src/webkit/browser/appcache/appcache_update_job.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 "webkit/browser/appcache/appcache_update_job.h"
   6
   7 #include "base/bind.h"
   8 #include "base/bind_helpers.h"
   9 #include "base/compiler_specific.h"
  10 #include "base/message_loop/message_loop.h"
  11 #include "base/strings/string_util.h"
  12 #include "base/strings/stringprintf.h"
  13 #include "net/base/io_buffer.h"
  14 #include "net/base/load_flags.h"
  15 #include "net/base/net_errors.h"
  16 #include "net/base/request_priority.h"
  17 #include "net/http/http_request_headers.h"
  18 #include "net/http/http_response_headers.h"
  19 #include "net/url_request/url_request_context.h"
  20 #include "webkit/browser/appcache/appcache_group.h"
  21 #include "webkit/browser/appcache/appcache_histograms.h"
  22
  23 namespace appcache {
  24
  25 static const int kBufferSize = 32768;
  26 static const size_t kMaxConcurrentUrlFetches = 2;
  27 static const int kMax503Retries = 3;
  28
  29 static std::string FormatUrlErrorMessage(
  30       const char* format, const GURL& url,
  31       AppCacheUpdateJob::ResultType error,
  32       int response_code) {
  33     // Show the net response code if we have one.
  34     int code = response_code;
  35     if (error != AppCacheUpdateJob::SERVER_ERROR)
  36       code = static_cast<int>(error);
  37     return base::StringPrintf(format, code, url.spec().c_str());
  38 }
  39
  40 // Helper class for collecting hosts per frontend when sending notifications
  41 // so that only one notification is sent for all hosts using the same frontend.
  42 class HostNotifier {
  43  public:
  44   typedef std::vector<int> HostIds;
  45   typedef std::map<AppCacheFrontend*, HostIds> NotifyHostMap;
  46
  47   // Caller is responsible for ensuring there will be no duplicate hosts.
  48   void AddHost(AppCacheHost* host) {
  49     std::pair<NotifyHostMap::iterator , bool> ret = hosts_to_notify.insert(
  50         NotifyHostMap::value_type(host->frontend(), HostIds()));
  51     ret.first->second.push_back(host->host_id());
  52   }
  53
  54   void AddHosts(const std::set<AppCacheHost*>& hosts) {
  55     for (std::set<AppCacheHost*>::const_iterator it = hosts.begin();
  56          it != hosts.end(); ++it) {
  57       AddHost(*it);
  58     }
  59   }
  60
  61   void SendNotifications(EventID event_id) {
  62     for (NotifyHostMap::iterator it = hosts_to_notify.begin();
  63          it != hosts_to_notify.end(); ++it) {
  64       AppCacheFrontend* frontend = it->first;
  65       frontend->OnEventRaised(it->second, event_id);
  66     }
  67   }
  68
  69   void SendProgressNotifications(
  70       const GURL& url, int num_total, int num_complete) {
  71     for (NotifyHostMap::iterator it = hosts_to_notify.begin();
  72          it != hosts_to_notify.end(); ++it) {
  73       AppCacheFrontend* frontend = it->first;
  74       frontend->OnProgressEventRaised(it->second, url,
  75                                       num_total, num_complete);
  76     }
  77   }
  78
  79   void SendErrorNotifications(const ErrorDetails& details) {
  80     DCHECK(!details.message.empty());
  81     for (NotifyHostMap::iterator it = hosts_to_notify.begin();
  82          it != hosts_to_notify.end(); ++it) {
  83       AppCacheFrontend* frontend = it->first;
  84       frontend->OnErrorEventRaised(it->second, details);
  85     }
  86   }
  87
  88   void SendLogMessage(const std::string& message) {
  89     for (NotifyHostMap::iterator it = hosts_to_notify.begin();
  90          it != hosts_to_notify.end(); ++it) {
  91       AppCacheFrontend* frontend = it->first;
  92       for (HostIds::iterator id = it->second.begin();
  93            id != it->second.end(); ++id) {
  94         frontend->OnLogMessage(*id, LOG_WARNING, message);
  95       }
  96     }
  97   }
  98
  99  private:
 100   NotifyHostMap hosts_to_notify;
 101 };
 102
 103 AppCacheUpdateJob::UrlToFetch::UrlToFetch(const GURL& url,
 104                                           bool checked,
 105                                           AppCacheResponseInfo* info)
 106     : url(url),
 107       storage_checked(checked),
 108       existing_response_info(info) {
 109 }
 110
 111 AppCacheUpdateJob::UrlToFetch::~UrlToFetch() {
 112 }
 113
 114 // Helper class to fetch resources. Depending on the fetch type,
 115 // can either fetch to an in-memory string or write the response
 116 // data out to the disk cache.
 117 AppCacheUpdateJob::URLFetcher::URLFetcher(const GURL& url,
 118                                           FetchType fetch_type,
 119                                           AppCacheUpdateJob* job)
 120     : url_(url),
 121       job_(job),
 122       fetch_type_(fetch_type),
 123       retry_503_attempts_(0),
 124       buffer_(new net::IOBuffer(kBufferSize)),
 125       request_(job->service_->request_context()
 126                    ->CreateRequest(url, net::DEFAULT_PRIORITY, this, NULL)),
 127       result_(UPDATE_OK),
 128       redirect_response_code_(-1) {}
 129
 130 AppCacheUpdateJob::URLFetcher::~URLFetcher() {
 131 }
 132
 133 void AppCacheUpdateJob::URLFetcher::Start() {
 134   request_->set_first_party_for_cookies(job_->manifest_url_);
 135   request_->SetLoadFlags(request_->load_flags() |
 136                          net::LOAD_DISABLE_INTERCEPT);
 137   if (existing_response_headers_.get())
 138     AddConditionalHeaders(existing_response_headers_.get());
 139   request_->Start();
 140 }
 141
 142 void AppCacheUpdateJob::URLFetcher::OnReceivedRedirect(
 143     net::URLRequest* request, const GURL& new_url,  bool* defer_redirect) {
 144   DCHECK(request_ == request);
 145   // Redirect is not allowed by the update process.
 146   job_->MadeProgress();
 147   redirect_response_code_ = request->GetResponseCode();
 148   request->Cancel();
 149   result_ = REDIRECT_ERROR;
 150   OnResponseCompleted();
 151 }
 152
 153 void AppCacheUpdateJob::URLFetcher::OnResponseStarted(
 154     net::URLRequest *request) {
 155   DCHECK(request == request_);
 156   int response_code = -1;
 157   if (request->status().is_success()) {
 158     response_code = request->GetResponseCode();
 159     job_->MadeProgress();
 160   }
 161   if ((response_code / 100) == 2) {
 162
 163     // See http://code.google.com/p/chromium/issues/detail?id=69594
 164     // We willfully violate the HTML5 spec at this point in order
 165     // to support the appcaching of cross-origin HTTPS resources.
 166     // We've opted for a milder constraint and allow caching unless
 167     // the resource has a "no-store" header. A spec change has been
 168     // requested on the whatwg list.
 169     // TODO(michaeln): Consider doing this for cross-origin HTTP resources too.
 170     if (url_.SchemeIsSecure() &&
 171         url_.GetOrigin() != job_->manifest_url_.GetOrigin()) {
 172       if (request->response_headers()->
 173               HasHeaderValue("cache-control", "no-store")) {
 174         DCHECK_EQ(-1, redirect_response_code_);
 175         request->Cancel();
 176         result_ = SERVER_ERROR;  // Not the best match?
 177         OnResponseCompleted();
 178         return;
 179       }
 180     }
 181
 182     // Write response info to storage for URL fetches. Wait for async write
 183     // completion before reading any response data.
