diff options
| -rw-r--r-- | include/qemu/hbitmap.h | 79 | ||||
| -rw-r--r-- | util/hbitmap.c | 137 |
2 files changed, 216 insertions, 0 deletions
diff --git a/include/qemu/hbitmap.h b/include/qemu/hbitmap.h index 1725919..eb46475 100644 --- a/include/qemu/hbitmap.h +++ b/include/qemu/hbitmap.h @@ -146,6 +146,85 @@ void hbitmap_reset_all(HBitmap *hb); bool hbitmap_get(const HBitmap *hb, uint64_t item); /** + * hbitmap_serialization_granularity: + * @hb: HBitmap to operate on. + * + * Granularity of serialization chunks, used by other serialization functions. + * For every chunk: + * 1. Chunk start should be aligned to this granularity. + * 2. Chunk size should be aligned too, except for last chunk (for which + * start + count == hb->size) + */ +uint64_t hbitmap_serialization_granularity(const HBitmap *hb); + +/** + * hbitmap_serialization_size: + * @hb: HBitmap to operate on. + * @start: Starting bit + * @count: Number of bits + * + * Return number of bytes hbitmap_(de)serialize_part needs + */ +uint64_t hbitmap_serialization_size(const HBitmap *hb, + uint64_t start, uint64_t count); + +/** + * hbitmap_serialize_part + * @hb: HBitmap to operate on. + * @buf: Buffer to store serialized bitmap. + * @start: First bit to store. + * @count: Number of bits to store. + * + * Stores HBitmap data corresponding to given region. The format of saved data + * is linear sequence of bits, so it can be used by hbitmap_deserialize_part + * independently of endianness and size of HBitmap level array elements + */ +void hbitmap_serialize_part(const HBitmap *hb, uint8_t *buf, + uint64_t start, uint64_t count); + +/** + * hbitmap_deserialize_part + * @hb: HBitmap to operate on. + * @buf: Buffer to restore bitmap data from. + * @start: First bit to restore. + * @count: Number of bits to restore. + * @finish: Whether to call hbitmap_deserialize_finish automatically. + * + * Restores HBitmap data corresponding to given region. The format is the same + * as for hbitmap_serialize_part. + * + * If @finish is false, caller must call hbitmap_serialize_finish before using + * the bitmap. + */ +void hbitmap_deserialize_part(HBitmap *hb, uint8_t *buf, + uint64_t start, uint64_t count, + bool finish); + +/** + * hbitmap_deserialize_zeroes + * @hb: HBitmap to operate on. + * @start: First bit to restore. + * @count: Number of bits to restore. + * @finish: Whether to call hbitmap_deserialize_finish automatically. + * + * Fills the bitmap with zeroes. + * + * If @finish is false, caller must call hbitmap_serialize_finish before using + * the bitmap. + */ +void hbitmap_deserialize_zeroes(HBitmap *hb, uint64_t start, uint64_t count, + bool finish); + +/** + * hbitmap_deserialize_finish + * @hb: HBitmap to operate on. + * + * Repair HBitmap after calling hbitmap_deserialize_data. Actually, all HBitmap + * layers are restored here. + */ +void hbitmap_deserialize_finish(HBitmap *hb); + +/** * hbitmap_free: * @hb: HBitmap to operate on. * diff --git a/util/hbitmap.c b/util/hbitmap.c index f303975..5d1a21c 100644 --- a/util/hbitmap.c +++ b/util/hbitmap.c @@ -397,6 +397,143 @@ bool hbitmap_get(const HBitmap *hb, uint64_t item) return (hb->levels[HBITMAP_LEVELS - 1][pos >> BITS_PER_LEVEL] & bit) != 0; } +uint64_t hbitmap_serialization_granularity(const