Resetting the HttpRequestInfo pointers in HttpNetworkTransaction and streams

net/http/http_stream_parser.cc

 // Copyright (c) 2012 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.
 
 #include "net/http/http_stream_parser.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
@@ skipping 362 matching lines @@
   // Added to investigate crbug.com/499663.
   CHECK(buf);
 
   if (io_state_ == STATE_DONE)
     return OK;
 
   user_read_buf_ = buf;
   user_read_buf_len_ = buf_len;
   io_state_ = STATE_READ_BODY;
 
+  // Invalidate HttpRequestInfo pointer. This is to allow the stream to be
+  // shared across multiple HttpCache::Transactions which might require this
+  // stream to outlive the request_'s owner URLRequestHttpJob.

[Randy Smith (Not in Mondays), 2016/09/01 20:18:31]

As noted elsewhere, I'm really uncomfortable with comments making references to
owning code/code further up the stack; that kind of dependency gets in the way
of modularity.  Can you make these comments just talk about a generic owner of
this class and what it allows that owner to do?

[shivanisha, 2016/09/08 20:43:54]

done.

+  if (request_)
+    ResetRequestInfo();
+
   int result = DoLoop(OK);
   if (result == ERR_IO_PENDING)
     callback_ = callback;
 
   return result;
 }
 
 void HttpStreamParser::OnIOComplete(int result) {
   result = DoLoop(result);
 
@@ skipping 690 matching lines @@
       chunked_decoder_.reset(new HttpChunkedDecoder());
     } else {
       response_body_length_ = response_->headers->GetContentLength();
       // If response_body_length_ is still -1, then we have to wait
       // for the server to close the connection.
     }
   }
 }
 
 UploadProgress HttpStreamParser::GetUploadProgress() const {
+  if (!request_)
+    return upload_progress_;
+
   if (!request_->upload_data_stream)
     return UploadProgress();
 
   return UploadProgress(request_->upload_data_stream->position(),
                         request_->upload_data_stream->size());
 }
 
 bool HttpStreamParser::IsResponseBodyComplete() const {
   if (chunked_decoder_.get())
     return chunked_decoder_->reached_eof();
@@ skipping 113 matching lines @@
       HttpStatusLineValidator::ValidateStatusLine(status_line);
   UMA_HISTOGRAM_ENUMERATION("Net.HttpStatusLineStatus", status,
                             HttpStatusLineValidator::STATUS_LINE_MAX);
 }
 
 bool HttpStreamParser::SendRequestBuffersEmpty() {
   return request_headers_ == nullptr && request_body_send_buf_ == nullptr &&
          request_body_send_buf_ == nullptr;
 }
 
+void HttpStreamParser::ResetRequestInfo() {
+  // Only allowed when Read state machine starts. It is safe to reset it at this
+  // point since request_->upload_data_stream is also not needed anymore.
+  DCHECK_EQ(STATE_READ_BODY, io_state_);
+
+  // save upload progress if any.
+  upload_progress_ = GetUploadProgress();
+  request_ = nullptr;
+}
+
 }  // namespace net