*/
struct HBitmap {
+ /*
+ * Size of the bitmap, as requested in hbitmap_alloc or in hbitmap_truncate.
+ */
+ uint64_t orig_size;
+
/* Number of total bits in the bottom level. */
uint64_t size;
/* 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;
}
}
-int64_t hbitmap_next_zero(const HBitmap *hb, uint64_t start)
+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];
- uint64_t sz = hb->sizes[HBITMAP_LEVELS - 1];
unsigned long cur = last_lev[pos];
- unsigned start_bit_offset =
- (start >> hb->granularity) & (BITS_PER_LONG - 1);
+ unsigned start_bit_offset;
+ uint64_t end_bit, sz;
int64_t res;
+ assert(start >= 0 && count >= 0);
+
+ if (start >= hb->orig_size || count == 0) {
+ return -1;
+ }
+
+ end_bit = count > hb->orig_size - start ?
+ hb->size :
+ ((start + count - 1) >> hb->granularity) + 1;
+ sz = (end_bit + BITS_PER_LONG - 1) >> BITS_PER_LEVEL;
+
+ /* There may be some zero bits in @cur before @start. We are not interested
+ * in them, let's set them.
+ */
+ start_bit_offset = (start >> hb->granularity) & (BITS_PER_LONG - 1);
cur |= (1UL << start_bit_offset) - 1;
assert((start >> hb->granularity) < hb->size);
}
res = (pos << BITS_PER_LEVEL) + ctol(cur);
- if (res >= hb->size) {
+ if (res >= end_bit) {
return -1;
}
return res;
}
+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)
+{
+ int64_t next_zero;
+
+ assert(start >= 0 && end >= 0 && max_dirty_count > 0);
+
+ end = MIN(end, hb->orig_size);
+ if (start >= end) {
+ return false;
+ }
+
+ start = hbitmap_next_dirty(hb, start, end - start);
+ if (start < 0) {
+ return false;
+ }
+
+ end = start + MIN(end - start, max_dirty_count);
+
+ next_zero = hbitmap_next_zero(hb, start, end - start);
+ if (next_zero >= 0) {
+ end = next_zero;
+ }
+
+ *dirty_start = start;
+ *dirty_count = end - start;
+
+ return true;
+}
+
+bool hbitmap_status(const HBitmap *hb, int64_t start, int64_t count,
+ int64_t *pnum)
+{
+ int64_t next_dirty, next_zero;
+
+ assert(start >= 0);
+ assert(count > 0);
+ assert(start + count <= hb->orig_size);
+
+ next_dirty = hbitmap_next_dirty(hb, start, count);
+ if (next_dirty == -1) {
+ *pnum = count;
+ return false;
+ }
+
+ if (next_dirty > start) {
+ *pnum = next_dirty - start;
+ return false;
+ }
+
+ assert(next_dirty == start);
+
+ next_zero = hbitmap_next_zero(hb, start, count);
+ if (next_zero == -1) {
+ *pnum = count;
+ return true;
+ }
+
+ assert(next_zero > start);
+ *pnum = next_zero - start;
+ return true;
+}
+
bool hbitmap_empty(const HBitmap *hb)
{
return hb->count == 0;
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.
*/
uint64_t first, n;
uint64_t last = start + count - 1;
+ if (count == 0) {
+ return;
+ }
+
trace_hbitmap_set(hb, start, count,
start >> hb->granularity, last >> hb->granularity);
/* Compute range in the last layer. */
uint64_t first;
uint64_t last = start + count - 1;
+ uint64_t gran = 1ULL << hb->granularity;
+
+ if (count == 0) {
+ return;
+ }
+
+ assert(QEMU_IS_ALIGNED(start, gran));
+ assert(QEMU_IS_ALIGNED(count, gran) || (start + count == hb->orig_size));
trace_hbitmap_reset(hb, start, count,
start >> hb->granularity, last >> hb->granularity);
HBitmap *hb = g_new0(struct HBitmap, 1);
unsigned i;
+ assert(size <= INT64_MAX);
+ hb->orig_size = size;
+
assert(granularity >= 0 && granularity < 64);
size = (size + (1ULL << granularity) - 1) >> granularity;
assert(size <= ((uint64_t)1 << HBITMAP_LOG_MAX_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. */
size = (size + (1ULL << hb->granularity) - 1) >> hb->granularity;
assert(size <= ((uint64_t)1 << HBITMAP_LOG_MAX_SIZE));
}
old = hb->sizes[i];
hb->sizes[i] = size;
- hb->levels[i] = g_realloc(hb->levels[i], size * sizeof(unsigned long));
+ hb->levels[i] = g_renew(unsigned long, hb->levels[i], size);
if (!shrink) {
memset(&hb->levels[i][old], 0x00,
(size - old) * sizeof(*hb->levels[i]));
}
}
+/**
+ * hbitmap_sparse_merge: performs dst = dst | src
+ * works with differing granularities.
+ * best used when src is sparsely populated.
+ */
+static void hbitmap_sparse_merge(HBitmap *dst, const HBitmap *src)
+{
+ int64_t offset;
+ int64_t count;
+
+ for (offset = 0;
+ hbitmap_next_dirty_area(src, offset, src->orig_size, INT64_MAX,
+ &offset, &count);
+ offset += count)
+ {
+ hbitmap_set(dst, offset, count);
+ }
+}
/**
- * Given HBitmaps A and B, let A := A (BITOR) B.
- * Bitmap B will not be modified.
- *
- * @return true if the merge was successful,
- * false if it was not attempted.
+ * Given HBitmaps A and B, let R := A (BITOR) B.
+ * Bitmaps A and B will not be modified,
+ * except when bitmap R is an alias of A or B.
+ * Bitmaps must have same size.
*/
-bool hbitmap_merge(HBitmap *a, const HBitmap *b)
+void hbitmap_merge(const HBitmap *a, const HBitmap *b, HBitmap *result)
{
int i;
uint64_t j;
- if ((a->size != b->size) || (a->granularity != b->granularity)) {
- return false;
+ assert(a->orig_size == result->orig_size);
+ assert(b->orig_size == result->orig_size);
+
+ if ((!hbitmap_count(a) && result == b) ||
+ (!hbitmap_count(b) && result == a)) {
+ return;
}
- if (hbitmap_count(b) == 0) {
- return true;
+ if (!hbitmap_count(a) && !hbitmap_count(b)) {
+ hbitmap_reset_all(result);
+ return;
+ }
+
+ if (a->granularity != b->granularity) {
+ if ((a != result) && (b != result)) {
+ hbitmap_reset_all(result);
+ }
+ if (a != result) {
+ hbitmap_sparse_merge(result, a);
+ }
+ if (b != result) {
+ hbitmap_sparse_merge(result, b);
+ }
+ return;
}
/* This merge is O(size), as BITS_PER_LONG and HBITMAP_LEVELS are constant.
* It may be possible to improve running times for sparsely populated maps
* by using hbitmap_iter_next, but this is suboptimal for dense maps.
*/
+ assert(a->size == b->size);
for (i = HBITMAP_LEVELS - 1; i >= 0; i--) {
for (j = 0; j < a->sizes[i]; j++) {
- a->levels[i][j] |= b->levels[i][j];
+ result->levels[i][j] = a->levels[i][j] | b->levels[i][j];
}
}
- 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;
+ /* Recompute the dirty count */
+ result->count = hb_count_between(result, 0, result->size - 1);
}
char *hbitmap_sha256(const HBitmap *bitmap, Error **errp)
projects / mirror_qemu.git / blobdiff