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 3 // found in the LICENSE file. 4 5 #include "media/mp4/offset_byte_queue.h" 6 7 #include "base/basictypes.h" 8 #include "base/logging.h" 9 10 namespace media { 11 12 OffsetByteQueue::OffsetByteQueue() : buf_(NULL), size_(0), head_(0) {} 13 OffsetByteQueue::~OffsetByteQueue() {} 14 15 void OffsetByteQueue::Reset() { 16 queue_.Reset(); 17 buf_ = NULL; 18 size_ = 0; 19 head_ = 0; 20 } 21 22 void OffsetByteQueue::Push(const uint8* buf, int size) { 23 queue_.Push(buf, size); 24 Sync(); 25 DVLOG(4) << "Buffer pushed. head=" << head() << " tail=" << tail(); 26 } 27 28 void OffsetByteQueue::Peek(const uint8** buf, int* size) { 29 *buf = size_ > 0 ? buf_ : NULL; 30 *size = size_; 31 } 32 33 void OffsetByteQueue::Pop(int count) { 34 queue_.Pop(count); 35 head_ += count; 36 Sync(); 37 } 38 39 void OffsetByteQueue::PeekAt(int64 offset, const uint8** buf, int* size) { 40 DCHECK(offset >= head()); 41 if (offset < head() || offset >= tail()) { 42 *buf = NULL; 43 *size = 0; 44 return; 45 } 46 *buf = &buf_[offset - head()]; 47 *size = tail() - offset; 48 } 49 50 bool OffsetByteQueue::Trim(int64 max_offset) { 51 if (max_offset < head_) return true; 52 if (max_offset > tail()) { 53 Pop(size_); 54 return false; 55 } 56 Pop(max_offset - head_); 57 return true; 58 } 59 60 void OffsetByteQueue::Sync() { 61 queue_.Peek(&buf_, &size_); 62 } 63 64 } // namespace media 65
