1 | /* Copyright 2016 The TensorFlow Authors. All Rights Reserved. |
2 | |
3 | Licensed under the Apache License, Version 2.0 (the "License"); |
4 | you may not use this file except in compliance with the License. |
5 | You may obtain a copy of the License at |
6 | |
7 | http://www.apache.org/licenses/LICENSE-2.0 |
8 | |
9 | Unless required by applicable law or agreed to in writing, software |
10 | distributed under the License is distributed on an "AS IS" BASIS, |
11 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
12 | See the License for the specific language governing permissions and |
13 | limitations under the License. |
14 | ==============================================================================*/ |
15 | |
16 | #ifndef TENSORFLOW_CORE_PLATFORM_STRONG_HASH_H_ |
17 | #define TENSORFLOW_CORE_PLATFORM_STRONG_HASH_H_ |
18 | |
19 | #include "highwayhash/sip_hash.h" // from @highwayhash |
20 | #include "highwayhash/state_helpers.h" // from @highwayhash |
21 | #include "tensorflow/core/platform/platform.h" |
22 | #include "tensorflow/core/platform/types.h" |
23 | |
24 | namespace tensorflow { |
25 | |
26 | // This is a strong keyed hash function interface for strings. |
27 | // The hash function is deterministic on the content of the string within the |
28 | // process. The key of the hash is an array of 2 uint64 elements. |
29 | // A strong hash makes it difficult, if not infeasible, to compute inputs that |
30 | // hash to the same bucket. |
31 | // |
32 | // Usage: |
33 | // uint64 key[2] = {123, 456}; |
34 | // string input = "input string"; |
35 | // uint64 hash_value = StrongKeyedHash(key, input); |
36 | // |
37 | inline uint64 StrongKeyedHash(const tensorflow::uint64 (&key)[2], |
38 | const string& s) { |
39 | return highwayhash::StringHasher<highwayhash::SipHashState>()( |
40 | {key[0], key[1]}, s); |
41 | } |
42 | |
43 | } // namespace tensorflow |
44 | |
45 | #endif // TENSORFLOW_CORE_PLATFORM_STRONG_HASH_H_ |
46 | |