 184     if (fetch_type_ == URL_FETCH || fetch_type_ == MASTER_ENTRY_FETCH) {
 185       response_writer_.reset(job_->CreateResponseWriter());
 186       scoped_refptr<HttpResponseInfoIOBuffer> io_buffer(
 187           new HttpResponseInfoIOBuffer(
 188               new net::HttpResponseInfo(request->response_info())));
 189       response_writer_->WriteInfo(
 190           io_buffer.get(),
 191           base::Bind(&URLFetcher::OnWriteComplete, base::Unretained(this)));
 192     } else {
 193       ReadResponseData();
 194     }
 195   } else {
 196     if (response_code > 0)
 197       result_ = SERVER_ERROR;
 198     else
 199       result_ = NETWORK_ERROR;
 200     OnResponseCompleted();
 201   }
 202 }
 203
 204 void AppCacheUpdateJob::URLFetcher::OnReadCompleted(
 205     net::URLRequest* request, int bytes_read) {
 206   DCHECK(request_ == request);
 207   bool data_consumed = true;
 208   if (request->status().is_success() && bytes_read > 0) {
 209     job_->MadeProgress();
 210     data_consumed = ConsumeResponseData(bytes_read);
 211     if (data_consumed) {
 212       bytes_read = 0;
 213       while (request->Read(buffer_.get(), kBufferSize, &bytes_read)) {
 214         if (bytes_read > 0) {
 215           data_consumed = ConsumeResponseData(bytes_read);
 216           if (!data_consumed)
 217             break;  // wait for async data processing, then read more
 218         } else {
 219           break;
 220         }
 221       }
 222     }
 223   }
 224   if (data_consumed && !request->status().is_io_pending()) {
 225     DCHECK_EQ(UPDATE_OK, result_);
 226     OnResponseCompleted();
 227   }
 228 }
 229
 230 void AppCacheUpdateJob::URLFetcher::AddConditionalHeaders(
 231     const net::HttpResponseHeaders* headers) {
 232   DCHECK(request_.get() && headers);
 233   net::HttpRequestHeaders extra_headers;
 234
 235   // Add If-Modified-Since header if response info has Last-Modified header.
 236   const std::string last_modified = "Last-Modified";
 237   std::string last_modified_value;
 238   headers->EnumerateHeader(NULL, last_modified, &last_modified_value);
 239   if (!last_modified_value.empty()) {
 240     extra_headers.SetHeader(net::HttpRequestHeaders::kIfModifiedSince,
 241                             last_modified_value);
 242   }
 243
 244   // Add If-None-Match header if response info has ETag header.
 245   const std::string etag = "ETag";
 246   std::string etag_value;
 247   headers->EnumerateHeader(NULL, etag, &etag_value);
 248   if (!etag_value.empty()) {
 249     extra_headers.SetHeader(net::HttpRequestHeaders::kIfNoneMatch,
 250                             etag_value);
 251   }
 252   if (!extra_headers.IsEmpty())
 253     request_->SetExtraRequestHeaders(extra_headers);
 254 }
 255
 256 void  AppCacheUpdateJob::URLFetcher::OnWriteComplete(int result) {
 257   if (result < 0) {
 258     request_->Cancel();
 259     result_ = DISKCACHE_ERROR;
 260     OnResponseCompleted();
 261     return;
 262   }
 263   ReadResponseData();
 264 }
 265
 266 void AppCacheUpdateJob::URLFetcher::ReadResponseData() {
 267   InternalUpdateState state = job_->internal_state_;
 268   if (state == CACHE_FAILURE || state == CANCELLED || state == COMPLETED)
 269     return;
 270   int bytes_read = 0;
 271   request_->Read(buffer_.get(), kBufferSize, &bytes_read);
 272   OnReadCompleted(request_.get(), bytes_read);
 273 }
 274
 275 // Returns false if response data is processed asynchronously, in which
 276 // case ReadResponseData will be invoked when it is safe to continue
 277 // reading more response data from the request.
 278 bool AppCacheUpdateJob::URLFetcher::ConsumeResponseData(int bytes_read) {
 279   DCHECK_GT(bytes_read, 0);
 280   switch (fetch_type_) {
 281     case MANIFEST_FETCH:
 282     case MANIFEST_REFETCH:
 283       manifest_data_.append(buffer_->data(), bytes_read);
 284       break;
 285     case URL_FETCH:
 286     case MASTER_ENTRY_FETCH:
 287       DCHECK(response_writer_.get());
 288       response_writer_->WriteData(
 289           buffer_.get(),
 290           bytes_read,
 291           base::Bind(&URLFetcher::OnWriteComplete, base::Unretained(this)));
 292       return false;  // wait for async write completion to continue reading
 293     default:
 294       NOTREACHED();
 295   }
 296   return true;
 297 }
 298
 299 void AppCacheUpdateJob::URLFetcher::OnResponseCompleted() {
 300   if (request_->status().is_success())
 301     job_->MadeProgress();
 302
 303   // Retry for 503s where retry-after is 0.
 304   if (request_->status().is_success() &&
 305       request_->GetResponseCode() == 503 &&
 306       MaybeRetryRequest()) {
 307     return;
 308   }
 309
 310   switch (fetch_type_) {
 311     case MANIFEST_FETCH:
 312       job_->HandleManifestFetchCompleted(this);
 313       break;
 314     case URL_FETCH:
 315       job_->HandleUrlFetchCompleted(this);
 316       break;
 317     case MASTER_ENTRY_FETCH:
 318       job_->HandleMasterEntryFetchCompleted(this);
 319       break;
 320     case MANIFEST_REFETCH:
 321       job_->HandleManifestRefetchCompleted(this);
 322       break;
 323     default:
 324       NOTREACHED();
 325   }
 326
 327   delete this;
 328 }
 329
 330 bool AppCacheUpdateJob::URLFetcher::MaybeRetryRequest() {
 331   if (retry_503_attempts_ >= kMax503Retries ||
 332       !request_->response_headers()->HasHeaderValue("retry-after", "0")) {
 333     return false;
 334   }
 335   ++retry_503_attempts_;
 336   result_ = UPDATE_OK;
 337   request_ = job_->service_->request_context()->CreateRequest(
 338       url_, net::DEFAULT_PRIORITY, this, NULL);
 339   Start();
 340   return true;
 341 }
 342
 343 AppCacheUpdateJob::AppCacheUpdateJob(AppCacheService* service,
 344                                      AppCacheGroup* group)
 345     : service_(service),
 346       manifest_url_(group->manifest_url()),
 347       group_(group),
 348       update_type_(UNKNOWN_TYPE),
 349       internal_state_(FETCH_MANIFEST),
 350       master_entries_completed_(0),
 351       url_fetches_completed_(0),
 352       manifest_fetcher_(NULL),
 353       manifest_has_valid_mime_type_(false),
 354       stored_state_(UNSTORED),
 355       storage_(service->storage()) {
 356     service_->AddObserver(this);
 357 }
 358
 359 AppCacheUpdateJob::~AppCacheUpdateJob() {
 360   if (service_)
 361     service_->RemoveObserver(this);
 362   if (internal_state_ != COMPLETED)
 363     Cancel();
 364
 365   DCHECK(!manifest_fetcher_);
 366   DCHECK(pending_url_fetches_.empty());
 367   DCHECK(!inprogress_cache_.get());
 368   DCHECK(pending_master_entries_.empty());
 369   DCHECK(master_entry_fetches_.empty());
 370
 371   if (group_)
 372     group_->SetUpdateStatus(AppCacheGroup::IDLE);
 373 }
 374
 375 void AppCacheUpdateJob::StartUpdate(AppCacheHost* host,
 376                                     const GURL& new_master_resource) {
 377   DCHECK(group_->update_job() == this);
 378   DCHECK(!group_->is_obsolete());
 379
 380   bool is_new_pending_master_entry = false;
 381   if (!new_master_resource.is_empty()) {
 382     DCHECK(new_master_resource == host->pending_master_entry_url());
 383     DCHECK(!new_master_resource.has_ref());
 384     DCHECK(new_master_resource.GetOrigin() == manifest_url_.GetOrigin());
 385
 386     // Cannot add more to this update if already terminating.
 387     if (IsTerminating()) {
 388       group_->QueueUpdate(host, new_master_resource);
 389       return;
 390     }
 391
 392     std::pair<PendingMasters::iterator, bool> ret =
 393         pending_master_entries_.insert(
 394             PendingMasters::value_type(new_master_resource, PendingHosts()));
 395     is_new_pending_master_entry = ret.second;
 396     ret.first->second.push_back(host);
 397     host->AddObserver(this);
 398   }
 399
 400   // Notify host (if any) if already checking or downloading.
 401   AppCacheGroup::UpdateStatus update_status = group_->update_status();
 402   if (update_status == AppCacheGroup::CHECKING ||
 403       update_status == AppCacheGroup::DOWNLOADING) {
 404     if (host) {
 405       NotifySingleHost(host, CHECKING_EVENT);
 406       if (update_status == AppCacheGroup::DOWNLOADING)
 407         NotifySingleHost(host, DOWNLOADING_EVENT);
 408
 409       // Add to fetch list or an existing entry if already fetched.
 410       if (!new_master_resource.is_empty()) {
 411         AddMasterEntryToFetchList(host, new_master_resource,
 412                                   is_new_pending_master_entry);
 413       }
 414     }
 415     return;
 416   }
 417
 418   // Begin update process for the group.