HBitmap *hb) +{ + /* Require at least 64 bit granularity to be safe on both 64 bit and 32 bit + * hosts. */ + return 64 << hb->granularity; +} + +/* Start should be aligned to serialization granularity, chunk size should be + * aligned to serialization granularity too, except for last chunk. + */ +static void serialization_chunk(const HBitmap *hb, + uint64_t start, uint64_t count, + unsigned long **first_el, uint64_t *el_count) +{ + uint64_t last = start + count - 1; + uint64_t gran = hbitmap_serialization_granularity(hb); + + assert((start & (gran - 1)) == 0); + assert((last >> hb->granularity) < hb->size); + if ((last >> hb->granularity) != hb->size - 1) { + assert((count & (gran - 1)) == 0); + } + + start = (start >> hb->granularity) >> BITS_PER_LEVEL; + last = (last >> hb->granularity) >> BITS_PER_LEVEL; + + *first_el = &hb->levels[HBITMAP_LEVELS - 1][start]; + *el_count = last - start + 1; +} + +uint64_t hbitmap_serialization_size(const HBitmap *hb, + uint64_t start, uint64_t count) +{ + uint64_t el_count; + unsigned long *cur; + + if (!count) { + return 0; + } + serialization_chunk(hb, start, count, &cur, &el_count); + + return el_count * sizeof(unsigned long); +} + +void hbitmap_serialize_part(const HBitmap *hb, uint8_t *buf, + uint64_t start, uint64_t count) +{ + uint64_t el_count; + unsigned long *cur, *end; + + if (!count) { + return; + } + serialization_chunk(hb, start, count, &cur, &el_count); + end = cur + el_count; + + while (cur != end) { + unsigned long el = + (BITS_PER_LONG == 32 ? cpu_to_le32(*cur) : cpu_to_le64(*cur)); + + memcpy(buf, &el, sizeof(el)); + buf += sizeof(el); + cur++; + } +} + +void hbitmap_deserialize_part(HBitmap *hb, uint8_t *buf, + uint64_t start, uint64_t count, + bool finish) +{ + uint64_t el_count; + unsigned long *cur, *end; + + if (!count) { + return; + } + serialization_chunk(hb, start, count, &cur, &el_count); + end = cur + el_count; + + while (cur != end) { + memcpy(cur, buf, sizeof(*cur)); + + if (BITS_PER_LONG == 32) { + le32_to_cpus((uint32_t *)cur); + } else { + le64_to_cpus((uint64_t *)cur); + } + + buf += sizeof(unsigned long); + cur++; + } + if (finish) { + hbitmap_deserialize_finish(hb); + } +} + +void hbitmap_deserialize_zeroes(HBitmap *hb, uint64_t start, uint64_t count, + bool finish) +{ + uint64_t el_count; + unsigned long *first; + + if (!count) { + return; + } + serialization_chunk(hb, start, count, &first, &el_count); + + memset(first, 0, el_count * sizeof(unsigned long)); + if (finish) { + hbitmap_deserialize_finish(hb); + } +} + +void hbitmap_deserialize_finish(HBitmap *bitmap) +{ + int64_t i, size, prev_size; + int lev; + + /* restore levels starting from penultimate to zero level, assuming + * that the last level is ok */ + size = MAX((bitmap->size + BITS_PER_LONG - 1) >> BITS_PER_LEVEL, 1); + for (lev = HBITMAP_LEVELS - 1; lev-- > 0; ) { + prev_size = size; + size = MAX((size + BITS_PER_LONG - 1) >> BITS_PER_LEVEL, 1); + memset(bitmap->levels[lev], 0, size * sizeof(unsigned long)); + + for (i = 0; i < prev_size; ++i) { + if (bitmap->levels[lev + 1][i]) { + bitmap->levels[lev][i >> BITS_PER_LEVEL] |= + 1UL << (i & (BITS_PER_LONG - 1)); + } + } + } + + bitmap->levels[0][0] |= 1UL << (BITS_PER_LONG - 1); +} + void hbitmap_free(HBitmap *hb) { unsigned i; |