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Issue 17315021: Refactored DataBuffer to use unix_hacker style methods. (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: Refactor DataBuffer Created 7 years, 6 months ago
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1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 1 // Copyright (c) 2012 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 #include "media/base/seekable_buffer.h" 5 #include "media/base/seekable_buffer.h"
6 6
7 #include <algorithm> 7 #include <algorithm>
8 8
9 #include "base/logging.h" 9 #include "base/logging.h"
10 #include "media/base/data_buffer.h" 10 #include "media/base/data_buffer.h"
11 11
12 namespace media { 12 namespace media {
13 13
14 SeekableBuffer::SeekableBuffer(int backward_capacity, 14 SeekableBuffer::SeekableBuffer(int backward_capacity, int forward_capacity)
15 int forward_capacity)
16 : current_buffer_offset_(0), 15 : current_buffer_offset_(0),
17 backward_capacity_(backward_capacity), 16 backward_capacity_(backward_capacity),
18 backward_bytes_(0), 17 backward_bytes_(0),
19 forward_capacity_(forward_capacity), 18 forward_capacity_(forward_capacity),
20 forward_bytes_(0), 19 forward_bytes_(0),
21 current_time_(kNoTimestamp()) { 20 current_time_(kNoTimestamp()) {
22 current_buffer_ = buffers_.begin(); 21 current_buffer_ = buffers_.begin();
23 } 22 }
24 23
25 SeekableBuffer::~SeekableBuffer() { 24 SeekableBuffer::~SeekableBuffer() {}
26 }
27 25
28 void SeekableBuffer::Clear() { 26 void SeekableBuffer::Clear() {
29 buffers_.clear(); 27 buffers_.clear();
30 current_buffer_ = buffers_.begin(); 28 current_buffer_ = buffers_.begin();
31 current_buffer_offset_ = 0; 29 current_buffer_offset_ = 0;
32 backward_bytes_ = 0; 30 backward_bytes_ = 0;
33 forward_bytes_ = 0; 31 forward_bytes_ = 0;
34 current_time_ = kNoTimestamp(); 32 current_time_ = kNoTimestamp();
35 } 33 }
36 34
37 int SeekableBuffer::Read(uint8* data, int size) { 35 int SeekableBuffer::Read(uint8* data, int size) {
38 DCHECK(data); 36 DCHECK(data);
39 return InternalRead(data, size, true, 0); 37 return InternalRead(data, size, true, 0);
40 } 38 }
41 39
42 int SeekableBuffer::Peek(uint8* data, int size, int forward_offset) { 40 int SeekableBuffer::Peek(uint8* data, int size, int forward_offset) {
43 DCHECK(data); 41 DCHECK(data);
44 return InternalRead(data, size, false, forward_offset); 42 return InternalRead(data, size, false, forward_offset);
45 } 43 }
46 44
47 bool SeekableBuffer::GetCurrentChunk(const uint8** data, int* size) const { 45 bool SeekableBuffer::GetCurrentChunk(const uint8** data, int* size) const {
48 BufferQueue::iterator current_buffer = current_buffer_; 46 BufferQueue::iterator current_buffer = current_buffer_;
49 int current_buffer_offset = current_buffer_offset_; 47 int current_buffer_offset = current_buffer_offset_;
50 // Advance position if we are in the end of the current buffer. 48 // Advance position if we are in the end of the current buffer.
