1 /*-------------------------------------------------------------------------
4 * PostgreSQL generic bitmap set package
6 * A bitmap set can represent any set of nonnegative integers, although
7 * it is mainly intended for sets where the maximum value is not large,
8 * say at most a few hundred. By convention, a NULL pointer is always
9 * accepted by all operations to represent the empty set. (But beware
10 * that this is not the only representation of the empty set. Use
11 * bms_is_empty() in preference to testing for NULL.)
14 * Copyright (c) 2003-2019, PostgreSQL Global Development Group
16 * src/include/nodes/bitmapset.h
18 *-------------------------------------------------------------------------
24 * Forward decl to save including pg_list.h
31 * Larger bitmap word sizes generally give better performance, so long as
32 * they're not wider than the processor can handle efficiently. We use
33 * 64-bit words if pointers are that large, else 32-bit words.
35 #if SIZEOF_VOID_P >= 8
37 #define BITS_PER_BITMAPWORD 64
38 typedef uint64 bitmapword; /* must be an unsigned type */
39 typedef int64 signedbitmapword; /* must be the matching signed type */
43 #define BITS_PER_BITMAPWORD 32
44 typedef uint32 bitmapword; /* must be an unsigned type */
45 typedef int32 signedbitmapword; /* must be the matching signed type */
49 typedef struct Bitmapset
51 int nwords; /* number of words in array */
52 bitmapword words[FLEXIBLE_ARRAY_MEMBER]; /* really [nwords] */
56 /* result of bms_subset_compare */
59 BMS_EQUAL, /* sets are equal */
60 BMS_SUBSET1, /* first set is a subset of the second */
61 BMS_SUBSET2, /* second set is a subset of the first */
62 BMS_DIFFERENT /* neither set is a subset of the other */
65 /* result of bms_membership */
68 BMS_EMPTY_SET, /* 0 members */
69 BMS_SINGLETON, /* 1 member */
70 BMS_MULTIPLE /* >1 member */
75 * function prototypes in nodes/bitmapset.c
78 extern Bitmapset *bms_copy(const Bitmapset *a);
79 extern bool bms_equal(const Bitmapset *a, const Bitmapset *b);
80 extern int bms_compare(const Bitmapset *a, const Bitmapset *b);
81 extern Bitmapset *bms_make_singleton(int x);
82 extern void bms_free(Bitmapset *a);
84 extern Bitmapset *bms_union(const Bitmapset *a, const Bitmapset *b);
85 extern Bitmapset *bms_intersect(const Bitmapset *a, const Bitmapset *b);
86 extern Bitmapset *bms_difference(const Bitmapset *a, const Bitmapset *b);
87 extern bool bms_is_subset(const Bitmapset *a, const Bitmapset *b);
88 extern BMS_Comparison bms_subset_compare(const Bitmapset *a, const Bitmapset *b);
89 extern bool bms_is_member(int x, const Bitmapset *a);
90 extern int bms_member_index(Bitmapset *a, int x);
91 extern bool bms_overlap(const Bitmapset *a, const Bitmapset *b);
92 extern bool bms_overlap_list(const Bitmapset *a, const struct List *b);
93 extern bool bms_nonempty_difference(const Bitmapset *a, const Bitmapset *b);
94 extern int bms_singleton_member(const Bitmapset *a);
95 extern bool bms_get_singleton_member(const Bitmapset *a, int *member);
96 extern int bms_num_members(const Bitmapset *a);
98 /* optimized tests when we don't need to know exact membership count: */
99 extern BMS_Membership bms_membership(const Bitmapset *a);
100 extern bool bms_is_empty(const Bitmapset *a);
102 /* these routines recycle (modify or free) their non-const inputs: */
104 extern Bitmapset *bms_add_member(Bitmapset *a, int x);
105 extern Bitmapset *bms_del_member(Bitmapset *a, int x);
106 extern Bitmapset *bms_add_members(Bitmapset *a, const Bitmapset *b);
107 extern Bitmapset *bms_add_range(Bitmapset *a, int lower, int upper);
108 extern Bitmapset *bms_int_members(Bitmapset *a, const Bitmapset *b);
109 extern Bitmapset *bms_del_members(Bitmapset *a, const Bitmapset *b);
110 extern Bitmapset *bms_join(Bitmapset *a, Bitmapset *b);
112 /* support for iterating through the integer elements of a set: */
113 extern int bms_first_member(Bitmapset *a);
114 extern int bms_next_member(const Bitmapset *a, int prevbit);
115 extern int bms_prev_member(const Bitmapset *a, int prevbit);
117 /* support for hashtables using Bitmapsets as keys: */
118 extern uint32 bms_hash_value(const Bitmapset *a);
120 #endif /* BITMAPSET_H */