Move SkBitSet to utils.

Review URL: https://codereview.appspot.com/5875043

git-svn-id: http://skia.googlecode.com/svn/trunk@3460 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 83 insertions, 0 deletions

diff --git a/src/utils/SkBitSet.cpp b/src/utils/SkBitSet.cpp
new file mode 100755
index 0000000000..664c8cd86f
--- /dev/null
+++ b/src/utils/SkBitSet.cpp
@@ -0,0 +1,83 @@
+
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#include "SkBitSet.h"
+
+SkBitSet::SkBitSet(int numberOfBits)
+    : fBitData(NULL), fDwordCount(0), fBitCount(numberOfBits) {
+    SkASSERT(numberOfBits > 0);
+    // Round up size to 32-bit boundary.
+    fDwordCount = (numberOfBits + 31) / 32;
+    fBitData.set(malloc(fDwordCount * sizeof(uint32_t)));
+    clearAll();
+}
+
+SkBitSet::SkBitSet(const SkBitSet& source)
+    : fBitData(NULL), fDwordCount(0), fBitCount(0) {
+    *this = source;
+}
+
+const SkBitSet& SkBitSet::operator=(const SkBitSet& rhs) {
+    if (this == &rhs) {
+        return *this;
+    }
+    fBitCount = rhs.fBitCount;
+    fBitData.free();
+    fDwordCount = rhs.fDwordCount;
+    fBitData.set(malloc(fDwordCount * sizeof(uint32_t)));
+    memcpy(fBitData.get(), rhs.fBitData.get(), fDwordCount * sizeof(uint32_t));
+    return *this;
+}
+
+bool SkBitSet::operator==(const SkBitSet& rhs) {
+    if (fBitCount == rhs.fBitCount) {
+        if (fBitData.get() != NULL) {
+            return (memcmp(fBitData.get(), rhs.fBitData.get(),
+                           fDwordCount * sizeof(uint32_t)) == 0);
+        }
+        return true;
+    }
+    return false;
+}
+
+bool SkBitSet::operator!=(const SkBitSet& rhs) {
+    return !(*this == rhs);
+}
+
+void SkBitSet::clearAll() {
+    if (fBitData.get() != NULL) {
+        sk_bzero(fBitData.get(), fDwordCount * sizeof(uint32_t));
+    }
+}
+
+void SkBitSet::setBit(int index, bool value) {
+    uint32_t mask = 1 << (index % 32);
+    if (value) {
+        *(internalGet(index)) |= mask;
+    } else {
+        *(internalGet(index)) &= ~mask;
+    }
+}
+
+bool SkBitSet::isBitSet(int index) const {
+    uint32_t mask = 1 << (index % 32);
+    return 0 != (*internalGet(index) & mask);
+}
+
+bool SkBitSet::orBits(const SkBitSet& source) {
+    if (fBitCount != source.fBitCount) {
+        return false;
+    }
+    uint32_t* targetBitmap = internalGet(0);
+    uint32_t* sourceBitmap = source.internalGet(0);
+    for (size_t i = 0; i < fDwordCount; ++i) {
+        targetBitmap[i] |= sourceBitmap[i];
+    }
+    return true;
+}