Refactor the guts of ResourceDispatcherHostImpl into a new class named

content/browser/renderer_host/resource_loader.cc

Index: content/browser/renderer_host/resource_loader.cc
===================================================================
--- content/browser/renderer_host/resource_loader.cc	(revision 0)
+++ content/browser/renderer_host/resource_loader.cc	(revision 0)
@@ -0,0 +1,660 @@
+// 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 "content/browser/renderer_host/resource_loader.h"
+
+#include "base/message_loop.h"
+#include "base/time.h"
+#include "content/browser/child_process_security_policy_impl.h"
+#include "content/browser/renderer_host/doomed_resource_handler.h"
+#include "content/browser/renderer_host/resource_loader_delegate.h"
+#include "content/browser/renderer_host/resource_request_info_impl.h"
+#include "content/browser/ssl/ssl_client_auth_handler.h"
+#include "content/browser/ssl/ssl_manager.h"
+#include "content/common/ssl_status_serialization.h"
+#include "content/public/browser/cert_store.h"
+#include "content/public/browser/resource_dispatcher_host_login_delegate.h"
+#include "content/public/common/resource_response.h"
+#include "net/base/load_flags.h"
+#include "net/http/http_response_headers.h"
+#include "webkit/appcache/appcache_interceptor.h"
+
+using base::TimeDelta;
+using base::TimeTicks;
+
+namespace content {
+namespace {
+
+void PopulateResourceResponse(net::URLRequest* request,
+                              ResourceResponse* response) {
+  response->status = request->status();
+  response->request_time = request->request_time();
+  response->response_time = request->response_time();
+  response->headers = request->response_headers();
+  request->GetCharset(&response->charset);
+  response->content_length = request->GetExpectedContentSize();
+  request->GetMimeType(&response->mime_type);
+  net::HttpResponseInfo response_info = request->response_info();
+  response->was_fetched_via_spdy = response_info.was_fetched_via_spdy;
+  response->was_npn_negotiated = response_info.was_npn_negotiated;
+  response->npn_negotiated_protocol = response_info.npn_negotiated_protocol;
+  response->was_fetched_via_proxy = request->was_fetched_via_proxy();
+  response->socket_address = request->GetSocketAddress();
+  appcache::AppCacheInterceptor::GetExtraResponseInfo(
+      request,
+      &response->appcache_id,
+      &response->appcache_manifest_url);
+}
+
+}  // namespace
+
+ResourceLoader::ResourceLoader(scoped_ptr<net::URLRequest> request,
+                               scoped_ptr<ResourceHandler> handler,
+                               ResourceLoaderDelegate* delegate)
+    : deferred_stage_(DEFERRED_NONE),
+      request_(request.Pass()),
+      handler_(handler.Pass()),
+      delegate_(delegate),
+      last_upload_position_(0),
+      waiting_for_upload_progress_ack_(false),
+      called_on_response_started_(false),
+      has_started_reading_(false),
+      is_paused_(false),
+      pause_count_(0),
+      paused_read_bytes_(0),
+      is_transferring_(false) {
+  request_->set_delegate(this);
+  handler_->SetController(this);
+}
+
+ResourceLoader::~ResourceLoader() {
+  if (login_delegate_)
+    login_delegate_->OnRequestCancelled();
+  if (ssl_client_auth_handler_)
+    ssl_client_auth_handler_->OnRequestCancelled();
+
+  // Run ResourceHandler destructor before we tear-down the rest of our state
+  // as the ResourceHandler may want to inspect the URLRequest and other state.
+  handler_.reset();
+}
+
+void ResourceLoader::StartRequest() {
+  if (delegate_->HandleExternalProtocol(this, request_->url())) {
+    CancelRequestInternal(net::ERR_UNKNOWN_URL_SCHEME, false);
+    return;
+  }
+
+  // Give the handler a chance to delay the URLRequest from being started.