51 while (current_buffer != buffers_.end() && 49 while (current_buffer != buffers_.end() &&
52 current_buffer_offset >= (*current_buffer)->GetDataSize()) { 50 current_buffer_offset >= (*current_buffer)->get_data_size()) {
53 ++current_buffer; 51 ++current_buffer;
54 current_buffer_offset = 0; 52 current_buffer_offset = 0;
55 } 53 }
56 if (current_buffer == buffers_.end()) 54 if (current_buffer == buffers_.end()) return false;
57 return false; 55 *data = (*current_buffer)->get_data() + current_buffer_offset;
58 *data = (*current_buffer)->GetData() + current_buffer_offset; 56 *size = (*current_buffer)->get_data_size() - current_buffer_offset;
59 *size = (*current_buffer)->GetDataSize() - current_buffer_offset;
60 return true; 57 return true;
61 } 58 }
62 59
63 bool SeekableBuffer::Append(const scoped_refptr<DataBuffer>& buffer_in) { 60 bool SeekableBuffer::Append(const scoped_refptr<DataBuffer>& buffer_in) {
64 if (buffers_.empty() && buffer_in->GetTimestamp() != kNoTimestamp()) { 61 if (buffers_.empty() && buffer_in->get_timestamp() != kNoTimestamp()) {
65 current_time_ = buffer_in->GetTimestamp(); 62 current_time_ = buffer_in->get_timestamp();
66 } 63 }
67 64
68 // Since the forward capacity is only used to check the criteria for buffer 65 // Since the forward capacity is only used to check the criteria for buffer
69 // full, we always append data to the buffer. 66 // full, we always append data to the buffer.
70 buffers_.push_back(buffer_in); 67 buffers_.push_back(buffer_in);
71 68
72 // After we have written the first buffer, update |current_buffer_| to point 69 // After we have written the first buffer, update |current_buffer_| to point
73 // to it. 70 // to it.
74 if (current_buffer_ == buffers_.end()) { 71 if (current_buffer_ == buffers_.end()) {
75 DCHECK_EQ(0, forward_bytes_); 72 DCHECK_EQ(0, forward_bytes_);
76 current_buffer_ = buffers_.begin(); 73 current_buffer_ = buffers_.begin();
77 } 74 }
78 75
79 // Update the |forward_bytes_| counter since we have more bytes. 76 // Update the |forward_bytes_| counter since we have more bytes.
80 forward_bytes_ += buffer_in->GetDataSize(); 77 forward_bytes_ += buffer_in->get_data_size();
81 78
82 // Advise the user to stop append if the amount of forward bytes exceeds 79 // Advise the user to stop append if the amount of forward bytes exceeds
83 // the forward capacity. A false return value means the user should stop 80 // the forward capacity. A false return value means the user should stop
84 // appending more data to this buffer. 81 // appending more data to this buffer.
85 if (forward_bytes_ >= forward_capacity_) 82 if (forward_bytes_ >= forward_capacity_) return false;
86 return false;
87 return true; 83 return true;
88 } 84 }
89 85
90 bool SeekableBuffer::Append(const uint8* data, int size) { 86 bool SeekableBuffer::Append(const uint8* data, int size) {
91 if (size > 0) { 87 if (size > 0) {
92 scoped_refptr<DataBuffer> data_buffer = DataBuffer::CopyFrom(data, size); 88 scoped_refptr<DataBuffer> data_buffer = DataBuffer::copy_from(data, size);
93 return Append(data_buffer); 89 return Append(data_buffer);
94 } else { 90 } else {
95 // Return true if we have forward capacity. 91 // Return true if we have forward capacity.
96 return forward_bytes_ < forward_capacity_; 92 return forward_bytes_ < forward_capacity_;
97 } 93 }
98 } 94 }
99 95
100 bool SeekableBuffer::Seek(int32 offset) { 96 bool SeekableBuffer::Seek(int32 offset) {
101 if (offset > 0) 97 if (offset > 0)
102 return SeekForward(offset); 98 return SeekForward(offset);
103 else if (offset < 0) 99 else if (offset < 0)
104 return SeekBackward(-offset); 100 return SeekBackward(-offset);
105 return true; 101 return true;
106 } 102 }
107 103
108 bool SeekableBuffer::SeekForward(int size) { 104 bool SeekableBuffer::SeekForward(int size) {
109 // Perform seeking forward only if we have enough bytes in the queue. 105 // Perform seeking forward only if we have enough bytes in the queue.
