Commit a33fbb4f authored by Max Reitz's avatar Max Reitz
Browse files

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: default avatarMax Reitz <mreitz@redhat.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Reviewed-by: default avatarJohn Snow <jsnow@redhat.com>
Message-id: 20180613181823.13618-8-mreitz@redhat.com
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
parent ec9f10fe

block/backup.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

block/dirty-bitmap.c

+1 −1
Original line number Diff line number Diff line
@@ -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 */

include/qemu/hbitmap.h

+4 −1
Original line number Diff line number Diff line
@@ -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:

tests/test-hbitmap.c

+13 −13
Original line number Diff line number Diff line
@@ -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)

util/hbitmap.c

+7 −3
Original line number Diff line number Diff line
@@ -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) 
        }

    }



    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;