net/url_request/url_fetcher_core.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 "net/url_request/url_fetcher_core.h"
   6
   7 #include <stdint.h>
   8
   9 #include "base/bind.h"
  10 #include "base/logging.h"
  11 #include "base/metrics/histogram.h"
  12 #include "base/profiler/scoped_tracker.h"
  13 #include "base/sequenced_task_runner.h"
  14 #include "base/single_thread_task_runner.h"
  15 #include "base/stl_util.h"
  16 #include "base/thread_task_runner_handle.h"
  17 #include "base/tracked_objects.h"
  18 #include "net/base/elements_upload_data_stream.h"
  19 #include "net/base/io_buffer.h"
  20 #include "net/base/load_flags.h"
  21 #include "net/base/net_errors.h"
  22 #include "net/base/request_priority.h"
  23 #include "net/base/upload_bytes_element_reader.h"
  24 #include "net/base/upload_data_stream.h"
  25 #include "net/base/upload_file_element_reader.h"
  26 #include "net/http/http_response_headers.h"
  27 #include "net/url_request/redirect_info.h"
  28 #include "net/url_request/url_fetcher_delegate.h"
  29 #include "net/url_request/url_fetcher_response_writer.h"
  30 #include "net/url_request/url_request_context.h"
  31 #include "net/url_request/url_request_context_getter.h"
  32 #include "net/url_request/url_request_throttler_manager.h"
  33
  34 namespace {
  35
  36 const int kBufferSize = 4096;
  37 const int kUploadProgressTimerInterval = 100;
  38 bool g_ignore_certificate_requests = false;
  39
  40 void EmptyCompletionCallback(int result) {}
  41
  42 }  // namespace
  43
  44 namespace net {
  45
  46 // URLFetcherCore::Registry ---------------------------------------------------
  47
  48 URLFetcherCore::Registry::Registry() {}
  49 URLFetcherCore::Registry::~Registry() {}
  50
  51 void URLFetcherCore::Registry::AddURLFetcherCore(URLFetcherCore* core) {
  52   DCHECK(!ContainsKey(fetchers_, core));
  53   fetchers_.insert(core);
  54 }
  55
  56 void URLFetcherCore::Registry::RemoveURLFetcherCore(URLFetcherCore* core) {
  57   DCHECK(ContainsKey(fetchers_, core));
  58   fetchers_.erase(core);
  59 }
  60
  61 void URLFetcherCore::Registry::CancelAll() {
  62   while (!fetchers_.empty())
  63     (*fetchers_.begin())->CancelURLRequest(ERR_ABORTED);
  64 }
  65
  66 // URLFetcherCore -------------------------------------------------------------
  67
  68 // static
  69 base::LazyInstance<URLFetcherCore::Registry>
  70     URLFetcherCore::g_registry = LAZY_INSTANCE_INITIALIZER;
  71
  72 URLFetcherCore::URLFetcherCore(URLFetcher* fetcher,
  73                                const GURL& original_url,
  74                                URLFetcher::RequestType request_type,
  75                                URLFetcherDelegate* d)
  76     : fetcher_(fetcher),
  77       original_url_(original_url),
  78       request_type_(request_type),
  79       delegate_(d),
  80       delegate_task_runner_(base::ThreadTaskRunnerHandle::Get()),
  81       load_flags_(LOAD_NORMAL),
  82       response_code_(URLFetcher::RESPONSE_CODE_INVALID),
  83       buffer_(new IOBuffer(kBufferSize)),
  84       url_request_data_key_(NULL),
  85       was_fetched_via_proxy_(false),
  86       upload_content_set_(false),
  87       upload_range_offset_(0),
  88       upload_range_length_(0),
  89       referrer_policy_(
  90           URLRequest::CLEAR_REFERRER_ON_TRANSITION_FROM_SECURE_TO_INSECURE),
  91       is_chunked_upload_(false),
  92       was_cancelled_(false),
  93       stop_on_redirect_(false),
  94       stopped_on_redirect_(false),
  95       automatically_retry_on_5xx_(true),
  96       num_retries_on_5xx_(0),
  97       max_retries_on_5xx_(0),
  98       num_retries_on_network_changes_(0),
  99       max_retries_on_network_changes_(0),
 100       current_upload_bytes_(-1),
 101       current_response_bytes_(0),
 102       total_response_bytes_(-1) {
 103   CHECK(original_url_.is_valid());
 104 }
 105
 106 void URLFetcherCore::Start() {
 107   DCHECK(delegate_task_runner_.get());
 108   DCHECK(request_context_getter_.get()) << "We need an URLRequestContext!";
 109   if (network_task_runner_.get()) {
 110     DCHECK_EQ(network_task_runner_,
 111               request_context_getter_->GetNetworkTaskRunner());
 112   } else {
 113     network_task_runner_ = request_context_getter_->GetNetworkTaskRunner();
 114   }
 115   DCHECK(network_task_runner_.get()) << "We need an IO task runner";
 116
 117   network_task_runner_->PostTask(
 118       FROM_HERE, base::Bind(&URLFetcherCore::StartOnIOThread, this));
 119 }
 120
 121 void URLFetcherCore::Stop() {
 122   if (delegate_task_runner_.get())  // May be NULL in tests.