+  bool defer_start = false;
+  if (!handler_->OnWillStart(GetRequestInfo()->GetRequestID(), request_->url(),
+                             &defer_start)) {
+    Cancel();
+    return;
+  }
+
+  if (defer_start) {
+    deferred_stage_ = DEFERRED_START;
+  } else {
+    StartRequestInternal();
+  }
+}
+
+void ResourceLoader::CancelRequest(bool from_renderer) {
+  CancelRequestInternal(net::ERR_ABORTED, from_renderer);
+}
+
+void ResourceLoader::ReportUploadProgress() {
+  ResourceRequestInfoImpl* info = GetRequestInfo();
+
+  if (waiting_for_upload_progress_ack_)
+    return;  // Send one progress event at a time.
+
+  uint64 size = info->GetUploadSize();
+  if (!size)
+    return;  // Nothing to upload.
+
+  uint64 position = request_->GetUploadProgress();
+  if (position == last_upload_position_)
+    return;  // No progress made since last time.
+
+  const uint64 kHalfPercentIncrements = 200;
+  const TimeDelta kOneSecond = TimeDelta::FromMilliseconds(1000);
+
+  uint64 amt_since_last = position - last_upload_position_;
+  TimeDelta time_since_last = TimeTicks::Now() - last_upload_ticks_;
+
+  bool is_finished = (size == position);
+  bool enough_new_progress = (amt_since_last > (size / kHalfPercentIncrements));
+  bool too_much_time_passed = time_since_last > kOneSecond;
+
+  if (is_finished || enough_new_progress || too_much_time_passed) {
+    if (request_->load_flags() & net::LOAD_ENABLE_UPLOAD_PROGRESS) {
+      handler_->OnUploadProgress(info->GetRequestID(), position, size);
+      waiting_for_upload_progress_ack_ = true;
+    }
+    last_upload_ticks_ = TimeTicks::Now();
+    last_upload_position_ = position;
+  }
+}
+
+void ResourceLoader::MarkAsTransferring() {
+  is_transferring_ = true;
+
+  // When an URLRequest is transferred to a new RenderViewHost, its
+  // ResourceHandler should not receive any notifications because it may depend
+  // on the state of the old RVH. We set a ResourceHandler that only allows
+  // canceling requests, because on shutdown of the RDH all pending requests
+  // are canceled. The RVH of requests that are being transferred may be gone
+  // by that time. In CompleteTransfer, the ResoureHandlers are substituted
+  // again.
+  handler_.reset(new DoomedResourceHandler(handler_.Pass()));
+}
+
+void ResourceLoader::CompleteTransfer(scoped_ptr<ResourceHandler> new_handler) {
+  DCHECK_EQ(DEFERRED_REDIRECT, deferred_stage_);
+
+  handler_ = new_handler.Pass();
+  handler_->SetController(this);
+  is_transferring_ = false;
+
+  Resume();
+}
+
+ResourceRequestInfoImpl* ResourceLoader::GetRequestInfo() {
+  return ResourceRequestInfoImpl::ForRequest(request_.get());
+}
+
+void ResourceLoader::ClearLoginDelegate() {
+  login_delegate_ = NULL;
+}
+
+void ResourceLoader::ClearSSLClientAuthHandler() {
+  ssl_client_auth_handler_ = NULL;
+}
+
+void ResourceLoader::OnUploadProgressACK() {
+  waiting_for_upload_progress_ack_ = false;
+}
+
+void ResourceLoader::OnFollowRedirect(bool has_new_first_party_for_cookies,
+                                      const GURL& new_first_party_for_cookies) {
+  if (!request_->status().is_success()) {
+    DVLOG(1) << "OnDeferredRedirect for invalid request";
+    return;
+  }
+
+  if (has_new_first_party_for_cookies)
+    request_->set_first_party_for_cookies(new_first_party_for_cookies);
+  request_->FollowDeferredRedirect();
+}
+
+void ResourceLoader::OnReceivedRedirect(net::URLRequest* unused,
+                                        const GURL& new_url,
+                                        bool* defer) {
+  DCHECK_EQ(request_.get(), unused);
+
+  VLOG(1) << "OnReceivedRedirect: " << request_->url().spec();
+  DCHECK(request_->status().is_success());
+
+  ResourceRequestInfoImpl* info = GetRequestInfo();
+
+  if (info->process_type() != PROCESS_TYPE_PLUGIN &&
+      !ChildProcessSecurityPolicyImpl::GetInstance()->
+          CanRequestURL(info->GetChildID(), new_url)) {
+    VLOG(1) << "Denied unauthorized request for "
+            << new_url.possibly_invalid_spec();
+
+    // Tell the renderer that this request was disallowed.
