content/browser/loader/resource_loader.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/browser/loader/resource_loader.h"
   6
   7 #include "base/command_line.h"
   8 #include "base/message_loop/message_loop.h"
   9 #include "base/metrics/histogram.h"
  10 #include "base/profiler/scoped_tracker.h"
  11 #include "base/time/time.h"
  12 #include "content/browser/appcache/appcache_interceptor.h"
  13 #include "content/browser/child_process_security_policy_impl.h"
  14 #include "content/browser/loader/cross_site_resource_handler.h"
  15 #include "content/browser/loader/detachable_resource_handler.h"
  16 #include "content/browser/loader/resource_loader_delegate.h"
  17 #include "content/browser/loader/resource_request_info_impl.h"
  18 #include "content/browser/service_worker/service_worker_request_handler.h"
  19 #include "content/browser/ssl/ssl_client_auth_handler.h"
  20 #include "content/browser/ssl/ssl_manager.h"
  21 #include "content/common/ssl_status_serialization.h"
  22 #include "content/public/browser/cert_store.h"
  23 #include "content/public/browser/resource_context.h"
  24 #include "content/public/browser/resource_dispatcher_host_login_delegate.h"
  25 #include "content/public/browser/signed_certificate_timestamp_store.h"
  26 #include "content/public/common/content_client.h"
  27 #include "content/public/common/content_switches.h"
  28 #include "content/public/common/process_type.h"
  29 #include "content/public/common/resource_response.h"
  30 #include "net/base/io_buffer.h"
  31 #include "net/base/load_flags.h"
  32 #include "net/http/http_response_headers.h"
  33 #include "net/ssl/client_cert_store.h"
  34 #include "net/url_request/redirect_info.h"
  35 #include "net/url_request/url_request_status.h"
  36
  37 using base::TimeDelta;
  38 using base::TimeTicks;
  39
  40 namespace content {
  41 namespace {
  42
  43 void PopulateResourceResponse(ResourceRequestInfoImpl* info,
  44                               net::URLRequest* request,
  45                               ResourceResponse* response) {
  46   response->head.request_time = request->request_time();
  47   response->head.response_time = request->response_time();
  48   response->head.headers = request->response_headers();
  49   request->GetCharset(&response->head.charset);
  50   response->head.content_length = request->GetExpectedContentSize();
  51   request->GetMimeType(&response->head.mime_type);
  52   net::HttpResponseInfo response_info = request->response_info();
  53   response->head.was_fetched_via_spdy = response_info.was_fetched_via_spdy;
  54   response->head.was_npn_negotiated = response_info.was_npn_negotiated;
  55   response->head.npn_negotiated_protocol =
  56       response_info.npn_negotiated_protocol;
  57   response->head.connection_info = response_info.connection_info;
  58   response->head.was_fetched_via_proxy = request->was_fetched_via_proxy();
  59   response->head.proxy_server = response_info.proxy_server;
  60   response->head.socket_address = request->GetSocketAddress();
  61   if (ServiceWorkerRequestHandler* handler =
  62           ServiceWorkerRequestHandler::GetHandler(request)) {
  63     handler->GetExtraResponseInfo(
  64         &response->head.was_fetched_via_service_worker,
  65         &response->head.was_fallback_required_by_service_worker,
  66         &response->head.original_url_via_service_worker,
  67         &response->head.response_type_via_service_worker,
  68         &response->head.service_worker_fetch_start,
  69         &response->head.service_worker_fetch_ready,
  70         &response->head.service_worker_fetch_end);
  71   }
  72   AppCacheInterceptor::GetExtraResponseInfo(
  73       request,
  74       &response->head.appcache_id,
  75       &response->head.appcache_manifest_url);
  76   if (info->is_load_timing_enabled())
  77     request->GetLoadTimingInfo(&response->head.load_timing);
  78 }
  79
  80 }  // namespace
  81
  82 ResourceLoader::ResourceLoader(scoped_ptr<net::URLRequest> request,
  83                                scoped_ptr<ResourceHandler> handler,
  84                                ResourceLoaderDelegate* delegate)
  85     : deferred_stage_(DEFERRED_NONE),
  86       request_(request.Pass()),
  87       handler_(handler.Pass()),
  88       delegate_(delegate),
  89       last_upload_position_(0),
  90       waiting_for_upload_progress_ack_(false),
  91       is_transferring_(false),
  92       weak_ptr_factory_(this) {
  93   request_->set_delegate(this);
  94   handler_->SetController(this);
  95 }
  96
  97 ResourceLoader::~ResourceLoader() {
  98   if (login_delegate_.get())
  99     login_delegate_->OnRequestCancelled();
 100   ssl_client_auth_handler_.reset();
 101
 102   // Run ResourceHandler destructor before we tear-down the rest of our state
 103   // as the ResourceHandler may want to inspect the URLRequest and other state.
