Reorganize partitioning code

There's been a massive addition of partitioning code in PostgreSQL 11,
with little oversight on its placement, resulting in a
catalog/partition.c with poorly defined boundaries and responsibilities.
This commit tries to set a couple of distinct modules to separate things
a little bit.  There are no code changes here, only code movement.

There are three new files:
  src/backend/utils/cache/partcache.c
  src/include/partitioning/partdefs.h
  src/include/utils/partcache.h

The previous arrangement of #including catalog/partition.h almost
everywhere is no more.

Authors: Amit Langote and Álvaro Herrera
Discussion: https://postgr.es/m/98e8d509-790a-128c-be7f-e48a5b2d8d97@lab.ntt.co.jp
	https://postgr.es/m/11aa0c50-316b-18bb-722d-c23814f39059@lab.ntt.co.jp
	https://postgr.es/m/143ed9a4-6038-76d4-9a55-502035815e68@lab.ntt.co.jp
	https://postgr.es/m/20180413193503.nynq7bnmgh6vs5vm@alvherre.pgsql

src/include/catalog/partition.h

@@ -14,22 +14,12 @@
 #define PARTITION_H
 
 #include "fmgr.h"
-#include "executor/tuptable.h"
-#include "nodes/execnodes.h"
-#include "parser/parse_node.h"
-#include "utils/rel.h"
+#include "partitioning/partdefs.h"
+#include "utils/relcache.h"
 
 /* Seed for the extended hash function */
 #define HASH_PARTITION_SEED UINT64CONST(0x7A5B22367996DCFD)
 
-/*
- * PartitionBoundInfo encapsulates a set of partition bounds.  It is usually
- * associated with partitioned tables as part of its partition descriptor.
- *
- * The internal structure appears in partbounds.h.
- */
-typedef struct PartitionBoundInfoData *PartitionBoundInfo;
-
 /*
  * Information about partitions of a partitioned table.
  */
@@ -40,37 +30,17 @@ typedef struct PartitionDescData
 	PartitionBoundInfo boundinfo;	/* collection of partition bounds */
 } PartitionDescData;
 
-typedef struct PartitionDescData *PartitionDesc;
-
-extern void RelationBuildPartitionDesc(Relation relation);
-extern bool partition_bounds_equal(int partnatts, int16 *parttyplen,
-					   bool *parttypbyval, PartitionBoundInfo b1,
-					   PartitionBoundInfo b2);
-extern PartitionBoundInfo partition_bounds_copy(PartitionBoundInfo src,
-					  PartitionKey key);
-
-extern void check_new_partition_bound(char *relname, Relation parent,
-						  PartitionBoundSpec *spec);
 extern Oid	get_partition_parent(Oid relid);
 extern List *get_partition_ancestors(Oid relid);
-extern List *get_qual_from_partbound(Relation rel, Relation parent,
-						PartitionBoundSpec *spec);
 extern List *map_partition_varattnos(List *expr, int fromrel_varno,
 						Relation to_rel, Relation from_rel,
 						bool *found_whole_row);
-extern List *RelationGetPartitionQual(Relation rel);
-extern Expr *get_partition_qual_relid(Oid relid);
 extern bool has_partition_attrs(Relation rel, Bitmapset *attnums,
 					bool *used_in_expr);
 
 extern Oid	get_default_oid_from_partdesc(PartitionDesc partdesc);
 extern Oid	get_default_partition_oid(Oid parentId);
 extern void update_default_partition_oid(Oid parentId, Oid defaultPartId);
-extern void check_default_allows_bound(Relation parent, Relation defaultRel,
-						   PartitionBoundSpec *new_spec);
 extern List *get_proposed_default_constraint(List *new_part_constaints);
 
-extern int get_partition_for_tuple(Relation relation, Datum *values,
-						bool *isnull);
-
 #endif							/* PARTITION_H */

src/include/commands/tablecmds.h

@@ -18,7 +18,6 @@
 #include "catalog/dependency.h"
 #include "catalog/objectaddress.h"
 #include "nodes/parsenodes.h"
-#include "catalog/partition.h"
 #include "storage/lock.h"
 #include "utils/relcache.h"
 

src/include/executor/execPartition.h

@@ -13,7 +13,6 @@
 #ifndef EXECPARTITION_H
 #define EXECPARTITION_H
 
-#include "catalog/partition.h"
 #include "nodes/execnodes.h"
 #include "nodes/parsenodes.h"
 #include "nodes/plannodes.h"

src/include/executor/executor.h

@@ -14,7 +14,6 @@
 #ifndef EXECUTOR_H
 #define EXECUTOR_H
 
-#include "catalog/partition.h"
 #include "executor/execdesc.h"
 #include "nodes/parsenodes.h"
 #include "utils/memutils.h"

src/include/nodes/parsenodes.h

@@ -26,6 +26,8 @@
 #include "nodes/lockoptions.h"
 #include "nodes/primnodes.h"
 #include "nodes/value.h"
+#include "partitioning/partdefs.h"
+
 
 typedef enum OverridingKind
 {
@@ -803,7 +805,7 @@ typedef struct PartitionSpec
  * This represents the portion of the partition key space assigned to a
  * particular partition.  These are stored on disk in pg_class.relpartbound.
  */
-typedef struct PartitionBoundSpec
+struct PartitionBoundSpec
 {
 	NodeTag		type;
 