+    Cancel();
+    return;
+  }
+
+  delegate_->DidReceiveRedirect(this, new_url);
+
+  if (delegate_->HandleExternalProtocol(this, new_url)) {
+    // The request is complete so we can remove it.
+    CancelRequestInternal(net::ERR_UNKNOWN_URL_SCHEME, false);
+    return;
+  }
+
+  scoped_refptr<ResourceResponse> response(new ResourceResponse());
+  PopulateResourceResponse(request_.get(), response);
+
+  if (!handler_->OnRequestRedirected(info->GetRequestID(), new_url, response,
+                                     defer)) {
+    Cancel();
+  }
+
+  if (*defer)
+    deferred_stage_ = DEFERRED_REDIRECT;
+}
+
+void ResourceLoader::OnAuthRequired(net::URLRequest* unused,
+                                    net::AuthChallengeInfo* auth_info) {
+  DCHECK_EQ(request_.get(), unused);
+
+  if (request_->load_flags() & net::LOAD_DO_NOT_PROMPT_FOR_LOGIN) {
+    request_->CancelAuth();
+    return;
+  }
+
+  if (!delegate_->AcceptAuthRequest(this, auth_info)) {
+    request_->CancelAuth();
+    return;
+  }
+
+  // Create a login dialog on the UI thread to get authentication data, or pull
+  // from cache and continue on the IO thread.
+
+  DCHECK(!login_delegate_) <<
+      "OnAuthRequired called with login_delegate pending";
+  login_delegate_ = delegate_->CreateLoginDelegate(this, auth_info);
+  if (!login_delegate_)
+    request_->CancelAuth();
+}
+
+void ResourceLoader::OnCertificateRequested(
+    net::URLRequest* unused,
+    net::SSLCertRequestInfo* cert_info) {
+  DCHECK_EQ(request_.get(), unused);
+
+  if (!delegate_->AcceptSSLClientCertificateRequest(this, cert_info)) {
+    request_->Cancel();
+    return;
+  }
+
+  if (cert_info->client_certs.empty()) {
+    // No need to query the user if there are no certs to choose from.
+    request_->ContinueWithCertificate(NULL);
+    return;
+  }
+
+  DCHECK(!ssl_client_auth_handler_) <<
+      "OnCertificateRequested called with ssl_client_auth_handler pending";
+  ssl_client_auth_handler_ = new SSLClientAuthHandler(request_.get(),
+                                                      cert_info);
+  ssl_client_auth_handler_->SelectCertificate();
+}
+
+void ResourceLoader::OnSSLCertificateError(net::URLRequest* request,
+                                           const net::SSLInfo& ssl_info,
+                                           bool fatal) {
+  ResourceRequestInfoImpl* info = GetRequestInfo();
+
+  int render_process_id;
+  int render_view_id;
+  if (!info->GetAssociatedRenderView(&render_process_id, &render_view_id))
+    NOTREACHED();
+
+  SSLManager::OnSSLCertificateError(
+      AsWeakPtr(),
+      info->GetGlobalRequestID(),
+      info->GetResourceType(),
+      request_->url(),
+      render_process_id,
+      render_view_id,
+      ssl_info,
+      fatal);
+}
+
+void ResourceLoader::OnResponseStarted(net::URLRequest* unused) {
+  DCHECK_EQ(request_.get(), unused);
+
+  VLOG(1) << "OnResponseStarted: " << request_->url().spec();
+
+  if (request_->status().is_success()) {
+    if (PauseRequestIfNeeded()) {
+      VLOG(1) << "OnResponseStarted pausing: " << request_->url().spec();
+      return;
+    }
+
+    // We want to send a final upload progress message prior to sending the
+    // response complete message even if we're waiting for an ack to to a
+    // previous upload progress message.
