blob: ad1fa7c96dda564ffb8cce56aca8ebc4282ddd09 [file] [log] [blame]
/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GrMurmur3HashKey_DEFINED
#define GrMurmur3HashKey_DEFINED
#include "SkChecksum.h"
#include "GrTypes.h"
/**
* GrMurmur3HashKey is a hash key class that can take a data chunk of any predetermined
* length. It uses the Murmur3 hash function. It is intended to be used with
* SkTDynamicHash (where GrBinHashKey is for GrTHashTable).
*/
template<size_t KEY_SIZE_IN_BYTES>
class GrMurmur3HashKey {
public:
GrMurmur3HashKey() {
this->reset();
}
void reset() {
fHash = 0;
#ifdef SK_DEBUG
fIsValid = false;
#endif
}
void setKeyData(const uint32_t* data) {
SK_COMPILE_ASSERT(KEY_SIZE_IN_BYTES % 4 == 0, key_size_mismatch);
memcpy(fData, data, KEY_SIZE_IN_BYTES);
fHash = SkChecksum::Murmur3(fData, KEY_SIZE_IN_BYTES);
#ifdef SK_DEBUG
fIsValid = true;
#endif
}
bool operator==(const GrMurmur3HashKey& other) const {
if (fHash != other.fHash) {
return false;
}
return !memcmp(fData, other.fData, KEY_SIZE_IN_BYTES);
}
uint32_t getHash() const {
SkASSERT(fIsValid);
return fHash;
}
const uint8_t* getData() const {
SkASSERT(fIsValid);
return reinterpret_cast<const uint8_t*>(fData);
}
private:
uint32_t fHash;
uint32_t fData[KEY_SIZE_IN_BYTES / sizeof(uint32_t)]; // Buffer for key storage.
#ifdef SK_DEBUG
public:
bool fIsValid;
#endif
};
#endif