OLD | NEW |
1 // Copyright 2013 the V8 project authors. All rights reserved. | 1 // Copyright 2013 the V8 project authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #ifndef V8_BASE_UTILS_RANDOM_NUMBER_GENERATOR_H_ | 5 #ifndef V8_BASE_UTILS_RANDOM_NUMBER_GENERATOR_H_ |
6 #define V8_BASE_UTILS_RANDOM_NUMBER_GENERATOR_H_ | 6 #define V8_BASE_UTILS_RANDOM_NUMBER_GENERATOR_H_ |
7 | 7 |
8 #include "src/base/macros.h" | 8 #include "src/base/macros.h" |
9 | 9 |
10 namespace v8 { | 10 namespace v8 { |
(...skipping 50 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
61 return Next(1) != 0; | 61 return Next(1) != 0; |
62 } | 62 } |
63 | 63 |
64 // Returns the next pseudorandom, uniformly distributed double value between | 64 // Returns the next pseudorandom, uniformly distributed double value between |
65 // 0.0 and 1.0 from this random number generator's sequence. | 65 // 0.0 and 1.0 from this random number generator's sequence. |
66 // The general contract of |NextDouble()| is that one double value, chosen | 66 // The general contract of |NextDouble()| is that one double value, chosen |
67 // (approximately) uniformly from the range 0.0 (inclusive) to 1.0 | 67 // (approximately) uniformly from the range 0.0 (inclusive) to 1.0 |
68 // (exclusive), is pseudorandomly generated and returned. | 68 // (exclusive), is pseudorandomly generated and returned. |
69 double NextDouble() WARN_UNUSED_RESULT; | 69 double NextDouble() WARN_UNUSED_RESULT; |
70 | 70 |
| 71 // Returns the next pseudorandom, uniformly distributed int64 value from this |
| 72 // random number generator's sequence. The general contract of |NextInt64()| |
| 73 // is that one 64-bit int value is pseudorandomly generated and returned. |
| 74 // All 2^64 possible integer values are produced with (approximately) equal |
| 75 // probability. |
| 76 int64_t NextInt64() WARN_UNUSED_RESULT; |
| 77 |
71 // Fills the elements of a specified array of bytes with random numbers. | 78 // Fills the elements of a specified array of bytes with random numbers. |
72 void NextBytes(void* buffer, size_t buflen); | 79 void NextBytes(void* buffer, size_t buflen); |
73 | 80 |
74 // Override the current ssed. | 81 // Override the current ssed. |
75 void SetSeed(int64_t seed); | 82 void SetSeed(int64_t seed); |
76 | 83 |
77 int64_t initial_seed() const { return initial_seed_; } | 84 int64_t initial_seed() const { return initial_seed_; } |
78 | 85 |
79 private: | 86 private: |
80 static const int64_t kMultiplier = V8_2PART_UINT64_C(0x5, deece66d); | 87 static const int64_t kMultiplier = V8_2PART_UINT64_C(0x5, deece66d); |
81 static const int64_t kAddend = 0xb; | 88 static const int64_t kAddend = 0xb; |
82 static const int64_t kMask = V8_2PART_UINT64_C(0xffff, ffffffff); | 89 static const int64_t kMask = V8_2PART_UINT64_C(0xffff, ffffffff); |
83 | 90 |
84 int Next(int bits) WARN_UNUSED_RESULT; | 91 int Next(int bits) WARN_UNUSED_RESULT; |
85 | 92 |
86 int64_t initial_seed_; | 93 int64_t initial_seed_; |
87 int64_t seed_; | 94 int64_t seed_; |
88 }; | 95 }; |
89 | 96 |
90 } } // namespace v8::base | 97 } } // namespace v8::base |
91 | 98 |
92 #endif // V8_BASE_UTILS_RANDOM_NUMBER_GENERATOR_H_ | 99 #endif // V8_BASE_UTILS_RANDOM_NUMBER_GENERATOR_H_ |
OLD | NEW |