+    waiting_for_upload_progress_ack_ = false;
+    ReportUploadProgress();
+
+    if (!CompleteResponseStarted()) {
+      Cancel();
+    } else {
+      // Check if the handler paused the request in their OnResponseStarted.
+      if (PauseRequestIfNeeded()) {
+        VLOG(1) << "OnResponseStarted pausing2: " << request_->url().spec();
+        return;
+      }
+
+      StartReading();
+    }
+  } else {
+    ResponseCompleted();
+  }
+}
+
+void ResourceLoader::OnReadCompleted(net::URLRequest* unused, int bytes_read) {
+  DCHECK_EQ(request_.get(), unused);
+  VLOG(1) << "OnReadCompleted: \"" << request_->url().spec() << "\""
+          << " bytes_read = " << bytes_read;
+
+  // bytes_read == -1 always implies an error, so we want to skip the pause
+  // checks and just call ResponseCompleted.
+  if (bytes_read == -1) {
+    DCHECK(!request_->status().is_success());
+
+    ResponseCompleted();
+    return;
+  }
+
+  // OnReadCompleted can be called without Read (e.g., for chrome:// URLs).
+  // Make sure we know that a read has begun.
+  has_started_reading_ = true;
+
+  if (PauseRequestIfNeeded()) {
+    paused_read_bytes_ = bytes_read;
+    VLOG(1) << "OnReadCompleted pausing: \"" << request_->url().spec() << "\""
+            << " bytes_read = " << bytes_read;
+    return;
+  }
+
+  if (request_->status().is_success() && CompleteRead(&bytes_read)) {
+    // The request can be paused if we realize that the renderer is not
+    // servicing messages fast enough.
+    if (pause_count_ == 0 && ReadMore(&bytes_read) &&
+        request_->status().is_success()) {
+      if (bytes_read == 0) {
+        CompleteRead(&bytes_read);
+      } else {
+        // Force the next CompleteRead / Read pair to run as a separate task.
+        // This avoids a fast, large network request from monopolizing the IO
+        // thread and starving other IO operations from running.
+        VLOG(1) << "OnReadCompleted postponing: \""
+                << request_->url().spec() << "\""
+                << " bytes_read = " << bytes_read;
+
+        paused_read_bytes_ = bytes_read;
+        is_paused_ = true;
+
+        MessageLoop::current()->PostTask(
+            FROM_HERE, base::Bind(&ResourceLoader::ResumeRequest, AsWeakPtr()));
+        return;
+      }
+    }
+  }
+
+  if (PauseRequestIfNeeded()) {
+    paused_read_bytes_ = bytes_read;
+    VLOG(1) << "OnReadCompleted (CompleteRead) pausing: \""
+            << request_->url().spec() << "\""
+            << " bytes_read = " << bytes_read;
+    return;
+  }
+
+  // If the status is not IO pending then we've either finished (success) or we
+  // had an error.  Either way, we're done!
+  if (!request_->status().is_io_pending())
+    ResponseCompleted();
+}
+
+void ResourceLoader::CancelSSLRequest(const GlobalRequestID& id,
+                                      int error,
+                                      const net::SSLInfo* ssl_info) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  // The request can be NULL if it was cancelled by the renderer (as the
+  // request of the user navigating to a new page from the location bar).
