diff options
Diffstat (limited to 'absl/hash/internal/hash.cc')
| -rw-r--r-- | absl/hash/internal/hash.cc | 35 |
1 files changed, 25 insertions, 10 deletions
diff --git a/absl/hash/internal/hash.cc b/absl/hash/internal/hash.cc index b44ecb3a..1433eb9d 100644 --- a/absl/hash/internal/hash.cc +++ b/absl/hash/internal/hash.cc @@ -18,9 +18,9 @@ namespace absl { ABSL_NAMESPACE_BEGIN namespace hash_internal { -uint64_t CityHashState::CombineLargeContiguousImpl32(uint64_t state, - const unsigned char* first, - size_t len) { +uint64_t HashState::CombineLargeContiguousImpl32(uint64_t state, + const unsigned char* first, + size_t len) { while (len >= PiecewiseChunkSize()) { state = Mix(state, absl::hash_internal::CityHash32(reinterpret_cast<const char*>(first), @@ -33,13 +33,11 @@ uint64_t CityHashState::CombineLargeContiguousImpl32(uint64_t state, std::integral_constant<int, 4>{}); } -uint64_t CityHashState::CombineLargeContiguousImpl64(uint64_t state, - const unsigned char* first, - size_t len) { +uint64_t HashState::CombineLargeContiguousImpl64(uint64_t state, + const unsigned char* first, + size_t len) { while (len >= PiecewiseChunkSize()) { - state = - Mix(state, absl::hash_internal::CityHash64(reinterpret_cast<const char*>(first), - PiecewiseChunkSize())); + state = Mix(state, Hash64(first, PiecewiseChunkSize())); len -= PiecewiseChunkSize(); first += PiecewiseChunkSize(); } @@ -48,7 +46,24 @@ uint64_t CityHashState::CombineLargeContiguousImpl64(uint64_t state, std::integral_constant<int, 8>{}); } -ABSL_CONST_INIT const void* const CityHashState::kSeed = &kSeed; +ABSL_CONST_INIT const void* const HashState::kSeed = &kSeed; + +// The salt array used by Wyhash. This array is NOT the mechanism used to make +// absl::Hash non-deterministic between program invocations. See `Seed()` for +// that mechanism. +// +// Any random values are fine. These values are just digits from the decimal +// part of pi. +// https://en.wikipedia.org/wiki/Nothing-up-my-sleeve_number +constexpr uint64_t kWyhashSalt[5] = { + uint64_t{0x243F6A8885A308D3}, uint64_t{0x13198A2E03707344}, + uint64_t{0xA4093822299F31D0}, uint64_t{0x082EFA98EC4E6C89}, + uint64_t{0x452821E638D01377}, +}; + +uint64_t HashState::WyhashImpl(const unsigned char* data, size_t len) { + return Wyhash(data, len, Seed(), kWyhashSalt); +} } // namespace hash_internal ABSL_NAMESPACE_END |