Add Resource Handler for creating Streams to forward to extensions

content/browser/streams/stream.cc

 // Copyright (c) 2013 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 "content/browser/streams/stream.h"
 
 #include "base/bind.h"
 #include "base/message_loop_proxy.h"
+#include "content/browser/streams/stream_handle_impl.h"
 #include "content/browser/streams/stream_read_observer.h"
 #include "content/browser/streams/stream_registry.h"
 #include "content/browser/streams/stream_write_observer.h"
 #include "net/base/io_buffer.h"
 
 namespace {
 // Start throttling the connection at about 1MB.
 const size_t kDeferSizeThreshold = 40 * 32768;
 }
 
 namespace content {
 
 Stream::Stream(StreamRegistry* registry,
                StreamWriteObserver* write_observer,
                const GURL& security_origin,
                const GURL& url)
     : bytes_read_(0),
       can_add_data_(true),
       security_origin_(security_origin),
       url_(url),
       data_length_(0),
       registry_(registry),
       read_observer_(NULL),
       write_observer_(write_observer),
+      stream_handle_(NULL),
       weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
   CreateByteStream(base::MessageLoopProxy::current(),
                    base::MessageLoopProxy::current(),
                    kDeferSizeThreshold,
                    &writer_,
                    &reader_);
 
   // Setup callback for writing.
   writer_->RegisterCallback(base::Bind(&Stream::OnSpaceAvailable,
                                        weak_ptr_factory_.GetWeakPtr()));
@@ skipping 11 matching lines @@
     return false;
   read_observer_ = observer;
   return true;
 }
 
 void Stream::RemoveReadObserver(StreamReadObserver* observer) {
   DCHECK(observer == read_observer_);
   read_observer_ = NULL;
 }
 
+void Stream::RemoveWriteObserver(StreamWriteObserver* observer) {
+  DCHECK(observer == write_observer_);
+  write_observer_ = NULL;
+}
+
 void Stream::AddData(scoped_refptr<net::IOBuffer> buffer, size_t size) {
   can_add_data_ = writer_->Write(buffer, size);
 }
 
 void Stream::Finalize() {
   writer_->Close(DOWNLOAD_INTERRUPT_REASON_NONE);
   writer_.reset(NULL);
 
   OnDataAvailable();
 }
 
 Stream::StreamState Stream::ReadRawData(net::IOBuffer* buf,
                                         int buf_size,
                                         int* bytes_read) {
   if (!data_) {
     data_length_ = 0;
     bytes_read_ = 0;
     ByteStreamReader::StreamState state = reader_->Read(&data_, &data_length_);
     switch (state) {
       case ByteStreamReader::STREAM_HAS_DATA:
         break;
       case ByteStreamReader::STREAM_COMPLETE:
+        if (stream_handle_)
+          stream_handle_->SendCloseEvent();
         registry_->UnregisterStream(url());

[darin (slow to review), 2013/03/19 06:12:51]

is there any possibility that SendCloseEvent could end up deleting |this|? 
should you consider calling UnregisterStream first to play it safe?

[Zachary Kuznia, 2013/03/19 06:59:35]

Done.

         return STREAM_COMPLETE;
       case ByteStreamReader::STREAM_EMPTY:
         return STREAM_EMPTY;
     }
   }
 
   size_t remaining_bytes = data_length_ - bytes_read_;
   size_t to_read =
       static_cast<size_t>(buf_size) < remaining_bytes ?
       buf_size : remaining_bytes;
   memcpy(buf->data(), data_->data() + bytes_read_, to_read);
   bytes_read_ += to_read;
   if (bytes_read_ >= data_length_)
     data_ = NULL;
 
   *bytes_read = to_read;
   return STREAM_HAS_DATA;
 }
 
+scoped_ptr<StreamHandle> Stream::CreateHandle() {
+  CHECK(!stream_handle_);
+  stream_handle_ = new StreamHandleImpl(weak_ptr_factory_.GetWeakPtr());
+  return scoped_ptr<StreamHandle>(stream_handle_).Pass();
+}
+
+void Stream::CloseHandle() {
+  CHECK(stream_handle_);
+  stream_handle_ = NULL;
+  if (write_observer_)
+    write_observer_->OnClose(this);

[darin (slow to review), 2013/03/19 06:12:51]

ditto:  calling out to the write observer is calling out to foreign code.  how
do you know that |this| will still be valid memory upon return from OnClose?  do
we need to worry about dereferencing registry_?

[Zachary Kuznia, 2013/03/19 06:59:35]

Done.

+  registry_->UnregisterStream(url());
+}
+
 void Stream::OnSpaceAvailable() {
   can_add_data_ = true;
-  write_observer_->OnSpaceAvailable(this);
+  if (write_observer_)
+    write_observer_->OnSpaceAvailable(this);
 }
 
 void Stream::OnDataAvailable() {
   if (read_observer_)
     read_observer_->OnDataAvailable(this);
 }
 
 }  // namespace content