[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;
}
--
2.6.2