| /* |
| * Copyright (C) the libgit2 contributors. All rights reserved. |
| * |
| * This file is part of libgit2, distributed under the GNU GPL v2 with |
| * a Linking Exception. For full terms see the included COPYING file. |
| */ |
| #ifndef INCLUDE_bitvec_h__ |
| #define INCLUDE_bitvec_h__ |
| |
| #include "common.h" |
| |
| /* |
| * This is a silly little fixed length bit vector type that will store |
| * vectors of 64 bits or less directly in the structure and allocate |
| * memory for vectors longer than 64 bits. You can use the two versions |
| * transparently through the API and avoid heap allocation completely when |
| * using a short bit vector as a result. |
| */ |
| typedef struct { |
| size_t length; |
| union { |
| uint64_t *words; |
| uint64_t bits; |
| } u; |
| } git_bitvec; |
| |
| GIT_INLINE(int) git_bitvec_init(git_bitvec *bv, size_t capacity) |
| { |
| memset(bv, 0x0, sizeof(*bv)); |
| |
| if (capacity >= 64) { |
| bv->length = (capacity / 64) + 1; |
| bv->u.words = git__calloc(bv->length, sizeof(uint64_t)); |
| if (!bv->u.words) |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| #define GIT_BITVEC_MASK(BIT) ((uint64_t)1 << (BIT % 64)) |
| #define GIT_BITVEC_WORD(BV, BIT) (BV->length ? &BV->u.words[BIT / 64] : &BV->u.bits) |
| |
| GIT_INLINE(void) git_bitvec_set(git_bitvec *bv, size_t bit, bool on) |
| { |
| uint64_t *word = GIT_BITVEC_WORD(bv, bit); |
| uint64_t mask = GIT_BITVEC_MASK(bit); |
| |
| if (on) |
| *word |= mask; |
| else |
| *word &= ~mask; |
| } |
| |
| GIT_INLINE(bool) git_bitvec_get(git_bitvec *bv, size_t bit) |
| { |
| uint64_t *word = GIT_BITVEC_WORD(bv, bit); |
| return (*word & GIT_BITVEC_MASK(bit)) != 0; |
| } |
| |
| GIT_INLINE(void) git_bitvec_clear(git_bitvec *bv) |
| { |
| if (!bv->length) |
| bv->u.bits = 0; |
| else |
| memset(bv->u.words, 0x0, bv->length * sizeof(uint64_t)); |
| } |
| |
| GIT_INLINE(void) git_bitvec_free(git_bitvec *bv) |
| { |
| if (bv->length) |
| git__free(bv->u.words); |
| } |
| |
| #endif |