Delete StreamInterface methods GetPosition, SetPosition and Rewind

Keep methods on subclasses where they are used: FifoBuffer and
MemoryStream. Also FileStream gets to keep SetPosition, because it's
used by a downstream subclass.

Bug: webrtc:6424
Change-Id: If2a00855aba7c2c9dc0909cda7c8a8ef00e0b9af
Reviewed-on: https://webrtc-review.googlesource.com/c/116487
Commit-Queue: Niels Moller <[email protected]>
Reviewed-by: Karl Wiberg <[email protected]>
Cr-Commit-Position: refs/heads/master@{#26237}

Author: Niels Möller

rtc_base/logging_unittest.cc

@@ -40,8 +40,6 @@ class StringStream : public StreamInterface {
                      size_t* written,
                      int* error) override;
   void Close() override;
-  bool SetPosition(size_t position) override;
-  bool GetPosition(size_t* position) const override;
 
  private:
   std::string& str_;
@@ -92,19 +90,6 @@ StreamResult StringStream::Write(const void* data,
 
 void StringStream::Close() {}
 
-bool StringStream::SetPosition(size_t position) {
-  if (position > str_.size())
-    return false;
-  read_pos_ = position;
-  return true;
-}
-
-bool StringStream::GetPosition(size_t* position) const {
-  if (position)
-    *position = read_pos_;
-  return true;
-}
-
 }  // namespace
 
 template <typename Base>

rtc_base/memory_stream.cc

@@ -91,6 +91,10 @@ bool MemoryStream::GetPosition(size_t* position) const {
   return true;
 }
 
+void MemoryStream::Rewind() {
+  seek_position_ = 0;
+}
+
 bool MemoryStream::GetSize(size_t* size) const {
   if (size)
     *size = data_length_;

rtc_base/memory_stream.h

@@ -36,11 +36,13 @@ class MemoryStream final : public StreamInterface {
                      size_t* bytes_written,
                      int* error) override;
   void Close() override;
-  bool SetPosition(size_t position) override;
-  bool GetPosition(size_t* position) const override;
   bool GetSize(size_t* size) const;
   bool ReserveSize(size_t size);
 
+  bool SetPosition(size_t position);
+  bool GetPosition(size_t* position) const;
+  void Rewind();
+
   char* GetBuffer() { return buffer_; }
   const char* GetBuffer() const { return buffer_; }
 

rtc_base/stream.cc

@@ -77,14 +77,6 @@ void StreamInterface::PostEvent(int events, int err) {
   PostEvent(Thread::Current(), events, err);
 }
 
-bool StreamInterface::SetPosition(size_t position) {
-  return false;
-}
-
-bool StreamInterface::GetPosition(size_t* position) const {
-  return false;
-}
-
 bool StreamInterface::Flush() {
   return false;
 }
@@ -129,14 +121,6 @@ void StreamAdapterInterface::Close() {
   stream_->Close();
 }
 
-bool StreamAdapterInterface::SetPosition(size_t position) {
-  return stream_->SetPosition(position);
-}
-
-bool StreamAdapterInterface::GetPosition(size_t* position) const {
-  return stream_->GetPosition(position);
-}
-
 bool StreamAdapterInterface::Flush() {
   return stream_->Flush();
 }
@@ -288,18 +272,6 @@ bool FileStream::SetPosition(size_t position) {
   return (fseek(file_, static_cast<int>(position), SEEK_SET) == 0);
 }
 
-bool FileStream::GetPosition(size_t* position) const {
-  RTC_DCHECK(nullptr != position);
-  if (!file_)
-    return false;
-  long result = ftell(file_);
-  if (result < 0)
-    return false;
-  if (position)
-    *position = result;
-  return true;
-}
-
 bool FileStream::Flush() {
   if (file_) {
     return (0 == fflush(file_));

rtc_base/stream.h

@@ -107,15 +107,6 @@ class StreamInterface : public MessageHandler {
   // Like the aforementioned method, but posts to the current thread.
   void PostEvent(int events, int err);
 