 104   handler_.reset();
 105 }
 106
 107 void ResourceLoader::StartRequest() {
 108   if (delegate_->HandleExternalProtocol(this, request_->url())) {
 109     CancelAndIgnore();
 110     return;
 111   }
 112
 113   // Give the handler a chance to delay the URLRequest from being started.
 114   bool defer_start = false;
 115   {
 116     // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 117     tracked_objects::ScopedTracker tracking_profile(
 118         FROM_HERE_WITH_EXPLICIT_FUNCTION(
 119             "423948 ResourceLoader::StartRequest"));
 120
 121     if (!handler_->OnWillStart(request_->url(), &defer_start)) {
 122       Cancel();
 123       return;
 124     }
 125   }
 126
 127   if (defer_start) {
 128     deferred_stage_ = DEFERRED_START;
 129   } else {
 130     StartRequestInternal();
 131   }
 132 }
 133
 134 void ResourceLoader::CancelRequest(bool from_renderer) {
 135   CancelRequestInternal(net::ERR_ABORTED, from_renderer);
 136 }
 137
 138 void ResourceLoader::CancelAndIgnore() {
 139   ResourceRequestInfoImpl* info = GetRequestInfo();
 140   info->set_was_ignored_by_handler(true);
 141   CancelRequest(false);
 142 }
 143
 144 void ResourceLoader::CancelWithError(int error_code) {
 145   CancelRequestInternal(error_code, false);
 146 }
 147
 148 void ResourceLoader::ReportUploadProgress() {
 149   if (waiting_for_upload_progress_ack_)
 150     return;  // Send one progress event at a time.
 151
 152   net::UploadProgress progress = request_->GetUploadProgress();
 153   if (!progress.size())
 154     return;  // Nothing to upload.
 155
 156   if (progress.position() == last_upload_position_)
 157     return;  // No progress made since last time.
 158
 159   const uint64 kHalfPercentIncrements = 200;
 160   const TimeDelta kOneSecond = TimeDelta::FromMilliseconds(1000);
 161
 162   uint64 amt_since_last = progress.position() - last_upload_position_;
 163   TimeDelta time_since_last = TimeTicks::Now() - last_upload_ticks_;
 164
 165   bool is_finished = (progress.size() == progress.position());
 166   bool enough_new_progress =
 167       (amt_since_last > (progress.size() / kHalfPercentIncrements));
 168   bool too_much_time_passed = time_since_last > kOneSecond;
 169
 170   if (is_finished || enough_new_progress || too_much_time_passed) {
 171     ResourceRequestInfoImpl* info = GetRequestInfo();
 172     if (info->is_upload_progress_enabled()) {
 173       // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is
 174       // fixed.
