blob: ebbf4ff712b19f08ea510eeececaec34688ac147 [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 "SkTemplates.h"
#include <vector>
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;
}
template<typename T>
void setAll(T* array, int len) {
static_assert(std::is_integral<T>::value, "T is integral");
for (int i = 0; i < len; ++i) {
this->set(static_cast<int>(array[i]));
}
}
bool has(int index) const {
const uint32_t* chunk = this->internalGet(index);
uint32_t mask = 1 << (index & 31);
return chunk && SkToBool(*chunk & mask);
}
/** Export indices of set bits to T array. */
template<typename T>
void exportTo(std::vector<T>* array) const {
static_assert(std::is_integral<T>::value, "T is integral");
SkASSERT(array);
uint32_t* data = reinterpret_cast<uint32_t*>(fBitData.get());
for (unsigned int i = 0; i < fDwordCount; ++i) {
uint32_t value = data[i];
if (value) { // There are set bits
unsigned int index = i * 32;
for (unsigned int j = 0; j < 32; ++j) {
if (0x1 & (value >> j)) {
array->push_back(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