i
+r
+g
+y
+\N
+i
+o
+r
+y
+y
+g
+o
+o
+g
+y
+r
+g
+v
+r
+i
+r
+i
+r
+y
+v
+b
+i
+o
+r
+\N
+o
+i
+v
+o
+b
+\N
+b
+g
+y
+o
+v
+b
+i
+v
+v
+o
+y
+i
+i
+i
+g
+b
+b
+g
+r
+i
+y
+o
+\N
+r
+\N
+i
+i
+g
+v
+o
+y
+y
+o
+i
+b
+r
+y
+y
+o
+g
+g
+g
+\N
+y
+o
+v
+g
+y
+g
+v
+\N
+i
+o
+v
+b
+b
+\N
+y
+v
+\N
+v
+\N
+i
+\N
+r
+b
+r
+o
+r
+b
+o
+g
+i
+r
+b
+g
+g
+y
+b
+b
+g
+y
+g
+v
+v
+b
+\N
+i
+v
+y
+b
+b
+o
+g
+b
+v
+g
+g
+b
+\N
+y
+r
+r
+b
+\N
+r
+g
+i
+o
+v
+\N
+o
+r
+b
+o
+b
+i
+\N
+\N
+y
+b
+y
+\N
+i
+i
+i
+o
+y
+o
+i
+b
+o
+g
+r
+\N
+b
+y
+\N
+g
+b
+y
+y
+o
+o
+b
+g
+i
+i
+v
+b
+o
+o
+v
+i
+g
+i
+o
+r
+o
+i
+i
+r
+b
+g
+o
+o
+y
+v
+g
+g
+g
+r
+o
+i
+i
+g
+\N
+o
+v
+b
+b
+v
+i
+g
+y
+i
+i
+g
+r
+y
+i
+b
+\N
+g
+y
+o
+\N
+i
+i
+b
+v
+o
+b
+v
+r
+g
+o
+v
+v
+y
+r
+v
+g
+\N
+v
+v
+b
+y
+o
+g
+i
+o
+b
+r
+y
+r
+v
+b
+b
+\N
+i
+v
+y
+r
+b
+i
+y
+g
+\N
+g
+r
+y
+y
+g
+b
+o
+v
+r
+i
+g
+r
+b
+b
+b
+\N
+y
+y
+y
+i
+o
+r
+g
+g
+i
+y
+g
+y
+v
+o
+o
+g
+\N
+b
+v
+o
+y
+r
+\N
+o
+i
+g
+\N
+i
+i
+i
+o
+b
+\N
+\N
+b
+\N
+v
+v
+r
+\N
+o
+b
+r
+o
+b
+o
+r
+y
+\N
+r
+i
+b
+b
+y
+v
+r
+g
+r
+r
+\N
+g
+\N
+v
+v
+y
+r
+o
+r
+o
+i
+o
+\N
+r
+\N
+i
+v
+b
+v
+\N
+b
+r
+v
+o
+\N
+i
+r
+b
+g
+o
+\N
+o
+g
+r
+v
+y
+g
+v
+r
+b
+r
+v
+o
+g
+i
+i
+g
+i
+y
+b
+i
+y
+r
+y
+o
+r
+b
+y
+y
+b
+y
+g
+b
+\N
+r
+g
+b
+o
+y
+o
+g
+r
+g
+b
+\N
+v
+v
+v
+g
+b
+y
+v
+o
+v
+g
+o
+g
+i
+b
+v
+i
+r
+r
+i
+b
+i
+b
+o
+\N
+\N
+y
+r
+g
+v
+o
+y
+\N
+g
+v
+o
+b
+v
+v
+\N
+r
+v
+y
+g
+b
+o
+v
+b
+v
+b
+r
+r
+i
+r
+v
+y
+v
+y
+o
+v
+g
+i
+r
+o
+o
+i
+y
+r
+\N
+y
+r
+b
+y
+y
+\N
+b
+\N
+\N
+i
+v

