google_apis/gaia/oauth2_token_service.cc

   1 // Copyright 2013 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 "google_apis/gaia/oauth2_token_service.h"
   6
   7 #include <vector>
   8
   9 #include "base/bind.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "base/message_loop/message_loop.h"
  12 #include "base/rand_util.h"
  13 #include "base/stl_util.h"
  14 #include "base/time/time.h"
  15 #include "base/timer/timer.h"
  16 #include "google_apis/gaia/gaia_urls.h"
  17 #include "google_apis/gaia/google_service_auth_error.h"
  18 #include "google_apis/gaia/oauth2_access_token_fetcher_impl.h"
  19 #include "net/url_request/url_request_context_getter.h"
  20
  21 int OAuth2TokenService::max_fetch_retry_num_ = 5;
  22
  23 OAuth2TokenService::RequestParameters::RequestParameters(
  24     const std::string& client_id,
  25     const std::string& account_id,
  26     const ScopeSet& scopes)
  27     : client_id(client_id),
  28       account_id(account_id),
  29       scopes(scopes) {
  30 }
  31
  32 OAuth2TokenService::RequestParameters::~RequestParameters() {
  33 }
  34
  35 bool OAuth2TokenService::RequestParameters::operator<(
  36     const RequestParameters& p) const {
  37   if (client_id < p.client_id)
  38     return true;
  39   else if (p.client_id < client_id)
  40     return false;
  41
  42   if (account_id < p.account_id)
  43     return true;
  44   else if (p.account_id < account_id)
  45     return false;
  46
  47   return scopes < p.scopes;
  48 }
  49
  50 OAuth2TokenService::RequestImpl::RequestImpl(
  51     const std::string& account_id,
  52     OAuth2TokenService::Consumer* consumer)
  53     : account_id_(account_id),
  54       consumer_(consumer) {
  55 }
  56
  57 OAuth2TokenService::RequestImpl::~RequestImpl() {
  58   DCHECK(CalledOnValidThread());
  59 }
  60
  61 std::string OAuth2TokenService::RequestImpl::GetAccountId() const {
  62   return account_id_;
  63 }
  64
  65 std::string OAuth2TokenService::RequestImpl::GetConsumerId() const {
  66   return consumer_->id();
  67 }
  68
  69 void OAuth2TokenService::RequestImpl::InformConsumer(
  70     const GoogleServiceAuthError& error,
  71     const std::string& access_token,
  72     const base::Time& expiration_date) {
  73   DCHECK(CalledOnValidThread());
  74   if (error.state() == GoogleServiceAuthError::NONE)
  75     consumer_->OnGetTokenSuccess(this, access_token, expiration_date);
  76   else
  77     consumer_->OnGetTokenFailure(this, error);
  78 }
  79
  80 OAuth2TokenService::ScopedBacthChange::ScopedBacthChange(
  81     OAuth2TokenService* token_service) : token_service_(token_service) {
  82   DCHECK(token_service_);
  83   token_service_->StartBatchChanges();
  84 }
  85
  86 OAuth2TokenService::ScopedBacthChange::~ScopedBacthChange() {
  87   token_service_->EndBatchChanges();
  88 }
  89
  90 // Class that fetches an OAuth2 access token for a given account id and set of
  91 // scopes.
  92 //
  93 // It aims to meet OAuth2TokenService's requirements on token fetching. Retry
  94 // mechanism is used to handle failures.
  95 //
  96 // To use this class, call CreateAndStart() to create and start a Fetcher.
  97 //
  98 // The Fetcher will call back the service by calling
  99 // OAuth2TokenService::OnFetchComplete() when it completes fetching, if it is
 100 // not destructed before it completes fetching; if the Fetcher is destructed
 101 // before it completes fetching, the service will never be called back. The
 102 // Fetcher destructs itself after calling back the service when finishes
 103 // fetching.
 104 //
 105 // Requests that are waiting for the fetching results of this Fetcher can be
 106 // added to the Fetcher by calling
 107 // OAuth2TokenService::Fetcher::AddWaitingRequest() before the Fetcher
 108 // completes fetching.
 109 //
 110 // The waiting requests are taken as weak pointers and they can be deleted.