 419   MadeProgress();
 420   group_->SetUpdateStatus(AppCacheGroup::CHECKING);
 421   if (group_->HasCache()) {
 422     update_type_ = UPGRADE_ATTEMPT;
 423     NotifyAllAssociatedHosts(CHECKING_EVENT);
 424   } else {
 425     update_type_ = CACHE_ATTEMPT;
 426     DCHECK(host);
 427     NotifySingleHost(host, CHECKING_EVENT);
 428   }
 429
 430   if (!new_master_resource.is_empty()) {
 431     AddMasterEntryToFetchList(host, new_master_resource,
 432                               is_new_pending_master_entry);
 433   }
 434
 435   FetchManifest(true);
 436 }
 437
 438 AppCacheResponseWriter* AppCacheUpdateJob::CreateResponseWriter() {
 439   AppCacheResponseWriter* writer =
 440       storage_->CreateResponseWriter(manifest_url_,
 441                                                 group_->group_id());
 442   stored_response_ids_.push_back(writer->response_id());
 443   return writer;
 444 }
 445
 446 void AppCacheUpdateJob::HandleCacheFailure(const ErrorDetails& error_details,
 447                                            ResultType result,
 448                                            const GURL& failed_resource_url) {
 449   // 6.9.4 cache failure steps 2-8.
 450   DCHECK(internal_state_ != CACHE_FAILURE);
 451   DCHECK(!error_details.message.empty());
 452   DCHECK(result != UPDATE_OK);
 453   internal_state_ = CACHE_FAILURE;
 454   LogHistogramStats(result, failed_resource_url);
 455   CancelAllUrlFetches();
 456   CancelAllMasterEntryFetches(error_details);
 457   NotifyAllError(error_details);
 458   DiscardInprogressCache();
 459   internal_state_ = COMPLETED;
 460   DeleteSoon();  // To unwind the stack prior to deletion.
 461 }
 462
 463 void AppCacheUpdateJob::FetchManifest(bool is_first_fetch) {
 464   DCHECK(!manifest_fetcher_);
 465   manifest_fetcher_ = new URLFetcher(
 466      manifest_url_,
 467      is_first_fetch ? URLFetcher::MANIFEST_FETCH :
 468                       URLFetcher::MANIFEST_REFETCH,
 469      this);
 470
 471   // Add any necessary Http headers before sending fetch request.
 472   if (is_first_fetch) {
 473     AppCacheEntry* entry = (update_type_ == UPGRADE_ATTEMPT) ?
 474         group_->newest_complete_cache()->GetEntry(manifest_url_) : NULL;
 475     if (entry) {
 476       // Asynchronously load response info for manifest from newest cache.
 477       storage_->LoadResponseInfo(manifest_url_, group_->group_id(),
 478                                  entry->response_id(), this);
 479     } else {
 480       manifest_fetcher_->Start();
 481     }
 482   } else {
 483     DCHECK(internal_state_ == REFETCH_MANIFEST);
 484     DCHECK(manifest_response_info_.get());
 485     manifest_fetcher_->set_existing_response_headers(
 486         manifest_response_info_->headers.get());
 487     manifest_fetcher_->Start();
 488   }
 489 }
 490
 491
 492 void AppCacheUpdateJob::HandleManifestFetchCompleted(
 493     URLFetcher* fetcher) {
 494   DCHECK_EQ(internal_state_, FETCH_MANIFEST);
 495   DCHECK_EQ(manifest_fetcher_, fetcher);
 496   manifest_fetcher_ = NULL;
 497
 498   net::URLRequest* request = fetcher->request();
 499   int response_code = -1;
 500   bool is_valid_response_code = false;
 501   if (request->status().is_success()) {
 502     response_code = request->GetResponseCode();
 503     is_valid_response_code = (response_code / 100 == 2);
 504
 505     std::string mime_type;
 506     request->GetMimeType(&mime_type);
 507     manifest_has_valid_mime_type_ = (mime_type == "text/cache-manifest");
 508   }
 509
 510   if (is_valid_response_code) {
 511     manifest_data_ = fetcher->manifest_data();
 512     manifest_response_info_.reset(
 513         new net::HttpResponseInfo(request->response_info()));
 514     if (update_type_ == UPGRADE_ATTEMPT)
 515       CheckIfManifestChanged();  // continues asynchronously
 516     else
 517       ContinueHandleManifestFetchCompleted(true);
 518   } else if (response_code == 304 && update_type_ == UPGRADE_ATTEMPT) {
 519     ContinueHandleManifestFetchCompleted(false);
 520   } else if ((response_code == 404 || response_code == 410) &&
 521              update_type_ == UPGRADE_ATTEMPT) {
 522     storage_->MakeGroupObsolete(group_, this, response_code);  // async
 523   } else {
 524     const char* kFormatString = "Manifest fetch failed (%d) %s";
 525     std::string message = FormatUrlErrorMessage(
 526         kFormatString, manifest_url_, fetcher->result(), response_code);
 527     HandleCacheFailure(ErrorDetails(message,
 528                                     appcache::MANIFEST_ERROR,
 529                                     manifest_url_,
 530                                     response_code,
 531                                     false /*is_cross_origin*/),
 532                        fetcher->result(),
 533                        GURL());
 534   }
 535 }
 536
 537 void AppCacheUpdateJob::OnGroupMadeObsolete(AppCacheGroup* group,
 538                                             bool success,
 539                                             int response_code) {
 540   DCHECK(master_entry_fetches_.empty());
 541   CancelAllMasterEntryFetches(ErrorDetails(
 542       "The cache has been made obsolete, "
 543       "the manifest file returned 404 or 410",
 544       appcache::MANIFEST_ERROR,
 545       GURL(),
 546       response_code,
 547       false /*is_cross_origin*/));
 548   if (success) {
 549     DCHECK(group->is_obsolete());
 550     NotifyAllAssociatedHosts(OBSOLETE_EVENT);
 551     internal_state_ = COMPLETED;
 552     MaybeCompleteUpdate();
 553   } else {
 554     // Treat failure to mark group obsolete as a cache failure.
 555     HandleCacheFailure(ErrorDetails("Failed to mark the cache as obsolete",
 556                                     UNKNOWN_ERROR,
 557                                     GURL(),
 558                                     0,
 559                                     false /*is_cross_origin*/),
 560                        DB_ERROR,
 561                        GURL());
 562   }
 563 }
 564
 565 void AppCacheUpdateJob::ContinueHandleManifestFetchCompleted(bool changed) {
 566   DCHECK(internal_state_ == FETCH_MANIFEST);
 567
 568   if (!changed) {
 569     DCHECK(update_type_ == UPGRADE_ATTEMPT);
 570     internal_state_ = NO_UPDATE;
 571
 572     // Wait for pending master entries to download.
 573     FetchMasterEntries();
 574     MaybeCompleteUpdate();  // if not done, run async 6.9.4 step 7 substeps
 575     return;
 576   }
 577
 578   Manifest manifest;
 579   if (!ParseManifest(manifest_url_, manifest_data_.data(),
 580                      manifest_data_.length(),
 581                      manifest_has_valid_mime_type_ ?
 582                         PARSE_MANIFEST_ALLOWING_INTERCEPTS :
 583                         PARSE_MANIFEST_PER_STANDARD,
 584                      manifest)) {
 585     const char* kFormatString = "Failed to parse manifest %s";
 586     const std::string message = base::StringPrintf(kFormatString,
 587         manifest_url_.spec().c_str());
 588     HandleCacheFailure(
 589         ErrorDetails(
 590             message, SIGNATURE_ERROR, GURL(), 0, false /*is_cross_origin*/),
 591         MANIFEST_ERROR,
 592         GURL());
 593     VLOG(1) << message;
 594     return;
 595   }
 596
 597   // Proceed with update process. Section 6.9.4 steps 8-20.
 598   internal_state_ = DOWNLOADING;
 599   inprogress_cache_ = new AppCache(storage_, storage_->NewCacheId());
 600   BuildUrlFileList(manifest);
 601   inprogress_cache_->InitializeWithManifest(&manifest);
 602
 603   // Associate all pending master hosts with the newly created cache.
 604   for (PendingMasters::iterator it = pending_master_entries_.begin();
 605        it != pending_master_entries_.end(); ++it) {
 606     PendingHosts& hosts = it->second;
 607     for (PendingHosts::iterator host_it = hosts.begin();
 608          host_it != hosts.end(); ++host_it) {
 609       (*host_it)
 610           ->AssociateIncompleteCache(inprogress_cache_.get(), manifest_url_);
 611     }
 612   }
 613
 614   if (manifest.did_ignore_intercept_namespaces) {
 615     // Must be done after associating all pending master hosts.
