12bc53e031
-- c99f979ad34f155fbeeea69b88bdc7458d89a21c by Derek Mauro <dmauro@google.com>: Remove a floating point division by zero test. This isn't testing behavior related to the library, and MSVC warns about it in opt mode. PiperOrigin-RevId: 285220804 -- 68b015491f0dbf1ab547994673281abd1f34cd4b by Gennadiy Rozental <rogeeff@google.com>: This CL introduces following changes to the class FlagImpl: * We eliminate the CommandLineFlagLocks struct. Instead callback guard and callback function are combined into a single CallbackData struct, while primary data lock is stored separately. * CallbackData member of class FlagImpl is initially set to be nullptr and is only allocated and initialized when a flag's callback is being set. For most flags we do not pay for the extra space and extra absl::Mutex now. * Primary data guard is stored in data_guard_ data member. This is a properly aligned character buffer of necessary size. During initialization of the flag we construct absl::Mutex in this space using placement new call. * We now avoid extra value copy after successful attempt to parse value out of string. Instead we swap flag's current value with tentative value we just produced. PiperOrigin-RevId: 285132636 -- ed45d118fb818969eb13094cf7827c885dfc562c by Tom Manshreck <shreck@google.com>: Change null-term* (and nul-term*) to NUL-term* in comments PiperOrigin-RevId: 285036610 -- 729619017944db895ce8d6d29c1995aa2e5628a5 by Derek Mauro <dmauro@google.com>: Use the Posix implementation of thread identity on MinGW. Some versions of MinGW suffer from thread_local bugs. PiperOrigin-RevId: 285022920 -- 39a25493503c76885bc3254c28f66a251c5b5bb0 by Greg Falcon <gfalcon@google.com>: Implementation detail change. Add further ABSL_NAMESPACE_BEGIN and _END annotation macros to files in Abseil. PiperOrigin-RevId: 285012012 GitOrigin-RevId: c99f979ad34f155fbeeea69b88bdc7458d89a21c Change-Id: I4c85d3704e45d11a9ac50d562f39640a6adbedc1
63 lines
2.3 KiB
C++
63 lines
2.3 KiB
C++
// Copyright 2017 The Abseil Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// https://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#ifndef ABSL_RANDOM_INTERNAL_RANDEN_TRAITS_H_
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#define ABSL_RANDOM_INTERNAL_RANDEN_TRAITS_H_
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// HERMETIC NOTE: The randen_hwaes target must not introduce duplicate
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// symbols from arbitrary system and other headers, since it may be built
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// with different flags from other targets, using different levels of
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// optimization, potentially introducing ODR violations.
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#include <cstddef>
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#include "absl/base/config.h"
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namespace absl {
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ABSL_NAMESPACE_BEGIN
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namespace random_internal {
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// RANDen = RANDom generator or beetroots in Swiss German.
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// 'Strong' (well-distributed, unpredictable, backtracking-resistant) random
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// generator, faster in some benchmarks than std::mt19937_64 and pcg64_c32.
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//
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// RandenTraits contains the basic algorithm traits, such as the size of the
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// state, seed, sponge, etc.
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struct RandenTraits {
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// Size of the entire sponge / state for the randen PRNG.
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static constexpr size_t kStateBytes = 256; // 2048-bit
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// Size of the 'inner' (inaccessible) part of the sponge. Larger values would
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// require more frequent calls to RandenGenerate.
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static constexpr size_t kCapacityBytes = 16; // 128-bit
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// Size of the default seed consumed by the sponge.
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static constexpr size_t kSeedBytes = kStateBytes - kCapacityBytes;
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// Largest size for which security proofs are known.
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static constexpr size_t kFeistelBlocks = 16;
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// Type-2 generalized Feistel => one round function for every two blocks.
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static constexpr size_t kFeistelFunctions = kFeistelBlocks / 2; // = 8
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// Ensures SPRP security and two full subblock diffusions.
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// Must be > 4 * log2(kFeistelBlocks).
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static constexpr size_t kFeistelRounds = 16 + 1;
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};
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} // namespace random_internal
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ABSL_NAMESPACE_END
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} // namespace absl
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#endif // ABSL_RANDOM_INTERNAL_RANDEN_TRAITS_H_
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