diff options
author | Andy Hung <hunga@google.com> | 2020-10-29 02:09:57 +0000 |
---|---|---|
committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | 2020-10-29 02:09:57 +0000 |
commit | 6305a290a0e261dbf61354f298a799297de54360 (patch) | |
tree | 35d73359fd09cc16d1fbb857909581bad75b765e /third_party/abseil-cpp/absl/container/internal/raw_hash_set.cc | |
parent | bdcf7c15937fa6f88b52f091024bd667d6b2b302 (diff) | |
parent | b02c729712188d3420b78a1bbb1b779544bd4427 (diff) | |
download | webrtc-6305a290a0e261dbf61354f298a799297de54360.tar.gz |
Merge "Import abseil-cpp to third_party" am: aa2897cdcb am: 2cc1e455f9 am: 4211622fc5 am: b02c729712
Original change: https://android-review.googlesource.com/c/platform/external/webrtc/+/1477956
Change-Id: I2157494054f0fdd15375163dda6ee668e2b90f0b
Diffstat (limited to 'third_party/abseil-cpp/absl/container/internal/raw_hash_set.cc')
-rw-r--r-- | third_party/abseil-cpp/absl/container/internal/raw_hash_set.cc | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/third_party/abseil-cpp/absl/container/internal/raw_hash_set.cc b/third_party/abseil-cpp/absl/container/internal/raw_hash_set.cc new file mode 100644 index 0000000000..919ac07405 --- /dev/null +++ b/third_party/abseil-cpp/absl/container/internal/raw_hash_set.cc @@ -0,0 +1,48 @@ +// 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/container/internal/raw_hash_set.h" + +#include <atomic> +#include <cstddef> + +#include "absl/base/config.h" + +namespace absl { +ABSL_NAMESPACE_BEGIN +namespace container_internal { + +constexpr size_t Group::kWidth; + +// Returns "random" seed. +inline size_t RandomSeed() { +#if ABSL_HAVE_THREAD_LOCAL + static thread_local size_t counter = 0; + size_t value = ++counter; +#else // ABSL_HAVE_THREAD_LOCAL + static std::atomic<size_t> counter(0); + size_t value = counter.fetch_add(1, std::memory_order_relaxed); +#endif // ABSL_HAVE_THREAD_LOCAL + return value ^ static_cast<size_t>(reinterpret_cast<uintptr_t>(&counter)); +} + +bool ShouldInsertBackwards(size_t hash, ctrl_t* ctrl) { + // To avoid problems with weak hashes and single bit tests, we use % 13. + // TODO(kfm,sbenza): revisit after we do unconditional mixing + return (H1(hash, ctrl) ^ RandomSeed()) % 13 > 6; +} + +} // namespace container_internal +ABSL_NAMESPACE_END +} // namespace absl |