+  if (!request_->is_pending())
+    return;
+  DVLOG(1) << "CancelSSLRequest() url: " << request_->url().spec();
+
+  if (ssl_info) {
+    request_->CancelWithSSLError(error, *ssl_info);
+  } else {
+    request_->CancelWithError(error);
+  }
+}
+
+void ResourceLoader::ContinueSSLRequest(const GlobalRequestID& id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  DVLOG(1) << "ContinueSSLRequest() url: " << request_->url().spec();
+
+  request_->ContinueDespiteLastError();
+}
+
+void ResourceLoader::Resume() {
+  DCHECK(!is_transferring_);
+
+  DeferredStage stage = deferred_stage_;
+  deferred_stage_ = DEFERRED_NONE;
+  switch (stage) {
+    case DEFERRED_NONE:
+      NOTREACHED();
+      break;
+    case DEFERRED_START:
+      StartRequestInternal();
+      break;
+    case DEFERRED_REDIRECT:
+      request_->FollowDeferredRedirect();
+      break;
+    case DEFERRED_RESPONSE:
+    case DEFERRED_READ:
+      PauseRequest(false);
+      break;
+    case DEFERRED_FINISH:
+      // Delay self-destruction since we don't know how we were reached.
+      MessageLoop::current()->PostTask(
+          FROM_HERE,
+          base::Bind(&ResourceLoader::CallDidFinishLoading, AsWeakPtr()));
+      break;
+  }
+}
+
+void ResourceLoader::Cancel() {
+  CancelRequest(false);
+}
+
+void ResourceLoader::StartRequestInternal() {
+  DCHECK(!request_->is_pending());
+  request_->Start();
+
+  delegate_->DidStartRequest(this);
+}
+
+void ResourceLoader::CancelRequestInternal(int error, bool from_renderer) {
+  VLOG(1) << "CancelRequestInternal: " << request_->url().spec();
+
+  ResourceRequestInfoImpl* info = GetRequestInfo();
+
+  // WebKit will send us a cancel for downloads since it no longer handles
+  // them.  In this case, ignore the cancel since we handle downloads in the
+  // browser.
+  if (from_renderer && info->is_download())
+    return;
+
+  bool was_pending = request_->is_pending();
+
+  if (login_delegate_) {
+    login_delegate_->OnRequestCancelled();
+    login_delegate_ = NULL;
+  }
+  if (ssl_client_auth_handler_) {
+    ssl_client_auth_handler_->OnRequestCancelled();
+    ssl_client_auth_handler_ = NULL;
+  }
+
+  request_->CancelWithError(error);
+
+  if (!was_pending) {
+    // If the request isn't in flight, then we won't get an asynchronous
+    // notification from the request, so we have to signal ourselves to finish
+    // this request.
+    MessageLoop::current()->PostTask(
+        FROM_HERE, base::Bind(&ResourceLoader::ResponseCompleted, AsWeakPtr()));
+  }
+}
+
+bool ResourceLoader::CompleteResponseStarted() {
+  ResourceRequestInfoImpl* info = GetRequestInfo();
+
+  scoped_refptr<ResourceResponse> response(new ResourceResponse());
+  PopulateResourceResponse(request_.get(), response);
+
+  if (request_->ssl_info().cert) {
+    int cert_id =
+        CertStore::GetInstance()->StoreCert(request_->ssl_info().cert,
+                                            info->GetChildID());
+    response->security_info = SerializeSecurityInfo(
+        cert_id,
+        request_->ssl_info().cert_status,
+        request_->ssl_info().security_bits,
+        request_->ssl_info().connection_status);
+  } else {
+    // We should not have any SSL state.
+    DCHECK(!request_->ssl_info().cert_status &&
+           request_->ssl_info().security_bits == -1 &&
+           !request_->ssl_info().connection_status);
+  }
+
+  delegate_->DidReceiveResponse(this);
+  called_on_response_started_ = true;
+
+  bool defer = false;
+  if (!handler_->OnResponseStarted(info->GetRequestID(), response, &defer))
+    return false;
+
+  if (defer) {
+    deferred_stage_ = DEFERRED_RESPONSE;
+    PauseRequest(true);
+  }
+
+  return true;
+}
+
+void ResourceLoader::StartReading() {
+  int bytes_read = 0;
+  if (ReadMore(&bytes_read)) {
+    OnReadCompleted(request_.get(), bytes_read);
+  } else if (!request_->status().is_io_pending()) {
+    DCHECK(!is_paused_);
+    // If the error is not an IO pending, then we're done reading.