 616     std::string message(
 617         "Ignoring the INTERCEPT section of the application cache manifest "
 618         "because the content type is not text/cache-manifest");
 619     LogConsoleMessageToAll(message);
 620   }
 621
 622   group_->SetUpdateStatus(AppCacheGroup::DOWNLOADING);
 623   NotifyAllAssociatedHosts(DOWNLOADING_EVENT);
 624   FetchUrls();
 625   FetchMasterEntries();
 626   MaybeCompleteUpdate();  // if not done, continues when async fetches complete
 627 }
 628
 629 void AppCacheUpdateJob::HandleUrlFetchCompleted(URLFetcher* fetcher) {
 630   DCHECK(internal_state_ == DOWNLOADING);
 631
 632   net::URLRequest* request = fetcher->request();
 633   const GURL& url = request->original_url();
 634   pending_url_fetches_.erase(url);
 635   NotifyAllProgress(url);
 636   ++url_fetches_completed_;
 637
 638   int response_code = request->status().is_success()
 639                           ? request->GetResponseCode()
 640                           : fetcher->redirect_response_code();
 641
 642   AppCacheEntry& entry = url_file_list_.find(url)->second;
 643
 644   if (response_code / 100 == 2) {
 645     // Associate storage with the new entry.
 646     DCHECK(fetcher->response_writer());
 647     entry.set_response_id(fetcher->response_writer()->response_id());
 648     entry.set_response_size(fetcher->response_writer()->amount_written());
 649     if (!inprogress_cache_->AddOrModifyEntry(url, entry))
 650       duplicate_response_ids_.push_back(entry.response_id());
 651
 652     // TODO(michaeln): Check for <html manifest=xxx>
 653     // See http://code.google.com/p/chromium/issues/detail?id=97930
 654     // if (entry.IsMaster() && !(entry.IsExplicit() || fallback || intercept))
 655     //   if (!manifestAttribute) skip it
 656
 657     // Foreign entries will be detected during cache selection.
 658     // Note: 6.9.4, step 17.9 possible optimization: if resource is HTML or XML
 659     // file whose root element is an html element with a manifest attribute
 660     // whose value doesn't match the manifest url of the application cache
 661     // being processed, mark the entry as being foreign.
 662   } else {
 663     VLOG(1) << "Request status: " << request->status().status()
 664             << " error: " << request->status().error()
 665             << " response code: " << response_code;
 666     if (entry.IsExplicit() || entry.IsFallback() || entry.IsIntercept()) {
 667       if (response_code == 304 && fetcher->existing_entry().has_response_id()) {
 668         // Keep the existing response.
 669         entry.set_response_id(fetcher->existing_entry().response_id());
 670         entry.set_response_size(fetcher->existing_entry().response_size());
 671         inprogress_cache_->AddOrModifyEntry(url, entry);
 672       } else {
 673         const char* kFormatString = "Resource fetch failed (%d) %s";
 674         std::string message = FormatUrlErrorMessage(
 675             kFormatString, url, fetcher->result(), response_code);
 676         ResultType result = fetcher->result();
 677         bool is_cross_origin = url.GetOrigin() != manifest_url_.GetOrigin();
 678         switch (result) {
 679           case DISKCACHE_ERROR:
 680             HandleCacheFailure(
 681                 ErrorDetails(
 682                     message, UNKNOWN_ERROR, GURL(), 0, is_cross_origin),
 683                 result,
 684                 url);
 685             break;
 686           case NETWORK_ERROR:
 687             HandleCacheFailure(
 688                 ErrorDetails(message, RESOURCE_ERROR, url, 0, is_cross_origin),
 689                 result,
 690                 url);
 691             break;
 692           default:
 693             HandleCacheFailure(ErrorDetails(message,
 694                                             RESOURCE_ERROR,
 695                                             url,
 696                                             response_code,
 697                                             is_cross_origin),
 698                                result,
 699                                url);
 700             break;
 701         }
 702         return;
 703       }
 704     } else if (response_code == 404 || response_code == 410) {
 705       // Entry is skipped.  They are dropped from the cache.
 706     } else if (update_type_ == UPGRADE_ATTEMPT &&
 707                fetcher->existing_entry().has_response_id()) {
 708       // Keep the existing response.
 709       // TODO(michaeln): Not sure this is a good idea. This is spec compliant
 710       // but the old resource may or may not be compatible with the new contents
 711       // of the cache. Impossible to know one way or the other.
 712       entry.set_response_id(fetcher->existing_entry().response_id());
 713       entry.set_response_size(fetcher->existing_entry().response_size());
 714       inprogress_cache_->AddOrModifyEntry(url, entry);
 715     }
 716   }
 717
 718   // Fetch another URL now that one request has completed.
 719   DCHECK(internal_state_ != CACHE_FAILURE);
 720   FetchUrls();
 721   MaybeCompleteUpdate();
 722 }
 723
 724 void AppCacheUpdateJob::HandleMasterEntryFetchCompleted(
 725     URLFetcher* fetcher) {
 726   DCHECK(internal_state_ == NO_UPDATE || internal_state_ == DOWNLOADING);
 727
 728   // TODO(jennb): Handle downloads completing during cache failure when update
 729   // no longer fetches master entries directly. For now, we cancel all pending
 730   // master entry fetches when entering cache failure state so this will never
 731   // be called in CACHE_FAILURE state.
 732
 733   net::URLRequest* request = fetcher->request();
 734   const GURL& url = request->original_url();
 735   master_entry_fetches_.erase(url);
 736   ++master_entries_completed_;
 737
 738   int response_code = request->status().is_success()
 739       ? request->GetResponseCode() : -1;
 740
 741   PendingMasters::iterator found = pending_master_entries_.find(url);
 742   DCHECK(found != pending_master_entries_.end());
 743   PendingHosts& hosts = found->second;
 744
 745   // Section 6.9.4. No update case: step 7.3, else step 22.
 746   if (response_code / 100 == 2) {
 747     // Add fetched master entry to the appropriate cache.
 748     AppCache* cache = inprogress_cache_.get() ? inprogress_cache_.get()
 749                                               : group_->newest_complete_cache();
 750     DCHECK(fetcher->response_writer());
 751     AppCacheEntry master_entry(AppCacheEntry::MASTER,
 752                                fetcher->response_writer()->response_id(),
 753                                fetcher->response_writer()->amount_written());
 754     if (cache->AddOrModifyEntry(url, master_entry))
 755       added_master_entries_.push_back(url);
 756     else
 757       duplicate_response_ids_.push_back(master_entry.response_id());
 758
 759     // In no-update case, associate host with the newest cache.
 760     if (!inprogress_cache_.get()) {
 761       // TODO(michaeln): defer until the updated cache has been stored
 762       DCHECK(cache == group_->newest_complete_cache());
 763       for (PendingHosts::iterator host_it = hosts.begin();
 764            host_it != hosts.end(); ++host_it) {
 765         (*host_it)->AssociateCompleteCache(cache);
 766       }
 767     }
 768   } else {
 769     HostNotifier host_notifier;
 770     for (PendingHosts::iterator host_it = hosts.begin();
 771          host_it != hosts.end(); ++host_it) {
 772       AppCacheHost* host = *host_it;
 773       host_notifier.AddHost(host);
 774
 775       // In downloading case, disassociate host from inprogress cache.
 776       if (inprogress_cache_.get())
 777         host->AssociateNoCache(GURL());
 778
 779       host->RemoveObserver(this);
 780     }
 781     hosts.clear();
 782
 783     const char* kFormatString = "Manifest fetch failed (%d) %s";
 784     std::string message = FormatUrlErrorMessage(
 785         kFormatString, request->url(), fetcher->result(), response_code);
 786     host_notifier.SendErrorNotifications(
 787         ErrorDetails(message,
 788                      appcache::MANIFEST_ERROR,
 789                      request->url(),
 790                      response_code,
 791                      false /*is_cross_origin*/));
 792
 793     // In downloading case, update result is different if all master entries
 794     // failed vs. only some failing.
 795     if (inprogress_cache_.get()) {
 796       // Only count successful downloads to know if all master entries failed.
 797       pending_master_entries_.erase(found);
 798       --master_entries_completed_;
 799
 800       // Section 6.9.4, step 22.3.
