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Diffstat (limited to 'gfx/angle/checkout/src/common/hash_utils.h')
-rw-r--r-- | gfx/angle/checkout/src/common/hash_utils.h | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/gfx/angle/checkout/src/common/hash_utils.h b/gfx/angle/checkout/src/common/hash_utils.h new file mode 100644 index 0000000000..aec4e7f77c --- /dev/null +++ b/gfx/angle/checkout/src/common/hash_utils.h @@ -0,0 +1,39 @@ +// +// Copyright 2018 The ANGLE Project Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. +// +// hash_utils.h: Hashing based helper functions. + +#ifndef COMMON_HASHUTILS_H_ +#define COMMON_HASHUTILS_H_ + +#include "common/debug.h" +#include "common/third_party/xxhash/xxhash.h" + +namespace angle +{ +// Computes a hash of "key". Any data passed to this function must be multiples of +// 4 bytes, since the PMurHash32 method can only operate increments of 4-byte words. +inline std::size_t ComputeGenericHash(const void *key, size_t keySize) +{ + static constexpr unsigned int kSeed = 0xABCDEF98; + + // We can't support "odd" alignments. ComputeGenericHash requires aligned types + ASSERT(keySize % 4 == 0); +#if defined(ANGLE_IS_64_BIT_CPU) + return XXH64(key, keySize, kSeed); +#else + return XXH32(key, keySize, kSeed); +#endif // defined(ANGLE_IS_64_BIT_CPU) +} + +template <typename T> +std::size_t ComputeGenericHash(const T &key) +{ + static_assert(sizeof(key) % 4 == 0, "ComputeGenericHash requires aligned types"); + return ComputeGenericHash(&key, sizeof(key)); +} +} // namespace angle + +#endif // COMMON_HASHUTILS_H_ |