110 if (size > forward_bytes_) 106 if (size > forward_bytes_) return false;
111 return false;
112 107
113 // Do a read of |size| bytes. 108 // Do a read of |size| bytes.
114 int taken = InternalRead(NULL, size, true, 0); 109 int taken = InternalRead(NULL, size, true, 0);
115 DCHECK_EQ(taken, size); 110 DCHECK_EQ(taken, size);
116 return true; 111 return true;
117 } 112 }
118 113
119 bool SeekableBuffer::SeekBackward(int size) { 114 bool SeekableBuffer::SeekBackward(int size) {
120 if (size > backward_bytes_) 115 if (size > backward_bytes_) return false;
121 return false;
122 // Record the number of bytes taken. 116 // Record the number of bytes taken.
123 int taken = 0; 117 int taken = 0;
124 // Loop until we taken enough bytes and rewind by the desired |size|. 118 // Loop until we taken enough bytes and rewind by the desired |size|.
125 while (taken < size) { 119 while (taken < size) {
126 // |current_buffer_| can never be invalid when we are in this loop. It can 120 // |current_buffer_| can never be invalid when we are in this loop. It can
127 // only be invalid before any data is appended. The invalid case should be 121 // only be invalid before any data is appended. The invalid case should be
128 // handled by checks before we enter this loop. 122 // handled by checks before we enter this loop.
129 DCHECK(current_buffer_ != buffers_.end()); 123 DCHECK(current_buffer_ != buffers_.end());
130 124
131 // We try to consume at most |size| bytes in the backward direction. We also 125 // We try to consume at most |size| bytes in the backward direction. We also
(...skipping 11 matching lines...) Expand all
143 137
144 // Forward bytes increases and backward bytes decreases by the amount 138 // Forward bytes increases and backward bytes decreases by the amount
145 // consumed in the current buffer. 139 // consumed in the current buffer.
146 forward_bytes_ += consumed; 140 forward_bytes_ += consumed;
147 backward_bytes_ -= consumed; 141 backward_bytes_ -= consumed;
148 DCHECK_GE(backward_bytes_, 0); 142 DCHECK_GE(backward_bytes_, 0);
149 143
150 // The current buffer pointed by current iterator has been consumed. Move 144 // The current buffer pointed by current iterator has been consumed. Move
151 // the iterator backward so it points to the previous buffer. 145 // the iterator backward so it points to the previous buffer.
152 if (current_buffer_offset_ == 0) { 146 if (current_buffer_offset_ == 0) {
153 if (current_buffer_ == buffers_.begin()) 147 if (current_buffer_ == buffers_.begin()) break;
154 break;
155 // Move the iterator backward. 148 // Move the iterator backward.
156 --current_buffer_; 149 --current_buffer_;
157 // Set the offset into the current buffer to be the buffer size as we 150 // Set the offset into the current buffer to be the buffer size as we
158 // are preparing for rewind for next iteration. 151 // are preparing for rewind for next iteration.
159 current_buffer_offset_ = (*current_buffer_)->GetDataSize(); 152 current_buffer_offset_ = (*current_buffer_)->get_data_size();
160 } 153 }
161 } 154 }
162 155
163 UpdateCurrentTime(current_buffer_, current_buffer_offset_); 156 UpdateCurrentTime(current_buffer_, current_buffer_offset_);
164 157
165 DCHECK_EQ(taken, size); 158 DCHECK_EQ(taken, size);
166 return true; 159 return true;
167 } 160 }
168 161
169 void SeekableBuffer::EvictBackwardBuffers() { 162 void SeekableBuffer::EvictBackwardBuffers() {
170 // Advances the iterator until we hit the current pointer. 163 // Advances the iterator until we hit the current pointer.