 175       tracked_objects::ScopedTracker tracking_profile(
 176           FROM_HERE_WITH_EXPLICIT_FUNCTION(
 177               "423948 ResourceLoader::ReportUploadProgress"));
 178
 179       handler_->OnUploadProgress(progress.position(), progress.size());
 180       waiting_for_upload_progress_ack_ = true;
 181     }
 182     last_upload_ticks_ = TimeTicks::Now();
 183     last_upload_position_ = progress.position();
 184   }
 185 }
 186
 187 void ResourceLoader::MarkAsTransferring() {
 188   CHECK(IsResourceTypeFrame(GetRequestInfo()->GetResourceType()))
 189       << "Can only transfer for navigations";
 190   is_transferring_ = true;
 191 }
 192
 193 void ResourceLoader::CompleteTransfer() {
 194   // Although CrossSiteResourceHandler defers at OnResponseStarted
 195   // (DEFERRED_READ), it may be seeing a replay of events via
 196   // BufferedResourceHandler, and so the request itself is actually deferred at
 197   // a later read stage.
 198   DCHECK(DEFERRED_READ == deferred_stage_ ||
 199          DEFERRED_RESPONSE_COMPLETE == deferred_stage_);
 200
 201   is_transferring_ = false;
 202   GetRequestInfo()->cross_site_handler()->ResumeResponse();
 203 }
 204
 205 ResourceRequestInfoImpl* ResourceLoader::GetRequestInfo() {
 206   return ResourceRequestInfoImpl::ForRequest(request_.get());
 207 }
 208
 209 void ResourceLoader::ClearLoginDelegate() {
 210   login_delegate_ = NULL;
 211 }
 212
 213 void ResourceLoader::OnUploadProgressACK() {
 214   waiting_for_upload_progress_ack_ = false;
 215 }
 216
 217 void ResourceLoader::OnReceivedRedirect(net::URLRequest* unused,
 218                                         const net::RedirectInfo& redirect_info,
 219                                         bool* defer) {
 220   DCHECK_EQ(request_.get(), unused);
 221
 222   VLOG(1) << "OnReceivedRedirect: " << request_->url().spec();
 223   DCHECK(request_->status().is_success());
 224
 225   ResourceRequestInfoImpl* info = GetRequestInfo();
 226
 227   if (info->GetProcessType() != PROCESS_TYPE_PLUGIN &&
 228       !ChildProcessSecurityPolicyImpl::GetInstance()->
 229           CanRequestURL(info->GetChildID(), redirect_info.new_url)) {
 230     VLOG(1) << "Denied unauthorized request for "
 231             << redirect_info.new_url.possibly_invalid_spec();
 232
 233     // Tell the renderer that this request was disallowed.
 234     Cancel();
 235     return;
 236   }
 237
 238   delegate_->DidReceiveRedirect(this, redirect_info.new_url);
 239
 240   if (delegate_->HandleExternalProtocol(this, redirect_info.new_url)) {
 241     // The request is complete so we can remove it.
 242     CancelAndIgnore();
 243     return;
 244   }
 245
 246   scoped_refptr<ResourceResponse> response(new ResourceResponse());
 247   PopulateResourceResponse(info, request_.get(), response.get());
 248
 249   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 250   tracked_objects::ScopedTracker tracking_profile(
 251       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 252           "423948 ResourceLoader::OnReceivedRedirect"));
 253
 254   if (!handler_->OnRequestRedirected(redirect_info, response.get(), defer)) {
 255     Cancel();
 256   } else if (*defer) {
 257     deferred_stage_ = DEFERRED_REDIRECT;  // Follow redirect when resumed.
 258   }
 259 }
 260
 261 void ResourceLoader::OnAuthRequired(net::URLRequest* unused,
 262                                     net::AuthChallengeInfo* auth_info) {
 263   DCHECK_EQ(request_.get(), unused);
 264
 265   if (request_->load_flags() & net::LOAD_DO_NOT_PROMPT_FOR_LOGIN) {
 266     request_->CancelAuth();
 267     return;
 268   }
 269
 270   // Create a login dialog on the UI thread to get authentication data, or pull
 271   // from cache and continue on the IO thread.
