blob: 770b0d8bce363bececcccf0aadd7336c5b3b57f2 [file] [log] [blame]
/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkBitSet_DEFINED
#define SkBitSet_DEFINED
#include "include/private/SkTemplates.h"
class SkBitSet {
public:
explicit SkBitSet(int numberOfBits) {
SkASSERT(numberOfBits >= 0);
fDwordCount = (numberOfBits + 31) / 32; // Round up size to 32-bit boundary.
if (fDwordCount > 0) {
fBitData.reset((uint32_t*)sk_calloc_throw(fDwordCount * sizeof(uint32_t)));
}
}
/** Set the value of the index-th bit to true. */
void set(int index) {
uint32_t mask = 1 << (index & 31);
uint32_t* chunk = this->internalGet(index);
SkASSERT(chunk);
*chunk |= mask;
}
bool has(int index) const {
const uint32_t* chunk = this->internalGet(index);
uint32_t mask = 1 << (index & 31);
return chunk && SkToBool(*chunk & mask);
}
// Calls f(unsigned) for each set value.
template<typename FN>
void getSetValues(FN f) const {
const uint32_t* data = fBitData.get();
for (unsigned i = 0; i < fDwordCount; ++i) {
if (uint32_t value = data[i]) { // There are set bits
unsigned index = i * 32;
for (unsigned j = 0; j < 32; ++j) {
if (0x1 & (value >> j)) {
f(index | j);
}
}
}
}
}
private:
std::unique_ptr<uint32_t, SkFunctionWrapper<void(void*), sk_free>> fBitData;
size_t fDwordCount; // Dword (32-bit) count of the bitset.
uint32_t* internalGet(int index) const {
size_t internalIndex = index / 32;
if (internalIndex >= fDwordCount) {
return nullptr;
}
return fBitData.get() + internalIndex;
}
};
#endif