+    ResponseCompleted();
+  }
+}
+
+bool ResourceLoader::ReadMore(int* bytes_read) {
+  ResourceRequestInfoImpl* info = GetRequestInfo();
+  DCHECK(!is_paused_);
+
+  net::IOBuffer* buf;
+  int buf_size;
+  if (!handler_->OnWillRead(info->GetRequestID(), &buf, &buf_size, -1))
+    return false;
+
+  DCHECK(buf);
+  DCHECK(buf_size > 0);
+
+  has_started_reading_ = true;
+  return request_->Read(buf, buf_size, bytes_read);
+}
+
+bool ResourceLoader::CompleteRead(int* bytes_read) {
+  if (!request_.get() || !request_->status().is_success()) {
+    NOTREACHED();
+    return false;
+  }
+
+  ResourceRequestInfoImpl* info = GetRequestInfo();
+
+  bool defer = false;
+  if (!handler_->OnReadCompleted(info->GetRequestID(), bytes_read, &defer)) {
+    Cancel();
+    return false;
+  }
+
+  if (defer) {
+    deferred_stage_ = DEFERRED_READ;
+    PauseRequest(true);
+  }
+
+  return *bytes_read != 0;
+}
+
+void ResourceLoader::ResponseCompleted() {
+  VLOG(1) << "ResponseCompleted: " << request_->url().spec();
+  ResourceRequestInfoImpl* info = GetRequestInfo();
+
+  std::string security_info;
+  const net::SSLInfo& ssl_info = request_->ssl_info();
+  if (ssl_info.cert != NULL) {
+    int cert_id = CertStore::GetInstance()->StoreCert(ssl_info.cert,
+                                                      info->GetChildID());
+    security_info = SerializeSecurityInfo(
+        cert_id, ssl_info.cert_status, ssl_info.security_bits,
+        ssl_info.connection_status);
+  }
+
+  if (handler_->OnResponseCompleted(info->GetRequestID(), request_->status(),
+                                    security_info)) {
+    // This will result in our destruction.
+    CallDidFinishLoading();
+  } else {
+    // The handler is not ready to die yet.  We will call DidFinishLoading when
+    // we resume.
+    deferred_stage_ = DEFERRED_FINISH;
+  }
+}
+
+bool ResourceLoader::PauseRequestIfNeeded() {
+  if (pause_count_ > 0)
+    is_paused_ = true;
+  return is_paused_;
+}
+
+void ResourceLoader::PauseRequest(bool pause) {
+  int pause_count = pause_count_ + (pause ? 1 : -1);
+  if (pause_count < 0) {
+    NOTREACHED();  // Unbalanced call to pause.
+    return;
+  }
+  pause_count_ = pause_count;
+
+  VLOG(1) << "To pause (" << pause << "): " << request_->url().spec();
+
+  // If we're resuming, kick the request to start reading again. Run the read
+  // asynchronously to avoid recursion problems.
+  if (pause_count_ == 0) {
+    MessageLoop::current()->PostTask(
+        FROM_HERE, base::Bind(&ResourceLoader::ResumeRequest, AsWeakPtr()));
+  }
+}
+
+void ResourceLoader::ResumeRequest() {
+  // We may already be unpaused, or the pause count may have increased since we
+  // posted the task to call ResumeRequest.
+  if (!is_paused_)
+    return;
+  is_paused_ = false;
+  if (PauseRequestIfNeeded())
+    return;
+
+  VLOG(1) << "Resuming: \"" << request_->url().spec() << "\""
+          << " paused_read_bytes = " << paused_read_bytes_
+          << " called response started = " << called_on_response_started_
+          << " started reading = " << has_started_reading_;
+
+  if (called_on_response_started_) {
+    if (has_started_reading_) {
+      OnReadCompleted(request_.get(), paused_read_bytes_);
+    } else {
+      StartReading();
+    }
+  } else {
+    OnResponseStarted(request_.get());
+  }
+}
+
+void ResourceLoader::CallDidFinishLoading() {
+  delegate_->DidFinishLoading(this);
+}
+
+}  // namespace content