1 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
2 //  This source code is licensed under both the GPLv2 (found in the
3 //  COPYING file in the root directory) and Apache 2.0 License
4 //  (found in the LICENSE.Apache file in the root directory).
5 //
6 /*
7   Murmurhash from http://sites.google.com/site/murmurhash/
8 
9   All code is released to the public domain. For business purposes, Murmurhash
10   is under the MIT license.
11 */
12 #pragma once
13 #include <stdint.h>
14 #include "rocksdb/slice.h"
15 
16 #if defined(__x86_64__)
17 #define MURMUR_HASH MurmurHash64A
18 uint64_t MurmurHash64A ( const void * key, int len, unsigned int seed );
19 #define MurmurHash MurmurHash64A
20 typedef uint64_t murmur_t;
21 
22 #elif defined(__i386__)
23 #define MURMUR_HASH MurmurHash2
24 unsigned int MurmurHash2 ( const void * key, int len, unsigned int seed );
25 #define MurmurHash MurmurHash2
26 typedef unsigned int murmur_t;
27 
28 #else
29 #define MURMUR_HASH MurmurHashNeutral2
30 unsigned int MurmurHashNeutral2 ( const void * key, int len, unsigned int seed );
31 #define MurmurHash MurmurHashNeutral2
32 typedef unsigned int murmur_t;
33 #endif
34 
35 // Allow slice to be hashable by murmur hash.
36 namespace ROCKSDB_NAMESPACE {
37 struct murmur_hash {
operatormurmur_hash38   size_t operator()(const Slice& slice) const {
39     return MurmurHash(slice.data(), static_cast<int>(slice.size()), 0);
40   }
41 };
42 }  // namespace ROCKSDB_NAMESPACE
43