 123     DCHECK(delegate_task_runner_->BelongsToCurrentThread());
 124
 125   delegate_ = NULL;
 126   fetcher_ = NULL;
 127   if (!network_task_runner_.get())
 128     return;
 129   if (network_task_runner_->RunsTasksOnCurrentThread()) {
 130     CancelURLRequest(ERR_ABORTED);
 131   } else {
 132     network_task_runner_->PostTask(
 133         FROM_HERE,
 134         base::Bind(&URLFetcherCore::CancelURLRequest, this, ERR_ABORTED));
 135   }
 136 }
 137
 138 void URLFetcherCore::SetUploadData(const std::string& upload_content_type,
 139                                    const std::string& upload_content) {
 140   DCHECK(!is_chunked_upload_);
 141   DCHECK(!upload_content_set_);
 142   DCHECK(upload_content_.empty());
 143   DCHECK(upload_file_path_.empty());
 144   DCHECK(upload_content_type_.empty());
 145
 146   // Empty |upload_content_type| is allowed iff the |upload_content| is empty.
 147   DCHECK(upload_content.empty() || !upload_content_type.empty());
 148
 149   upload_content_type_ = upload_content_type;
 150   upload_content_ = upload_content;
 151   upload_content_set_ = true;
 152 }
 153
 154 void URLFetcherCore::SetUploadFilePath(
 155     const std::string& upload_content_type,
 156     const base::FilePath& file_path,
 157     uint64 range_offset,
 158     uint64 range_length,
 159     scoped_refptr<base::TaskRunner> file_task_runner) {
 160   DCHECK(!is_chunked_upload_);
 161   DCHECK(!upload_content_set_);
 162   DCHECK(upload_content_.empty());
 163   DCHECK(upload_file_path_.empty());
 164   DCHECK_EQ(upload_range_offset_, 0ULL);
 165   DCHECK_EQ(upload_range_length_, 0ULL);
 166   DCHECK(upload_content_type_.empty());
 167   DCHECK(!upload_content_type.empty());
 168
 169   upload_content_type_ = upload_content_type;
 170   upload_file_path_ = file_path;
 171   upload_range_offset_ = range_offset;
 172   upload_range_length_ = range_length;
 173   upload_file_task_runner_ = file_task_runner;
 174   upload_content_set_ = true;
 175 }
 176
 177 void URLFetcherCore::SetChunkedUpload(const std::string& content_type) {
 178   DCHECK(is_chunked_upload_ ||
 179          (upload_content_type_.empty() &&
 180           upload_content_.empty()));
 181
 182   // Empty |content_type| is not allowed here, because it is impossible
 183   // to ensure non-empty upload content as it is not yet supplied.
 184   DCHECK(!content_type.empty());
 185
 186   upload_content_type_ = content_type;
 187   upload_content_.clear();
 188   is_chunked_upload_ = true;
 189 }
 190
 191 void URLFetcherCore::AppendChunkToUpload(const std::string& content,
 192                                          bool is_last_chunk) {
 193   DCHECK(delegate_task_runner_.get());
 194   DCHECK(network_task_runner_.get());
 195   network_task_runner_->PostTask(
 196       FROM_HERE,
 197       base::Bind(&URLFetcherCore::CompleteAddingUploadDataChunk, this, content,
 198                  is_last_chunk));
 199 }
 200
 201 void URLFetcherCore::SetLoadFlags(int load_flags) {
 202   load_flags_ = load_flags;
 203 }
 204
 205 int URLFetcherCore::GetLoadFlags() const {
 206   return load_flags_;
 207 }
 208
 209 void URLFetcherCore::SetReferrer(const std::string& referrer) {
 210   referrer_ = referrer;
 211 }
 212
 213 void URLFetcherCore::SetReferrerPolicy(
