Change Read() size and return value to a size_t for clarity

BUG=100641



TEST=N/A
Review URL: http://codereview.chromium.org/8352019

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@106533 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 12 insertions, 15 deletions

diff --git a/media/filters/ffmpeg_demuxer.cc b/media/filters/ffmpeg_demuxer.cc
index 623a6e5..45e5298 100644
--- a/media/filters/ffmpeg_demuxer.cc
+++ b/media/filters/ffmpeg_demuxer.cc
@@ -368,7 +368,7 @@ base::TimeDelta FFmpegDemuxer::GetStartTime() const {
   return start_time_;
 }
 
-int FFmpegDemuxer::Read(int size, uint8* data) {
+size_t FFmpegDemuxer::Read(size_t size, uint8* data) {
   DCHECK(data_source_);
 
   // If read has ever failed, return with an error.
diff --git a/media/filters/ffmpeg_demuxer.h b/media/filters/ffmpeg_demuxer.h
index 2622111..1c1dfc2 100644
--- a/media/filters/ffmpeg_demuxer.h
+++ b/media/filters/ffmpeg_demuxer.h
@@ -148,8 +148,8 @@ class MEDIA_EXPORT FFmpegDemuxer : public Demuxer, public FFmpegURLProtocol {
   virtual void SetPreload(Preload preload) OVERRIDE;
   virtual base::TimeDelta GetStartTime() const OVERRIDE;
 
-  // FFmpegProtocol implementation.
-  virtual int Read(int size, uint8* data) OVERRIDE;
+  // FFmpegURLProtocol implementation.
+  virtual size_t Read(size_t size, uint8* data) OVERRIDE;
   virtual bool GetPosition(int64* position_out) OVERRIDE;
   virtual bool SetPosition(int64 position) OVERRIDE;
   virtual bool GetSize(int64* size_out) OVERRIDE;
diff --git a/media/filters/ffmpeg_demuxer_unittest.cc b/media/filters/ffmpeg_demuxer_unittest.cc
index 24fcdc3..64c6095 100644
--- a/media/filters/ffmpeg_demuxer_unittest.cc
+++ b/media/filters/ffmpeg_demuxer_unittest.cc
@@ -553,18 +553,18 @@ TEST_F(FFmpegDemuxerTest, ProtocolRead) {
       .WillOnce(DoAll(SetArgPointee<0>(1024), Return(true)));
 
   // First read.
-  EXPECT_EQ(512, demuxer->Read(512, kBuffer));
+  EXPECT_EQ(512u, demuxer->Read(512, kBuffer));
   int64 position;
   EXPECT_TRUE(demuxer->GetPosition(&position));
   EXPECT_EQ(512, position);
 
   // Second read.
-  EXPECT_EQ(512, demuxer->Read(512, kBuffer));
+  EXPECT_EQ(512u, demuxer->Read(512, kBuffer));
   EXPECT_TRUE(demuxer->GetPosition(&position));
   EXPECT_EQ(1024, position);
 
   // Third read will get an end-of-file error, which is represented as zero.
-  EXPECT_EQ(0, demuxer->Read(512, kBuffer));
+  EXPECT_EQ(0u, demuxer->Read(512, kBuffer));
 
   // This read complete signal is generated when demuxer is stopped.
   EXPECT_CALL(*demuxer, SignalReadCompleted(DataSource::kReadError));
diff --git a/media/filters/ffmpeg_glue.h b/media/filters/ffmpeg_glue.h
index 570dd80..257915e 100644
--- a/media/filters/ffmpeg_glue.h
+++ b/media/filters/ffmpeg_glue.h
@@ -45,7 +45,7 @@ class MEDIA_EXPORT FFmpegURLProtocol {
 
   // Read the given amount of bytes into data, returns the number of bytes read
   // if successful, kReadError otherwise.
-  virtual int Read(int size, uint8* data) = 0;
+  virtual size_t Read(size_t size, uint8* data) = 0;
 
   // Returns true and the current file position for this file, false if the
   // file position could not be retrieved.
diff --git a/media/filters/ffmpeg_glue_unittest.cc b/media/filters/ffmpeg_glue_unittest.cc
index 0ea91f1..94258e9 100644
--- a/media/filters/ffmpeg_glue_unittest.cc
+++ b/media/filters/ffmpeg_glue_unittest.cc
@@ -23,7 +23,7 @@ class MockProtocol : public FFmpegURLProtocol {
   MockProtocol() {
   }
 
-  MOCK_METHOD2(Read, int(int size, uint8* data));
+  MOCK_METHOD2(Read, size_t(size_t size, uint8* data));
   MOCK_METHOD1(GetPosition, bool(int64* position_out));
   MOCK_METHOD1(SetPosition, bool(int64 position));
   MOCK_METHOD1(GetSize, bool(int64* size_out));
diff --git a/media/filters/in_memory_url_protocol.cc b/media/filters/in_memory_url_protocol.cc
index dd7d984b..cdff519 100644
--- a/media/filters/in_memory_url_protocol.cc
+++ b/media/filters/in_memory_url_protocol.cc
@@ -9,18 +9,15 @@ namespace media {
 InMemoryUrlProtocol::InMemoryUrlProtocol(const uint8* data, int64 size,
                                          bool streaming)
     : data_(data),
-      size_(size),
+      size_(size >= 0 ? size : 0),
       position_(0),
       streaming_(streaming) {
 }
 
 InMemoryUrlProtocol::~InMemoryUrlProtocol() {}
 
-int InMemoryUrlProtocol::Read(int size, uint8* data) {
-  if (size < 0)
-    return -1;
-
-  int available_bytes = static_cast<int>(size_ - position_);
+size_t InMemoryUrlProtocol::Read(size_t size, uint8* data) {
+  size_t available_bytes = size_ - position_;
   if (size > available_bytes)
     size = available_bytes;
 
diff --git a/media/filters/in_memory_url_protocol.h b/media/filters/in_memory_url_protocol.h
index 7a5c468..1e6309a 100644
--- a/media/filters/in_memory_url_protocol.h
+++ b/media/filters/in_memory_url_protocol.h
@@ -21,7 +21,7 @@ class MEDIA_EXPORT InMemoryUrlProtocol : public FFmpegURLProtocol {
   virtual ~InMemoryUrlProtocol();
 
   // FFmpegURLProtocol methods.
-  virtual int Read(int size, uint8* data);
+  virtual size_t Read(size_t size, uint8* data);
   virtual bool GetPosition(int64* position_out);
   virtual bool SetPosition(int64 position);
   virtual bool GetSize(int64* size_out);