Prototype of chunked transfer encoded POST.

net/base/upload_data_stream.h

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_BASE_UPLOAD_DATA_STREAM_H_
 #define NET_BASE_UPLOAD_DATA_STREAM_H_
 #pragma once
 
 #include "base/scoped_ptr.h"
+#include "net/base/completion_callback.h"

[vandebo (ex-Chrome), 2011/01/18 21:51:17]

This header isn't needed.

 #include "net/base/upload_data.h"
 
 namespace net {
 
 class FileStream;
 class IOBuffer;
 
-class UploadDataStream {
+class UploadDataStream : public UploadData::ChunkCallback {

[vandebo (ex-Chrome), 2011/01/18 21:51:17]

nit: This class doesn't really have to implement ChunkCallback.  You could just
have UploadDataStream::set_chunk_callback call data_->set_chunk_callback.  And
change DidConsume to just do FillBuf if the amount consumed was 0 and call
FillBuf in UploadDataStream::OnChunkAvailable regardless of the amount consumed.

[Satish, 2011/01/19 16:05:25]

Could you clarify the last part? OnChunkAvailable won't be there anymore if this
doesn't implement UploadData::ChunkCallback, so I'm not sure what you mean here.

[vandebo (ex-Chrome), 2011/01/19 17:00:49]

Sorry, I mistyped.  I meant "... and call DidConsume in
HttpStreamParser::DoSendBody regardless of the amount consumed."

[vandebo (ex-Chrome), 2011/01/19 19:26:01]

It occurs to me, if you do decide to do this, you should probably change the
name of DidConsume to ConsumeAndFillBuffer or something similar.

  public:
+  // Interface implemented by callers who require callbacks when new chunks
+  // of data are received.
+  class ChunkCallback {

[vandebo (ex-Chrome), 2011/01/18 21:51:17]

This is the same interface as UploadData::ChunkCallback.  Is there a good reason
to re-define it?

+   public:
+    // Invoked when a new data chunk was given for a chunked transfer upload.
+    virtual void OnChunkAvailable() = 0;
+
+   protected:
+    virtual ~ChunkCallback() {}
+  };
+
   // Returns a new instance of UploadDataStream if it can be created and
   // initialized successfully. If not, NULL will be returned and the error
   // code will be set if the output parameter error_code is not empty.
   static UploadDataStream* Create(UploadData* data, int* error_code);
 
   ~UploadDataStream();
 
   // Returns the stream's buffer and buffer length.
   IOBuffer* buf() const { return buf_; }
   size_t buf_len() const { return buf_len_; }
 
   // Call to indicate that a portion of the stream's buffer was consumed.  This
   // call modifies the stream's buffer so that it contains the next segment of
   // the upload data to be consumed.
   void DidConsume(size_t num_bytes);
 
+  // Sets the callback to be invoked when new data is available to upload.

[vandebo (ex-Chrome), 2011/01/18 21:51:17]

This comment is out dated, please update.

+  // The callback is invoked only once and needs to be set again if the caller
+  // needs to be indicated again in future.
+  void set_chunk_callback(ChunkCallback* callback);
+
   // Returns the total size of the data stream and the current position.
   // size() is not to be used to determine whether the stream has ended
   // because it is possible for the stream to end before its size is reached,
   // for example, if the file is truncated.
   uint64 size() const { return total_size_; }
   uint64 position() const { return current_position_; }
 
+  bool is_chunked() const { return data_->is_chunked(); }
+
   // Returns whether there is no more data to read, regardless of whether
   // position < size.
   bool eof() const { return eof_; }
 
+  // UploadData::ChunkCallback members.
+
+  // Callback invoked by UploadData when new data is available.

[wtc, 2011/01/20 00:29:47]

Nit: new data => new chunk

Make the same change to line 109 below.

+  void OnChunkAvailable();
+
  private:
   // Protects from public access since now we have a static creator function
   // which will do both creation and initialization and might return an error.
   explicit UploadDataStream(UploadData* data);
 
   // Fills the buffer with any remaining data and sets eof_ if there was nothing
   // left to fill the buffer with.
   // Returns OK if the operation succeeds. Otherwise error code is returned.
   int FillBuf();
 
   UploadData* data_;
 
   // This buffer is filled with data to be uploaded.  The data to be sent is
   // always at the front of the buffer.  If we cannot send all of the buffer at
   // once, then we memmove the remaining portion and back-fill the buffer for
   // the next "write" call.  buf_len_ indicates how much data is in the buffer.
   enum { kBufSize = 16384 };
   scoped_refptr<IOBuffer> buf_;
   size_t buf_len_;
 
-  // Iterator to the upload element to be written to the send buffer next.
-  std::vector<UploadData::Element>::iterator next_element_;
+  // Index of the upload element to be written to the send buffer next.
+  size_t next_element_;
 
   // The byte offset into next_element_'s data buffer if the next element is
   // a TYPE_BYTES element.
   size_t next_element_offset_;
 
   // A stream to the currently open file, for next_element_ if the next element
   // is a TYPE_FILE element.
   scoped_ptr<FileStream> next_element_stream_;
 
   // The number of bytes remaining to be read from the currently open file
   // if the next element is of TYPE_FILE.
   uint64 next_element_remaining_;
 
   // Size and current read position within the stream.
   uint64 total_size_;
   uint64 current_position_;
 
+  // Callback to be invoked by us when new data is available.
+  ChunkCallback* chunk_callback_;
+
   // Whether there is no data left to read.
   bool eof_;
 
   DISALLOW_COPY_AND_ASSIGN(UploadDataStream);
 };
 
 }  // namespace net
 
 #endif  // NET_BASE_UPLOAD_DATA_STREAM_H_