1 files changed, 294 insertions, 0 deletions
diff --git a/libutils/include/utils/BitSet.h b/libutils/include/utils/BitSet.h
new file mode 100644
index 000000000..8c612931d
--- /dev/null
+++ b/libutils/include/utils/BitSet.h
@@ -0,0 +1,294 @@
+/*
+ * 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(0UL) { }
+    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 0x80000000UL >> n; }
+
+    // Clears the bit set.
+    inline void clear() { clear(value); }
+
+    static inline void clear(uint32_t& value) { value = 0UL; }
+
+    // Returns the number of marked bits in the set.
+    inline uint32_t count() const { return count(value); }
+
+    static inline uint32_t count(uint32_t value) { return __builtin_popcountl(value); }
+
+    // Returns true if the bit set does not contain any marked bits.
+    inline bool isEmpty() const { return isEmpty(value); }
+
+    static inline bool isEmpty(uint32_t value) { return ! value; }
+
+    // Returns true if the bit set does not contain any unmarked bits.
+    inline bool isFull() const { return isFull(value); }
+
+    static inline bool isFull(uint32_t value) { return value == 0xffffffffUL; }
+
+    // Returns true if the specified bit is marked.
+    inline bool hasBit(uint32_t n) const { return hasBit(value, n); }
+
+    static inline bool hasBit(uint32_t value, uint32_t n) { return value & valueForBit(n); }
+
+    // Marks the specified bit.
+    inline void markBit(uint32_t n) { markBit(value, n); }
+
+    static inline void markBit (uint32_t& value, uint32_t n) { value |= valueForBit(n); }
+
+    // Clears the specified bit.
+    inline void clearBit(uint32_t n) { clearBit(value, n); }
+
+    static inline void clearBit(uint32_t& value, 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 firstMarkedBit(value); }
+
+    static uint32_t firstMarkedBit(uint32_t value) { return clz_checked(value); }
+
+    // Finds the first unmarked bit in the set.
+    // Result is undefined if all bits are marked.
+    inline uint32_t firstUnmarkedBit() const { return firstUnmarkedBit(value); }
+
+    static inline uint32_t firstUnmarkedBit(uint32_t value) { return clz_checked(~ value); }
+
+    // Finds the last marked bit in the set.
+    // Result is undefined if all bits are unmarked.
+    inline uint32_t lastMarkedBit() const { return lastMarkedBit(value); }
+
+    static inline uint32_t lastMarkedBit(uint32_t value) { return 31 - ctz_checked(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() { return clearFirstMarkedBit(value); }
+
+    static inline uint32_t clearFirstMarkedBit(uint32_t& value) {
+        uint32_t n = firstMarkedBit(value);
+        clearBit(value, 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() { return markFirstUnmarkedBit(value); }
+
+    static inline uint32_t markFirstUnmarkedBit(uint32_t& value) {
+        uint32_t n = firstUnmarkedBit(value);
+        markBit(value, 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() { return clearLastMarkedBit(value); }
+
+    static inline uint32_t clearLastMarkedBit(uint32_t& value) {
+        uint32_t n = lastMarkedBit(value);
+        clearBit(value, 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 getIndexOfBit(value, n);
+    }
+
+    static inline uint32_t getIndexOfBit(uint32_t value, uint32_t n) {
+        return __builtin_popcountl(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;
+    }
+
+private:
+    // We use these helpers as the signature of __builtin_c{l,t}z has "unsigned int" for the
+    // input, which is only guaranteed to be 16b, not 32. The compiler should optimize this away.
+    static inline uint32_t clz_checked(uint32_t value) {
+        if (sizeof(unsigned int) == sizeof(uint32_t)) {
+            return __builtin_clz(value);
+        } else {
+            return __builtin_clzl(value);
+        }
+    }
+
+    static inline uint32_t ctz_checked(uint32_t value) {
+        if (sizeof(unsigned int) == sizeof(uint32_t)) {
+            return __builtin_ctz(value);
+        } else {
+            return __builtin_ctzl(value);
+        }
+    }
+};
+
+ANDROID_BASIC_TYPES_TRAITS(BitSet32)
+
+// A simple set of 64 bits that can be individually marked or cleared.