 111 // The waiting requests will be called back with fetching results if they are
 112 // not deleted
 113 // - when the Fetcher completes fetching, if the Fetcher is not destructed
 114 //   before it completes fetching, or
 115 // - when the Fetcher is destructed if the Fetcher is destructed before it
 116 //   completes fetching (in this case, the waiting requests will be called
 117 //   back with error).
 118 class OAuth2TokenService::Fetcher : public OAuth2AccessTokenConsumer {
 119  public:
 120   // Creates a Fetcher and starts fetching an OAuth2 access token for
 121   // |account_id| and |scopes| in the request context obtained by |getter|.
 122   // The given |oauth2_token_service| will be informed when fetching is done.
 123   static Fetcher* CreateAndStart(OAuth2TokenService* oauth2_token_service,
 124                                  const std::string& account_id,
 125                                  net::URLRequestContextGetter* getter,
 126                                  const std::string& client_id,
 127                                  const std::string& client_secret,
 128                                  const ScopeSet& scopes,
 129                                  base::WeakPtr<RequestImpl> waiting_request);
 130   virtual ~Fetcher();
 131
 132   // Add a request that is waiting for the result of this Fetcher.
 133   void AddWaitingRequest(base::WeakPtr<RequestImpl> waiting_request);
 134
 135   // Returns count of waiting requests.
 136   size_t GetWaitingRequestCount() const;
 137
 138   const std::vector<base::WeakPtr<RequestImpl> >& waiting_requests() const {
 139     return waiting_requests_;
 140   }
 141
 142   void Cancel();
 143
 144   const ScopeSet& GetScopeSet() const;
 145   const std::string& GetClientId() const;
 146   const std::string& GetAccountId() const;
 147
 148   // The error result from this fetcher.
 149   const GoogleServiceAuthError& error() const { return error_; }
 150
 151  protected:
 152    // OAuth2AccessTokenConsumer
 153   virtual void OnGetTokenSuccess(const std::string& access_token,
 154                                  const base::Time& expiration_date) OVERRIDE;
 155   virtual void OnGetTokenFailure(
 156       const GoogleServiceAuthError& error) OVERRIDE;
 157
 158  private:
 159   Fetcher(OAuth2TokenService* oauth2_token_service,
 160           const std::string& account_id,
 161           net::URLRequestContextGetter* getter,
 162           const std::string& client_id,
 163           const std::string& client_secret,
 164           const OAuth2TokenService::ScopeSet& scopes,
 165           base::WeakPtr<RequestImpl> waiting_request);
 166   void Start();
 167   void InformWaitingRequests();
 168   void InformWaitingRequestsAndDelete();
 169   static bool ShouldRetry(const GoogleServiceAuthError& error);
 170   int64 ComputeExponentialBackOffMilliseconds(int retry_num);
 171
 172   // |oauth2_token_service_| remains valid for the life of this Fetcher, since
 173   // this Fetcher is destructed in the dtor of the OAuth2TokenService or is
 174   // scheduled for deletion at the end of OnGetTokenFailure/OnGetTokenSuccess
 175   // (whichever comes first).
 176   OAuth2TokenService* const oauth2_token_service_;
 177   scoped_refptr<net::URLRequestContextGetter> getter_;
 178   const std::string account_id_;
 179   const ScopeSet scopes_;
 180   std::vector<base::WeakPtr<RequestImpl> > waiting_requests_;
 181
 182   int retry_number_;
 183   base::OneShotTimer<Fetcher> retry_timer_;
 184   scoped_ptr<OAuth2AccessTokenFetcher> fetcher_;
 185
 186   // Variables that store fetch results.
 187   // Initialized to be GoogleServiceAuthError::SERVICE_UNAVAILABLE to handle
 188   // destruction.
 189   GoogleServiceAuthError error_;
 190   std::string access_token_;
 191   base::Time expiration_date_;
 192
 193   // OAuth2 client id and secret.
