Changes to provide asynchronous read in data source:

1. FFmpegGlue now taks a FFmpegProtocol instead of DataSource as input
2. FFmpegDemuxr implements FFmpegProtocol and does the blocking read and submit asynchronous read request to DataSource (with unit tests)
3. Changed SimpleDataSource to work with asynchronous read (with unit tests)
4. Reimplemented BufferedDataSource to work with asynchronous read (with unit tests)
5. Moved BufferedDataSource from chrome/renderer/media to webkit/glue/media (for faster build/debug and better coverage in automated testing)

TEST=BufferedDataSourceTest.*, SimpleDataSourceTest.*, FFmpegDemuxerTest.*
Review URL: http://codereview.chromium.org/149567

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@21326 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 17 insertions, 16 deletions

diff --git a/media/base/filters.h b/media/base/filters.h
index 84df0966..3029cbc 100644
--- a/media/base/filters.h
+++ b/media/base/filters.h
@@ -123,6 +123,9 @@ class MediaFilter : public base::RefCountedThreadSafe<MediaFilter> {
 
 class DataSource : public MediaFilter {
  public:
+  typedef Callback1<size_t>::Type ReadCallback;
+  static const size_t kReadError = static_cast<size_t>(-1);
+
   static const FilterType filter_type() {
     return FILTER_DATA_SOURCE;
   }
@@ -133,8 +136,6 @@ class DataSource : public MediaFilter {
             mime_type == mime_type::kURL);
   }
 
-  static const size_t kReadError = static_cast<size_t>(-1);
-
   // Initialize a DataSource for the given URL, executing the callback upon
   // completion.
   virtual void Initialize(const std::string& url, FilterCallback* callback) = 0;
@@ -142,16 +143,13 @@ class DataSource : public MediaFilter {
   // Returns the MediaFormat for this filter.
   virtual const MediaFormat& media_format() = 0;
 
-  // Read the given amount of bytes into data, returns the number of bytes read
-  // if successful, kReadError otherwise.
-  virtual size_t Read(uint8* data, size_t size) = 0;
-
-  // Returns true and the current file position for this file, false if the
-  // file position could not be retrieved.
-  virtual bool GetPosition(int64* position_out) = 0;
-
-  // Returns true if the file position could be set, false otherwise.
-  virtual bool SetPosition(int64 position) = 0;
+  // Reads |size| bytes from |position| into |data|. And when the read is done
+  // or failed, |read_callback| is called with the number of bytes read or
+  // kReadError in case of error.
+  // TODO(hclam): should change |size| to int! It makes the code so messy
+  // with size_t and int all over the place..
+  virtual void Read(int64 position, size_t size,
+                    uint8* data, ReadCallback* read_callback) = 0;
 
   // Returns true and the file size, false if the file size could not be
   // retrieved.
diff --git a/media/base/mock_filters.h b/media/base/mock_filters.h
index 8c44996..c933bd2 100644
--- a/media/base/mock_filters.h
+++ b/media/base/mock_filters.h
@@ -99,9 +99,8 @@ class MockDataSource : public DataSource {
   MOCK_METHOD2(Initialize, void(const std::string& url,
                                 FilterCallback* callback));
   const MediaFormat& media_format() { return media_format_; }
-  MOCK_METHOD2(Read, size_t(uint8* data, size_t size));
-  MOCK_METHOD1(GetPosition, bool(int64* position_out));
-  MOCK_METHOD1(SetPosition, bool(int64 position));
+  MOCK_METHOD4(Read, void(int64 position, size_t size, uint8* data,
+                          DataSource::ReadCallback* callback));
   MOCK_METHOD1(GetSize, bool(int64* size_out));
   MOCK_METHOD0(IsSeekable, bool());
 
diff --git a/media/base/pipeline_impl.cc b/media/base/pipeline_impl.cc
index 9c2fb10..7fc4695 100644
--- a/media/base/pipeline_impl.cc
+++ b/media/base/pipeline_impl.cc
@@ -524,7 +524,11 @@ void PipelineInternal::ErrorTask(PipelineError error) {
   DCHECK_NE(PIPELINE_OK, error) << "PIPELINE_OK isn't an error!";
 
   // Suppress executing additional error logic.
-  if (state_ == kError) {
+  // TODO(hclam): Remove the condition for kStopped. It is there only because
+  // FFmpegDemuxer submits a read error while reading after it is called to
+  // stop. After FFmpegDemuxer is cleaned up we should remove this condition
+  // and add an extra assert.
+  if (state_ == kError || state_ == kStopped) {
     return;
   }