@@ -822,7 +824,7 @@ typedef struct PartitionBoundSpec
 	List	   *upperdatums;	/* List of PartitionRangeDatums */
 
 	int			location;		/* token location, or -1 if unknown */
-} PartitionBoundSpec;
+};
 
 /*
  * PartitionRangeDatum - one of the values in a range partition bound

src/include/partitioning/partbounds.h

@@ -11,7 +11,11 @@
 #ifndef PARTBOUNDS_H
 #define PARTBOUNDS_H
 
-#include "catalog/partition.h"
+#include "fmgr.h"
+#include "nodes/parsenodes.h"
+#include "nodes/pg_list.h"
+#include "partitioning/partdefs.h"
+#include "utils/relcache.h"
 
 
 /*
@@ -101,7 +105,34 @@ typedef struct PartitionRangeBound
 } PartitionRangeBound;
 
 extern int	get_hash_partition_greatest_modulus(PartitionBoundInfo b);
-extern int partition_list_bsearch(FmgrInfo *partsupfunc, Oid *partcollation,
+extern uint64 compute_hash_value(int partnatts, FmgrInfo *partsupfunc,
+				   Datum *values, bool *isnull);
+extern List *get_qual_from_partbound(Relation rel, Relation parent,
+						PartitionBoundSpec *spec);
+extern bool partition_bounds_equal(int partnatts, int16 *parttyplen,
+					   bool *parttypbyval, PartitionBoundInfo b1,
+					   PartitionBoundInfo b2);
+extern PartitionBoundInfo partition_bounds_copy(PartitionBoundInfo src,
+					  PartitionKey key);
+extern void check_new_partition_bound(char *relname, Relation parent,
+						  PartitionBoundSpec *spec);
+extern void check_default_allows_bound(Relation parent, Relation defaultRel,
+						   PartitionBoundSpec *new_spec);
+
+extern PartitionRangeBound *make_one_range_bound(PartitionKey key, int index,
+					 List *datums, bool lower);
+extern int32 partition_hbound_cmp(int modulus1, int remainder1, int modulus2,
+					 int remainder2);
+extern int32 partition_rbound_cmp(int partnatts, FmgrInfo *partsupfunc,
+					 Oid *partcollation, Datum *datums1,
+					 PartitionRangeDatumKind *kind1, bool lower1,
+					 PartitionRangeBound *b2);
+extern int32 partition_rbound_datum_cmp(FmgrInfo *partsupfunc,
+						   Oid *partcollation,
+						   Datum *rb_datums, PartitionRangeDatumKind *rb_kind,
+						   Datum *tuple_datums, int n_tuple_datums);
+extern int partition_list_bsearch(FmgrInfo *partsupfunc,
+					   Oid *partcollation,
 					   PartitionBoundInfo boundinfo,
 					   Datum value, bool *is_equal);
 extern int partition_range_bsearch(int partnatts, FmgrInfo *partsupfunc,
@@ -114,11 +145,5 @@ extern int partition_range_datum_bsearch(FmgrInfo *partsupfunc,
 							  int nvalues, Datum *values, bool *is_equal);
 extern int partition_hash_bsearch(PartitionBoundInfo boundinfo,
 					   int modulus, int remainder);
-extern uint64 compute_hash_value(int partnatts, FmgrInfo *partsupfunc,
-				   Datum *values, bool *isnull);
-extern int32 partition_rbound_datum_cmp(FmgrInfo *partsupfunc,
-						   Oid *partcollation,
-						   Datum *rb_datums, PartitionRangeDatumKind *rb_kind,
-						   Datum *tuple_datums, int n_tuple_datums);
 
 #endif							/* PARTBOUNDS_H */

src/include/partitioning/partdefs.h

@@ -0,0 +1,24 @@
+/*-------------------------------------------------------------------------
+ *
+ * partdefs.h
+ *		Base definitions for partitioned table handling
+ *
+ * Copyright (c) 2007-2018, PostgreSQL Global Development Group
+ *
+ * src/include/partitioning/partdefs.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PARTDEFS_H
+#define PARTDEFS_H
+
+
+typedef struct PartitionBoundInfoData *PartitionBoundInfo;
+
+typedef struct PartitionKeyData *PartitionKey;
+
+typedef struct PartitionBoundSpec PartitionBoundSpec;
+
+typedef struct PartitionDescData *PartitionDesc;
+
+#endif							/* PARTDEFS_H */

src/include/partitioning/partprune.h

@@ -14,9 +14,10 @@
 #ifndef PARTPRUNE_H
 #define PARTPRUNE_H
 
-#include "catalog/partition.h"
+#include "nodes/execnodes.h"
 #include "nodes/relation.h"
 
