random/internal/randen_hwaes.h

0001 // Copyright 2017 The Abseil Authors.
0002 //
0003 // Licensed under the Apache License, Version 2.0 (the "License");
0004 // you may not use this file except in compliance with the License.
0005 // You may obtain a copy of the License at
0006 //
0007 //      https://www.apache.org/licenses/LICENSE-2.0
0008 //
0009 // Unless required by applicable law or agreed to in writing, software
0010 // distributed under the License is distributed on an "AS IS" BASIS,
0011 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0012 // See the License for the specific language governing permissions and
0013 // limitations under the License.
0014
0015 #ifndef ABSL_RANDOM_INTERNAL_RANDEN_HWAES_H_
0016 #define ABSL_RANDOM_INTERNAL_RANDEN_HWAES_H_
0017
0018 #include "absl/base/config.h"
0019
0020 // HERMETIC NOTE: The randen_hwaes target must not introduce duplicate
0021 // symbols from arbitrary system and other headers, since it may be built
0022 // with different flags from other targets, using different levels of
0023 // optimization, potentially introducing ODR violations.
0024
0025 namespace absl {
0026 ABSL_NAMESPACE_BEGIN
0027 namespace random_internal {
0028
0029 // RANDen = RANDom generator or beetroots in Swiss High German.
0030 // 'Strong' (well-distributed, unpredictable, backtracking-resistant) random
0031 // generator, faster in some benchmarks than std::mt19937_64 and pcg64_c32.
0032 //
0033 // RandenHwAes implements the basic state manipulation methods.
0034 class RandenHwAes {
0035  public:
0036   static void Generate(const void* keys, void* state_void);
0037   static void Absorb(const void* seed_void, void* state_void);
0038   static const void* GetKeys();
0039 };
0040
0041 // HasRandenHwAesImplementation returns true when there is an accelerated
0042 // implementation, and false otherwise.  If there is no implementation,
0043 // then attempting to use it will abort the program.
0044 bool HasRandenHwAesImplementation();
0045
0046 }  // namespace random_internal
0047 ABSL_NAMESPACE_END
0048 }  // namespace absl
0049
0050 #endif  // ABSL_RANDOM_INTERNAL_RANDEN_HWAES_H_