/*
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* Copyright 2011 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#ifndef SkBitSet_DEFINED
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#define SkBitSet_DEFINED
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#include "SkTemplates.h"
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class SkBitSet {
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public:
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explicit SkBitSet(int numberOfBits) {
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SkASSERT(numberOfBits >= 0);
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fDwordCount = (numberOfBits + 31) / 32; // Round up size to 32-bit boundary.
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if (fDwordCount > 0) {
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fBitData.reset((uint32_t*)sk_calloc_throw(fDwordCount * sizeof(uint32_t)));
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}
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}
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/** Set the value of the index-th bit to true. */
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void set(int index) {
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uint32_t mask = 1 << (index & 31);
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uint32_t* chunk = this->internalGet(index);
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SkASSERT(chunk);
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*chunk |= mask;
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}
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bool has(int index) const {
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const uint32_t* chunk = this->internalGet(index);
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uint32_t mask = 1 << (index & 31);
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return chunk && SkToBool(*chunk & mask);
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}
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// Calls f(unsigned) for each set value.
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template<typename FN>
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void getSetValues(FN f) const {
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const uint32_t* data = fBitData.get();
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for (unsigned i = 0; i < fDwordCount; ++i) {
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if (uint32_t value = data[i]) { // There are set bits
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unsigned index = i * 32;
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for (unsigned j = 0; j < 32; ++j) {
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if (0x1 & (value >> j)) {
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f(index | j);
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}
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}
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}
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}
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}
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private:
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std::unique_ptr<uint32_t, SkFunctionWrapper<void, void, sk_free>> fBitData;
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size_t fDwordCount; // Dword (32-bit) count of the bitset.
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uint32_t* internalGet(int index) const {
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size_t internalIndex = index / 32;
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if (internalIndex >= fDwordCount) {
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return nullptr;
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}
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return fBitData.get() + internalIndex;
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}
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};
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#endif
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