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 //
StrongKeyedHash(const tensorflow::uint64 (& key)[2],const string & s)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