 194   std::string client_id_;
 195   std::string client_secret_;
 196
 197   DISALLOW_COPY_AND_ASSIGN(Fetcher);
 198 };
 199
 200 // static
 201 OAuth2TokenService::Fetcher* OAuth2TokenService::Fetcher::CreateAndStart(
 202     OAuth2TokenService* oauth2_token_service,
 203     const std::string& account_id,
 204     net::URLRequestContextGetter* getter,
 205     const std::string& client_id,
 206     const std::string& client_secret,
 207     const OAuth2TokenService::ScopeSet& scopes,
 208     base::WeakPtr<RequestImpl> waiting_request) {
 209   OAuth2TokenService::Fetcher* fetcher = new Fetcher(
 210       oauth2_token_service,
 211       account_id,
 212       getter,
 213       client_id,
 214       client_secret,
 215       scopes,
 216       waiting_request);
 217   fetcher->Start();
 218   return fetcher;
 219 }
 220
 221 OAuth2TokenService::Fetcher::Fetcher(
 222     OAuth2TokenService* oauth2_token_service,
 223     const std::string& account_id,
 224     net::URLRequestContextGetter* getter,
 225     const std::string& client_id,
 226     const std::string& client_secret,
 227     const OAuth2TokenService::ScopeSet& scopes,
 228     base::WeakPtr<RequestImpl> waiting_request)
 229     : oauth2_token_service_(oauth2_token_service),
 230       getter_(getter),
 231       account_id_(account_id),
 232       scopes_(scopes),
 233       retry_number_(0),
 234       error_(GoogleServiceAuthError::SERVICE_UNAVAILABLE),
 235       client_id_(client_id),
 236       client_secret_(client_secret) {
 237   DCHECK(oauth2_token_service_);
 238   DCHECK(getter_.get());
 239   waiting_requests_.push_back(waiting_request);
 240 }
 241
 242 OAuth2TokenService::Fetcher::~Fetcher() {
 243   // Inform the waiting requests if it has not done so.
 244   if (waiting_requests_.size())
 245     InformWaitingRequests();
 246 }
 247
 248 void OAuth2TokenService::Fetcher::Start() {
 249   fetcher_.reset(oauth2_token_service_->CreateAccessTokenFetcher(
 250       account_id_, getter_.get(), this));
 251   DCHECK(fetcher_);
 252   fetcher_->Start(client_id_,
 253                   client_secret_,
 254                   std::vector<std::string>(scopes_.begin(), scopes_.end()));
 255   retry_timer_.Stop();
 256 }
 257
 258 void OAuth2TokenService::Fetcher::OnGetTokenSuccess(
 259     const std::string& access_token,
 260     const base::Time& expiration_date) {
 261   fetcher_.reset();
 262
 263   // Fetch completes.
 264   error_ = GoogleServiceAuthError::AuthErrorNone();
 265   access_token_ = access_token;
 266   expiration_date_ = expiration_date;
 267
 268   // Subclasses may override this method to skip caching in some cases, but
 269   // we still inform all waiting Consumers of a successful token fetch below.
 270   // This is intentional -- some consumers may need the token for cleanup
 271   // tasks. https://chromiumcodereview.appspot.com/11312124/
 272   oauth2_token_service_->RegisterCacheEntry(client_id_,
 273                                             account_id_,
 274                                             scopes_,
 275                                             access_token_,
 276                                             expiration_date_);
 277   InformWaitingRequestsAndDelete();
 278 }
 279
 280 void OAuth2TokenService::Fetcher::OnGetTokenFailure(
 281     const GoogleServiceAuthError& error) {
 282   fetcher_.reset();
 283
 284   if (ShouldRetry(error) && retry_number_ < max_fetch_retry_num_) {
 285     base::TimeDelta backoff = base::TimeDelta::FromMilliseconds(
 286         ComputeExponentialBackOffMilliseconds(retry_number_));
 287     ++retry_number_;
 288     retry_timer_.Stop();
 289     retry_timer_.Start(FROM_HERE,
 290                        backoff,
 291                        this,
 292                        &OAuth2TokenService::Fetcher::Start);
 293     return;
 294   }
 295
 296   error_ = error;
 297   InformWaitingRequestsAndDelete();
 298 }
 299
 300 // Returns an exponential backoff in milliseconds including randomness less than
 301 // 1000 ms when retrying fetching an OAuth2 access token.