 214     URLRequest::ReferrerPolicy referrer_policy) {
 215   referrer_policy_ = referrer_policy;
 216 }
 217
 218 void URLFetcherCore::SetExtraRequestHeaders(
 219     const std::string& extra_request_headers) {
 220   extra_request_headers_.Clear();
 221   extra_request_headers_.AddHeadersFromString(extra_request_headers);
 222 }
 223
 224 void URLFetcherCore::AddExtraRequestHeader(const std::string& header_line) {
 225   extra_request_headers_.AddHeaderFromString(header_line);
 226 }
 227
 228 void URLFetcherCore::SetRequestContext(
 229     URLRequestContextGetter* request_context_getter) {
 230   DCHECK(!request_context_getter_.get());
 231   DCHECK(request_context_getter);
 232   request_context_getter_ = request_context_getter;
 233 }
 234
 235 void URLFetcherCore::SetFirstPartyForCookies(
 236     const GURL& first_party_for_cookies) {
 237   DCHECK(first_party_for_cookies_.is_empty());
 238   first_party_for_cookies_ = first_party_for_cookies;
 239 }
 240
 241 void URLFetcherCore::SetURLRequestUserData(
 242     const void* key,
 243     const URLFetcher::CreateDataCallback& create_data_callback) {
 244   DCHECK(key);
 245   DCHECK(!create_data_callback.is_null());
 246   url_request_data_key_ = key;
 247   url_request_create_data_callback_ = create_data_callback;
 248 }
 249
 250 void URLFetcherCore::SetStopOnRedirect(bool stop_on_redirect) {
 251   stop_on_redirect_ = stop_on_redirect;
 252 }
 253
 254 void URLFetcherCore::SetAutomaticallyRetryOn5xx(bool retry) {
 255   automatically_retry_on_5xx_ = retry;
 256 }
 257
 258 void URLFetcherCore::SetMaxRetriesOn5xx(int max_retries) {
 259   max_retries_on_5xx_ = max_retries;
 260 }
 261
 262 int URLFetcherCore::GetMaxRetriesOn5xx() const {
 263   return max_retries_on_5xx_;
 264 }
 265
 266 base::TimeDelta URLFetcherCore::GetBackoffDelay() const {
 267   return backoff_delay_;
 268 }
 269
 270 void URLFetcherCore::SetAutomaticallyRetryOnNetworkChanges(int max_retries) {
 271   max_retries_on_network_changes_ = max_retries;
 272 }
 273
 274 void URLFetcherCore::SaveResponseToFileAtPath(
 275     const base::FilePath& file_path,
 276     scoped_refptr<base::SequencedTaskRunner> file_task_runner) {
 277   DCHECK(delegate_task_runner_->BelongsToCurrentThread());
 278   SaveResponseWithWriter(scoped_ptr<URLFetcherResponseWriter>(
 279       new URLFetcherFileWriter(file_task_runner, file_path)));
 280 }
 281
 282 void URLFetcherCore::SaveResponseToTemporaryFile(
 283     scoped_refptr<base::SequencedTaskRunner> file_task_runner) {
 284   DCHECK(delegate_task_runner_->BelongsToCurrentThread());
 285   SaveResponseWithWriter(scoped_ptr<URLFetcherResponseWriter>(
 286       new URLFetcherFileWriter(file_task_runner, base::FilePath())));
 287 }
 288
 289 void URLFetcherCore::SaveResponseWithWriter(
 290     scoped_ptr<URLFetcherResponseWriter> response_writer) {
 291   DCHECK(delegate_task_runner_->BelongsToCurrentThread());
 292   response_writer_ = response_writer.Pass();
 293 }
 294
 295 HttpResponseHeaders* URLFetcherCore::GetResponseHeaders() const {
 296   return response_headers_.get();
 297 }
 298
 299 // TODO(panayiotis): socket_address_ is written in the IO thread,
 300 // if this is accessed in the UI thread, this could result in a race.
 301 // Same for response_headers_ above and was_fetched_via_proxy_ below.
