Re: [libvirt] [PATCH 26/34] util: bitmap: Introduce bitmap subtraction

Performs binary subtraction of two bitmaps. Stores result in the first operand. --- src/libvirt_private.syms | 1 + src/util/virbitmap.c | 21 ++++++++++++++++++ src/util/virbitmap.h | 3 +++ tests/virbitmaptest.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 80 insertions(+) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 9cebaeb..8213ff3 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1151,6 +1151,7 @@ virBitmapSetAll; virBitmapSetBit; virBitmapSize; virBitmapString; +virBitmapSubtract; virBitmapToData; virBitmapToDataBuf; diff --git a/src/util/virbitmap.c b/src/util/virbitmap.c index 57135a0..f116607 100644 --- a/src/util/virbitmap.c +++ b/src/util/virbitmap.c @@ -859,3 +859,24 @@ virBitmapOverlaps(virBitmapPtr b1, return false; } + +/** + * virBitmapSubtract: + * @a: minuend/result + * @b: subtrahend + * + * Performs bitwise subtraction: a = a - b + */ +void +virBitmapSubtract(virBitmapPtr a, + virBitmapPtr b) +{ + size_t i; + size_t max = a->map_len; + + if (max > b->map_len) + max = b->map_len; + + for (i = 0; i < max; i++) + a->map[i] &= ~b->map[i]; +} diff --git a/src/util/virbitmap.h b/src/util/virbitmap.h index 47488de..846aca3 100644 --- a/src/util/virbitmap.h +++ b/src/util/virbitmap.h @@ -129,4 +129,7 @@ bool virBitmapOverlaps(virBitmapPtr b1, virBitmapPtr b2) ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2); +void virBitmapSubtract(virBitmapPtr a, virBitmapPtr b) + ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2); + #endif diff --git a/tests/virbitmaptest.c b/tests/virbitmaptest.c index 8e458d2..967a5c8 100644 --- a/tests/virbitmaptest.c +++ b/tests/virbitmaptest.c @@ -552,9 +552,55 @@ test10(const void *opaque ATTRIBUTE_UNUSED) return ret; } +struct testBinaryOpData { + const char *a; + const char *b; + const char *res; +}; + +static int +test11(const void *opaque) +{ + const struct testBinaryOpData *data = opaque; + virBitmapPtr amap = NULL; + virBitmapPtr bmap = NULL; + virBitmapPtr resmap = NULL; + int ret = -1; + + if (virBitmapParse(data->a, 0, &amap, 256) < 0 || + virBitmapParse(data->b, 0, &bmap, 256) < 0 || + virBitmapParse(data->res, 0, &resmap, 256) < 0) + goto cleanup; + + virBitmapSubtract(amap, bmap); + + if (!virBitmapEqual(amap, resmap)) { + fprintf(stderr, "\n bitmap subtraction failed: '%s'-'%s'!='%s'\n", + data->a, data->b, data->res); + goto cleanup; + } + + ret = 0; + + cleanup: + virBitmapFree(amap); + virBitmapFree(bmap); + virBitmapFree(resmap); + + return ret; +} + +#define TESTBINARYOP(A, B, RES, FUNC) \ + testBinaryOpData.a = A; \ + testBinaryOpData.b = B; \ + testBinaryOpData.res = RES; \ + if (virtTestRun(virtTestCounterNext(), FUNC, &testBinaryOpData) < 0) \ + ret = -1; + static int mymain(void) { + struct testBinaryOpData testBinaryOpData; int ret = 0; if (virtTestRun("test1", test1, NULL) < 0) @@ -578,6 +624,15 @@ mymain(void) if (virtTestRun("test10", test10, NULL) < 0) ret = -1; + virtTestCounterReset("test11-"); + TESTBINARYOP("0", "0", "0,^0", test11); + TESTBINARYOP("0-3", "0", "1-3", test11); + TESTBINARYOP("0-3", "0,3", "1-2", test11); + TESTBINARYOP("0,^0", "0", "0,^0", test11); + TESTBINARYOP("0-3", "0-3", "0,^0", test11); + TESTBINARYOP("0-3", "0,^0", "0-3", test11); + TESTBINARYOP("0,2", "1,3", "0,2", test11); +

return ret; }