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1 // Copyright 2013 The Chromium Authors. All rights reserved. | 1 // Copyright 2013 The Chromium 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 CC_DEBUG_RING_BUFFER_H_ | 5 #ifndef CC_DEBUG_RING_BUFFER_H_ |
6 #define CC_DEBUG_RING_BUFFER_H_ | 6 #define CC_DEBUG_RING_BUFFER_H_ |
7 | 7 |
8 #include "base/logging.h" | 8 #include "base/logging.h" |
9 | 9 |
10 namespace cc { | 10 namespace cc { |
11 | 11 |
12 template<typename T, size_t size> | 12 template<typename T, size_t kSize> |
danakj
2013/03/25 17:23:31
Ooh.. informative.
| |
13 class RingBuffer { | 13 class RingBuffer { |
14 public: | 14 public: |
15 explicit RingBuffer() | 15 explicit RingBuffer() |
16 : current_index_(0) { | 16 : current_index_(0) { |
17 } | 17 } |
18 | 18 |
19 size_t BufferSize() const { | 19 size_t BufferSize() const { |
20 return size; | 20 return kSize; |
21 } | 21 } |
22 | 22 |
23 size_t CurrentIndex() const { | 23 size_t CurrentIndex() const { |
24 return current_index_; | 24 return current_index_; |
25 } | 25 } |
26 | 26 |
27 // tests if a value was saved to this index | 27 // tests if a value was saved to this index |
28 bool IsFilledIndex(size_t n) const { | 28 bool IsFilledIndex(size_t n) const { |
29 return BufferIndex(n) < current_index_; | 29 return BufferIndex(n) < current_index_; |
30 } | 30 } |
(...skipping 22 matching lines...) Expand all Loading... | |
53 // Iterator has const access to the RingBuffer it got retrieved from. | 53 // Iterator has const access to the RingBuffer it got retrieved from. |
54 class Iterator { | 54 class Iterator { |
55 public: | 55 public: |
56 size_t index() const { return index_; } | 56 size_t index() const { return index_; } |
57 | 57 |
58 const T* operator->() const { return &buffer_.ReadBuffer(index_); } | 58 const T* operator->() const { return &buffer_.ReadBuffer(index_); } |
59 const T* operator*() const { return &buffer_.ReadBuffer(index_); } | 59 const T* operator*() const { return &buffer_.ReadBuffer(index_); } |
60 | 60 |
61 Iterator& operator++() { | 61 Iterator& operator++() { |
62 index_++; | 62 index_++; |
63 if (index_ == size) | 63 if (index_ == kSize) |
64 out_of_range_ = true; | 64 out_of_range_ = true; |
65 return *this; | 65 return *this; |
66 } | 66 } |
67 | 67 |
68 Iterator& operator--() { | 68 Iterator& operator--() { |
69 if (index_ == 0) | 69 if (index_ == 0) |
70 out_of_range_ = true; | 70 out_of_range_ = true; |
71 index_--; | 71 index_--; |
72 return *this; | 72 return *this; |
73 } | 73 } |
74 | 74 |
75 operator bool() const { | 75 operator bool() const { |
76 return buffer_.IsFilledIndex(index_) && !out_of_range_; | 76 return buffer_.IsFilledIndex(index_) && !out_of_range_; |
77 } | 77 } |
78 | 78 |
79 private: | 79 private: |
80 Iterator(const RingBuffer<T, size>& buffer, size_t index) | 80 Iterator(const RingBuffer<T, kSize>& buffer, size_t index) |
81 : buffer_(buffer), | 81 : buffer_(buffer), |
82 index_(index), | 82 index_(index), |
83 out_of_range_(false) { | 83 out_of_range_(false) { |
84 } | 84 } |
85 | 85 |
86 const RingBuffer<T, size>& buffer_; | 86 const RingBuffer<T, kSize>& buffer_; |
87 size_t index_; | 87 size_t index_; |
88 bool out_of_range_; | 88 bool out_of_range_; |
89 | 89 |
90 friend class RingBuffer<T, size>; | 90 friend class RingBuffer<T, kSize>; |
91 }; | 91 }; |
92 | 92 |
93 // Returns an Iterator pointing to the oldest value in the buffer. | 93 // Returns an Iterator pointing to the oldest value in the buffer. |
94 // Example usage (iterate from oldest to newest value): | 94 // Example usage (iterate from oldest to newest value): |
95 // for (RingBuffer<T, size>::Iterator it = ring_buffer.Begin(); it; ++it) ... | 95 // for (RingBuffer<T, kSize>::Iterator it = ring_buffer.Begin(); it; ++it) {} |
96 Iterator Begin() const { | 96 Iterator Begin() const { |
97 if (current_index_ < size) | 97 if (current_index_ < kSize) |
98 return Iterator(*this, size - current_index_); | 98 return Iterator(*this, kSize - current_index_); |
99 return Iterator(*this, 0); | 99 return Iterator(*this, 0); |
100 } | 100 } |
101 | 101 |
102 // Returns an Iterator pointing to the newest value in the buffer. | 102 // Returns an Iterator pointing to the newest value in the buffer. |
103 // Example usage (iterate backwards from newest to oldest value): | 103 // Example usage (iterate backwards from newest to oldest value): |
104 // for (RingBuffer<T, size>::Iterator it = ring_buffer.End(); it; --it) ... | 104 // for (RingBuffer<T, kSize>::Iterator it = ring_buffer.End(); it; --it) {} |
105 Iterator End() const { | 105 Iterator End() const { |
106 return Iterator(*this, size - 1); | 106 return Iterator(*this, kSize - 1); |
107 } | 107 } |
108 | 108 |
109 private: | 109 private: |
110 inline size_t BufferIndex(size_t n) const { | 110 inline size_t BufferIndex(size_t n) const { |
111 return (current_index_ + n) % size; | 111 return (current_index_ + n) % kSize; |
112 } | 112 } |
113 | 113 |
114 T buffer_[size]; | 114 T buffer_[kSize]; |
115 size_t current_index_; | 115 size_t current_index_; |
116 }; | 116 }; |
117 | 117 |
118 } // namespace cc | 118 } // namespace cc |
119 | 119 |
120 #endif // CC_DEBUG_RING_BUFFER_H_ | 120 #endif // CC_DEBUG_RING_BUFFER_H_ |
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