 302 HostPortPair URLFetcherCore::GetSocketAddress() const {
 303   return socket_address_;
 304 }
 305
 306 bool URLFetcherCore::WasFetchedViaProxy() const {
 307   return was_fetched_via_proxy_;
 308 }
 309
 310 const GURL& URLFetcherCore::GetOriginalURL() const {
 311   return original_url_;
 312 }
 313
 314 const GURL& URLFetcherCore::GetURL() const {
 315   return url_;
 316 }
 317
 318 const URLRequestStatus& URLFetcherCore::GetStatus() const {
 319   return status_;
 320 }
 321
 322 int URLFetcherCore::GetResponseCode() const {
 323   return response_code_;
 324 }
 325
 326 const ResponseCookies& URLFetcherCore::GetCookies() const {
 327   return cookies_;
 328 }
 329
 330 void URLFetcherCore::ReceivedContentWasMalformed() {
 331   DCHECK(delegate_task_runner_->BelongsToCurrentThread());
 332   if (network_task_runner_.get()) {
 333     network_task_runner_->PostTask(
 334         FROM_HERE, base::Bind(&URLFetcherCore::NotifyMalformedContent, this));
 335   }
 336 }
 337
 338 bool URLFetcherCore::GetResponseAsString(
 339     std::string* out_response_string) const {
 340   URLFetcherStringWriter* string_writer =
 341       response_writer_ ? response_writer_->AsStringWriter() : NULL;
 342   if (!string_writer)
 343     return false;
 344
 345   *out_response_string = string_writer->data();
 346   UMA_HISTOGRAM_MEMORY_KB("UrlFetcher.StringResponseSize",
 347                           (string_writer->data().length() / 1024));
 348   return true;
 349 }
 350
 351 bool URLFetcherCore::GetResponseAsFilePath(bool take_ownership,
 352                                            base::FilePath* out_response_path) {
 353   DCHECK(delegate_task_runner_->BelongsToCurrentThread());
 354
 355   URLFetcherFileWriter* file_writer =
 356       response_writer_ ? response_writer_->AsFileWriter() : NULL;
 357   if (!file_writer)
 358     return false;
 359
 360   *out_response_path = file_writer->file_path();
 361
 362   if (take_ownership) {
 363     // Intentionally calling a file_writer_ method directly without posting
 364     // the task to network_task_runner_.
 365     //
 366     // This is for correctly handling the case when file_writer_->DisownFile()
 367     // is soon followed by URLFetcherCore::Stop(). We have to make sure that
 368     // DisownFile takes effect before Stop deletes file_writer_.
 369     //
 370     // This direct call should be thread-safe, since DisownFile itself does no
 371     // file operation. It just flips the state to be referred in destruction.
 372     file_writer->DisownFile();
 373   }
 374   return true;
 375 }
 376
 377 void URLFetcherCore::OnReceivedRedirect(URLRequest* request,
 378                                         const RedirectInfo& redirect_info,
 379                                         bool* defer_redirect) {
 380   DCHECK_EQ(request, request_.get());
 381   DCHECK(network_task_runner_->BelongsToCurrentThread());
 382   if (stop_on_redirect_) {
 383     stopped_on_redirect_ = true;
 384     url_ = redirect_info.new_url;
 385     response_code_ = request_->GetResponseCode();
 386     was_fetched_via_proxy_ = request_->was_fetched_via_proxy();
 387     request->Cancel();
 388     OnReadCompleted(request, 0);
 389   }
 390 }
 391
 392 void URLFetcherCore::OnResponseStarted(URLRequest* request) {
 393   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 394   tracked_objects::ScopedTracker tracking_profile(
 395       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 396           "423948 URLFetcherCore::OnResponseStarted"));
 397
 398   DCHECK_EQ(request, request_.get());
 399   DCHECK(network_task_runner_->BelongsToCurrentThread());
 400   if (request_->status().is_success()) {
 401     response_code_ = request_->GetResponseCode();
 402     response_headers_ = request_->response_headers();
 403     socket_address_ = request_->GetSocketAddress();
 404     was_fetched_via_proxy_ = request_->was_fetched_via_proxy();
 405     total_response_bytes_ = request_->GetExpectedContentSize();
 406   }
 407
 408   ReadResponse();
 409 }
 410
 411 void URLFetcherCore::OnCertificateRequested(
 412     URLRequest* request,
 413     SSLCertRequestInfo* cert_request_info) {
 414   DCHECK_EQ(request, request_.get());
 415   DCHECK(network_task_runner_->BelongsToCurrentThread());
 416
 417   if (g_ignore_certificate_requests) {
 418     request->ContinueWithCertificate(NULL);
 419   } else {
 420     request->Cancel();
 421   }
 422 }
 423
 424 void URLFetcherCore::OnReadCompleted(URLRequest* request,
 425                                      int bytes_read) {
 426   // TODO(vadimt): Remove ScopedTracker below once crbug.com/423948 is fixed.
 427   tracked_objects::ScopedTracker tracking_profile(
 428       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 429           "423948 URLFetcherCore::OnReadCompleted"));
 430
 431   DCHECK(request == request_);
 432   DCHECK(network_task_runner_->BelongsToCurrentThread());
 433
 434   if (!stopped_on_redirect_)
 435     url_ = request->url();
 436   URLRequestThrottlerManager* throttler_manager =
 437       request->context()->throttler_manager();
 438   if (throttler_manager) {
 439     url_throttler_entry_ = throttler_manager->RegisterRequestUrl(url_);
 440   }
 441
 442   do {
 443     if (!request_->status().is_success() || bytes_read <= 0)
 444       break;
 445
 446     current_response_bytes_ += bytes_read;
 447     InformDelegateDownloadProgress();
 448
 449     const int result =
 450         WriteBuffer(new DrainableIOBuffer(buffer_.get(), bytes_read));
 451     if (result < 0) {
 452       // Write failed or waiting for write completion.