 272
 273   DCHECK(!login_delegate_.get())
 274       << "OnAuthRequired called with login_delegate pending";
 275   login_delegate_ = delegate_->CreateLoginDelegate(this, auth_info);
 276   if (!login_delegate_.get())
 277     request_->CancelAuth();
 278 }
 279
 280 void ResourceLoader::OnCertificateRequested(
 281     net::URLRequest* unused,
 282     net::SSLCertRequestInfo* cert_info) {
 283   DCHECK_EQ(request_.get(), unused);
 284
 285   if (request_->load_flags() & net::LOAD_PREFETCH) {
 286     request_->Cancel();
 287     return;
 288   }
 289
 290   DCHECK(!ssl_client_auth_handler_)
 291       << "OnCertificateRequested called with ssl_client_auth_handler pending";
 292   ssl_client_auth_handler_.reset(new SSLClientAuthHandler(
 293       GetRequestInfo()->GetContext()->CreateClientCertStore(),
 294       request_.get(),
 295       cert_info,
 296       base::Bind(&ResourceLoader::ContinueWithCertificate,
 297                  weak_ptr_factory_.GetWeakPtr())));
 298   ssl_client_auth_handler_->SelectCertificate();
 299 }
 300
 301 void ResourceLoader::OnSSLCertificateError(net::URLRequest* request,
 302                                            const net::SSLInfo& ssl_info,
 303                                            bool fatal) {
 304   ResourceRequestInfoImpl* info = GetRequestInfo();
 305
 306   int render_process_id;
 307   int render_frame_id;
 308   if (!info->GetAssociatedRenderFrame(&render_process_id, &render_frame_id))
 309     NOTREACHED();
 310
 311   SSLManager::OnSSLCertificateError(
 312       weak_ptr_factory_.GetWeakPtr(),
 313       info->GetResourceType(),
 314       request_->url(),
 315       render_process_id,
 316       render_frame_id,
 317       ssl_info,
 318       fatal);
 319 }
 320
 321 void ResourceLoader::OnBeforeNetworkStart(net::URLRequest* unused,
 322                                           bool* defer) {
 323   DCHECK_EQ(request_.get(), unused);
 324
 325   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 326   tracked_objects::ScopedTracker tracking_profile(
 327       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 328           "423948 ResourceLoader::OnBeforeNetworkStart"));
 329
 330   // Give the handler a chance to delay the URLRequest from using the network.
 331   if (!handler_->OnBeforeNetworkStart(request_->url(), defer)) {
 332     Cancel();
 333     return;
 334   } else if (*defer) {
 335     deferred_stage_ = DEFERRED_NETWORK_START;
 336   }
 337 }
 338
 339 void ResourceLoader::OnResponseStarted(net::URLRequest* unused) {
 340   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 341   tracked_objects::ScopedTracker tracking_profile(
 342       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 343           "423948 ResourceLoader::OnResponseStarted"));
 344
 345   DCHECK_EQ(request_.get(), unused);
 346
 347   VLOG(1) << "OnResponseStarted: " << request_->url().spec();
 348
 349   // The CanLoadPage check should take place after any server redirects have
 350   // finished, at the point in time that we know a page will commit in the
 351   // renderer process.
 352   ResourceRequestInfoImpl* info = GetRequestInfo();
 353   ChildProcessSecurityPolicyImpl* policy =
 354       ChildProcessSecurityPolicyImpl::GetInstance();
 355   if (!policy->CanLoadPage(info->GetChildID(),
 356                            request_->url(),
 357                            info->GetResourceType())) {
 358     Cancel();
 359     return;
 360   }
 361
 362   if (!request_->status().is_success()) {
 363     ResponseCompleted();
 364     return;
 365   }
 366
 367   // We want to send a final upload progress message prior to sending the
 368   // response complete message even if we're waiting for an ack to to a
 369   // previous upload progress message.