 302 int64 OAuth2TokenService::Fetcher::ComputeExponentialBackOffMilliseconds(
 303     int retry_num) {
 304   DCHECK(retry_num < max_fetch_retry_num_);
 305   int64 exponential_backoff_in_seconds = 1 << retry_num;
 306   // Returns a backoff with randomness < 1000ms
 307   return (exponential_backoff_in_seconds + base::RandDouble()) * 1000;
 308 }
 309
 310 // static
 311 bool OAuth2TokenService::Fetcher::ShouldRetry(
 312     const GoogleServiceAuthError& error) {
 313   GoogleServiceAuthError::State error_state = error.state();
 314   return error_state == GoogleServiceAuthError::CONNECTION_FAILED ||
 315          error_state == GoogleServiceAuthError::REQUEST_CANCELED ||
 316          error_state == GoogleServiceAuthError::SERVICE_UNAVAILABLE;
 317 }
 318
 319 void OAuth2TokenService::Fetcher::InformWaitingRequests() {
 320   std::vector<base::WeakPtr<RequestImpl> >::const_iterator iter =
 321       waiting_requests_.begin();
 322   for (; iter != waiting_requests_.end(); ++iter) {
 323     base::WeakPtr<RequestImpl> waiting_request = *iter;
 324     if (waiting_request.get())
 325       waiting_request->InformConsumer(error_, access_token_, expiration_date_);
 326   }
 327   waiting_requests_.clear();
 328 }
 329
 330 void OAuth2TokenService::Fetcher::InformWaitingRequestsAndDelete() {
 331   // Deregisters itself from the service to prevent more waiting requests to
 332   // be added when it calls back the waiting requests.
 333   oauth2_token_service_->OnFetchComplete(this);
 334   InformWaitingRequests();
 335   base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
 336 }
 337
 338 void OAuth2TokenService::Fetcher::AddWaitingRequest(
 339     base::WeakPtr<OAuth2TokenService::RequestImpl> waiting_request) {
 340   waiting_requests_.push_back(waiting_request);
 341 }
 342
 343 size_t OAuth2TokenService::Fetcher::GetWaitingRequestCount() const {
 344   return waiting_requests_.size();
 345 }
 346
 347 void OAuth2TokenService::Fetcher::Cancel() {
 348   fetcher_.reset();
 349   retry_timer_.Stop();
 350   error_ = GoogleServiceAuthError(GoogleServiceAuthError::REQUEST_CANCELED);
 351   InformWaitingRequestsAndDelete();
 352 }
 353
 354 const OAuth2TokenService::ScopeSet& OAuth2TokenService::Fetcher::GetScopeSet()
 355     const {
 356   return scopes_;
 357 }
 358
 359 const std::string& OAuth2TokenService::Fetcher::GetClientId() const {
 360   return client_id_;
 361 }
 362
 363 const std::string& OAuth2TokenService::Fetcher::GetAccountId() const {
 364   return account_id_;
 365 }
 366
 367 OAuth2TokenService::Request::Request() {
 368 }
 369
 370 OAuth2TokenService::Request::~Request() {
 371 }
 372
 373 OAuth2TokenService::Consumer::Consumer(const std::string& id)
 374     : id_(id) {}
 375
 376 OAuth2TokenService::Consumer::~Consumer() {
 377 }
 378
 379 OAuth2TokenService::OAuth2TokenService() : batch_change_depth_(0) {
 380 }
 381
 382 OAuth2TokenService::~OAuth2TokenService() {
 383   // Release all the pending fetchers.