 453       return;
 454     }
 455   } while (request_->Read(buffer_.get(), kBufferSize, &bytes_read));
 456
 457   const URLRequestStatus status = request_->status();
 458
 459   if (status.is_success())
 460     request_->GetResponseCookies(&cookies_);
 461
 462   // See comments re: HEAD requests in ReadResponse().
 463   if (!status.is_io_pending() || request_type_ == URLFetcher::HEAD) {
 464     status_ = status;
 465     ReleaseRequest();
 466
 467     // No more data to write.
 468     const int result = response_writer_->Finish(
 469         base::Bind(&URLFetcherCore::DidFinishWriting, this));
 470     if (result != ERR_IO_PENDING)
 471       DidFinishWriting(result);
 472   }
 473 }
 474
 475 void URLFetcherCore::CancelAll() {
 476   g_registry.Get().CancelAll();
 477 }
 478
 479 int URLFetcherCore::GetNumFetcherCores() {
 480   return g_registry.Get().size();
 481 }
 482
 483 void URLFetcherCore::SetIgnoreCertificateRequests(bool ignored) {
 484   g_ignore_certificate_requests = ignored;
 485 }
 486
 487 URLFetcherCore::~URLFetcherCore() {
 488   // |request_| should be NULL. If not, it's unsafe to delete it here since we
 489   // may not be on the IO thread.
 490   DCHECK(!request_.get());
 491 }
 492
 493 void URLFetcherCore::StartOnIOThread() {
 494   DCHECK(network_task_runner_->BelongsToCurrentThread());
 495
 496   if (!response_writer_)
 497     response_writer_.reset(new URLFetcherStringWriter);
 498
 499   const int result = response_writer_->Initialize(
 500       base::Bind(&URLFetcherCore::DidInitializeWriter, this));
 501   if (result != ERR_IO_PENDING)
 502     DidInitializeWriter(result);
 503 }
 504
 505 void URLFetcherCore::StartURLRequest() {
 506   DCHECK(network_task_runner_->BelongsToCurrentThread());
 507
 508   if (was_cancelled_) {
 509     // Since StartURLRequest() is posted as a *delayed* task, it may
 510     // run after the URLFetcher was already stopped.
 511     return;
 512   }
 513
 514   DCHECK(request_context_getter_.get());
 515   DCHECK(!request_.get());
 516
 517   g_registry.Get().AddURLFetcherCore(this);
 518   current_response_bytes_ = 0;
 519   request_ = request_context_getter_->GetURLRequestContext()->CreateRequest(
 520       original_url_, DEFAULT_PRIORITY, this, NULL);
 521   request_->set_stack_trace(stack_trace_);
 522   int flags = request_->load_flags() | load_flags_;
 523
 524   if (is_chunked_upload_)
 525     request_->EnableChunkedUpload();
 526   request_->SetLoadFlags(flags);
 527   request_->SetReferrer(referrer_);
 528   request_->set_referrer_policy(referrer_policy_);
 529   request_->set_first_party_for_cookies(first_party_for_cookies_.is_empty() ?
 530       original_url_ : first_party_for_cookies_);
 531   if (url_request_data_key_ && !url_request_create_data_callback_.is_null()) {
 532     request_->SetUserData(url_request_data_key_,
 533                           url_request_create_data_callback_.Run());
 534   }
 535
 536   switch (request_type_) {
 537     case URLFetcher::GET:
 538       break;
 539
 540     case URLFetcher::POST:
 541     case URLFetcher::PUT:
 542     case URLFetcher::PATCH:
 543       // Upload content must be set.
 544       DCHECK(is_chunked_upload_ || upload_content_set_);
 545
 546       request_->set_method(
 547           request_type_ == URLFetcher::POST ? "POST" :
 548           request_type_ == URLFetcher::PUT ? "PUT" : "PATCH");
 549       if (!upload_content_type_.empty()) {
 550         extra_request_headers_.SetHeader(HttpRequestHeaders::kContentType,
 551                                          upload_content_type_);
 552       }
 553       if (!upload_content_.empty()) {
 554         scoped_ptr<UploadElementReader> reader(new UploadBytesElementReader(
 555             upload_content_.data(), upload_content_.size()));
 556         request_->set_upload(
 557             ElementsUploadDataStream::CreateWithReader(reader.Pass(), 0));
 558       } else if (!upload_file_path_.empty()) {
 559         scoped_ptr<UploadElementReader> reader(
 560             new UploadFileElementReader(upload_file_task_runner_.get(),
 561                                         upload_file_path_,
 562                                         upload_range_offset_,
 563                                         upload_range_length_,
 564                                         base::Time()));
 565         request_->set_upload(
 566             ElementsUploadDataStream::CreateWithReader(reader.Pass(), 0));
 567       }
 568
 569       current_upload_bytes_ = -1;
 570       // TODO(kinaba): http://crbug.com/118103. Implement upload callback in the
 571       //  layer and avoid using timer here.