 801       if (update_type_ == CACHE_ATTEMPT && pending_master_entries_.empty()) {
 802         HandleCacheFailure(ErrorDetails(message,
 803                                         appcache::MANIFEST_ERROR,
 804                                         request->url(),
 805                                         response_code,
 806                                         false /*is_cross_origin*/),
 807                            fetcher->result(),
 808                            GURL());
 809         return;
 810       }
 811     }
 812   }
 813
 814   DCHECK(internal_state_ != CACHE_FAILURE);
 815   FetchMasterEntries();
 816   MaybeCompleteUpdate();
 817 }
 818
 819 void AppCacheUpdateJob::HandleManifestRefetchCompleted(
 820     URLFetcher* fetcher) {
 821   DCHECK(internal_state_ == REFETCH_MANIFEST);
 822   DCHECK(manifest_fetcher_ == fetcher);
 823   manifest_fetcher_ = NULL;
 824
 825   net::URLRequest* request = fetcher->request();
 826   int response_code = request->status().is_success()
 827       ? request->GetResponseCode() : -1;
 828   if (response_code == 304 || manifest_data_ == fetcher->manifest_data()) {
 829     // Only need to store response in storage if manifest is not already
 830     // an entry in the cache.
 831     AppCacheEntry* entry = inprogress_cache_->GetEntry(manifest_url_);
 832     if (entry) {
 833       entry->add_types(AppCacheEntry::MANIFEST);
 834       StoreGroupAndCache();
 835     } else {
 836       manifest_response_writer_.reset(CreateResponseWriter());
 837       scoped_refptr<HttpResponseInfoIOBuffer> io_buffer(
 838           new HttpResponseInfoIOBuffer(manifest_response_info_.release()));
 839       manifest_response_writer_->WriteInfo(
 840           io_buffer.get(),
 841           base::Bind(&AppCacheUpdateJob::OnManifestInfoWriteComplete,
 842                      base::Unretained(this)));
 843     }
 844   } else {
 845     VLOG(1) << "Request status: " << request->status().status()
 846             << " error: " << request->status().error()
 847             << " response code: " << response_code;
 848     ScheduleUpdateRetry(kRerunDelayMs);
 849     if (response_code == 200) {
 850       HandleCacheFailure(ErrorDetails("Manifest changed during update",
 851                                       CHANGED_ERROR,
 852                                       GURL(),
 853                                       0,
 854                                       false /*is_cross_origin*/),
 855                          MANIFEST_ERROR,
 856                          GURL());
 857     } else {
 858       const char* kFormatString = "Manifest re-fetch failed (%d) %s";
 859       std::string message = FormatUrlErrorMessage(
 860           kFormatString, manifest_url_, fetcher->result(), response_code);
 861       HandleCacheFailure(ErrorDetails(message,
 862                                       appcache::MANIFEST_ERROR,
 863                                       GURL(),
 864                                       response_code,
 865                                       false /*is_cross_origin*/),
 866                          fetcher->result(),
 867                          GURL());
 868     }
 869   }
 870 }
 871
 872 void AppCacheUpdateJob::OnManifestInfoWriteComplete(int result) {
 873   if (result > 0) {
 874     scoped_refptr<net::StringIOBuffer> io_buffer(
 875         new net::StringIOBuffer(manifest_data_));
 876     manifest_response_writer_->WriteData(
 877         io_buffer.get(),
 878         manifest_data_.length(),
 879         base::Bind(&AppCacheUpdateJob::OnManifestDataWriteComplete,
 880                    base::Unretained(this)));
 881   } else {
 882     HandleCacheFailure(
 883         ErrorDetails("Failed to write the manifest headers to storage",
 884                      UNKNOWN_ERROR,
 885                      GURL(),
 886                      0,
 887                      false /*is_cross_origin*/),
 888         DISKCACHE_ERROR,
 889         GURL());
 890   }
 891 }
 892
 893 void AppCacheUpdateJob::OnManifestDataWriteComplete(int result) {
 894   if (result > 0) {
 895     AppCacheEntry entry(AppCacheEntry::MANIFEST,
 896         manifest_response_writer_->response_id(),
 897         manifest_response_writer_->amount_written());
 898     if (!inprogress_cache_->AddOrModifyEntry(manifest_url_, entry))
 899       duplicate_response_ids_.push_back(entry.response_id());
 900     StoreGroupAndCache();
 901   } else {
 902     HandleCacheFailure(
 903         ErrorDetails("Failed to write the manifest data to storage",
 904                      UNKNOWN_ERROR,
 905                      GURL(),
 906                      0,
 907                      false /*is_cross_origin*/),
 908         DISKCACHE_ERROR,
 909         GURL());
 910   }
 911 }
 912
 913 void AppCacheUpdateJob::StoreGroupAndCache() {
 914   DCHECK(stored_state_ == UNSTORED);
 915   stored_state_ = STORING;
 916   scoped_refptr<AppCache> newest_cache;
 917   if (inprogress_cache_.get())
 918     newest_cache.swap(inprogress_cache_);
 919   else
 920     newest_cache = group_->newest_complete_cache();
 921   newest_cache->set_update_time(base::Time::Now());
 922
 923   // TODO(michaeln): dcheck is fishing for clues to crbug/95101
 924   DCHECK_EQ(manifest_url_, group_->manifest_url());
 925   storage_->StoreGroupAndNewestCache(group_, newest_cache.get(), this);
 926 }
 927
 928 void AppCacheUpdateJob::OnGroupAndNewestCacheStored(AppCacheGroup* group,
 929                                                     AppCache* newest_cache,
 930                                                     bool success,
 931                                                     bool would_exceed_quota) {
 932   DCHECK(stored_state_ == STORING);
 933   if (success) {
 934     stored_state_ = STORED;
 935     MaybeCompleteUpdate();  // will definitely complete
 936   } else {
 937     stored_state_ = UNSTORED;
 938
 939     // Restore inprogress_cache_ to get the proper events delivered
 940     // and the proper cleanup to occur.
 941     if (newest_cache != group->newest_complete_cache())
 942       inprogress_cache_ = newest_cache;
 943
 944     ResultType result = DB_ERROR;
 945     ErrorReason reason = UNKNOWN_ERROR;
 946     std::string message("Failed to commit new cache to storage");
 947     if (would_exceed_quota) {
 948       message.append(", would exceed quota");
 949       result = QUOTA_ERROR;
 950       reason = appcache::QUOTA_ERROR;
 951     }
 952     HandleCacheFailure(
 953         ErrorDetails(message, reason, GURL(), 0, false /*is_cross_origin*/),
 954         result,
 955         GURL());
 956   }
 957 }
 958
 959 void AppCacheUpdateJob::NotifySingleHost(AppCacheHost* host,
 960                                          EventID event_id) {
 961   std::vector<int> ids(1, host->host_id());
 962   host->frontend()->OnEventRaised(ids, event_id);
 963 }
 964
 965 void AppCacheUpdateJob::NotifyAllAssociatedHosts(EventID event_id) {
 966   HostNotifier host_notifier;
 967   AddAllAssociatedHostsToNotifier(&host_notifier);
 968   host_notifier.SendNotifications(event_id);
 969 }
 970
 971 void AppCacheUpdateJob::NotifyAllProgress(const GURL& url) {
 972   HostNotifier host_notifier;
 973   AddAllAssociatedHostsToNotifier(&host_notifier);
 974   host_notifier.SendProgressNotifications(
 975       url, url_file_list_.size(), url_fetches_completed_);
 976 }
 977
 978 void AppCacheUpdateJob::NotifyAllFinalProgress() {
 979   DCHECK(url_file_list_.size() == url_fetches_completed_);
 980   NotifyAllProgress(GURL());
 981 }
 982
 983 void AppCacheUpdateJob::NotifyAllError(const ErrorDetails& details) {
 984   HostNotifier host_notifier;
 985   AddAllAssociatedHostsToNotifier(&host_notifier);
 986   host_notifier.SendErrorNotifications(details);
 987 }
 988
 989 void AppCacheUpdateJob::LogConsoleMessageToAll(const std::string& message) {
 990   HostNotifier host_notifier;
 991   AddAllAssociatedHostsToNotifier(&host_notifier);
 992   host_notifier.SendLogMessage(message);
 993 }
 994
 995 void AppCacheUpdateJob::AddAllAssociatedHostsToNotifier(
 996     HostNotifier* host_notifier) {
 997   // Collect hosts so we only send one notification per frontend.
 998   // A host can only be associated with a single cache so no need to worry
 999   // about duplicate hosts being added to the notifier.