 384   STLDeleteContainerPairSecondPointers(
 385       pending_fetchers_.begin(), pending_fetchers_.end());
 386 }
 387
 388 void OAuth2TokenService::AddObserver(Observer* observer) {
 389   observer_list_.AddObserver(observer);
 390 }
 391
 392 void OAuth2TokenService::RemoveObserver(Observer* observer) {
 393   observer_list_.RemoveObserver(observer);
 394 }
 395
 396 void OAuth2TokenService::AddDiagnosticsObserver(DiagnosticsObserver* observer) {
 397   diagnostics_observer_list_.AddObserver(observer);
 398 }
 399
 400 void OAuth2TokenService::RemoveDiagnosticsObserver(
 401     DiagnosticsObserver* observer) {
 402   diagnostics_observer_list_.RemoveObserver(observer);
 403 }
 404
 405 std::vector<std::string> OAuth2TokenService::GetAccounts() {
 406   return std::vector<std::string>();
 407 }
 408
 409 scoped_ptr<OAuth2TokenService::Request> OAuth2TokenService::StartRequest(
 410     const std::string& account_id,
 411     const OAuth2TokenService::ScopeSet& scopes,
 412     OAuth2TokenService::Consumer* consumer) {
 413   return StartRequestForClientWithContext(
 414       account_id,
 415       GetRequestContext(),
 416       GaiaUrls::GetInstance()->oauth2_chrome_client_id(),
 417       GaiaUrls::GetInstance()->oauth2_chrome_client_secret(),
 418       scopes,
 419       consumer);
 420 }
 421
 422 scoped_ptr<OAuth2TokenService::Request>
 423 OAuth2TokenService::StartRequestForClient(
 424     const std::string& account_id,
 425     const std::string& client_id,
 426     const std::string& client_secret,
 427     const OAuth2TokenService::ScopeSet& scopes,
 428     OAuth2TokenService::Consumer* consumer) {
 429   return StartRequestForClientWithContext(
 430       account_id,
 431       GetRequestContext(),
 432       client_id,
 433       client_secret,
 434       scopes,
 435       consumer);
 436 }
 437
 438 scoped_ptr<OAuth2TokenService::Request>
 439 OAuth2TokenService::StartRequestWithContext(
 440     const std::string& account_id,
 441     net::URLRequestContextGetter* getter,
 442     const ScopeSet& scopes,
 443     Consumer* consumer) {
 444   return StartRequestForClientWithContext(
 445       account_id,
 446       getter,
 447       GaiaUrls::GetInstance()->oauth2_chrome_client_id(),
 448       GaiaUrls::GetInstance()->oauth2_chrome_client_secret(),
 449       scopes,
 450       consumer);
 451 }
 452
 453 scoped_ptr<OAuth2TokenService::Request>
 454 OAuth2TokenService::StartRequestForClientWithContext(
 455     const std::string& account_id,
 456     net::URLRequestContextGetter* getter,
 457     const std::string& client_id,
 458     const std::string& client_secret,
 459     const ScopeSet& scopes,
 460     Consumer* consumer) {
 461   DCHECK(CalledOnValidThread());
 462
 463   scoped_ptr<RequestImpl> request(new RequestImpl(account_id, consumer));
 464   FOR_EACH_OBSERVER(DiagnosticsObserver, diagnostics_observer_list_,
 465                     OnAccessTokenRequested(account_id,
 466                                            consumer->id(),
 467                                            scopes));
 468
 469   if (!RefreshTokenIsAvailable(account_id)) {
 470     GoogleServiceAuthError error(GoogleServiceAuthError::USER_NOT_SIGNED_UP);
 471
 472     FOR_EACH_OBSERVER(DiagnosticsObserver, diagnostics_observer_list_,
 473                       OnFetchAccessTokenComplete(
 474                           account_id, consumer->id(), scopes, error,
 475                           base::Time()));
 476
 477     base::MessageLoop::current()->PostTask(FROM_HERE, base::Bind(
 478         &RequestImpl::InformConsumer,
 479         request->AsWeakPtr(),
 480         error,
 481         std::string(),
 482         base::Time()));
 483     return request.PassAs<Request>();
 484   }
 485
 486   RequestParameters request_parameters(client_id,
 487                                        account_id,
 488                                        scopes);
 489   if (HasCacheEntry(request_parameters)) {
 490     StartCacheLookupRequest(request.get(), request_parameters, consumer);
 491   } else {
 492     FetchOAuth2Token(request.get(),
 493                      account_id,
 494                      getter,
 495                      client_id,
 496                      client_secret,
 497                      scopes);
 498   }
 499   return request.PassAs<Request>();
 500 }
 501
 502 void OAuth2TokenService::FetchOAuth2Token(RequestImpl* request,
 503                                           const std::string& account_id,
 504                                           net::URLRequestContextGetter* getter,
 505                                           const std::string& client_id,
 506                                           const std::string& client_secret,
 507                                           const ScopeSet& scopes) {
 508   // If there is already a pending fetcher for |scopes| and |account_id|,
 509   // simply register this |request| for those results rather than starting
 510   // a new fetcher.