+
 /*
  * PartitionPruneContext
  *

src/include/utils/partcache.h

@@ -0,0 +1,96 @@
+/*-------------------------------------------------------------------------
+ *
+ * partcache.h
+ *
+ * Copyright (c) 1996-2018, PostgreSQL Global Development Group
+ *
+ * src/include/utils/partcache.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PARTCACHE_H
+#define PARTCACHE_H
+
+#include "access/attnum.h"
+#include "fmgr.h"
+#include "nodes/pg_list.h"
+#include "nodes/primnodes.h"
+#include "partitioning/partdefs.h"
+#include "utils/relcache.h"
+
+/*
+ * Information about the partition key of a relation
+ */
+typedef struct PartitionKeyData
+{
+	char		strategy;		/* partitioning strategy */
+	int16		partnatts;		/* number of columns in the partition key */
+	AttrNumber *partattrs;		/* attribute numbers of columns in the
+								 * partition key */
+	List	   *partexprs;		/* list of expressions in the partitioning
+								 * key, or NIL */
+
+	Oid		   *partopfamily;	/* OIDs of operator families */
+	Oid		   *partopcintype;	/* OIDs of opclass declared input data types */
+	FmgrInfo   *partsupfunc;	/* lookup info for support funcs */
+
+	/* Partitioning collation per attribute */
+	Oid		   *partcollation;
+
+	/* Type information per attribute */
+	Oid		   *parttypid;
+	int32	   *parttypmod;
+	int16	   *parttyplen;
+	bool	   *parttypbyval;
+	char	   *parttypalign;
+	Oid		   *parttypcoll;
+} PartitionKeyData;
+
+extern void RelationBuildPartitionKey(Relation relation);
+extern void RelationBuildPartitionDesc(Relation rel);
+extern List *RelationGetPartitionQual(Relation rel);
+extern Expr *get_partition_qual_relid(Oid relid);
+
+/*
+ * PartitionKey inquiry functions
+ */
+static inline int
+get_partition_strategy(PartitionKey key)
+{
+	return key->strategy;
+}
+
+static inline int
+get_partition_natts(PartitionKey key)
+{
+	return key->partnatts;
+}
+
+static inline List *
+get_partition_exprs(PartitionKey key)
+{
+	return key->partexprs;
+}
+
+/*
+ * PartitionKey inquiry functions - one column
+ */
+static inline int16
+get_partition_col_attnum(PartitionKey key, int col)
+{
+	return key->partattrs[col];
+}
+
+static inline Oid
+get_partition_col_typid(PartitionKey key, int col)
+{
+	return key->parttypid[col];
+}
+
+static inline int32
+get_partition_col_typmod(PartitionKey key, int col)
+{
+	return key->parttypmod[col];
+}
+
+#endif							/* PARTCACHE_H */

src/include/utils/rel.h

@@ -46,36 +46,6 @@ typedef struct LockInfoData
 
 typedef LockInfoData *LockInfo;
 
-/*
- * Information about the partition key of a relation
- */
-typedef struct PartitionKeyData
-{
-	char		strategy;		/* partitioning strategy */
-	int16		partnatts;		/* number of columns in the partition key */
-	AttrNumber *partattrs;		/* attribute numbers of columns in the
-								 * partition key */
-	List	   *partexprs;		/* list of expressions in the partitioning
-								 * key, or NIL */
-
-	Oid		   *partopfamily;	/* OIDs of operator families */
-	Oid		   *partopcintype;	/* OIDs of opclass declared input data types */
-	FmgrInfo   *partsupfunc;	/* lookup info for support funcs */
-
-	/* Partitioning collation per attribute */
-	Oid		   *partcollation;
-
-	/* Type information per attribute */
-	Oid		   *parttypid;
-	int32	   *parttypmod;
-	int16	   *parttyplen;
-	bool	   *parttypbyval;
-	char	   *parttypalign;
-	Oid		   *parttypcoll;
-}			PartitionKeyData;
-
-typedef struct PartitionKeyData *PartitionKey;
-
 /*
  * Here are the contents of a relation cache entry.
  */
@@ -618,48 +588,6 @@ typedef struct ViewOptions
  */
 #define RelationGetPartitionKey(relation) ((relation)->rd_partkey)
 
-/*
- * PartitionKey inquiry functions
- */
-static inline int
-get_partition_strategy(PartitionKey key)
-{
-	return key->strategy;
-}
-
-static inline int
-get_partition_natts(PartitionKey key)
-{
-	return key->partnatts;
-}
-
-static inline List *
-get_partition_exprs(PartitionKey key)
-{
-	return key->partexprs;
-}
-
-/*
- * PartitionKey inquiry functions - one column
- */
-static inline int16
-get_partition_col_attnum(PartitionKey key, int col)
-{
-	return key->partattrs[col];
-}
-
-static inline Oid
-get_partition_col_typid(PartitionKey key, int col)
-{
-	return key->parttypid[col];
-}
-
-static inline int32
-get_partition_col_typmod(PartitionKey key, int col)
-{
-	return key->parttypmod[col];
-}
-
 /*
  * RelationGetPartitionDesc
  *		Returns partition descriptor for a relation.