1000   if (inprogress_cache_.get()) {
1001     DCHECK(internal_state_ == DOWNLOADING || internal_state_ == CACHE_FAILURE);
1002     host_notifier->AddHosts(inprogress_cache_->associated_hosts());
1003   }
1004
1005   AppCacheGroup::Caches old_caches = group_->old_caches();
1006   for (AppCacheGroup::Caches::const_iterator it = old_caches.begin();
1007        it != old_caches.end(); ++it) {
1008     host_notifier->AddHosts((*it)->associated_hosts());
1009   }
1010
1011   AppCache* newest_cache = group_->newest_complete_cache();
1012   if (newest_cache)
1013     host_notifier->AddHosts(newest_cache->associated_hosts());
1014 }
1015
1016 void AppCacheUpdateJob::OnDestructionImminent(AppCacheHost* host) {
1017   // The host is about to be deleted; remove from our collection.
1018   PendingMasters::iterator found =
1019       pending_master_entries_.find(host->pending_master_entry_url());
1020   DCHECK(found != pending_master_entries_.end());
1021   PendingHosts& hosts = found->second;
1022   PendingHosts::iterator it = std::find(hosts.begin(), hosts.end(), host);
1023   DCHECK(it != hosts.end());
1024   hosts.erase(it);
1025 }
1026
1027 void AppCacheUpdateJob::OnServiceReinitialized(
1028     AppCacheStorageReference* old_storage_ref) {
1029   // We continue to use the disabled instance, but arrange for its
1030   // deletion when its no longer needed.
1031   if (old_storage_ref->storage() == storage_)
1032     disabled_storage_reference_ = old_storage_ref;
1033 }
1034
1035 void AppCacheUpdateJob::CheckIfManifestChanged() {
1036   DCHECK(update_type_ == UPGRADE_ATTEMPT);
1037   AppCacheEntry* entry = NULL;
1038   if (group_->newest_complete_cache())
1039     entry = group_->newest_complete_cache()->GetEntry(manifest_url_);
1040   if (!entry) {
1041     // TODO(michaeln): This is just a bandaid to avoid a crash.
1042     // http://code.google.com/p/chromium/issues/detail?id=95101
1043     if (service_->storage() == storage_) {
1044       // Use a local variable because service_ is reset in HandleCacheFailure.
1045       AppCacheService* service = service_;
1046       HandleCacheFailure(
1047           ErrorDetails("Manifest entry not found in existing cache",
1048                        UNKNOWN_ERROR,
1049                        GURL(),
1050                        0,
1051                        false /*is_cross_origin*/),
1052           DB_ERROR,
1053           GURL());
1054       AppCacheHistograms::AddMissingManifestEntrySample();
1055       service->DeleteAppCacheGroup(manifest_url_, net::CompletionCallback());
1056     }
1057     return;
1058   }
1059
1060   // Load manifest data from storage to compare against fetched manifest.
1061   manifest_response_reader_.reset(
1062       storage_->CreateResponseReader(manifest_url_,
1063                                      group_->group_id(),
1064                                      entry->response_id()));
1065   read_manifest_buffer_ = new net::IOBuffer(kBufferSize);
1066   manifest_response_reader_->ReadData(
1067       read_manifest_buffer_.get(),
1068       kBufferSize,
1069       base::Bind(&AppCacheUpdateJob::OnManifestDataReadComplete,
1070                  base::Unretained(this)));  // async read
1071 }
1072
1073 void AppCacheUpdateJob::OnManifestDataReadComplete(int result) {
1074   if (result > 0) {
1075     loaded_manifest_data_.append(read_manifest_buffer_->data(), result);
1076     manifest_response_reader_->ReadData(
1077         read_manifest_buffer_.get(),
1078         kBufferSize,
1079         base::Bind(&AppCacheUpdateJob::OnManifestDataReadComplete,
1080                    base::Unretained(this)));  // read more
1081   } else {
1082     read_manifest_buffer_ = NULL;
1083     manifest_response_reader_.reset();
1084     ContinueHandleManifestFetchCompleted(
1085         result < 0 || manifest_data_ != loaded_manifest_data_);
1086   }
1087 }
1088
1089 void AppCacheUpdateJob::BuildUrlFileList(const Manifest& manifest) {
1090   for (base::hash_set<std::string>::const_iterator it =
1091            manifest.explicit_urls.begin();
1092        it != manifest.explicit_urls.end(); ++it) {
1093     AddUrlToFileList(GURL(*it), AppCacheEntry::EXPLICIT);
1094   }
1095
1096   const std::vector<Namespace>& intercepts =
1097       manifest.intercept_namespaces;
1098   for (std::vector<Namespace>::const_iterator it = intercepts.begin();
1099        it != intercepts.end(); ++it) {
1100     int flags = AppCacheEntry::INTERCEPT;
1101     if (it->is_executable)
1102       flags |= AppCacheEntry::EXECUTABLE;
1103     AddUrlToFileList(it->target_url, flags);
1104   }
1105
1106   const std::vector<Namespace>& fallbacks =
1107       manifest.fallback_namespaces;
1108   for (std::vector<Namespace>::const_iterator it = fallbacks.begin();
1109        it != fallbacks.end(); ++it) {
1110      AddUrlToFileList(it->target_url, AppCacheEntry::FALLBACK);
1111   }
1112
1113   // Add all master entries from newest complete cache.
1114   if (update_type_ == UPGRADE_ATTEMPT) {
1115     const AppCache::EntryMap& entries =
1116         group_->newest_complete_cache()->entries();
1117     for (AppCache::EntryMap::const_iterator it = entries.begin();
1118          it != entries.end(); ++it) {
1119       const AppCacheEntry& entry = it->second;
1120       if (entry.IsMaster())
1121         AddUrlToFileList(it->first, AppCacheEntry::MASTER);
1122     }
1123   }
1124 }
1125
1126 void AppCacheUpdateJob::AddUrlToFileList(const GURL& url, int type) {
1127   std::pair<AppCache::EntryMap::iterator, bool> ret = url_file_list_.insert(
1128       AppCache::EntryMap::value_type(url, AppCacheEntry(type)));
1129
1130   if (ret.second)
1131     urls_to_fetch_.push_back(UrlToFetch(url, false, NULL));
1132   else
1133     ret.first->second.add_types(type);  // URL already exists. Merge types.
1134 }
1135
1136 void AppCacheUpdateJob::FetchUrls() {
1137   DCHECK(internal_state_ == DOWNLOADING);
1138
1139   // Fetch each URL in the list according to section 6.9.4 step 17.1-17.3.
1140   // Fetch up to the concurrent limit. Other fetches will be triggered as each
1141   // each fetch completes.
1142   while (pending_url_fetches_.size() < kMaxConcurrentUrlFetches &&
1143          !urls_to_fetch_.empty()) {
1144     UrlToFetch url_to_fetch = urls_to_fetch_.front();
1145     urls_to_fetch_.pop_front();
1146
1147     AppCache::EntryMap::iterator it = url_file_list_.find(url_to_fetch.url);
1148     DCHECK(it != url_file_list_.end());
1149     AppCacheEntry& entry = it->second;
1150     if (ShouldSkipUrlFetch(entry)) {
1151       NotifyAllProgress(url_to_fetch.url);
1152       ++url_fetches_completed_;
1153     } else if (AlreadyFetchedEntry(url_to_fetch.url, entry.types())) {
1154       NotifyAllProgress(url_to_fetch.url);
1155       ++url_fetches_completed_;  // saved a URL request
1156     } else if (!url_to_fetch.storage_checked &&
1157                MaybeLoadFromNewestCache(url_to_fetch.url, entry)) {
1158       // Continues asynchronously after data is loaded from newest cache.
1159     } else {
1160       URLFetcher* fetcher = new URLFetcher(
1161           url_to_fetch.url, URLFetcher::URL_FETCH, this);
1162       if (url_to_fetch.existing_response_info.get()) {
1163         DCHECK(group_->newest_complete_cache());
1164         AppCacheEntry* existing_entry =
1165             group_->newest_complete_cache()->GetEntry(url_to_fetch.url);
1166         DCHECK(existing_entry);
1167         DCHECK(existing_entry->response_id() ==
1168                url_to_fetch.existing_response_info->response_id());
1169         fetcher->set_existing_response_headers(
1170             url_to_fetch.existing_response_info->http_response_info()->headers
1171                 .get());
1172         fetcher->set_existing_entry(*existing_entry);
1173       }
1174       fetcher->Start();
1175       pending_url_fetches_.insert(
1176           PendingUrlFetches::value_type(url_to_fetch.url, fetcher));
1177     }
1178   }
1179 }
1180
1181 void AppCacheUpdateJob::CancelAllUrlFetches() {
1182   // Cancel any pending URL requests.