 572       upload_progress_checker_timer_.reset(
 573           new base::RepeatingTimer<URLFetcherCore>());
 574       upload_progress_checker_timer_->Start(
 575           FROM_HERE,
 576           base::TimeDelta::FromMilliseconds(kUploadProgressTimerInterval),
 577           this,
 578           &URLFetcherCore::InformDelegateUploadProgress);
 579       break;
 580
 581     case URLFetcher::HEAD:
 582       request_->set_method("HEAD");
 583       break;
 584
 585     case URLFetcher::DELETE_REQUEST:
 586       request_->set_method("DELETE");
 587       break;
 588
 589     default:
 590       NOTREACHED();
 591   }
 592
 593   if (!extra_request_headers_.IsEmpty())
 594     request_->SetExtraRequestHeaders(extra_request_headers_);
 595
 596   request_->Start();
 597 }
 598
 599 void URLFetcherCore::DidInitializeWriter(int result) {
 600   if (result != OK) {
 601     CancelURLRequest(result);
 602     delegate_task_runner_->PostTask(
 603         FROM_HERE,
 604         base::Bind(&URLFetcherCore::InformDelegateFetchIsComplete, this));
 605     return;
 606   }
 607   StartURLRequestWhenAppropriate();
 608 }
 609
 610 void URLFetcherCore::StartURLRequestWhenAppropriate() {
 611   DCHECK(network_task_runner_->BelongsToCurrentThread());
 612
 613   if (was_cancelled_)
 614     return;
 615
 616   DCHECK(request_context_getter_.get());
 617
 618   int64 delay = INT64_C(0);
 619   if (!original_url_throttler_entry_.get()) {
 620     URLRequestThrottlerManager* manager =
 621         request_context_getter_->GetURLRequestContext()->throttler_manager();
 622     if (manager) {
 623       original_url_throttler_entry_ =
 624           manager->RegisterRequestUrl(original_url_);
 625     }
 626   }
 627   if (original_url_throttler_entry_.get()) {
 628     delay = original_url_throttler_entry_->ReserveSendingTimeForNextRequest(
 629         GetBackoffReleaseTime());
 630   }
 631
 632   if (delay == INT64_C(0)) {
 633     StartURLRequest();
 634   } else {
 635     base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
 636         FROM_HERE, base::Bind(&URLFetcherCore::StartURLRequest, this),
 637         base::TimeDelta::FromMilliseconds(delay));
 638   }
 639 }
 640
 641 void URLFetcherCore::CancelURLRequest(int error) {
 642   DCHECK(network_task_runner_->BelongsToCurrentThread());
 643
 644   if (request_.get()) {
 645     request_->CancelWithError(error);
 646     ReleaseRequest();
 647   }
 648
 649   // Set the error manually.
 650   // Normally, calling URLRequest::CancelWithError() results in calling
 651   // OnReadCompleted() with bytes_read = -1 via an asynchronous task posted by
 652   // URLRequestJob::NotifyDone(). But, because the request was released
 653   // immediately after being canceled, the request could not call
 654   // OnReadCompleted() which overwrites |status_| with the error status.
 655   status_.set_status(URLRequestStatus::CANCELED);
 656   status_.set_error(error);
 657
 658   // Release the reference to the request context. There could be multiple
 659   // references to URLFetcher::Core at this point so it may take a while to
 660   // delete the object, but we cannot delay the destruction of the request
 661   // context.
 662   request_context_getter_ = NULL;
 663   first_party_for_cookies_ = GURL();
 664   url_request_data_key_ = NULL;
 665   url_request_create_data_callback_.Reset();
 666   was_cancelled_ = true;
 667 }
 668
 669 void URLFetcherCore::OnCompletedURLRequest(
 670     base::TimeDelta backoff_delay) {
 671   DCHECK(delegate_task_runner_->BelongsToCurrentThread());
 672
 673   // Save the status and backoff_delay so that delegates can read it.
