bitmap: Add bitmap_copy_with_{src|dst}_offset()

These helpers copy the source bitmap to destination bitmap with a
shift either on the src or dst bitmap.

Meanwhile, we never have bitmap tests but we should.

This patch also introduces the initial test cases for utils/bitmap.c
but it only tests the newly introduced functions.

Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20190603065056.25211-5-peterx@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

---

Bitmap test used sizeof(unsigned long) instead of BITS_PER_LONG.
This commit is contained in:
Peter Xu 2019-06-03 14:50:49 +08:00 committed by Juan Quintela
parent ae7a2bca8a
commit ad37f24d57
4 changed files with 168 additions and 0 deletions

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@ -41,6 +41,10 @@
* bitmap_find_next_zero_area(buf, len, pos, n, mask) Find bit free area
* bitmap_to_le(dst, src, nbits) Convert bitmap to little endian
* bitmap_from_le(dst, src, nbits) Convert bitmap from little endian
* bitmap_copy_with_src_offset(dst, src, offset, nbits)
* *dst = *src (with an offset into src)
* bitmap_copy_with_dst_offset(dst, src, offset, nbits)
* *dst = *src (with an offset into dst)
*/
/*
@ -271,4 +275,9 @@ void bitmap_to_le(unsigned long *dst, const unsigned long *src,
void bitmap_from_le(unsigned long *dst, const unsigned long *src,
long nbits);
void bitmap_copy_with_src_offset(unsigned long *dst, const unsigned long *src,
unsigned long offset, unsigned long nbits);
void bitmap_copy_with_dst_offset(unsigned long *dst, const unsigned long *src,
unsigned long shift, unsigned long nbits);
#endif /* BITMAP_H */

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@ -65,6 +65,7 @@ check-unit-y += tests/test-opts-visitor$(EXESUF)
check-unit-$(CONFIG_BLOCK) += tests/test-coroutine$(EXESUF)
check-unit-y += tests/test-visitor-serialization$(EXESUF)
check-unit-y += tests/test-iov$(EXESUF)
check-unit-y += tests/test-bitmap$(EXESUF)
check-unit-$(CONFIG_BLOCK) += tests/test-aio$(EXESUF)
check-unit-$(CONFIG_BLOCK) += tests/test-aio-multithread$(EXESUF)
check-unit-$(CONFIG_BLOCK) += tests/test-throttle$(EXESUF)
@ -538,6 +539,7 @@ tests/test-image-locking$(EXESUF): tests/test-image-locking.o $(test-block-obj-y
tests/test-thread-pool$(EXESUF): tests/test-thread-pool.o $(test-block-obj-y)
tests/test-iov$(EXESUF): tests/test-iov.o $(test-util-obj-y)
tests/test-hbitmap$(EXESUF): tests/test-hbitmap.o $(test-util-obj-y) $(test-crypto-obj-y)
tests/test-bitmap$(EXESUF): tests/test-bitmap.o $(test-util-obj-y)
tests/test-x86-cpuid$(EXESUF): tests/test-x86-cpuid.o
tests/test-xbzrle$(EXESUF): tests/test-xbzrle.o migration/xbzrle.o migration/page_cache.o $(test-util-obj-y)
tests/test-cutils$(EXESUF): tests/test-cutils.o util/cutils.o $(test-util-obj-y)

