tvl-depot/absl/hash/internal/hash.cc
Abseil Team e96ae2203b Export of internal Abseil changes
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074a799119ac881b8b8ce59ef7a3166d1aa025ac by Tom Manshreck <shreck@google.com>:

nit: Add return info for StrCat

PiperOrigin-RevId: 278647298

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d58a2a39ab6f50266cc695506ba2e86bdb45d795 by Mark Barolak <mbar@google.com>:

Stop suppressing no-nested-anon-types warnings because there aren't actually any warnings to suppress.

PiperOrigin-RevId: 278440548

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445051bd280b9a6f608a8c80b3d7cafcc1377a03 by Abseil Team <absl-team@google.com>:

ResetThreadIdentity does not need to clear identity->waiter_state.

ResetThreadIdentity is only called by NewThreadIdentity. NewThreadIdentity is
only called by CreateThreadIdentity. CreateThreadIdentity calls
PerThreadSem::Init, which initializes identity->waiter_state, immediately after
calling NewThreadIdentity. Therefore ResetThreadIdentity does not need to clear
identity->waiter_state.
PiperOrigin-RevId: 278429844

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c2079b664d92be40d5e365abcca4e9b3505a75a6 by Abseil Team <absl-team@google.com>:

Delete the f->header.magic check in LowLevelAlloc::Free().

The f->header.magic check in LowLevelAlloc::Free() is redundant, because
AddToFreeList() will immediately perform the same check.

Also fix a typo in the comment that documents the lock requirements for
Next(). The comment should say "L >= arena->mu", which is equivalent to
EXCLUSIVE_LOCKS_REQUIRED(arena->mu).

NOTE: LowLevelAlloc::Free() performs the f->header.magic check without
holding the arena lock. This may have caused the TSAN data race warning
reported in bug 143697235.
PiperOrigin-RevId: 278414140

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5534f35ce677165700117d868f51607ed1f0d73b by Greg Falcon <gfalcon@google.com>:

Add an internal (unsupported) PiecewiseCombiner class to allow hashing buffers piecewise.

PiperOrigin-RevId: 278388902
GitOrigin-RevId: 074a799119ac881b8b8ce59ef7a3166d1aa025ac
Change-Id: I61734850cbbb01c7585e8c736a5bb56e416512a8
2019-11-05 16:41:17 -05:00

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// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "absl/hash/internal/hash.h"
namespace absl {
namespace hash_internal {
uint64_t CityHashState::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),
PiecewiseChunkSize()));
len -= PiecewiseChunkSize();
first += PiecewiseChunkSize();
}
// Handle the remainder.
return CombineContiguousImpl(state, first, len,
std::integral_constant<int, 4>{});
}
uint64_t CityHashState::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()));
len -= PiecewiseChunkSize();
first += PiecewiseChunkSize();
}
// Handle the remainder.
return CombineContiguousImpl(state, first, len,
std::integral_constant<int, 8>{});
}
ABSL_CONST_INIT const void* const CityHashState::kSeed = &kSeed;
} // namespace hash_internal
} // namespace absl