 674   if (delegate_) {
 675     backoff_delay_ = backoff_delay;
 676     InformDelegateFetchIsComplete();
 677   }
 678 }
 679
 680 void URLFetcherCore::InformDelegateFetchIsComplete() {
 681   DCHECK(delegate_task_runner_->BelongsToCurrentThread());
 682   if (delegate_)
 683     delegate_->OnURLFetchComplete(fetcher_);
 684 }
 685
 686 void URLFetcherCore::NotifyMalformedContent() {
 687   DCHECK(network_task_runner_->BelongsToCurrentThread());
 688   if (url_throttler_entry_.get()) {
 689     int status_code = response_code_;
 690     if (status_code == URLFetcher::RESPONSE_CODE_INVALID) {
 691       // The status code will generally be known by the time clients
 692       // call the |ReceivedContentWasMalformed()| function (which ends up
 693       // calling the current function) but if it's not, we need to assume
 694       // the response was successful so that the total failure count
 695       // used to calculate exponential back-off goes up.
 696       status_code = 200;
 697     }
 698     url_throttler_entry_->ReceivedContentWasMalformed(status_code);
 699   }
 700 }
 701
 702 void URLFetcherCore::DidFinishWriting(int result) {
 703   if (result != OK) {
 704     CancelURLRequest(result);
 705     delegate_task_runner_->PostTask(
 706         FROM_HERE,
 707         base::Bind(&URLFetcherCore::InformDelegateFetchIsComplete, this));
 708     return;
 709   }
 710   // If the file was successfully closed, then the URL request is complete.
 711   RetryOrCompleteUrlFetch();
 712 }
 713
 714 void URLFetcherCore::RetryOrCompleteUrlFetch() {
 715   DCHECK(network_task_runner_->BelongsToCurrentThread());
 716   base::TimeDelta backoff_delay;
 717
 718   // Checks the response from server.
 719   if (response_code_ >= 500 ||
 720       status_.error() == ERR_TEMPORARILY_THROTTLED) {
 721     // When encountering a server error, we will send the request again
 722     // after backoff time.
 723     ++num_retries_on_5xx_;
 724
 725     // Note that backoff_delay may be 0 because (a) the
 726     // URLRequestThrottlerManager and related code does not
 727     // necessarily back off on the first error, (b) it only backs off
 728     // on some of the 5xx status codes, (c) not all URLRequestContexts
 729     // have a throttler manager.
 730     base::TimeTicks backoff_release_time = GetBackoffReleaseTime();
 731     backoff_delay = backoff_release_time - base::TimeTicks::Now();
 732     if (backoff_delay < base::TimeDelta())
 733       backoff_delay = base::TimeDelta();
 734
 735     if (automatically_retry_on_5xx_ &&
 736         num_retries_on_5xx_ <= max_retries_on_5xx_) {
 737       StartOnIOThread();
 738       return;
 739     }
 740   } else {
 741     backoff_delay = base::TimeDelta();
 742   }
 743
 744   // Retry if the request failed due to network changes.
 745   if (status_.error() == ERR_NETWORK_CHANGED &&
 746       num_retries_on_network_changes_ < max_retries_on_network_changes_) {
 747     ++num_retries_on_network_changes_;
 748
 749     // Retry soon, after flushing all the current tasks which may include
 750     // further network change observers.
 751     network_task_runner_->PostTask(
 752         FROM_HERE, base::Bind(&URLFetcherCore::StartOnIOThread, this));
 753     return;
 754   }
 755
 756   request_context_getter_ = NULL;
 757   first_party_for_cookies_ = GURL();
 758   url_request_data_key_ = NULL;
 759   url_request_create_data_callback_.Reset();
 760   bool posted = delegate_task_runner_->PostTask(
 761       FROM_HERE,
 762       base::Bind(&URLFetcherCore::OnCompletedURLRequest, this, backoff_delay));
 763
 764   // If the delegate message loop does not exist any more, then the delegate
 765   // should be gone too.
 766   DCHECK(posted || !delegate_);
 767 }
 768
 769 void URLFetcherCore::ReleaseRequest() {
 770   upload_progress_checker_timer_.reset();
 771   request_.reset();
 772   g_registry.Get().RemoveURLFetcherCore(this);
 773 }
 774
 775 base::TimeTicks URLFetcherCore::GetBackoffReleaseTime() {
 776   DCHECK(network_task_runner_->BelongsToCurrentThread());
 777
 778   if (!original_url_throttler_entry_.get())
 779     return base::TimeTicks();
 780
 781   base::TimeTicks original_url_backoff =
 782       original_url_throttler_entry_->GetExponentialBackoffReleaseTime();
 783   base::TimeTicks destination_url_backoff;
 784   if (url_throttler_entry_.get() &&
 785       original_url_throttler_entry_.get() != url_throttler_entry_.get()) {
 786     destination_url_backoff =
 787         url_throttler_entry_->GetExponentialBackoffReleaseTime();
 788   }
 789
 790   return original_url_backoff > destination_url_backoff ?
 791       original_url_backoff : destination_url_backoff;
 792 }
 793
 794 void URLFetcherCore::CompleteAddingUploadDataChunk(
 795     const std::string& content, bool is_last_chunk) {
 796   if (was_cancelled_) {
 797     // Since CompleteAddingUploadDataChunk() is posted as a *delayed* task, it
 798     // may run after the URLFetcher was already stopped.