 511   RequestParameters request_parameters = RequestParameters(client_id,
 512                                                            account_id,
 513                                                            scopes);
 514   std::map<RequestParameters, Fetcher*>::iterator iter =
 515       pending_fetchers_.find(request_parameters);
 516   if (iter != pending_fetchers_.end()) {
 517     iter->second->AddWaitingRequest(request->AsWeakPtr());
 518     return;
 519   }
 520
 521   pending_fetchers_[request_parameters] =
 522       Fetcher::CreateAndStart(this,
 523                               account_id,
 524                               getter,
 525                               client_id,
 526                               client_secret,
 527                               scopes,
 528                               request->AsWeakPtr());
 529 }
 530
 531 void OAuth2TokenService::StartCacheLookupRequest(
 532     RequestImpl* request,
 533     const OAuth2TokenService::RequestParameters& request_parameters,
 534     OAuth2TokenService::Consumer* consumer) {
 535   CHECK(HasCacheEntry(request_parameters));
 536   const CacheEntry* cache_entry = GetCacheEntry(request_parameters);
 537   FOR_EACH_OBSERVER(DiagnosticsObserver, diagnostics_observer_list_,
 538                     OnFetchAccessTokenComplete(
 539                         request_parameters.account_id,
 540                         consumer->id(),
 541                         request_parameters.scopes,
 542                         GoogleServiceAuthError::AuthErrorNone(),
 543                         cache_entry->expiration_date));
 544   base::MessageLoop::current()->PostTask(FROM_HERE, base::Bind(
 545       &RequestImpl::InformConsumer,
 546       request->AsWeakPtr(),
 547       GoogleServiceAuthError(GoogleServiceAuthError::NONE),
 548       cache_entry->access_token,
 549       cache_entry->expiration_date));
 550 }
 551
 552 void OAuth2TokenService::InvalidateToken(const std::string& account_id,
 553                                          const ScopeSet& scopes,
 554                                          const std::string& access_token) {
 555   InvalidateOAuth2Token(account_id,
 556                         GaiaUrls::GetInstance()->oauth2_chrome_client_id(),
 557                         scopes,
 558                         access_token);
 559 }
 560
 561 void OAuth2TokenService::InvalidateTokenForClient(
 562     const std::string& account_id,
 563     const std::string& client_id,
 564     const ScopeSet& scopes,
 565     const std::string& access_token) {
 566   InvalidateOAuth2Token(account_id, client_id, scopes, access_token);
 567 }
 568
 569 void OAuth2TokenService::InvalidateOAuth2Token(
 570     const std::string& account_id,
 571     const std::string& client_id,
 572     const ScopeSet& scopes,
 573     const std::string& access_token) {
 574   DCHECK(CalledOnValidThread());
 575   RemoveCacheEntry(
 576       RequestParameters(client_id,
 577                         account_id,
 578                         scopes),
 579       access_token);
 580 }
 581
 582 void OAuth2TokenService::OnFetchComplete(Fetcher* fetcher) {
 583   DCHECK(CalledOnValidThread());
 584
 585   // Update the auth error state so auth errors are appropriately communicated
 586   // to the user.
 587   UpdateAuthError(fetcher->GetAccountId(), fetcher->error());
 588
 589   // Note |fetcher| is recorded in |pending_fetcher_| mapped to its refresh
 590   // token and scope set. This is guaranteed as follows; here a Fetcher is said
 591   // to be uncompleted if it has not finished calling back
 592   // OAuth2TokenService::OnFetchComplete().
 593   //
 594   // (1) All the live Fetchers are created by this service.
 595   //     This is because (1) all the live Fetchers are created by a live
 596   //     service, as all the fetchers created by a service are destructed in the
 597   //     service's dtor.
 598   //
 599   // (2) All the uncompleted Fetchers created by this service are recorded in
 600   //     |pending_fetchers_|.
 601   //     This is because (1) all the created Fetchers are added to
 602   //     |pending_fetchers_| (in method StartRequest()) and (2) method
 603   //     OnFetchComplete() is the only place where a Fetcher is erased from
 604   //     |pending_fetchers_|. Note no Fetcher is erased in method
 605   //     StartRequest().
 606   //
 607   // (3) Each of the Fetchers recorded in |pending_fetchers_| is mapped to its
 608   //     refresh token and ScopeSet. This is guaranteed by Fetcher creation in
 609   //     method StartRequest().
 610   //
 611   // When this method is called, |fetcher| is alive and uncompleted.
 612   // By (1), |fetcher| is created by this service.