1183   for (PendingUrlFetches::iterator it = pending_url_fetches_.begin();
1184        it != pending_url_fetches_.end(); ++it) {
1185     delete it->second;
1186   }
1187
1188   url_fetches_completed_ +=
1189       pending_url_fetches_.size() + urls_to_fetch_.size();
1190   pending_url_fetches_.clear();
1191   urls_to_fetch_.clear();
1192 }
1193
1194 bool AppCacheUpdateJob::ShouldSkipUrlFetch(const AppCacheEntry& entry) {
1195   // 6.6.4 Step 17
1196   // If the resource URL being processed was flagged as neither an
1197   // "explicit entry" nor or a "fallback entry", then the user agent
1198   // may skip this URL.
1199   if (entry.IsExplicit() || entry.IsFallback() || entry.IsIntercept())
1200     return false;
1201
1202   // TODO(jennb): decide if entry should be skipped to expire it from cache
1203   return false;
1204 }
1205
1206 bool AppCacheUpdateJob::AlreadyFetchedEntry(const GURL& url,
1207                                             int entry_type) {
1208   DCHECK(internal_state_ == DOWNLOADING || internal_state_ == NO_UPDATE);
1209   AppCacheEntry* existing =
1210       inprogress_cache_.get() ? inprogress_cache_->GetEntry(url)
1211                               : group_->newest_complete_cache()->GetEntry(url);
1212   if (existing) {
1213     existing->add_types(entry_type);
1214     return true;
1215   }
1216   return false;
1217 }
1218
1219 void AppCacheUpdateJob::AddMasterEntryToFetchList(AppCacheHost* host,
1220                                                   const GURL& url,
1221                                                   bool is_new) {
1222   DCHECK(!IsTerminating());
1223
1224   if (internal_state_ == DOWNLOADING || internal_state_ == NO_UPDATE) {
1225     AppCache* cache;
1226     if (inprogress_cache_.get()) {
1227       // always associate
1228       host->AssociateIncompleteCache(inprogress_cache_.get(), manifest_url_);
1229       cache = inprogress_cache_.get();
1230     } else {
1231       cache = group_->newest_complete_cache();
1232     }
1233
1234     // Update existing entry if it has already been fetched.
1235     AppCacheEntry* entry = cache->GetEntry(url);
1236     if (entry) {
1237       entry->add_types(AppCacheEntry::MASTER);
1238       if (internal_state_ == NO_UPDATE && !inprogress_cache_.get()) {
1239         // only associate if have entry
1240         host->AssociateCompleteCache(cache);
1241       }
1242       if (is_new)
1243         ++master_entries_completed_;  // pretend fetching completed
1244       return;
1245     }
1246   }
1247
1248   // Add to fetch list if not already fetching.
1249   if (master_entry_fetches_.find(url) == master_entry_fetches_.end()) {
1250     master_entries_to_fetch_.insert(url);
1251     if (internal_state_ == DOWNLOADING || internal_state_ == NO_UPDATE)
1252       FetchMasterEntries();
1253   }
1254 }
1255
1256 void AppCacheUpdateJob::FetchMasterEntries() {
1257   DCHECK(internal_state_ == NO_UPDATE || internal_state_ == DOWNLOADING);
1258
1259   // Fetch each master entry in the list, up to the concurrent limit.
1260   // Additional fetches will be triggered as each fetch completes.
1261   while (master_entry_fetches_.size() < kMaxConcurrentUrlFetches &&
1262          !master_entries_to_fetch_.empty()) {
1263     const GURL& url = *master_entries_to_fetch_.begin();
1264
1265     if (AlreadyFetchedEntry(url, AppCacheEntry::MASTER)) {
1266       ++master_entries_completed_;  // saved a URL request
1267
1268       // In no update case, associate hosts to newest cache in group
1269       // now that master entry has been "successfully downloaded".
1270       if (internal_state_ == NO_UPDATE) {
1271         // TODO(michaeln): defer until the updated cache has been stored.
1272         DCHECK(!inprogress_cache_.get());
1273         AppCache* cache = group_->newest_complete_cache();
1274         PendingMasters::iterator found = pending_master_entries_.find(url);
1275         DCHECK(found != pending_master_entries_.end());
1276         PendingHosts& hosts = found->second;
1277         for (PendingHosts::iterator host_it = hosts.begin();
1278              host_it != hosts.end(); ++host_it) {
1279           (*host_it)->AssociateCompleteCache(cache);
1280         }
1281       }
1282     } else {
1283       URLFetcher* fetcher = new URLFetcher(
1284           url, URLFetcher::MASTER_ENTRY_FETCH, this);
1285       fetcher->Start();
1286       master_entry_fetches_.insert(PendingUrlFetches::value_type(url, fetcher));
1287     }
1288
1289     master_entries_to_fetch_.erase(master_entries_to_fetch_.begin());
1290   }
1291 }
1292
1293 void AppCacheUpdateJob::CancelAllMasterEntryFetches(
1294     const ErrorDetails& error_details) {
1295   // For now, cancel all in-progress fetches for master entries and pretend
1296   // all master entries fetches have completed.
1297   // TODO(jennb): Delete this when update no longer fetches master entries
1298   // directly.
1299
1300   // Cancel all in-progress fetches.
1301   for (PendingUrlFetches::iterator it = master_entry_fetches_.begin();
1302        it != master_entry_fetches_.end(); ++it) {
1303     delete it->second;
1304     master_entries_to_fetch_.insert(it->first);  // back in unfetched list
1305   }
1306   master_entry_fetches_.clear();
1307
1308   master_entries_completed_ += master_entries_to_fetch_.size();
1309
1310   // Cache failure steps, step 2.
1311   // Pretend all master entries that have not yet been fetched have completed
1312   // downloading. Unassociate hosts from any appcache and send ERROR event.
1313   HostNotifier host_notifier;
1314   while (!master_entries_to_fetch_.empty()) {
1315     const GURL& url = *master_entries_to_fetch_.begin();
1316     PendingMasters::iterator found = pending_master_entries_.find(url);
1317     DCHECK(found != pending_master_entries_.end());
1318     PendingHosts& hosts = found->second;
1319     for (PendingHosts::iterator host_it = hosts.begin();
1320          host_it != hosts.end(); ++host_it) {
1321       AppCacheHost* host = *host_it;
1322       host->AssociateNoCache(GURL());
1323       host_notifier.AddHost(host);
1324       host->RemoveObserver(this);
1325     }
1326     hosts.clear();
1327
1328     master_entries_to_fetch_.erase(master_entries_to_fetch_.begin());
1329   }
1330   host_notifier.SendErrorNotifications(error_details);
1331 }
1332
1333 bool AppCacheUpdateJob::MaybeLoadFromNewestCache(const GURL& url,
1334                                                  AppCacheEntry& entry) {
1335   if (update_type_ != UPGRADE_ATTEMPT)
1336     return false;
1337
1338   AppCache* newest = group_->newest_complete_cache();
1339   AppCacheEntry* copy_me = newest->GetEntry(url);
1340   if (!copy_me || !copy_me->has_response_id())
1341     return false;
1342
1343   // Load HTTP headers for entry from newest cache.
1344   loading_responses_.insert(
1345       LoadingResponses::value_type(copy_me->response_id(), url));
1346   storage_->LoadResponseInfo(manifest_url_, group_->group_id(),
1347                              copy_me->response_id(),
1348                              this);
1349   // Async: wait for OnResponseInfoLoaded to complete.
1350   return true;
1351 }
1352
1353 void AppCacheUpdateJob::OnResponseInfoLoaded(
1354     AppCacheResponseInfo* response_info, int64 response_id) {
1355   const net::HttpResponseInfo* http_info = response_info ?
1356       response_info->http_response_info() : NULL;
1357
1358   // Needed response info for a manifest fetch request.
1359   if (internal_state_ == FETCH_MANIFEST) {
1360     if (http_info)
1361       manifest_fetcher_->set_existing_response_headers(
1362           http_info->headers.get());
1363     manifest_fetcher_->Start();
1364     return;
1365   }
1366
1367   LoadingResponses::iterator found = loading_responses_.find(response_id);
1368   DCHECK(found != loading_responses_.end());
1369   const GURL& url = found->second;
1370
1371   if (!http_info) {
1372     LoadFromNewestCacheFailed(url, NULL);  // no response found
1373   } else {
1374     // Check if response can be re-used according to HTTP caching semantics.
1375     // Responses with a "vary" header get treated as expired.
