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1 | 1 |
2 /* | 2 /* |
3 * Copyright 2011 Google Inc. | 3 * Copyright 2011 Google Inc. |
4 * | 4 * |
5 * Use of this source code is governed by a BSD-style license that can be | 5 * Use of this source code is governed by a BSD-style license that can be |
6 * found in the LICENSE file. | 6 * found in the LICENSE file. |
7 */ | 7 */ |
8 | 8 |
9 | 9 |
10 #ifndef GrBinHashKey_DEFINED | 10 #ifndef GrBinHashKey_DEFINED |
11 #define GrBinHashKey_DEFINED | 11 #define GrBinHashKey_DEFINED |
12 | 12 |
13 #include "SkChecksum.h" | |
13 #include "GrTypes.h" | 14 #include "GrTypes.h" |
14 | 15 |
15 /** | 16 /** |
17 * GrMurmur3HashKey is a hash key class that can take a data chunk of any prede termined | |
18 * length. It uses the Murmur3 hash function. It is intended to be used with | |
19 * SkTDynamicHash (where GrBinHashKey is for GrTHashTable). | |
20 */ | |
21 template<size_t KEY_SIZE_IN_BYTES> | |
22 class GrMurmur3HashKey { | |
23 public: | |
24 GrMurmur3HashKey() { | |
25 this->reset(); | |
26 } | |
27 | |
28 void reset() { | |
29 fHash = 0; | |
30 #ifdef SK_DEBUG | |
31 fIsValid = false; | |
32 #endif | |
33 } | |
34 | |
35 void setKeyData(const uint32_t* data) { | |
36 SK_COMPILE_ASSERT(KEY_SIZE_IN_BYTES % 4 == 0, key_size_mismatch); | |
37 memcpy(fData, data, KEY_SIZE_IN_BYTES); | |
38 | |
39 fHash = SkChecksum::Murmur3(fData, KEY_SIZE_IN_BYTES); | |
40 #ifdef SK_DEBUG | |
41 fIsValid = true; | |
42 #endif | |
43 } | |
44 | |
45 bool operator==(const GrMurmur3HashKey& other) const { | |
46 if (fHash != other.fHash) { | |
mtklein
2014/07/19 14:38:57
I've always had half a mind to cache the hash insi
robertphillips
2014/07/20 16:12:30
I think it is worth a try.
| |
47 return false; | |
48 } | |
49 | |
50 return !memcmp(fData, other.fData, KEY_SIZE_IN_BYTES); | |
51 } | |
52 | |
53 uint32_t getHash() const { | |
54 SkASSERT(fIsValid); | |
55 return fHash; | |
56 } | |
57 | |
58 const uint8_t* getData() const { | |
59 SkASSERT(fIsValid); | |
60 return reinterpret_cast<const uint8_t*>(fData); | |
61 } | |
62 | |
63 private: | |
64 uint32_t fHash; | |
65 uint32_t fData[KEY_SIZE_IN_BYTES / sizeof(uint32_t)]; // Buffer for key sto rage. | |
66 | |
67 #ifdef SK_DEBUG | |
68 public: | |
69 bool fIsValid; | |
70 #endif | |
71 }; | |
72 | |
73 /** | |
16 * GrBinHashKey is a hash key class that can take a data chunk of any predeterm ined | 74 * GrBinHashKey is a hash key class that can take a data chunk of any predeterm ined |
17 * length. The hash function used is the One-at-a-Time Hash | 75 * length. The hash function used is the One-at-a-Time Hash |
18 * (http://burtleburtle.net/bob/hash/doobs.html). | 76 * (http://burtleburtle.net/bob/hash/doobs.html). |
19 */ | 77 */ |
20 template<size_t KEY_SIZE> | 78 template<size_t KEY_SIZE> |
21 class GrBinHashKey { | 79 class GrBinHashKey { |
22 public: | 80 public: |
23 enum { kKeySize = KEY_SIZE }; | 81 enum { kKeySize = KEY_SIZE }; |
24 | 82 |
25 GrBinHashKey() { | 83 GrBinHashKey() { |
(...skipping 67 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... | |
93 uint32_t fHash; | 151 uint32_t fHash; |
94 uint32_t fData[KEY_SIZE / sizeof(uint32_t)]; // Buffer for key s torage. | 152 uint32_t fData[KEY_SIZE / sizeof(uint32_t)]; // Buffer for key s torage. |
95 | 153 |
96 #ifdef SK_DEBUG | 154 #ifdef SK_DEBUG |
97 public: | 155 public: |
98 bool fIsValid; | 156 bool fIsValid; |
99 #endif | 157 #endif |
100 }; | 158 }; |
101 | 159 |
102 #endif | 160 #endif |
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