171 while (backward_bytes_ > backward_capacity_) { 164 while (backward_bytes_ > backward_capacity_) {
172 BufferQueue::iterator i = buffers_.begin(); 165 BufferQueue::iterator i = buffers_.begin();
173 if (i == current_buffer_) 166 if (i == current_buffer_) break;
174 break;
175 scoped_refptr<DataBuffer> buffer = *i; 167 scoped_refptr<DataBuffer> buffer = *i;
176 backward_bytes_ -= buffer->GetDataSize(); 168 backward_bytes_ -= buffer->get_data_size();
177 DCHECK_GE(backward_bytes_, 0); 169 DCHECK_GE(backward_bytes_, 0);
178 170
179 buffers_.erase(i); 171 buffers_.erase(i);
180 } 172 }
181 } 173 }
182 174
183 int SeekableBuffer::InternalRead(uint8* data, int size, 175 int SeekableBuffer::InternalRead(uint8* data, int size, bool advance_position,
184 bool advance_position,
185 int forward_offset) { 176 int forward_offset) {
186 // Counts how many bytes are actually read from the buffer queue. 177 // Counts how many bytes are actually read from the buffer queue.
187 int taken = 0; 178 int taken = 0;
188 179
189 BufferQueue::iterator current_buffer = current_buffer_; 180 BufferQueue::iterator current_buffer = current_buffer_;
190 int current_buffer_offset = current_buffer_offset_; 181 int current_buffer_offset = current_buffer_offset_;
191 182
192 int bytes_to_skip = forward_offset; 183 int bytes_to_skip = forward_offset;
193 while (taken < size) { 184 while (taken < size) {
194 // |current_buffer| is valid since the first time this buffer is appended 185 // |current_buffer| is valid since the first time this buffer is appended
195 // with data. 186 // with data.
196 if (current_buffer == buffers_.end()) 187 if (current_buffer == buffers_.end()) break;
197 break;
198 188
199 scoped_refptr<DataBuffer> buffer = *current_buffer; 189 scoped_refptr<DataBuffer> buffer = *current_buffer;
200 190
201 int remaining_bytes_in_buffer = 191 int remaining_bytes_in_buffer =
202 buffer->GetDataSize() - current_buffer_offset; 192 buffer->get_data_size() - current_buffer_offset;
203 193
204 if (bytes_to_skip == 0) { 194 if (bytes_to_skip == 0) {
205 // Find the right amount to copy from the current buffer referenced by 195 // Find the right amount to copy from the current buffer referenced by
206 // |buffer|. We shall copy no more than |size| bytes in total and each 196 // |buffer|. We shall copy no more than |size| bytes in total and each
207 // single step copied no more than the current buffer size. 197 // single step copied no more than the current buffer size.
208 int copied = std::min(size - taken, remaining_bytes_in_buffer); 198 int copied = std::min(size - taken, remaining_bytes_in_buffer);
209 199
210 // |data| is NULL if we are seeking forward, so there's no need to copy. 200 // |data| is NULL if we are seeking forward, so there's no need to copy.
211 if (data) 201 if (data)
212 memcpy(data + taken, buffer->GetData() + current_buffer_offset, copied); 202 memcpy(data + taken, buffer->get_data() + current_buffer_offset,
203 copied);
213 204
214 // Increase total number of bytes copied, which regulates when to end this 205 // Increase total number of bytes copied, which regulates when to end this
215 // loop. 206 // loop.
216 taken += copied; 207 taken += copied;
217 208
218 // We have read |copied| bytes from the current buffer. Advances the 209 // We have read |copied| bytes from the current buffer. Advances the
219 // offset. 210 // offset.
220 current_buffer_offset += copied; 211 current_buffer_offset += copied;
221 } else { 212 } else {
222 int skipped = std::min(remaining_bytes_in_buffer, bytes_to_skip); 213 int skipped = std::min(remaining_bytes_in_buffer, bytes_to_skip);
223 current_buffer_offset += skipped; 214 current_buffer_offset += skipped;
224 bytes_to_skip -= skipped; 215 bytes_to_skip -= skipped;
225 } 216 }
226 217
227 // The buffer has been consumed. 218 // The buffer has been consumed.
