Merge commit '536dea9d61a032e64bbe584a97463c6638ead009' into HEAD

Change-Id: I5c469a4b738629d99d721cad7ded02d6c35f56d5

1 files changed, 124 insertions, 0 deletions

diff --git a/include/utils/BitSet.h b/include/utils/BitSet.h
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+++ b/include/utils/BitSet.h
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+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef UTILS_BITSET_H
+#define UTILS_BITSET_H
+
+#include <stdint.h>
+#include <utils/TypeHelpers.h>
+
+/*
+ * Contains some bit manipulation helpers.
+ */
+
+namespace android {
+
+// A simple set of 32 bits that can be individually marked or cleared.
+struct BitSet32 {
+    uint32_t value;
+
+    inline BitSet32() : value(0) { }
+    explicit inline BitSet32(uint32_t value) : value(value) { }
+
+    // Gets the value associated with a particular bit index.
+    static inline uint32_t valueForBit(uint32_t n) { return 0x80000000 >> n; }
+
+    // Clears the bit set.
+    inline void clear() { value = 0; }
+
+    // Returns the number of marked bits in the set.
+    inline uint32_t count() const { return __builtin_popcount(value); }
+
+    // Returns true if the bit set does not contain any marked bits.
+    inline bool isEmpty() const { return ! value; }
+
+    // Returns true if the bit set does not contain any unmarked bits.
+    inline bool isFull() const { return value == 0xffffffff; }
+
+    // Returns true if the specified bit is marked.
+    inline bool hasBit(uint32_t n) const { return value & valueForBit(n); }
+
+    // Marks the specified bit.
+    inline void markBit(uint32_t n) { value |= valueForBit(n); }
+
+    // Clears the specified bit.
+    inline void clearBit(uint32_t n) { value &= ~ valueForBit(n); }
+
+    // Finds the first marked bit in the set.
+    // Result is undefined if all bits are unmarked.
+    inline uint32_t firstMarkedBit() const { return __builtin_clz(value); }
+
+    // Finds the first unmarked bit in the set.
+    // Result is undefined if all bits are marked.
+    inline uint32_t firstUnmarkedBit() const { return __builtin_clz(~ value); }
+
+    // Finds the last marked bit in the set.
+    // Result is undefined if all bits are unmarked.
+    inline uint32_t lastMarkedBit() const { return 31 - __builtin_ctz(value); }
+
+    // Finds the first marked bit in the set and clears it.  Returns the bit index.
+    // Result is undefined if all bits are unmarked.
+    inline uint32_t clearFirstMarkedBit() {
+        uint32_t n = firstMarkedBit();
+        clearBit(n);
+        return n;
+    }
+
+    // Finds the first unmarked bit in the set and marks it.  Returns the bit index.
+    // Result is undefined if all bits are marked.
+    inline uint32_t markFirstUnmarkedBit() {
+        uint32_t n = firstUnmarkedBit();
+        markBit(n);
+        return n;
+    }
+
+    // Finds the last marked bit in the set and clears it.  Returns the bit index.
+    // Result is undefined if all bits are unmarked.
+    inline uint32_t clearLastMarkedBit() {
+        uint32_t n = lastMarkedBit();
+        clearBit(n);
+        return n;
+    }
+
+    // Gets the index of the specified bit in the set, which is the number of
+    // marked bits that appear before the specified bit.
+    inline uint32_t getIndexOfBit(uint32_t n) const {
+        return __builtin_popcount(value & ~(0xffffffffUL >> n));
+    }
+
+    inline bool operator== (const BitSet32& other) const { return value == other.value; }
+    inline bool operator!= (const BitSet32& other) const { return value != other.value; }
+    inline BitSet32 operator& (const BitSet32& other) const {
+        return BitSet32(value & other.value);
+    }
+    inline BitSet32& operator&= (const BitSet32& other) {
+        value &= other.value;
+        return *this;
+    }
+    inline BitSet32 operator| (const BitSet32& other) const {
+        return BitSet32(value | other.value);
+    }
+    inline BitSet32& operator|= (const BitSet32& other) {
+        value |= other.value;
+        return *this;
+    }
+};
+
+ANDROID_BASIC_TYPES_TRAITS(BitSet32)
+
+} // namespace android
+
+#endif // UTILS_BITSET_H