 370   waiting_for_upload_progress_ack_ = false;
 371   ReportUploadProgress();
 372
 373   CompleteResponseStarted();
 374
 375   if (is_deferred())
 376     return;
 377
 378   if (request_->status().is_success()) {
 379     StartReading(false);  // Read the first chunk.
 380   } else {
 381     ResponseCompleted();
 382   }
 383 }
 384
 385 void ResourceLoader::OnReadCompleted(net::URLRequest* unused, int bytes_read) {
 386   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 387   tracked_objects::ScopedTracker tracking_profile(
 388       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 389           "423948 ResourceLoader::OnReadCompleted"));
 390
 391   DCHECK_EQ(request_.get(), unused);
 392   VLOG(1) << "OnReadCompleted: \"" << request_->url().spec() << "\""
 393           << " bytes_read = " << bytes_read;
 394
 395   // bytes_read == -1 always implies an error.
 396   if (bytes_read == -1 || !request_->status().is_success()) {
 397     ResponseCompleted();
 398     return;
 399   }
 400
 401   CompleteRead(bytes_read);
 402
 403   // If the handler cancelled or deferred the request, do not continue
 404   // processing the read. If cancelled, the URLRequest has already been
 405   // cancelled and will schedule an erroring OnReadCompleted later. If deferred,
 406   // do nothing until resumed.
 407   //
 408   // Note: if bytes_read is 0 (EOF) and the handler defers, resumption will call
 409   // ResponseCompleted().
 410   if (is_deferred() || !request_->status().is_success())
 411     return;
 412
 413   if (bytes_read > 0) {
 414     StartReading(true);  // Read the next chunk.
 415   } else {
 416     // URLRequest reported an EOF. Call ResponseCompleted.
 417     DCHECK_EQ(0, bytes_read);
 418     ResponseCompleted();
 419   }
 420 }
 421
 422 void ResourceLoader::CancelSSLRequest(int error,
 423                                       const net::SSLInfo* ssl_info) {
 424   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 425
 426   // The request can be NULL if it was cancelled by the renderer (as the
 427   // request of the user navigating to a new page from the location bar).
 428   if (!request_->is_pending())
 429     return;
 430   DVLOG(1) << "CancelSSLRequest() url: " << request_->url().spec();
 431
 432   if (ssl_info) {
 433     request_->CancelWithSSLError(error, *ssl_info);
 434   } else {
 435     request_->CancelWithError(error);
 436   }
 437 }
 438
 439 void ResourceLoader::ContinueSSLRequest() {
 440   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 441
 442   DVLOG(1) << "ContinueSSLRequest() url: " << request_->url().spec();
 443
 444   request_->ContinueDespiteLastError();
 445 }
 446
 447 void ResourceLoader::Resume() {
 448   DCHECK(!is_transferring_);
 449
 450   DeferredStage stage = deferred_stage_;
 451   deferred_stage_ = DEFERRED_NONE;
 452   switch (stage) {
 453     case DEFERRED_NONE:
 454       NOTREACHED();
 455       break;
 456     case DEFERRED_START:
 457       StartRequestInternal();
 458       break;
 459     case DEFERRED_NETWORK_START:
 460       request_->ResumeNetworkStart();
 461       break;
 462     case DEFERRED_REDIRECT:
 463       request_->FollowDeferredRedirect();
 464       break;
 465     case DEFERRED_READ:
 466       base::MessageLoop::current()->PostTask(
 467           FROM_HERE,
 468           base::Bind(&ResourceLoader::ResumeReading,
 469                      weak_ptr_factory_.GetWeakPtr()));
 470       break;
 471     case DEFERRED_RESPONSE_COMPLETE:
 472       base::MessageLoop::current()->PostTask(
 473           FROM_HERE,
 474           base::Bind(&ResourceLoader::ResponseCompleted,
 475                      weak_ptr_factory_.GetWeakPtr()));
 476       break;
 477     case DEFERRED_FINISH:
 478       // Delay self-destruction since we don't know how we were reached.
