PlzNavigate: Add first version of NavigationURLLoader.

content/browser/loader/navigation_url_loader_core.cc

+// Copyright 2014 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/loader/navigation_url_loader_core.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "content/browser/frame_host/frame_tree_node.h"
+#include "content/browser/frame_host/navigation_request_info.h"
+#include "content/browser/loader/navigation_resource_handler.h"
+#include "content/browser/loader/resource_dispatcher_host_impl.h"
+#include "content/common/navigation_params.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/stream_handle.h"
+#include "content/public/common/resource_response.h"
+#include "net/base/net_errors.h"
+#include "net/url_request/redirect_info.h"
+
+namespace content {
+
+NavigationURLLoaderCore::NavigationURLLoaderCore()
+    : delegate_(nullptr),
+      resource_handler_(nullptr) {
+}
+
+void NavigationURLLoaderCore::StartRequest(
+    BrowserContext* browser_context,
+    int64 frame_tree_node_id,
+    const CommonNavigationParams& common_params,
+    scoped_ptr<NavigationRequestInfo> request_info,
+    ResourceRequestBody* request_body) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&NavigationURLLoaderCore::StartRequestOnIOThread, this,
+                 browser_context->GetResourceContext(),
+                 frame_tree_node_id, common_params, base::Passed(&request_info),
+                 make_scoped_refptr(request_body)));
+}
+
+void NavigationURLLoaderCore::FollowRedirect() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&NavigationURLLoaderCore::FollowRedirectOnIOThread, this));
+}
+
+void NavigationURLLoaderCore::Cancel() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&NavigationURLLoaderCore::CancelOnIOThread, this));
+}
+
+void NavigationURLLoaderCore::RequestRedirectedOnIOThread(
+    const net::RedirectInfo& redirect_info,
+    ResourceResponse* response) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  // Make a copy of the ResourceResponse before it is passed to another thread.
+  //
+  // TODO(davidben): This copy could be avoided if ResourceResponse weren't
+  // reference counted and the loader stack passed unique ownership of the
+  // response. https://crbug.com/416050
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&NavigationURLLoaderCore::CallOnRequestRedirected,
+                 this, redirect_info, response->DeepCopy()));
+}
+
+void NavigationURLLoaderCore::ResponseStartedOnIOThread(
+    ResourceResponse* response,
+    scoped_ptr<StreamHandle> body) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  // Make a copy of the ResourceResponse before it is passed to another thread.
+  //
+  // TODO(davidben): This copy could be avoided if ResourceResponse weren't
+  // reference counted and the loader stack passed unique ownership of the
+  // response. https://crbug.com/416050
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&NavigationURLLoaderCore::CallOnResponseStarted,
+                 this, response->DeepCopy(), base::Passed(&body)));
+}
+
+void NavigationURLLoaderCore::RequestFailedOnIOThread(int net_error) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&NavigationURLLoaderCore::CallOnRequestFailed,
+                 this, net_error));
+}
+
+NavigationURLLoaderCore::~NavigationURLLoaderCore() {
+  // When the core is released by either the delegate or the resource handler,
+  // the corresponding pointers are nulled. At this point, both should be
+  // nullptr.
+  DCHECK(!delegate_);
+  DCHECK(!resource_handler_);
+}
+
+void NavigationURLLoaderCore::StartRequestOnIOThread(
+    ResourceContext* resource_context,
+    int64 frame_tree_node_id,
+    const CommonNavigationParams& common_params,
+    scoped_ptr<NavigationRequestInfo> request_info,
+    ResourceRequestBody* request_body) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  ResourceDispatcherHostImpl::Get()->BeginNavigationRequest(
+      resource_context, frame_tree_node_id,
+      common_params, *request_info, request_body,
+      this);
+}
+
+void NavigationURLLoaderCore::FollowRedirectOnIOThread() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  if (resource_handler_)
+    resource_handler_->FollowRedirect();
+}
+
+void NavigationURLLoaderCore::CancelOnIOThread() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  if (resource_handler_)
+    resource_handler_->Cancel();
+}
+
+void NavigationURLLoaderCore::CallOnRequestRedirected(
+    const net::RedirectInfo& redirect_info,
+    ResourceResponse* response) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  if (delegate_)
+    delegate_->OnRequestRedirected(redirect_info, response);
+}
+
+void NavigationURLLoaderCore::CallOnResponseStarted(
+    ResourceResponse* response,
+    scoped_ptr<StreamHandle> body) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  // If |delegate_| is nullptr, OnResponseStarted on the IO thread raced with
+  // Cancel on the UI thread. |body| will be destructed and the request released
+  // at that point.
+  if (delegate_)
+    delegate_->OnResponseStarted(response, body.Pass());
+}
+
+void NavigationURLLoaderCore::CallOnRequestFailed(int net_error) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  if (delegate_)
+    delegate_->OnRequestFailed(net_error);
+}
+
+}  // namespace content