228 if (current_buffer_offset == buffer->GetDataSize()) { 219 if (current_buffer_offset == buffer->get_data_size()) {
229 if (advance_position) { 220 if (advance_position) {
230 // Next buffer may not have timestamp, so we need to update current 221 // Next buffer may not have timestamp, so we need to update current
231 // timestamp before switching to the next buffer. 222 // timestamp before switching to the next buffer.
232 UpdateCurrentTime(current_buffer, current_buffer_offset); 223 UpdateCurrentTime(current_buffer, current_buffer_offset);
233 } 224 }
234 225
235 BufferQueue::iterator next = current_buffer; 226 BufferQueue::iterator next = current_buffer;
236 ++next; 227 ++next;
237 // If we are at the last buffer, don't advance. 228 // If we are at the last buffer, don't advance.
238 if (next == buffers_.end()) 229 if (next == buffers_.end()) break;
239 break;
240 230
241 // Advances the iterator. 231 // Advances the iterator.
242 current_buffer = next; 232 current_buffer = next;
243 current_buffer_offset = 0; 233 current_buffer_offset = 0;
244 } 234 }
245 } 235 }
246 236
247 if (advance_position) { 237 if (advance_position) {
248 // We have less forward bytes and more backward bytes. Updates these 238 // We have less forward bytes and more backward bytes. Updates these
249 // counters by |taken|. 239 // counters by |taken|.
250 forward_bytes_ -= taken; 240 forward_bytes_ -= taken;
251 backward_bytes_ += taken; 241 backward_bytes_ += taken;
252 DCHECK_GE(forward_bytes_, 0); 242 DCHECK_GE(forward_bytes_, 0);
253 DCHECK(current_buffer_ != buffers_.end() || forward_bytes_ == 0); 243 DCHECK(current_buffer_ != buffers_.end() || forward_bytes_ == 0);
254 244
255 current_buffer_ = current_buffer; 245 current_buffer_ = current_buffer;
256 current_buffer_offset_ = current_buffer_offset; 246 current_buffer_offset_ = current_buffer_offset;
257 247
258 UpdateCurrentTime(current_buffer_, current_buffer_offset_); 248 UpdateCurrentTime(current_buffer_, current_buffer_offset_);
259 EvictBackwardBuffers(); 249 EvictBackwardBuffers();
260 } 250 }
261 251
262 return taken; 252 return taken;
263 } 253 }
264 254
265 void SeekableBuffer::UpdateCurrentTime(BufferQueue::iterator buffer, 255 void SeekableBuffer::UpdateCurrentTime(BufferQueue::iterator buffer,
266 int offset) { 256 int offset) {
267 // Garbage values are unavoidable, so this check will remain. 257 // Garbage values are unavoidable, so this check will remain.
268 if (buffer != buffers_.end() && (*buffer)->GetTimestamp() != kNoTimestamp()) { 258 if (buffer != buffers_.end() &&
269 int64 time_offset = ((*buffer)->GetDuration().InMicroseconds() * 259 (*buffer)->get_timestamp() != kNoTimestamp()) {
270 offset) / (*buffer)->GetDataSize(); 260 int64 time_offset = ((*buffer)->get_duration().InMicroseconds() * offset) /
261 (*buffer)->get_data_size();
271 262
272 current_time_ = (*buffer)->GetTimestamp() + 263 current_time_ = (*buffer)->get_timestamp() +
273 base::TimeDelta::FromMicroseconds(time_offset); 264 base::TimeDelta::FromMicroseconds(time_offset);
274 } 265 }
275 } 266 }
276 267
277 } // namespace media 268 } // namespace media
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