1376     const std::string name = "vary";
1377     std::string value;
1378     void* iter = NULL;
1379     if (!http_info->headers.get() ||
1380         http_info->headers->RequiresValidation(http_info->request_time,
1381                                                http_info->response_time,
1382                                                base::Time::Now()) ||
1383         http_info->headers->EnumerateHeader(&iter, name, &value)) {
1384       LoadFromNewestCacheFailed(url, response_info);
1385     } else {
1386       DCHECK(group_->newest_complete_cache());
1387       AppCacheEntry* copy_me = group_->newest_complete_cache()->GetEntry(url);
1388       DCHECK(copy_me);
1389       DCHECK(copy_me->response_id() == response_id);
1390
1391       AppCache::EntryMap::iterator it = url_file_list_.find(url);
1392       DCHECK(it != url_file_list_.end());
1393       AppCacheEntry& entry = it->second;
1394       entry.set_response_id(response_id);
1395       entry.set_response_size(copy_me->response_size());
1396       inprogress_cache_->AddOrModifyEntry(url, entry);
1397       NotifyAllProgress(url);
1398       ++url_fetches_completed_;
1399     }
1400   }
1401   loading_responses_.erase(found);
1402
1403   MaybeCompleteUpdate();
1404 }
1405
1406 void AppCacheUpdateJob::LoadFromNewestCacheFailed(
1407     const GURL& url, AppCacheResponseInfo* response_info) {
1408   if (internal_state_ == CACHE_FAILURE)
1409     return;
1410
1411   // Re-insert url at front of fetch list. Indicate storage has been checked.
1412   urls_to_fetch_.push_front(UrlToFetch(url, true, response_info));
1413   FetchUrls();
1414 }
1415
1416 void AppCacheUpdateJob::MaybeCompleteUpdate() {
1417   DCHECK(internal_state_ != CACHE_FAILURE);
1418
1419   // Must wait for any pending master entries or url fetches to complete.
1420   if (master_entries_completed_ != pending_master_entries_.size() ||
1421       url_fetches_completed_ != url_file_list_.size()) {
1422     DCHECK(internal_state_ != COMPLETED);
1423     return;
1424   }
1425
1426   switch (internal_state_) {
1427     case NO_UPDATE:
1428       if (master_entries_completed_ > 0) {
1429         switch (stored_state_) {
1430           case UNSTORED:
1431             StoreGroupAndCache();
1432             return;
1433           case STORING:
1434             return;
1435           case STORED:
1436             break;
1437         }
1438       }
1439       // 6.9.4 steps 7.3-7.7.
1440       NotifyAllAssociatedHosts(NO_UPDATE_EVENT);
1441       DiscardDuplicateResponses();
1442       internal_state_ = COMPLETED;
1443       break;
1444     case DOWNLOADING:
1445       internal_state_ = REFETCH_MANIFEST;
1446       FetchManifest(false);
1447       break;
1448     case REFETCH_MANIFEST:
1449       DCHECK(stored_state_ == STORED);
1450       NotifyAllFinalProgress();
1451       if (update_type_ == CACHE_ATTEMPT)
1452         NotifyAllAssociatedHosts(CACHED_EVENT);
1453       else
1454         NotifyAllAssociatedHosts(UPDATE_READY_EVENT);
1455       DiscardDuplicateResponses();
1456       internal_state_ = COMPLETED;
1457       LogHistogramStats(UPDATE_OK, GURL());
1458       break;
1459     case CACHE_FAILURE:
1460       NOTREACHED();  // See HandleCacheFailure
1461       break;
1462     default:
1463       break;
1464   }
1465
1466   // Let the stack unwind before deletion to make it less risky as this
1467   // method is called from multiple places in this file.
1468   if (internal_state_ == COMPLETED)
1469     DeleteSoon();
1470 }
1471
1472 void AppCacheUpdateJob::ScheduleUpdateRetry(int delay_ms) {
1473   // TODO(jennb): post a delayed task with the "same parameters" as this job
1474   // to retry the update at a later time. Need group, URLs of pending master
1475   // entries and their hosts.
1476 }
1477
1478 void AppCacheUpdateJob::Cancel() {
1479   internal_state_ = CANCELLED;
1480
1481   LogHistogramStats(CANCELLED_ERROR, GURL());
1482
1483   if (manifest_fetcher_) {
1484     delete manifest_fetcher_;
1485     manifest_fetcher_ = NULL;
1486   }
1487
1488   for (PendingUrlFetches::iterator it = pending_url_fetches_.begin();
1489        it != pending_url_fetches_.end(); ++it) {
1490     delete it->second;
1491   }
1492   pending_url_fetches_.clear();
1493
1494   for (PendingUrlFetches::iterator it = master_entry_fetches_.begin();
1495        it != master_entry_fetches_.end(); ++it) {
1496     delete it->second;
1497   }
1498   master_entry_fetches_.clear();
1499
1500   ClearPendingMasterEntries();
1501   DiscardInprogressCache();
1502
1503   // Delete response writer to avoid any callbacks.
1504   if (manifest_response_writer_)
1505     manifest_response_writer_.reset();
1506
1507   storage_->CancelDelegateCallbacks(this);
1508 }
1509
1510 void AppCacheUpdateJob::ClearPendingMasterEntries() {
1511   for (PendingMasters::iterator it = pending_master_entries_.begin();
1512        it != pending_master_entries_.end(); ++it) {
1513     PendingHosts& hosts = it->second;
1514     for (PendingHosts::iterator host_it = hosts.begin();
1515          host_it != hosts.end(); ++host_it) {
1516       (*host_it)->RemoveObserver(this);
1517     }
1518   }
1519
1520   pending_master_entries_.clear();
1521 }
1522
1523 void AppCacheUpdateJob::DiscardInprogressCache() {
1524   if (stored_state_ == STORING) {
1525     // We can make no assumptions about whether the StoreGroupAndCacheTask
1526     // actually completed or not. This condition should only be reachable
1527     // during shutdown. Free things up and return to do no harm.
1528     inprogress_cache_ = NULL;
1529     added_master_entries_.clear();
1530     return;
1531   }
1532
1533   storage_->DoomResponses(manifest_url_, stored_response_ids_);
1534
1535   if (!inprogress_cache_.get()) {
1536     // We have to undo the changes we made, if any, to the existing cache.
1537     if (group_ && group_->newest_complete_cache()) {
1538       for (std::vector<GURL>::iterator iter = added_master_entries_.begin();
1539            iter != added_master_entries_.end(); ++iter) {
1540         group_->newest_complete_cache()->RemoveEntry(*iter);
1541       }
1542     }
1543     added_master_entries_.clear();
1544     return;
1545   }
1546
1547   AppCache::AppCacheHosts& hosts = inprogress_cache_->associated_hosts();
1548   while (!hosts.empty())
1549     (*hosts.begin())->AssociateNoCache(GURL());
1550
1551   inprogress_cache_ = NULL;
1552   added_master_entries_.clear();
1553 }
1554
1555 void AppCacheUpdateJob::DiscardDuplicateResponses() {
1556   storage_->DoomResponses(manifest_url_, duplicate_response_ids_);
1557 }
1558
1559 void AppCacheUpdateJob::LogHistogramStats(
1560       ResultType result, const GURL& failed_resource_url) {
1561   AppCacheHistograms::CountUpdateJobResult(result, manifest_url_.GetOrigin());
1562   if (result == UPDATE_OK)
1563     return;
1564
1565   int percent_complete = 0;
1566   if (url_file_list_.size() > 0) {
1567     size_t actual_fetches_completed = url_fetches_completed_;
1568     if (!failed_resource_url.is_empty() && actual_fetches_completed)
1569       --actual_fetches_completed;
1570     percent_complete = (static_cast<double>(actual_fetches_completed) /
1571                             static_cast<double>(url_file_list_.size())) * 100.0;
1572     percent_complete = std::min(percent_complete, 99);
1573   }
1574
1575   bool was_making_progress =
1576       base::Time::Now() - last_progress_time_ <
1577           base::TimeDelta::FromMinutes(5);
1578
1579   bool off_origin_resource_failure =
1580       !failed_resource_url.is_empty() &&
1581           (failed_resource_url.GetOrigin() != manifest_url_.GetOrigin());
1582
1583   AppCacheHistograms::LogUpdateFailureStats(
1584       manifest_url_.GetOrigin(),
1585       percent_complete,
1586       was_making_progress,
1587       off_origin_resource_failure);
1588 }
1589
1590 void AppCacheUpdateJob::DeleteSoon() {
1591   ClearPendingMasterEntries();
1592   manifest_response_writer_.reset();
1593   storage_->CancelDelegateCallbacks(this);
1594   service_->RemoveObserver(this);
1595   service_ = NULL;
1596
1597   // Break the connection with the group so the group cannot call delete
1598   // on this object after we've posted a task to delete ourselves.
1599   group_->SetUpdateStatus(AppCacheGroup::IDLE);
1600   group_ = NULL;
1601
1602   base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
1603 }
1604
1605 }  // namespace appcache