109 lines
3.9 KiB
C
109 lines
3.9 KiB
C
/* -------------------------------------------------------------------------
|
|
*
|
|
* bitmapset.h
|
|
* openGauss generic bitmap set package
|
|
*
|
|
* A bitmap set can represent any set of nonnegative integers, although
|
|
* it is mainly intended for sets where the maximum value is not large,
|
|
* say at most a few hundred. By convention, a NULL pointer is always
|
|
* accepted by all operations to represent the empty set. (But beware
|
|
* that this is not the only representation of the empty set. Use
|
|
* bms_is_empty() in preference to testing for NULL.)
|
|
*
|
|
*
|
|
* Copyright (c) 2003-2012, PostgreSQL Global Development Group
|
|
*
|
|
* src/include/nodes/bitmapset.h
|
|
*
|
|
* -------------------------------------------------------------------------
|
|
*/
|
|
#ifndef BITMAPSET_H
|
|
#define BITMAPSET_H
|
|
|
|
/*
|
|
* Data representation
|
|
*/
|
|
|
|
/* The unit size can be adjusted by changing these three declarations: */
|
|
#define BITS_PER_BITMAPWORD 32
|
|
typedef uint32 bitmapword; /* must be an unsigned type */
|
|
typedef int32 signedbitmapword; /* must be the matching signed type */
|
|
|
|
typedef struct Bitmapset {
|
|
int nwords; /* number of words in array */
|
|
bitmapword words[FLEXIBLE_ARRAY_MEMBER]; /* really [nwords] */
|
|
} Bitmapset;
|
|
|
|
/* result of bms_subset_compare */
|
|
typedef enum {
|
|
BMS_EQUAL, /* sets are equal */
|
|
BMS_SUBSET1, /* first set is a subset of the second */
|
|
BMS_SUBSET2, /* second set is a subset of the first */
|
|
BMS_DIFFERENT /* neither set is a subset of the other */
|
|
} BMS_Comparison;
|
|
|
|
/* result of bms_membership */
|
|
typedef enum {
|
|
BMS_EMPTY_SET, /* 0 members */
|
|
BMS_SINGLETON, /* 1 member */
|
|
BMS_MULTIPLE /* >1 member */
|
|
} BMS_Membership;
|
|
|
|
/*
|
|
* function prototypes in nodes/bitmapset.c
|
|
*/
|
|
extern Bitmapset* bms_copy(const Bitmapset* a);
|
|
extern bool bms_equal(const Bitmapset* a, const Bitmapset* b);
|
|
extern Bitmapset* bms_make_singleton(int x);
|
|
extern void bms_free(Bitmapset* a);
|
|
|
|
#define bms_free_ext(bms) \
|
|
do { \
|
|
if ((bms) != NULL) { \
|
|
bms_free(bms); \
|
|
bms = NULL; \
|
|
} \
|
|
} while (0)
|
|
|
|
extern Bitmapset* bms_union(const Bitmapset* a, const Bitmapset* b);
|
|
extern Bitmapset* bms_intersect(const Bitmapset* a, const Bitmapset* b);
|
|
extern Bitmapset* bms_difference(const Bitmapset* a, const Bitmapset* b);
|
|
extern bool bms_is_subset(const Bitmapset* a, const Bitmapset* b);
|
|
extern BMS_Comparison bms_subset_compare(const Bitmapset* a, const Bitmapset* b);
|
|
extern bool bms_is_member(int x, const Bitmapset* a);
|
|
extern bool bms_overlap(const Bitmapset* a, const Bitmapset* b);
|
|
extern bool bms_nonempty_difference(const Bitmapset* a, const Bitmapset* b);
|
|
extern int bms_singleton_member(const Bitmapset* a);
|
|
extern int bms_num_members(const Bitmapset* a);
|
|
|
|
/* These two macros are used to describe 1 byte. */
|
|
#define BYTE_NUMBER 8
|
|
#define BYTE_VALUE 255
|
|
|
|
#ifndef ENABLE_MULTIPLE_NODES
|
|
extern int bms_member_index(const Bitmapset *a, int x);
|
|
extern bool bms_get_singleton_member(const Bitmapset *a, int *member);
|
|
#endif
|
|
|
|
/* optimized tests when we don't need to know exact membership count: */
|
|
extern BMS_Membership bms_membership(const Bitmapset* a);
|
|
extern bool bms_is_empty(const Bitmapset* a);
|
|
|
|
/* these routines recycle (modify or free) their non-const inputs: */
|
|
extern Bitmapset* bms_add_member(Bitmapset* a, int x);
|
|
extern Bitmapset* bms_del_member(Bitmapset* a, int x);
|
|
extern Bitmapset* bms_add_members(Bitmapset* a, const Bitmapset* b);
|
|
extern Bitmapset* bms_int_members(Bitmapset* a, const Bitmapset* b);
|
|
extern Bitmapset* bms_del_members(Bitmapset* a, const Bitmapset* b);
|
|
extern Bitmapset* bms_join(Bitmapset* a, Bitmapset* b);
|
|
|
|
/* support for iterating through the integer elements of a set: */
|
|
extern int bms_first_member(Bitmapset* a);
|
|
extern int bms_next_member(const Bitmapset* a, int prevbit);
|
|
|
|
/* support for hashtables using Bitmapsets as keys: */
|
|
extern uint32 bms_hash_value(const Bitmapset* a);
|
|
|
|
#endif /* BITMAPSET_H */
|
|
|