 613   // Then by (2), |fetcher| is recorded in |pending_fetchers_|.
 614   // Then by (3), |fetcher_| is mapped to its refresh token and ScopeSet.
 615   RequestParameters request_param(fetcher->GetClientId(),
 616                                   fetcher->GetAccountId(),
 617                                   fetcher->GetScopeSet());
 618
 619   const OAuth2TokenService::CacheEntry* entry = GetCacheEntry(request_param);
 620   const std::vector<base::WeakPtr<RequestImpl> >& requests =
 621       fetcher->waiting_requests();
 622   for (size_t i = 0; i < requests.size(); ++i) {
 623     const RequestImpl* req = requests[i].get();
 624     if (req) {
 625       FOR_EACH_OBSERVER(DiagnosticsObserver, diagnostics_observer_list_,
 626                         OnFetchAccessTokenComplete(
 627                             req->GetAccountId(), req->GetConsumerId(),
 628                             fetcher->GetScopeSet(), fetcher->error(),
 629                             entry ? entry->expiration_date : base::Time()));
 630     }
 631   }
 632
 633   std::map<RequestParameters, Fetcher*>::iterator iter =
 634     pending_fetchers_.find(request_param);
 635   DCHECK(iter != pending_fetchers_.end());
 636   DCHECK_EQ(fetcher, iter->second);
 637   pending_fetchers_.erase(iter);
 638 }
 639
 640 bool OAuth2TokenService::HasCacheEntry(
 641     const RequestParameters& request_parameters) {
 642   const CacheEntry* cache_entry = GetCacheEntry(request_parameters);
 643   return cache_entry && cache_entry->access_token.length();
 644 }
 645
 646 const OAuth2TokenService::CacheEntry* OAuth2TokenService::GetCacheEntry(
 647     const RequestParameters& request_parameters) {
 648   DCHECK(CalledOnValidThread());
 649   TokenCache::iterator token_iterator = token_cache_.find(request_parameters);
 650   if (token_iterator == token_cache_.end())
 651     return NULL;
 652   if (token_iterator->second.expiration_date <= base::Time::Now()) {
 653     token_cache_.erase(token_iterator);
 654     return NULL;
 655   }
 656   return &token_iterator->second;
 657 }
 658
 659 bool OAuth2TokenService::RemoveCacheEntry(
 660     const RequestParameters& request_parameters,
 661     const std::string& token_to_remove) {
 662   DCHECK(CalledOnValidThread());
 663   TokenCache::iterator token_iterator = token_cache_.find(request_parameters);
 664   if (token_iterator != token_cache_.end() &&
 665       token_iterator->second.access_token == token_to_remove) {
 666     FOR_EACH_OBSERVER(DiagnosticsObserver, diagnostics_observer_list_,
 667                       OnTokenRemoved(request_parameters.account_id,
 668                                      request_parameters.scopes));
 669     token_cache_.erase(token_iterator);
 670     return true;
 671   }
 672   return false;
 673 }
 674
 675 void OAuth2TokenService::RegisterCacheEntry(
 676     const std::string& client_id,
 677     const std::string& account_id,
 678     const OAuth2TokenService::ScopeSet& scopes,
 679     const std::string& access_token,
 680     const base::Time& expiration_date) {
 681   DCHECK(CalledOnValidThread());
 682
 683   CacheEntry& token = token_cache_[RequestParameters(client_id,
 684                                                      account_id,
 685                                                      scopes)];
 686   token.access_token = access_token;
 687   token.expiration_date = expiration_date;
 688 }
 689
 690 void OAuth2TokenService::UpdateAuthError(
 691     const std::string& account_id,
 692     const GoogleServiceAuthError& error) {
 693   // Default implementation does nothing.