 799     return;
 800   }
 801   DCHECK(is_chunked_upload_);
 802   DCHECK(request_.get());
 803   DCHECK(!content.empty());
 804   request_->AppendChunkToUpload(content.data(),
 805                                 static_cast<int>(content.length()),
 806                                 is_last_chunk);
 807 }
 808
 809 int URLFetcherCore::WriteBuffer(scoped_refptr<DrainableIOBuffer> data) {
 810   while (data->BytesRemaining() > 0) {
 811     const int result = response_writer_->Write(
 812         data.get(),
 813         data->BytesRemaining(),
 814         base::Bind(&URLFetcherCore::DidWriteBuffer, this, data));
 815     if (result < 0) {
 816       if (result != ERR_IO_PENDING)
 817         DidWriteBuffer(data, result);
 818       return result;
 819     }
 820     data->DidConsume(result);
 821   }
 822   return OK;
 823 }
 824
 825 void URLFetcherCore::DidWriteBuffer(scoped_refptr<DrainableIOBuffer> data,
 826                                     int result) {
 827   if (result < 0) {  // Handle errors.
 828     CancelURLRequest(result);
 829     response_writer_->Finish(base::Bind(&EmptyCompletionCallback));
 830     delegate_task_runner_->PostTask(
 831         FROM_HERE,
 832         base::Bind(&URLFetcherCore::InformDelegateFetchIsComplete, this));
 833     return;
 834   }
 835
 836   // Continue writing.
 837   data->DidConsume(result);
 838   if (WriteBuffer(data) < 0)
 839     return;
 840
 841   // Finished writing buffer_. Read some more, unless the request has been
 842   // cancelled and deleted.
 843   DCHECK_EQ(0, data->BytesRemaining());
 844   if (request_.get())
 845     ReadResponse();
 846 }
 847
 848 void URLFetcherCore::ReadResponse() {
 849   // Some servers may treat HEAD requests as GET requests. To free up the
 850   // network connection as soon as possible, signal that the request has
 851   // completed immediately, without trying to read any data back (all we care
 852   // about is the response code and headers, which we already have).
 853   int bytes_read = 0;
 854   if (request_->status().is_success() &&
 855       (request_type_ != URLFetcher::HEAD)) {
 856     if (!request_->Read(buffer_.get(), kBufferSize, &bytes_read))
 857       bytes_read = -1;  // Match OnReadCompleted() interface contract.
 858   }
 859   OnReadCompleted(request_.get(), bytes_read);
 860 }
 861
 862 void URLFetcherCore::InformDelegateUploadProgress() {
 863   DCHECK(network_task_runner_->BelongsToCurrentThread());
 864   if (request_.get()) {
 865     int64 current = request_->GetUploadProgress().position();
 866     if (current_upload_bytes_ != current) {
 867       current_upload_bytes_ = current;
 868       int64 total = -1;
 869       if (!is_chunked_upload_) {
 870         total = static_cast<int64>(request_->GetUploadProgress().size());
 871         // Total may be zero if the UploadDataStream::Init has not been called
 872         // yet. Don't send the upload progress until the size is initialized.
 873         if (!total)
 874           return;
 875       }
 876       delegate_task_runner_->PostTask(
 877           FROM_HERE,
 878           base::Bind(
 879               &URLFetcherCore::InformDelegateUploadProgressInDelegateThread,
 880               this, current, total));
 881     }
 882   }
 883 }
 884
 885 void URLFetcherCore::InformDelegateUploadProgressInDelegateThread(
 886     int64 current, int64 total) {
 887   DCHECK(delegate_task_runner_->BelongsToCurrentThread());
 888   if (delegate_)
 889     delegate_->OnURLFetchUploadProgress(fetcher_, current, total);
 890 }
 891
 892 void URLFetcherCore::InformDelegateDownloadProgress() {
 893   DCHECK(network_task_runner_->BelongsToCurrentThread());
 894   delegate_task_runner_->PostTask(
 895       FROM_HERE,
 896       base::Bind(
 897           &URLFetcherCore::InformDelegateDownloadProgressInDelegateThread,
 898           this, current_response_bytes_, total_response_bytes_));
 899 }
 900
 901 void URLFetcherCore::InformDelegateDownloadProgressInDelegateThread(
 902     int64 current, int64 total) {
 903   DCHECK(delegate_task_runner_->BelongsToCurrentThread());
 904   if (delegate_)
 905     delegate_->OnURLFetchDownloadProgress(fetcher_, current, total);
 906 }
 907
 908 }  // namespace net