 479       base::MessageLoop::current()->PostTask(
 480           FROM_HERE,
 481           base::Bind(&ResourceLoader::CallDidFinishLoading,
 482                      weak_ptr_factory_.GetWeakPtr()));
 483       break;
 484   }
 485 }
 486
 487 void ResourceLoader::Cancel() {
 488   CancelRequest(false);
 489 }
 490
 491 void ResourceLoader::StartRequestInternal() {
 492   DCHECK(!request_->is_pending());
 493
 494   if (!request_->status().is_success()) {
 495     return;
 496   }
 497
 498   request_->Start();
 499
 500   delegate_->DidStartRequest(this);
 501 }
 502
 503 void ResourceLoader::CancelRequestInternal(int error, bool from_renderer) {
 504   VLOG(1) << "CancelRequestInternal: " << request_->url().spec();
 505
 506   ResourceRequestInfoImpl* info = GetRequestInfo();
 507
 508   // WebKit will send us a cancel for downloads since it no longer handles
 509   // them.  In this case, ignore the cancel since we handle downloads in the
 510   // browser.
 511   if (from_renderer && (info->IsDownload() || info->is_stream()))
 512     return;
 513
 514   if (from_renderer && info->detachable_handler()) {
 515     // TODO(davidben): Fix Blink handling of prefetches so they are not
 516     // cancelled on navigate away and end up in the local cache.
 517     info->detachable_handler()->Detach();
 518     return;
 519   }
 520
 521   // TODO(darin): Perhaps we should really be looking to see if the status is
 522   // IO_PENDING?
 523   bool was_pending = request_->is_pending();
 524
 525   if (login_delegate_.get()) {
 526     login_delegate_->OnRequestCancelled();
 527     login_delegate_ = NULL;
 528   }
 529   ssl_client_auth_handler_.reset();
 530
 531   request_->CancelWithError(error);
 532
 533   if (!was_pending) {
 534     // If the request isn't in flight, then we won't get an asynchronous
 535     // notification from the request, so we have to signal ourselves to finish
 536     // this request.
 537     base::MessageLoop::current()->PostTask(
 538         FROM_HERE,
 539         base::Bind(&ResourceLoader::ResponseCompleted,
 540                    weak_ptr_factory_.GetWeakPtr()));
 541   }
 542 }
 543
 544 void ResourceLoader::StoreSignedCertificateTimestamps(
 545     const net::SignedCertificateTimestampAndStatusList& sct_list,
 546     int process_id,
 547     SignedCertificateTimestampIDStatusList* sct_ids) {
 548   SignedCertificateTimestampStore* sct_store(
 549       SignedCertificateTimestampStore::GetInstance());
 550
 551   for (net::SignedCertificateTimestampAndStatusList::const_iterator iter =
 552        sct_list.begin(); iter != sct_list.end(); ++iter) {
 553     const int sct_id(sct_store->Store(iter->sct.get(), process_id));
 554     sct_ids->push_back(
 555         SignedCertificateTimestampIDAndStatus(sct_id, iter->status));
 556   }
 557 }
 558
 559 void ResourceLoader::CompleteResponseStarted() {
 560   ResourceRequestInfoImpl* info = GetRequestInfo();
 561
 562   scoped_refptr<ResourceResponse> response(new ResourceResponse());
 563   PopulateResourceResponse(info, request_.get(), response.get());
 564
 565   if (request_->ssl_info().cert.get()) {
 566     int cert_id = CertStore::GetInstance()->StoreCert(
 567         request_->ssl_info().cert.get(), info->GetChildID());
 568
 569     SignedCertificateTimestampIDStatusList signed_certificate_timestamp_ids;
 570     StoreSignedCertificateTimestamps(
 571         request_->ssl_info().signed_certificate_timestamps,
 572         info->GetChildID(),
 573         &signed_certificate_timestamp_ids);
 574
 575     response->head.security_info = SerializeSecurityInfo(
 576         cert_id,
 577         request_->ssl_info().cert_status,
 578         request_->ssl_info().security_bits,
 579         request_->ssl_info().connection_status,
 580         signed_certificate_timestamp_ids);
 581   } else {
 582     // We should not have any SSL state.
