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author | dimitri staessens <dimitri.staessens@ugent.be> | 2017-09-23 12:27:23 +0200 |
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committer | dimitri staessens <dimitri.staessens@ugent.be> | 2017-09-23 12:32:07 +0200 |
commit | 7ee95a3809aab3152837ceb5ffcd001ee9e83fde (patch) | |
tree | 506d539e05267f1e15d89da3f0a930e92dd879b1 /src | |
parent | 17ab2b6d6bc95337d5fd54e058c0822260dbacf1 (diff) | |
download | ouroboros-7ee95a3809aab3152837ceb5ffcd001ee9e83fde.tar.gz ouroboros-7ee95a3809aab3152837ceb5ffcd001ee9e83fde.zip |
lib: Clean up bitmap implementation
There was a return -1 in the allocate call which is unsafe since -1
may be a valid id in the bitmap. Since it's a data structure for
internal use, I replaced the NULL checks with assertions.
Diffstat (limited to 'src')
-rw-r--r-- | src/lib/bitmap.c | 85 |
1 files changed, 39 insertions, 46 deletions
diff --git a/src/lib/bitmap.c b/src/lib/bitmap.c index 6ddaaca4..75a201bc 100644 --- a/src/lib/bitmap.c +++ b/src/lib/bitmap.c @@ -100,69 +100,65 @@ struct bmp { struct bmp * bmp_create(size_t bits, ssize_t offset) { - struct bmp * tmp; + struct bmp * bmp; - if (bits == 0) - return NULL; + assert(bits); - tmp = malloc(sizeof(*tmp)); - if (tmp == NULL) + bmp = malloc(sizeof(*bmp)); + if (bmp == NULL) return NULL; - tmp->bitmap = malloc(BITS_TO_LONGS(bits) * sizeof(size_t)); - if (tmp->bitmap == NULL) { - free(tmp); + bmp->bitmap = malloc(BITS_TO_LONGS(bits) * sizeof(size_t)); + if (bmp->bitmap == NULL) { + free(bmp); return NULL; } - tmp->size = bits; - tmp->offset = offset; - bitmap_zero(tmp->bitmap, bits); + bmp->size = bits; + bmp->offset = offset; + bitmap_zero(bmp->bitmap, bits); - return tmp; + return bmp; } -void bmp_destroy(struct bmp * b) +void bmp_destroy(struct bmp * bmp) { - if (b == NULL) - return; + assert(bmp); - if (b->bitmap != NULL) - free(b->bitmap); + if (bmp->bitmap != NULL) + free(bmp->bitmap); - free(b); + free(bmp); } -static ssize_t bad_id(struct bmp * b) +static ssize_t bad_id(struct bmp * bmp) { - if (b == NULL) - return -1; + assert(bmp); - return b->offset - 1; + return bmp->offset - 1; } -ssize_t bmp_allocate(struct bmp * b) +ssize_t bmp_allocate(struct bmp * bmp) { size_t id; - if (b == NULL) - return -1; + assert(bmp); - id = find_next_zero_bit(b->bitmap, b->size); - if (id >= b->size) - return bad_id(b); + id = find_next_zero_bit(bmp->bitmap, bmp->size); + if (id >= bmp->size) + return bad_id(bmp); - bitmap_set(b->bitmap, id); + bitmap_set(bmp->bitmap, id); - return id + b->offset; + return id + bmp->offset; } -static bool is_id_valid(struct bmp * b, +static bool is_id_valid(struct bmp * bmp, ssize_t id) { - assert(b); + assert(bmp); - if ((id < b->offset) || (id > (ssize_t) (b->offset + b->size))) + if ((id < bmp->offset) || (id > (ssize_t) (bmp->offset + bmp->size))) return false; return true; @@ -177,34 +173,31 @@ static bool is_id_used(size_t * map, return (*p & mask) != 0; } -bool bmp_is_id_valid(struct bmp * b, +bool bmp_is_id_valid(struct bmp * bmp, ssize_t id) { - if (b == NULL) - return false; + assert(bmp); - return is_id_valid(b, id); + return is_id_valid(bmp, id); } -int bmp_release(struct bmp * b, +int bmp_release(struct bmp * bmp, ssize_t id) { - if (b == NULL) - return -1; + assert(bmp); - if (!is_id_valid(b, id)) + if (!is_id_valid(bmp, id)) return -1; - bitmap_clear(b->bitmap, id - b->offset); + bitmap_clear(bmp->bitmap, id - bmp->offset); return 0; } -bool bmp_is_id_used(struct bmp * b, +bool bmp_is_id_used(struct bmp * bmp, ssize_t id) { - if (b == NULL) - return false; + assert(bmp); - return is_id_used(b->bitmap, id - b->offset); + return is_id_used(bmp->bitmap, id - bmp->offset); } |