 694 }
 695
 696 void OAuth2TokenService::ClearCache() {
 697   DCHECK(CalledOnValidThread());
 698   for (TokenCache::iterator iter = token_cache_.begin();
 699        iter != token_cache_.end(); ++iter) {
 700     FOR_EACH_OBSERVER(DiagnosticsObserver, diagnostics_observer_list_,
 701                       OnTokenRemoved(iter->first.account_id,
 702                                      iter->first.scopes));
 703   }
 704
 705   token_cache_.clear();
 706 }
 707
 708 void OAuth2TokenService::ClearCacheForAccount(const std::string& account_id) {
 709   DCHECK(CalledOnValidThread());
 710   for (TokenCache::iterator iter = token_cache_.begin();
 711        iter != token_cache_.end();
 712        /* iter incremented in body */) {
 713     if (iter->first.account_id == account_id) {
 714       FOR_EACH_OBSERVER(DiagnosticsObserver, diagnostics_observer_list_,
 715                         OnTokenRemoved(account_id, iter->first.scopes));
 716       token_cache_.erase(iter++);
 717     } else {
 718       ++iter;
 719     }
 720   }
 721 }
 722
 723 void OAuth2TokenService::CancelAllRequests() {
 724   std::vector<Fetcher*> fetchers_to_cancel;
 725   for (std::map<RequestParameters, Fetcher*>::iterator iter =
 726            pending_fetchers_.begin();
 727        iter != pending_fetchers_.end();
 728        ++iter) {
 729     fetchers_to_cancel.push_back(iter->second);
 730   }
 731   CancelFetchers(fetchers_to_cancel);
 732 }
 733
 734 void OAuth2TokenService::CancelRequestsForAccount(
 735     const std::string& account_id) {
 736   std::vector<Fetcher*> fetchers_to_cancel;
 737   for (std::map<RequestParameters, Fetcher*>::iterator iter =
 738            pending_fetchers_.begin();
 739        iter != pending_fetchers_.end();
 740        ++iter) {
 741     if (iter->first.account_id == account_id)
 742       fetchers_to_cancel.push_back(iter->second);
 743   }
 744   CancelFetchers(fetchers_to_cancel);
 745 }
 746
 747 void OAuth2TokenService::CancelFetchers(
 748     std::vector<Fetcher*> fetchers_to_cancel) {
 749   for (std::vector<OAuth2TokenService::Fetcher*>::iterator iter =
 750            fetchers_to_cancel.begin();
 751        iter != fetchers_to_cancel.end();
 752        ++iter) {
 753     (*iter)->Cancel();
 754   }
 755 }
 756
 757 void OAuth2TokenService::FireRefreshTokenAvailable(
 758     const std::string& account_id) {
 759   FOR_EACH_OBSERVER(Observer, observer_list_,
 760                     OnRefreshTokenAvailable(account_id));
 761 }
 762
 763 void OAuth2TokenService::FireRefreshTokenRevoked(
 764     const std::string& account_id) {
 765   FOR_EACH_OBSERVER(Observer, observer_list_,
 766                     OnRefreshTokenRevoked(account_id));
 767 }
 768
 769 void OAuth2TokenService::FireRefreshTokensLoaded() {
 770   FOR_EACH_OBSERVER(Observer, observer_list_, OnRefreshTokensLoaded());
 771 }
 772
 773 void OAuth2TokenService::StartBatchChanges() {
 774   ++batch_change_depth_;
 775   if (batch_change_depth_ == 1)
 776     FOR_EACH_OBSERVER(Observer, observer_list_, OnStartBatchChanges());
 777 }
 778
 779 void OAuth2TokenService::EndBatchChanges() {
 780   --batch_change_depth_;
 781   DCHECK_LE(0, batch_change_depth_);
 782   if (batch_change_depth_ == 0)
 783     FOR_EACH_OBSERVER(Observer, observer_list_, OnEndBatchChanges());
 784 }
 785
 786 int OAuth2TokenService::cache_size_for_testing() const {
 787   return token_cache_.size();
 788 }
 789
 790 void OAuth2TokenService::set_max_authorization_token_fetch_retries_for_testing(
 791     int max_retries) {
 792   DCHECK(CalledOnValidThread());
 793   max_fetch_retry_num_ = max_retries;
 794 }
 795
 796 size_t OAuth2TokenService::GetNumPendingRequestsForTesting(
 797     const std::string& client_id,
 798     const std::string& account_id,
 799     const ScopeSet& scopes) const {
 800   PendingFetcherMap::const_iterator iter = pending_fetchers_.find(
 801       OAuth2TokenService::RequestParameters(
 802           client_id,
 803           account_id,
 804           scopes));
 805   return iter == pending_fetchers_.end() ?
 806              0 : iter->second->GetWaitingRequestCount();
 807 }