 583     DCHECK(!request_->ssl_info().cert_status &&
 584            request_->ssl_info().security_bits == -1 &&
 585            !request_->ssl_info().connection_status);
 586   }
 587
 588   delegate_->DidReceiveResponse(this);
 589
 590   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 591   tracked_objects::ScopedTracker tracking_profile(
 592       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 593           "423948 ResourceLoader::CompleteResponseStarted"));
 594
 595   bool defer = false;
 596   if (!handler_->OnResponseStarted(response.get(), &defer)) {
 597     Cancel();
 598   } else if (defer) {
 599     read_deferral_start_time_ = base::TimeTicks::Now();
 600     deferred_stage_ = DEFERRED_READ;  // Read first chunk when resumed.
 601   }
 602 }
 603
 604 void ResourceLoader::StartReading(bool is_continuation) {
 605   int bytes_read = 0;
 606   ReadMore(&bytes_read);
 607
 608   // If IO is pending, wait for the URLRequest to call OnReadCompleted.
 609   if (request_->status().is_io_pending())
 610     return;
 611
 612   if (!is_continuation || bytes_read <= 0) {
 613     OnReadCompleted(request_.get(), bytes_read);
 614   } else {
 615     // Else, trigger OnReadCompleted asynchronously to avoid starving the IO
 616     // thread in case the URLRequest can provide data synchronously.
 617     base::MessageLoop::current()->PostTask(
 618         FROM_HERE,
 619         base::Bind(&ResourceLoader::OnReadCompleted,
 620                    weak_ptr_factory_.GetWeakPtr(),
 621                    request_.get(),
 622                    bytes_read));
 623   }
 624 }
 625
 626 void ResourceLoader::ResumeReading() {
 627   DCHECK(!is_deferred());
 628
 629   if (!read_deferral_start_time_.is_null()) {
 630     UMA_HISTOGRAM_TIMES("Net.ResourceLoader.ReadDeferral",
 631                         base::TimeTicks::Now() - read_deferral_start_time_);
 632     read_deferral_start_time_ = base::TimeTicks();
 633   }
 634   if (request_->status().is_success()) {
 635     StartReading(false);  // Read the next chunk (OK to complete synchronously).
 636   } else {
 637     ResponseCompleted();
 638   }
 639 }
 640
 641 void ResourceLoader::ReadMore(int* bytes_read) {
 642   DCHECK(!is_deferred());
 643
 644   // Make sure we track the buffer in at least one place.  This ensures it gets
 645   // deleted even in the case the request has already finished its job and
 646   // doesn't use the buffer.
 647   scoped_refptr<net::IOBuffer> buf;
 648   int buf_size;
 649   {
 650     // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 651     tracked_objects::ScopedTracker tracking_profile(
 652         FROM_HERE_WITH_EXPLICIT_FUNCTION("423948 ResourceLoader::ReadMore"));
 653
 654     if (!handler_->OnWillRead(&buf, &buf_size, -1)) {
 655       Cancel();
 656       return;
 657     }
 658   }
 659
 660   DCHECK(buf.get());
 661   DCHECK(buf_size > 0);
 662
 663   request_->Read(buf.get(), buf_size, bytes_read);
 664
 665   // No need to check the return value here as we'll detect errors by
 666   // inspecting the URLRequest's status.
 667 }
 668
 669 void ResourceLoader::CompleteRead(int bytes_read) {
 670   DCHECK(bytes_read >= 0);
 671   DCHECK(request_->status().is_success());
 672
 673   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 674   tracked_objects::ScopedTracker tracking_profile(
 675       FROM_HERE_WITH_EXPLICIT_FUNCTION("423948 ResourceLoader::CompleteRead"));
 676
 677   bool defer = false;
 678   if (!handler_->OnReadCompleted(bytes_read, &defer)) {
 679     Cancel();
 680   } else if (defer) {
 681     deferred_stage_ =
 682         bytes_read > 0 ? DEFERRED_READ : DEFERRED_RESPONSE_COMPLETE;
 683   }
 684
 685   // Note: the request may still have been cancelled while OnReadCompleted
 686   // returns true if OnReadCompleted caused request to get cancelled
 687   // out-of-band. (In AwResourceDispatcherHostDelegate::DownloadStarting, for
 688   // instance.)
