Removed AlsaPcmOutputStrem::Packet. Fixed bug in AlsaPcmOutputStream::ScheduleNextWrite which would cause high CPU consumption.

BUG=28654
TEST=Audio still works on Linux

Review URL: http://codereview.chromium.org/2008010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@47333 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 45 insertions, 0 deletions

diff --git a/media/base/seekable_buffer.cc b/media/base/seekable_buffer.cc
index 0f1cc33c..15819c1 100644
--- a/media/base/seekable_buffer.cc
+++ b/media/base/seekable_buffer.cc
@@ -44,6 +44,22 @@ size_t SeekableBuffer::Peek(uint8* data, size_t size) {
   return InternalRead(data, size, false);
 }
 
+bool SeekableBuffer::GetCurrentChunk(const uint8** data, size_t* size) const {
+  BufferQueue::iterator current_buffer = current_buffer_;
+  size_t current_buffer_offset = current_buffer_offset_;
+  // Advance position if we are in the end of the current buffer.
+  while (current_buffer != buffers_.end() &&
+         current_buffer_offset >= (*current_buffer)->GetDataSize()) {
+    ++current_buffer;
+    current_buffer_offset = 0;
+  }
+  if (current_buffer == buffers_.end())
+    return false;
+  *data = (*current_buffer)->GetData() + current_buffer_offset;
+  *size = (*current_buffer)->GetDataSize() - current_buffer_offset;
+  return true;
+}
+
 bool SeekableBuffer::Append(Buffer* buffer_in) {
   if (buffers_.empty() && buffer_in->GetTimestamp().InMicroseconds() > 0) {
     current_time_ = buffer_in->GetTimestamp();
diff --git a/media/base/seekable_buffer.h b/media/base/seekable_buffer.h
index 9275cf8..1a423e0 100644
--- a/media/base/seekable_buffer.h
+++ b/media/base/seekable_buffer.h
@@ -64,6 +64,13 @@ class SeekableBuffer {
   // number of bytes copied. Doesn't advance current position.
   size_t Peek(uint8* data, size_t size);
 
+  // Returns pointer to the current chunk of data that is being consumed.
+  // If there is no data left in the buffer false is returned, otherwise
+  // true is returned and |data| and |size| are updated. The returned
+  // |data| value becomes invalid when Read(), Append() or Seek()
+  // are called.
+  bool GetCurrentChunk(const uint8** data, size_t* size) const;
+
   // Appends |buffer_in| to this buffer. Returns false if forward_bytes() is
   // greater than or equals to forward_capacity(), true otherwise. The data
   // is added to the buffer in any case.
diff --git a/media/base/seekable_buffer_unittest.cc b/media/base/seekable_buffer_unittest.cc
index 333833e..72e1933 100644
--- a/media/base/seekable_buffer_unittest.cc
+++ b/media/base/seekable_buffer_unittest.cc
@@ -222,6 +222,28 @@ TEST_F(SeekableBufferTest, SeekBackward) {
   }
 }
 
+TEST_F(SeekableBufferTest, GetCurrentChunk) {
+  const size_t kSeekSize = kWriteSize / 3;
+
+  scoped_refptr<media::DataBuffer> buffer = new media::DataBuffer(kWriteSize);
+  memcpy(buffer->GetWritableData(), data_, kWriteSize);
+  buffer->SetDataSize(kWriteSize);
+
+  const uint8* data;
+  size_t size;
+  EXPECT_FALSE(buffer_.GetCurrentChunk(&data, &size));
+
+  buffer_.Append(buffer.get());
+  EXPECT_TRUE(buffer_.GetCurrentChunk(&data, &size));
+  EXPECT_EQ(data, buffer->GetData());
+  EXPECT_EQ(size, buffer->GetDataSize());
+
+  buffer_.Seek(kSeekSize);
+  EXPECT_TRUE(buffer_.GetCurrentChunk(&data, &size));
+  EXPECT_EQ(data, buffer->GetData() + kSeekSize);
+  EXPECT_EQ(size, buffer->GetDataSize() - kSeekSize);
+}
+
 TEST_F(SeekableBufferTest, SeekForward) {
   size_t write_position = 0;
   size_t read_position = 0;