contrib/btree_gist/expected/enum.out

@@ -0,0 +1,91 @@
+-- enum check
+create type rainbow as enum ('r','o','y','g','b','i','v');
+CREATE TABLE enumtmp (a rainbow);
+\copy enumtmp from 'data/enum.data'
+SET enable_seqscan=on;
+select a, count(*) from enumtmp group by a order by 1;
+ a | count 
+---+-------
+ r |    76
+ o |    78
+ y |    73
+ g |    75
+ b |    77
+ i |    78
+ v |    75
+   |    63
+(8 rows)
+
+SELECT count(*) FROM enumtmp WHERE a <  'g'::rainbow;
+ count 
+-------
+   227
+(1 row)
+
+SELECT count(*) FROM enumtmp WHERE a <= 'g'::rainbow;
+ count 
+-------
+   302
+(1 row)
+
+SELECT count(*) FROM enumtmp WHERE a  = 'g'::rainbow;
+ count 
+-------
+    75
+(1 row)
+
+SELECT count(*) FROM enumtmp WHERE a >= 'g'::rainbow;
+ count 
+-------
+   305
+(1 row)
+
+SELECT count(*) FROM enumtmp WHERE a >  'g'::rainbow;
+ count 
+-------
+   230
+(1 row)
+
+CREATE INDEX enumidx ON enumtmp USING gist ( a );
+SET enable_seqscan=off;
+SELECT count(*) FROM enumtmp WHERE a <  'g'::rainbow;
+ count 
+-------
+   227
+(1 row)
+
+SELECT count(*) FROM enumtmp WHERE a <= 'g'::rainbow;
+ count 
+-------
+   302
+(1 row)
+
+SELECT count(*) FROM enumtmp WHERE a  = 'g'::rainbow;
+ count 
+-------
+    75
+(1 row)
+
+SELECT count(*) FROM enumtmp WHERE a >= 'g'::rainbow;
+ count 
+-------
+   305
+(1 row)
+
+SELECT count(*) FROM enumtmp WHERE a >  'g'::rainbow;
+ count 
+-------
+   230
+(1 row)
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM enumtmp WHERE a >= 'g'::rainbow;
+                  QUERY PLAN                   
+-----------------------------------------------
+ Aggregate
+   ->  Bitmap Heap Scan on enumtmp
+         Recheck Cond: (a >= 'g'::rainbow)
+         ->  Bitmap Index Scan on enumidx
+               Index Cond: (a >= 'g'::rainbow)
+(5 rows)
+

contrib/btree_gist/sql/enum.sql

@@ -0,0 +1,38 @@
+-- enum check
+
+create type rainbow as enum ('r','o','y','g','b','i','v');
+
+CREATE TABLE enumtmp (a rainbow);
+
+\copy enumtmp from 'data/enum.data'
+
+SET enable_seqscan=on;
+
+select a, count(*) from enumtmp group by a order by 1;
+
+SELECT count(*) FROM enumtmp WHERE a <  'g'::rainbow;
+
+SELECT count(*) FROM enumtmp WHERE a <= 'g'::rainbow;
+
+SELECT count(*) FROM enumtmp WHERE a  = 'g'::rainbow;
+
+SELECT count(*) FROM enumtmp WHERE a >= 'g'::rainbow;
+
+SELECT count(*) FROM enumtmp WHERE a >  'g'::rainbow;
+
+CREATE INDEX enumidx ON enumtmp USING gist ( a );
+
+SET enable_seqscan=off;
+
+SELECT count(*) FROM enumtmp WHERE a <  'g'::rainbow;
+
+SELECT count(*) FROM enumtmp WHERE a <= 'g'::rainbow;
+
+SELECT count(*) FROM enumtmp WHERE a  = 'g'::rainbow;
+
+SELECT count(*) FROM enumtmp WHERE a >= 'g'::rainbow;
+
+SELECT count(*) FROM enumtmp WHERE a >  'g'::rainbow;
+
+EXPLAIN (COSTS OFF)
+SELECT count(*) FROM enumtmp WHERE a >= 'g'::rainbow;

doc/src/sgml/btree-gist.sgml

@@ -17,7 +17,7 @@
   <type>oid</>, <type>money</>, <type>char</>,
   <type>varchar</>, <type>text</>, <type>bytea</>, <type>bit</>,
   <type>varbit</>, <type>macaddr</>, <type>macaddr8</>, <type>inet</>,
-  <type>cidr</> and <type>uuid</>.
+  <type>cidr</>, <type>uuid</>, and all <type>enum</> types.
  </para>
 
  <para>