Reland r187230: Implement the Stream registry in content

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_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),
+      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()));
+  reader_->RegisterCallback(base::Bind(&Stream::OnDataAvailable,
+                                       weak_ptr_factory_.GetWeakPtr()));
+
+  registry_->RegisterStream(this);
+}
+
+Stream::~Stream() {
+}
+
+bool Stream::SetReadObserver(StreamReadObserver* observer) {
+  if (read_observer_)
+    return false;
+  read_observer_ = observer;
+  return true;
+}
+
+void Stream::RemoveReadObserver(StreamReadObserver* observer) {
+  DCHECK(observer == read_observer_);
+  read_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:
+        registry_->UnregisterStream(url());
+        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;
+}
+
+void Stream::OnSpaceAvailable() {
+  can_add_data_ = true;
+  write_observer_->OnSpaceAvailable(this);
+}
+
+void Stream::OnDataAvailable() {
+  read_observer_->OnDataAvailable(this);
+}
+
+}  // namespace content
+