diff options
Diffstat (limited to 'util/hbitmap.c')
| -rw-r--r-- | util/hbitmap.c | 134 |
1 files changed, 83 insertions, 51 deletions
diff --git a/util/hbitmap.c b/util/hbitmap.c index 242c6e519c..305b894a63 100644 --- a/util/hbitmap.c +++ b/util/hbitmap.c @@ -104,7 +104,7 @@ struct HBitmap { /* Advance hbi to the next nonzero word and return it. hbi->pos * is updated. Returns zero if we reach the end of the bitmap. */ -unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi) +static unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi) { size_t pos = hbi->pos; const HBitmap *hb = hbi->hb; @@ -193,7 +193,31 @@ void hbitmap_iter_init(HBitmapIter *hbi, const HBitmap *hb, uint64_t first) } } -int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start, uint64_t count) +int64_t hbitmap_next_dirty(const HBitmap *hb, int64_t start, int64_t count) +{ + HBitmapIter hbi; + int64_t first_dirty_off; + uint64_t end; + + assert(start >= 0 && count >= 0); + + if (start >= hb->orig_size || count == 0) { + return -1; + } + + end = count > hb->orig_size - start ? hb->orig_size : start + count; + + hbitmap_iter_init(&hbi, hb, start); + first_dirty_off = hbitmap_iter_next(&hbi); + + if (first_dirty_off < 0 || first_dirty_off >= end) { + return -1; + } + + return MAX(start, first_dirty_off); +} + +int64_t hbitmap_next_zero(const HBitmap *hb, int64_t start, int64_t count) { size_t pos = (start >> hb->granularity) >> BITS_PER_LEVEL; unsigned long *last_lev = hb->levels[HBITMAP_LEVELS - 1]; @@ -202,6 +226,8 @@ int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start, uint64_t count) uint64_t end_bit, sz; int64_t res; + assert(start >= 0 && count >= 0); + if (start >= hb->orig_size || count == 0) { return -1; } @@ -244,41 +270,33 @@ int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start, uint64_t count) return res; } -bool hbitmap_next_dirty_area(const HBitmap *hb, uint64_t *start, - uint64_t *count) +bool hbitmap_next_dirty_area(const HBitmap *hb, int64_t start, int64_t end, + int64_t max_dirty_count, + int64_t *dirty_start, int64_t *dirty_count) { - HBitmapIter hbi; - int64_t firt_dirty_off, area_end; - uint32_t granularity = 1UL << hb->granularity; - uint64_t end; + int64_t next_zero; - if (*start >= hb->orig_size || *count == 0) { + assert(start >= 0 && end >= 0 && max_dirty_count > 0); + + end = MIN(end, hb->orig_size); + if (start >= end) { return false; } - end = *count > hb->orig_size - *start ? hb->orig_size : *start + *count; - - hbitmap_iter_init(&hbi, hb, *start); - firt_dirty_off = hbitmap_iter_next(&hbi); - - if (firt_dirty_off < 0 || firt_dirty_off >= end) { + start = hbitmap_next_dirty(hb, start, end - start); + if (start < 0) { return false; } - if (firt_dirty_off + granularity >= end) { - area_end = end; - } else { - area_end = hbitmap_next_zero(hb, firt_dirty_off + granularity, - end - firt_dirty_off - granularity); - if (area_end < 0) { - area_end = end; - } - } + end = start + MIN(end - start, max_dirty_count); - if (firt_dirty_off > *start) { - *start = firt_dirty_off; + next_zero = hbitmap_next_zero(hb, start, end - start); + if (next_zero >= 0) { + end = next_zero; } - *count = area_end - *start; + + *dirty_start = start; + *dirty_count = end - start; return true; } @@ -298,6 +316,35 @@ uint64_t hbitmap_count(const HBitmap *hb) return hb->count << hb->granularity; } +/** + * hbitmap_iter_next_word: + * @hbi: HBitmapIter to operate on. + * @p_cur: Location where to store the next non-zero word. + * + * Return the index of the next nonzero word that is set in @hbi's + * associated HBitmap, and set *p_cur to the content of that word + * (bits before the index that was passed to hbitmap_iter_init are + * trimmed on the first call). Return -1, and set *p_cur to zero, + * if all remaining words are zero. + */ +static size_t hbitmap_iter_next_word(HBitmapIter *hbi, unsigned long *p_cur) +{ + unsigned long cur = hbi->cur[HBITMAP_LEVELS - 1]; + + if (cur == 0) { + cur = hbitmap_iter_skip_words(hbi); + if (cur == 0) { + *p_cur = 0; + return -1; + } + } + + /* The next call will resume work from the next word. */ + hbi->cur[HBITMAP_LEVELS - 1] = 0; + *p_cur = cur; + return hbi->pos; +} + /* Count the number of set bits between start and end, not accounting for * the granularity. Also an example of how to use hbitmap_iter_next_word. */ @@ -716,6 +763,7 @@ HBitmap *hbitmap_alloc(uint64_t size, int granularity) HBitmap *hb = g_new0(struct HBitmap, 1); unsigned i; + assert(size <= INT64_MAX); hb->orig_size = size; assert(granularity >= 0 && granularity < 64); @@ -746,6 +794,7 @@ void hbitmap_truncate(HBitmap *hb, uint64_t size) uint64_t num_elements = size; uint64_t old; + assert(size <= INT64_MAX); hb->orig_size = size; /* Size comes in as logical elements, adjust for granularity. */ @@ -803,16 +852,15 @@ bool hbitmap_can_merge(const HBitmap *a, const HBitmap *b) */ static void hbitmap_sparse_merge(HBitmap *dst, const HBitmap *src) { - uint64_t offset = 0; - uint64_t count = src->orig_size; + int64_t offset; + int64_t count; - while (hbitmap_next_dirty_area(src, &offset, &count)) { + for (offset = 0; + hbitmap_next_dirty_area(src, offset, src->orig_size, INT64_MAX, + &offset, &count); + offset += count) + { hbitmap_set(dst, offset, count); - offset += count; - if (offset >= src->orig_size) { - break; - } - count = src->orig_size - offset; } } @@ -874,22 +922,6 @@ bool hbitmap_merge(const HBitmap *a, const HBitmap *b, HBitmap *result) return true; } -HBitmap *hbitmap_create_meta(HBitmap *hb, int chunk_size) -{ - assert(!(chunk_size & (chunk_size - 1))); - assert(!hb->meta); - hb->meta = hbitmap_alloc(hb->size << hb->granularity, - hb->granularity + ctz32(chunk_size)); - return hb->meta; -} - -void hbitmap_free_meta(HBitmap *hb) -{ - assert(hb->meta); - hbitmap_free(hb->meta); - hb->meta = NULL; -} - char *hbitmap_sha256(const HBitmap *bitmap, Error **errp) { size_t size = bitmap->sizes[HBITMAP_LEVELS - 1] * sizeof(unsigned long); |