127 lines
4.3 KiB
C
127 lines
4.3 KiB
C
/*-------------------------------------------------------------------------
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*
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* bitmapset.h
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* PostgreSQL generic bitmap set package
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*
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* A bitmap set can represent any set of nonnegative integers, although
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* it is mainly intended for sets where the maximum value is not large,
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* say at most a few hundred. By convention, we always represent the
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* empty set by a NULL pointer.
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*
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*
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* Copyright (c) 2003-2023, PostgreSQL Global Development Group
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*
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* src/include/nodes/bitmapset.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef BITMAPSET_H
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#define BITMAPSET_H
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#include "nodes/nodes.h"
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/*
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* Forward decl to save including pg_list.h
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*/
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struct List;
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/*
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* Data representation
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*
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* Larger bitmap word sizes generally give better performance, so long as
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* they're not wider than the processor can handle efficiently. We use
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* 64-bit words if pointers are that large, else 32-bit words.
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*/
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#if SIZEOF_VOID_P >= 8
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#define BITS_PER_BITMAPWORD 64
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typedef uint64 bitmapword; /* must be an unsigned type */
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typedef int64 signedbitmapword; /* must be the matching signed type */
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#else
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#define BITS_PER_BITMAPWORD 32
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typedef uint32 bitmapword; /* must be an unsigned type */
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typedef int32 signedbitmapword; /* must be the matching signed type */
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#endif
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typedef struct Bitmapset
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{
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pg_node_attr(custom_copy_equal, special_read_write, no_query_jumble)
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NodeTag type;
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int nwords; /* number of words in array */
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bitmapword words[FLEXIBLE_ARRAY_MEMBER]; /* really [nwords] */
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} Bitmapset;
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/* result of bms_subset_compare */
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typedef enum
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{
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BMS_EQUAL, /* sets are equal */
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BMS_SUBSET1, /* first set is a subset of the second */
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BMS_SUBSET2, /* second set is a subset of the first */
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BMS_DIFFERENT /* neither set is a subset of the other */
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} BMS_Comparison;
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/* result of bms_membership */
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typedef enum
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{
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BMS_EMPTY_SET, /* 0 members */
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BMS_SINGLETON, /* 1 member */
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BMS_MULTIPLE /* >1 member */
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} BMS_Membership;
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/*
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* function prototypes in nodes/bitmapset.c
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*/
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extern Bitmapset *bms_copy(const Bitmapset *a);
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extern bool bms_equal(const Bitmapset *a, const Bitmapset *b);
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extern int bms_compare(const Bitmapset *a, const Bitmapset *b);
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extern Bitmapset *bms_make_singleton(int x);
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extern void bms_free(Bitmapset *a);
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extern Bitmapset *bms_union(const Bitmapset *a, const Bitmapset *b);
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extern Bitmapset *bms_intersect(const Bitmapset *a, const Bitmapset *b);
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extern Bitmapset *bms_difference(const Bitmapset *a, const Bitmapset *b);
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extern bool bms_is_subset(const Bitmapset *a, const Bitmapset *b);
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extern BMS_Comparison bms_subset_compare(const Bitmapset *a, const Bitmapset *b);
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extern bool bms_is_member(int x, const Bitmapset *a);
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extern int bms_member_index(Bitmapset *a, int x);
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extern bool bms_overlap(const Bitmapset *a, const Bitmapset *b);
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extern bool bms_overlap_list(const Bitmapset *a, const struct List *b);
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extern bool bms_nonempty_difference(const Bitmapset *a, const Bitmapset *b);
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extern int bms_singleton_member(const Bitmapset *a);
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extern bool bms_get_singleton_member(const Bitmapset *a, int *member);
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extern int bms_num_members(const Bitmapset *a);
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/* optimized tests when we don't need to know exact membership count: */
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extern BMS_Membership bms_membership(const Bitmapset *a);
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/* NULL is now the only allowed representation of an empty bitmapset */
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#define bms_is_empty(a) ((a) == NULL)
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/* these routines recycle (modify or free) their non-const inputs: */
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extern Bitmapset *bms_add_member(Bitmapset *a, int x);
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extern Bitmapset *bms_del_member(Bitmapset *a, int x);
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extern Bitmapset *bms_add_members(Bitmapset *a, const Bitmapset *b);
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extern Bitmapset *bms_add_range(Bitmapset *a, int lower, int upper);
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extern Bitmapset *bms_int_members(Bitmapset *a, const Bitmapset *b);
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extern Bitmapset *bms_del_members(Bitmapset *a, const Bitmapset *b);
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extern Bitmapset *bms_join(Bitmapset *a, Bitmapset *b);
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/* support for iterating through the integer elements of a set: */
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extern int bms_next_member(const Bitmapset *a, int prevbit);
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extern int bms_prev_member(const Bitmapset *a, int prevbit);
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/* support for hashtables using Bitmapsets as keys: */
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extern uint32 bms_hash_value(const Bitmapset *a);
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extern uint32 bitmap_hash(const void *key, Size keysize);
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extern int bitmap_match(const void *key1, const void *key2, Size keysize);
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#endif /* BITMAPSET_H */
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