-  // Seek to a byte offset from the beginning of the stream.  Returns false if
-  // the stream does not support seeking, or cannot seek to the specified
-  // position.
-  virtual bool SetPosition(size_t position);
-
-  // Get the byte offset of the current position from the start of the stream.
-  // Returns false if the position is not known.
-  virtual bool GetPosition(size_t* position) const;
-
   // Return true if flush is successful.
   virtual bool Flush();
 
@@ -125,9 +116,6 @@ class StreamInterface : public MessageHandler {
   // These methods are implemented in terms of other methods, for convenience.
   //
 
-  // Seek to the start of the stream.
-  inline bool Rewind() { return SetPosition(0); }
-
   // WriteAll is a helper function which repeatedly calls Write until all the
   // data is written, or something other than SR_SUCCESS is returned.  Note that
   // unlike Write, the argument 'written' is always set, and may be non-zero
@@ -180,8 +168,6 @@ class StreamAdapterInterface : public StreamInterface,
                      int* error) override;
   void Close() override;
 
-  bool SetPosition(size_t position) override;
-  bool GetPosition(size_t* position) const override;
   bool Flush() override;
 
   void Attach(StreamInterface* stream, bool owned = true);
@@ -232,8 +218,7 @@ class FileStream : public StreamInterface {
                      size_t* written,
                      int* error) override;
   void Close() override;
-  bool SetPosition(size_t position) override;
-  bool GetPosition(size_t* position) const override;
+  virtual bool SetPosition(size_t position);
 
   bool Flush() override;
 
@@ -291,6 +276,19 @@ class FifoBuffer final : public StreamInterface {
                      size_t* bytes_written,
                      int* error) override;
   void Close() override;
+
+  // Seek to a byte offset from the beginning of the stream.  Returns false if
+  // the stream does not support seeking, or cannot seek to the specified
+  // position.
+  bool SetPosition(size_t position);
+
+  // Get the byte offset of the current position from the start of the stream.
+  // Returns false if the position is not known.
+  bool GetPosition(size_t* position) const;
+
+  // Seek to the start of the stream.
+  bool Rewind() { return SetPosition(0); }
+
   // GetReadData returns a pointer to a buffer which is owned by the stream.
   // The buffer contains data_len bytes.  null is returned if no data is
   // available, or if the method fails.  If the caller processes the data, it

rtc_base/stream_unittest.cc

@@ -50,17 +50,6 @@ class TestStream : public StreamInterface {
 
   void Close() override {}
 
-  bool SetPosition(size_t position) override {
-    pos_ = position;
-    return true;
-  }
-
-  bool GetPosition(size_t* position) const override {
-    if (position)
-      *position = pos_;
-    return true;
-  }
-
  private:
   size_t pos_;
 };
@@ -78,26 +67,6 @@ bool VerifyTestBuffer(unsigned char* buffer, size_t len, unsigned char value) {
   return passed;
 }
 
-void SeekTest(StreamInterface* stream, const unsigned char value) {
-  size_t bytes;
-  unsigned char buffer[13] = {0};
-  const size_t kBufSize = sizeof(buffer);
-
-  EXPECT_EQ(stream->Read(buffer, kBufSize, &bytes, nullptr), SR_SUCCESS);
-  EXPECT_EQ(bytes, kBufSize);
-  EXPECT_TRUE(VerifyTestBuffer(buffer, kBufSize, value));
-  EXPECT_TRUE(stream->GetPosition(&bytes));
-  EXPECT_EQ(13U, bytes);
-
-  EXPECT_TRUE(stream->SetPosition(7));
-
-  EXPECT_EQ(stream->Read(buffer, kBufSize, &bytes, nullptr), SR_SUCCESS);
-  EXPECT_EQ(bytes, kBufSize);
-  EXPECT_TRUE(VerifyTestBuffer(buffer, kBufSize, value + 7));
-  EXPECT_TRUE(stream->GetPosition(&bytes));
-  EXPECT_EQ(20U, bytes);
-}
-
 TEST(FifoBufferTest, TestAll) {
   const size_t kSize = 16;
   const char in[kSize * 2 + 1] = "0123456789ABCDEFGHIJKLMNOPQRSTUV";