+struct BitSet64 {
+    uint64_t value;
+
+    inline BitSet64() : value(0ULL) { }
+    explicit inline BitSet64(uint64_t value) : value(value) { }
+
+    // Gets the value associated with a particular bit index.
+    static inline uint64_t valueForBit(uint32_t n) { return 0x8000000000000000ULL >> n; }
+
+    // Clears the bit set.
+    inline void clear() { clear(value); }
+
+    static inline void clear(uint64_t& value) { value = 0ULL; }
+
+    // Returns the number of marked bits in the set.
+    inline uint32_t count() const { return count(value); }
+
+    static inline uint32_t count(uint64_t value) { return __builtin_popcountll(value); }
+
+    // Returns true if the bit set does not contain any marked bits.
+    inline bool isEmpty() const { return isEmpty(value); }
+
+    static inline bool isEmpty(uint64_t value) { return ! value; }
+
+    // Returns true if the bit set does not contain any unmarked bits.
+    inline bool isFull() const { return isFull(value); }
+
+    static inline bool isFull(uint64_t value) { return value == 0xffffffffffffffffULL; }
+
+    // Returns true if the specified bit is marked.
+    inline bool hasBit(uint32_t n) const { return hasBit(value, n); }
+
+    static inline bool hasBit(uint64_t value, uint32_t n) { return value & valueForBit(n); }
+
+    // Marks the specified bit.
+    inline void markBit(uint32_t n) { markBit(value, n); }
+
+    static inline void markBit(uint64_t& value, uint32_t n) { value |= valueForBit(n); }
+
+    // Clears the specified bit.
+    inline void clearBit(uint32_t n) { clearBit(value, n); }
+
+    static inline void clearBit(uint64_t& value, 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 firstMarkedBit(value); }
+
+    static inline uint32_t firstMarkedBit(uint64_t value) { return __builtin_clzll(value); }
+
+    // Finds the first unmarked bit in the set.
+    // Result is undefined if all bits are marked.
+    inline uint32_t firstUnmarkedBit() const { return firstUnmarkedBit(value); }
+
+    static inline uint32_t firstUnmarkedBit(uint64_t value) { return __builtin_clzll(~ value); }
+
+    // Finds the last marked bit in the set.
+    // Result is undefined if all bits are unmarked.
+    inline uint32_t lastMarkedBit() const { return lastMarkedBit(value); }
+
+    static inline uint32_t lastMarkedBit(uint64_t value) { return 63 - __builtin_ctzll(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() { return clearFirstMarkedBit(value); }
+
+    static inline uint32_t clearFirstMarkedBit(uint64_t& value) {
+        uint64_t n = firstMarkedBit(value);
+        clearBit(value, 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() { return markFirstUnmarkedBit(value); }
+
+    static inline uint32_t markFirstUnmarkedBit(uint64_t& value) {
+        uint64_t n = firstUnmarkedBit(value);
+        markBit(value, 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() { return clearLastMarkedBit(value); }
+
+    static inline uint32_t clearLastMarkedBit(uint64_t& value) {
+        uint64_t n = lastMarkedBit(value);
+        clearBit(value, 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 getIndexOfBit(value, n); }
+
+    static inline uint32_t getIndexOfBit(uint64_t value, uint32_t n) {
+        return __builtin_popcountll(value & ~(0xffffffffffffffffULL >> n));
+    }
+
+    inline bool operator== (const BitSet64& other) const { return value == other.value; }
+    inline bool operator!= (const BitSet64& other) const { return value != other.value; }
+    inline BitSet64 operator& (const BitSet64& other) const {
+        return BitSet64(value & other.value);
+    }
+    inline BitSet64& operator&= (const BitSet64& other) {
+        value &= other.value;
+        return *this;
+    }
+    inline BitSet64 operator| (const BitSet64& other) const {
+        return BitSet64(value | other.value);
+    }
+    inline BitSet64& operator|= (const BitSet64& other) {
+        value |= other.value;
+        return *this;
+    }
+};
+
+ANDROID_BASIC_TYPES_TRAITS(BitSet64)
+
+} // namespace android
+
+#endif // UTILS_BITSET_H