 689 }
 690
 691 void ResourceLoader::ResponseCompleted() {
 692   VLOG(1) << "ResponseCompleted: " << request_->url().spec();
 693   RecordHistograms();
 694   ResourceRequestInfoImpl* info = GetRequestInfo();
 695
 696   std::string security_info;
 697   const net::SSLInfo& ssl_info = request_->ssl_info();
 698   if (ssl_info.cert.get() != NULL) {
 699     int cert_id = CertStore::GetInstance()->StoreCert(ssl_info.cert.get(),
 700                                                       info->GetChildID());
 701     SignedCertificateTimestampIDStatusList signed_certificate_timestamp_ids;
 702     StoreSignedCertificateTimestamps(ssl_info.signed_certificate_timestamps,
 703                                      info->GetChildID(),
 704                                      &signed_certificate_timestamp_ids);
 705
 706     security_info = SerializeSecurityInfo(
 707         cert_id, ssl_info.cert_status, ssl_info.security_bits,
 708         ssl_info.connection_status, signed_certificate_timestamp_ids);
 709   }
 710
 711   bool defer = false;
 712   {
 713     // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 714     tracked_objects::ScopedTracker tracking_profile(
 715         FROM_HERE_WITH_EXPLICIT_FUNCTION(
 716             "423948 ResourceLoader::ResponseCompleted"));
 717
 718     handler_->OnResponseCompleted(request_->status(), security_info, &defer);
 719   }
 720   if (defer) {
 721     // The handler is not ready to die yet.  We will call DidFinishLoading when
 722     // we resume.
 723     deferred_stage_ = DEFERRED_FINISH;
 724   } else {
 725     // This will result in our destruction.
 726     CallDidFinishLoading();
 727   }
 728 }
 729
 730 void ResourceLoader::CallDidFinishLoading() {
 731   delegate_->DidFinishLoading(this);
 732 }
 733
 734 void ResourceLoader::RecordHistograms() {
 735   ResourceRequestInfoImpl* info = GetRequestInfo();
 736
 737   if (info->GetResourceType() == RESOURCE_TYPE_PREFETCH) {
 738     PrefetchStatus status = STATUS_UNDEFINED;
 739     TimeDelta total_time = base::TimeTicks::Now() - request_->creation_time();
 740
 741     switch (request_->status().status()) {
 742       case net::URLRequestStatus::SUCCESS:
 743         if (request_->was_cached()) {
 744           status = STATUS_SUCCESS_FROM_CACHE;
 745           UMA_HISTOGRAM_TIMES("Net.Prefetch.TimeSpentPrefetchingFromCache",
 746                               total_time);
 747         } else {
 748           status = STATUS_SUCCESS_FROM_NETWORK;
 749           UMA_HISTOGRAM_TIMES("Net.Prefetch.TimeSpentPrefetchingFromNetwork",
 750                               total_time);
 751         }
 752         break;
 753       case net::URLRequestStatus::CANCELED:
 754         status = STATUS_CANCELED;
 755         UMA_HISTOGRAM_TIMES("Net.Prefetch.TimeBeforeCancel", total_time);
 756         break;
 757       case net::URLRequestStatus::IO_PENDING:
 758       case net::URLRequestStatus::FAILED:
 759         status = STATUS_UNDEFINED;
 760         break;
 761     }
 762
 763     UMA_HISTOGRAM_ENUMERATION("Net.Prefetch.Pattern", status, STATUS_MAX);
 764   }
 765 }
 766
 767 void ResourceLoader::ContinueWithCertificate(net::X509Certificate* cert) {
 768   ssl_client_auth_handler_.reset();
 769   request_->ContinueWithCertificate(cert);
 770 }
 771
 772 }  // namespace content