hbitmap: Add @advance param to hbitmap_iter_next()

This new parameter allows the caller to just query the next dirty
position without moving the iterator.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20180613181823.13618-8-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Max Reitz 2018-06-13 20:18:16 +02:00
parent ec9f10fe06
commit a33fbb4f8b
5 changed files with 26 additions and 19 deletions

View File

@ -354,7 +354,7 @@ static int coroutine_fn backup_run_incremental(BackupBlockJob *job)
HBitmapIter hbi;
hbitmap_iter_init(&hbi, job->copy_bitmap, 0);
while ((cluster = hbitmap_iter_next(&hbi)) != -1) {
while ((cluster = hbitmap_iter_next(&hbi, true)) != -1) {
do {
if (yield_and_check(job)) {
return 0;

View File

@ -519,7 +519,7 @@ void bdrv_dirty_iter_free(BdrvDirtyBitmapIter *iter)
int64_t bdrv_dirty_iter_next(BdrvDirtyBitmapIter *iter)
{
return hbitmap_iter_next(&iter->hbi);
return hbitmap_iter_next(&iter->hbi, true);
}
/* Called within bdrv_dirty_bitmap_lock..unlock */

View File

@ -324,11 +324,14 @@ void hbitmap_free_meta(HBitmap *hb);
/**
* hbitmap_iter_next:
* @hbi: HBitmapIter to operate on.
* @advance: If true, advance the iterator. Otherwise, the next call
* of this function will return the same result (if that
* position is still dirty).
*
* Return the next bit that is set in @hbi's associated HBitmap,
* or -1 if all remaining bits are zero.
*/
int64_t hbitmap_iter_next(HBitmapIter *hbi);
int64_t hbitmap_iter_next(HBitmapIter *hbi, bool advance);
/**
* hbitmap_iter_next_word:

View File

@ -46,7 +46,7 @@ static void hbitmap_test_check(TestHBitmapData *data,
i = first;
for (;;) {
next = hbitmap_iter_next(&hbi);
next = hbitmap_iter_next(&hbi, true);
if (next < 0) {
next = data->size;
}
@ -435,25 +435,25 @@ static void test_hbitmap_iter_granularity(TestHBitmapData *data,
/* Note that hbitmap_test_check has to be invoked manually in this test. */
hbitmap_test_init(data, 131072 << 7, 7);
hbitmap_iter_init(&hbi, data->hb, 0);
g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0);
g_assert_cmpint(hbitmap_iter_next(&hbi, true), <, 0);
hbitmap_test_set(data, ((L2 + L1 + 1) << 7) + 8, 8);
hbitmap_iter_init(&hbi, data->hb, 0);
g_assert_cmpint(hbitmap_iter_next(&hbi), ==, (L2 + L1 + 1) << 7);
g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0);
g_assert_cmpint(hbitmap_iter_next(&hbi, true), ==, (L2 + L1 + 1) << 7);
g_assert_cmpint(hbitmap_iter_next(&hbi, true), <, 0);
hbitmap_iter_init(&hbi, data->hb, (L2 + L1 + 2) << 7);
g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0);
g_assert_cmpint(hbitmap_iter_next(&hbi, true), <, 0);
hbitmap_test_set(data, (131072 << 7) - 8, 8);
hbitmap_iter_init(&hbi, data->hb, 0);
g_assert_cmpint(hbitmap_iter_next(&hbi), ==, (L2 + L1 + 1) << 7);
g_assert_cmpint(hbitmap_iter_next(&hbi), ==, 131071 << 7);
g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0);
g_assert_cmpint(hbitmap_iter_next(&hbi, true), ==, (L2 + L1 + 1) << 7);
g_assert_cmpint(hbitmap_iter_next(&hbi, true), ==, 131071 << 7);
g_assert_cmpint(hbitmap_iter_next(&hbi, true), <, 0);
hbitmap_iter_init(&hbi, data->hb, (L2 + L1 + 2) << 7);
g_assert_cmpint(hbitmap_iter_next(&hbi), ==, 131071 << 7);
g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0);
g_assert_cmpint(hbitmap_iter_next(&hbi, true), ==, 131071 << 7);
g_assert_cmpint(hbitmap_iter_next(&hbi, true), <, 0);
}
static void hbitmap_test_set_boundary_bits(TestHBitmapData *data, ssize_t diff)
@ -893,7 +893,7 @@ static void test_hbitmap_serialize_zeroes(TestHBitmapData *data,
for (i = 0; i < num_positions; i++) {
hbitmap_deserialize_zeroes(data->hb, positions[i], min_l1, true);
hbitmap_iter_init(&iter, data->hb, 0);
next = hbitmap_iter_next(&iter);
next = hbitmap_iter_next(&iter, true);
if (i == num_positions - 1) {
g_assert_cmpint(next, ==, -1);
} else {
@ -919,10 +919,10 @@ static void test_hbitmap_iter_and_reset(TestHBitmapData *data,
hbitmap_iter_init(&hbi, data->hb, BITS_PER_LONG - 1);
hbitmap_iter_next(&hbi);
hbitmap_iter_next(&hbi, true);
hbitmap_reset_all(data->hb);
hbitmap_iter_next(&hbi);
hbitmap_iter_next(&hbi, true);
}
static void test_hbitmap_next_zero_check(TestHBitmapData *data, int64_t start)

View File

@ -141,7 +141,7 @@ unsigned long hbitmap_iter_skip_words(HBitmapIter *hbi)
return cur;
}
int64_t hbitmap_iter_next(HBitmapIter *hbi)
int64_t hbitmap_iter_next(HBitmapIter *hbi, bool advance)
{
unsigned long cur = hbi->cur[HBITMAP_LEVELS - 1] &
hbi->hb->levels[HBITMAP_LEVELS - 1][hbi->pos];
@ -154,8 +154,12 @@ int64_t hbitmap_iter_next(HBitmapIter *hbi)
}
}
/* The next call will resume work from the next bit. */
hbi->cur[HBITMAP_LEVELS - 1] = cur & (cur - 1);
if (advance) {
/* The next call will resume work from the next bit. */
hbi->cur[HBITMAP_LEVELS - 1] = cur & (cur - 1);
} else {
hbi->cur[HBITMAP_LEVELS - 1] = cur;
}
item = ((uint64_t)hbi->pos << BITS_PER_LEVEL) + ctzl(cur);
return item << hbi->granularity;