72
tests/test-bitmap.c Normal file
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@ -0,0 +1,72 @@
/*
* SPDX-License-Identifier: GPL-2.0-or-later
*
* Bitmap.c unit-tests.
*
* Copyright (C) 2019, Red Hat, Inc.
*
* Author: Peter Xu <peterx@redhat.com>
*/
#include <stdlib.h>
#include "qemu/osdep.h"
#include "qemu/bitmap.h"
#define BMAP_SIZE 1024
static void check_bitmap_copy_with_offset(void)
{
unsigned long *bmap1, *bmap2, *bmap3, total;
bmap1 = bitmap_new(BMAP_SIZE);
bmap2 = bitmap_new(BMAP_SIZE);
bmap3 = bitmap_new(BMAP_SIZE);
bmap1[0] = random();
bmap1[1] = random();
bmap1[2] = random();
bmap1[3] = random();
total = BITS_PER_LONG * 4;
/* Shift 115 bits into bmap2 */
bitmap_copy_with_dst_offset(bmap2, bmap1, 115, total);
/* Shift another 85 bits into bmap3 */
bitmap_copy_with_dst_offset(bmap3, bmap2, 85, total + 115);
/* Shift back 200 bits back */
bitmap_copy_with_src_offset(bmap2, bmap3, 200, total);
g_assert_cmpmem(bmap1, total / BITS_PER_LONG,
bmap2, total / BITS_PER_LONG);
bitmap_clear(bmap1, 0, BMAP_SIZE);
/* Set bits in bmap1 are 100-245 */
bitmap_set(bmap1, 100, 145);
/* Set bits in bmap2 are 60-205 */
bitmap_copy_with_src_offset(bmap2, bmap1, 40, 250);
g_assert_cmpint(find_first_bit(bmap2, 60), ==, 60);
g_assert_cmpint(find_next_zero_bit(bmap2, 205, 60), ==, 205);
g_assert(test_bit(205, bmap2) == 0);
/* Set bits in bmap3 are 135-280 */
bitmap_copy_with_dst_offset(bmap3, bmap1, 35, 250);
g_assert_cmpint(find_first_bit(bmap3, 135), ==, 135);
g_assert_cmpint(find_next_zero_bit(bmap3, 280, 135), ==, 280);
g_assert(test_bit(280, bmap3) == 0);
g_free(bmap1);
g_free(bmap2);
g_free(bmap3);
}
int main(int argc, char **argv)
{
g_test_init(&argc, &argv, NULL);
g_test_add_func("/bitmap/bitmap_copy_with_offset",
check_bitmap_copy_with_offset);
g_test_run();
return 0;
}

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@ -402,3 +402,88 @@ void bitmap_to_le(unsigned long *dst, const unsigned long *src,
{
bitmap_to_from_le(dst, src, nbits);
}
/*
* Copy "src" bitmap with a positive offset and put it into the "dst"
* bitmap. The caller needs to make sure the bitmap size of "src"
* is bigger than (shift + nbits).
*/
void bitmap_copy_with_src_offset(unsigned long *dst, const unsigned long *src,
unsigned long shift, unsigned long nbits)
{
unsigned long left_mask, right_mask, last_mask;
/* Proper shift src pointer to the first word to copy from */
src += BIT_WORD(shift);
shift %= BITS_PER_LONG;
if (!shift) {
/* Fast path */
bitmap_copy(dst, src, nbits);
return;
}
right_mask = (1ul << shift) - 1;
left_mask = ~right_mask;
while (nbits >= BITS_PER_LONG) {
*dst = (*src & left_mask) >> shift;
*dst |= (src[1] & right_mask) << (BITS_PER_LONG - shift);
dst++;
src++;
nbits -= BITS_PER_LONG;
}
if (nbits > BITS_PER_LONG - shift) {
*dst = (*src & left_mask) >> shift;
nbits -= BITS_PER_LONG - shift;
last_mask = (1ul << nbits) - 1;
*dst |= (src[1] & last_mask) << (BITS_PER_LONG - shift);
} else if (nbits) {
last_mask = (1ul << nbits) - 1;
*dst = (*src >> shift) & last_mask;
}
}
/*
* Copy "src" bitmap into the "dst" bitmap with an offset in the
* "dst". The caller needs to make sure the bitmap size of "dst" is
* bigger than (shift + nbits).
*/
void bitmap_copy_with_dst_offset(unsigned long *dst, const unsigned long *src,
unsigned long shift, unsigned long nbits)
{
unsigned long left_mask, right_mask, last_mask;
/* Proper shift dst pointer to the first word to copy from */
dst += BIT_WORD(shift);
shift %= BITS_PER_LONG;
if (!shift) {
/* Fast path */
bitmap_copy(dst, src, nbits);
return;
}
right_mask = (1ul << (BITS_PER_LONG - shift)) - 1;
left_mask = ~right_mask;
*dst &= (1ul << shift) - 1;
while (nbits >= BITS_PER_LONG) {
*dst |= (*src & right_mask) << shift;
dst[1] = (*src & left_mask) >> (BITS_PER_LONG - shift);
dst++;
src++;
nbits -= BITS_PER_LONG;
}
if (nbits > BITS_PER_LONG - shift) {
*dst |= (*src & right_mask) << shift;
nbits -= BITS_PER_LONG - shift;
last_mask = ((1ul << nbits) - 1) << (BITS_PER_LONG - shift);
dst[1] = (*src & last_mask) >> (BITS_PER_LONG - shift);
} else if (nbits) {
last_mask = (1ul << nbits) - 1;
*dst |= (*src & last_mask) << shift;
}
}