chrome/browser/component_updater/component_updater

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This source file includes following definitions.
IsVersionNewer
CanTryDiffUpdate
AppendDownloadMetrics
diff_extra_code1
allow_background_download
UnblockResourceThrottle
UnblockandReapAllThrottles
running_
Start
Stop
HasOnDemandItems
IsOnDemand
ScheduleNextRun
FindUpdateItemById
ChangeItemState
ChangeItemStatus
RegisterComponent
OnDemandUpdate
OnDemandUpdateInternal
GetComponents
ProcessPendingItems
FindReadyComponent
IsReadyOnDemand
IsReady
CheckForUpdates
UpdateComponent
UpdateCheckComplete
OnUpdateCheckSucceeded
OnUpdateCheckFailed
DownloadComplete
Install
EndUnpacking
DoneInstalling
NotifyComponentObservers
GetOnDemandResourceThrottle
OnNewResourceThrottle
WillStartRequest
WillRedirectRequest
GetNameForLogging
Unblock
ComponentUpdateServiceFactory
// Copyright 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/component_updater/component_updater_service.h"

#include <algorithm>
#include <set>
#include <vector>

#include "base/at_exit.h"
#include "base/bind.h"
#include "base/compiler_specific.h"
#include "base/file_util.h"
#include "base/files/file_path.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/memory/weak_ptr.h"
#include "base/sequenced_task_runner.h"
#include "base/stl_util.h"
#include "base/threading/sequenced_worker_pool.h"
#include "base/timer/timer.h"
#include "chrome/browser/browser_process.h"
#include "chrome/browser/component_updater/component_unpacker.h"
#include "chrome/browser/component_updater/component_updater_ping_manager.h"
#include "chrome/browser/component_updater/component_updater_utils.h"
#include "chrome/browser/component_updater/crx_downloader.h"
#include "chrome/browser/component_updater/crx_update_item.h"
#include "chrome/browser/component_updater/update_checker.h"
#include "chrome/browser/component_updater/update_response.h"
#include "chrome/common/chrome_version_info.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/resource_controller.h"
#include "content/public/browser/resource_throttle.h"
#include "url/gurl.h"

using content::BrowserThread;

namespace component_updater {

// The component updater is designed to live until process shutdown, so
// base::Bind() calls are not refcounted.

namespace {

// Returns true if the |proposed| version is newer than |current| version.
bool IsVersionNewer(const Version& current, const std::string& proposed) {
  Version proposed_ver(proposed);
  return proposed_ver.IsValid() && current.CompareTo(proposed_ver) < 0;
}

// Returns true if a differential update is available, it has not failed yet,
// and the configuration allows it.
bool CanTryDiffUpdate(const CrxUpdateItem* update_item,
                      const ComponentUpdateService::Configurator& config) {
  return HasDiffUpdate(update_item) &&
         !update_item->diff_update_failed &&
         config.DeltasEnabled();
}

void AppendDownloadMetrics(
    const std::vector<CrxDownloader::DownloadMetrics>& source,
    std::vector<CrxDownloader::DownloadMetrics>* destination) {
  destination->insert(destination->end(), source.begin(), source.end());
}

}  // namespace

CrxUpdateItem::CrxUpdateItem()
    : status(kNew),
      on_demand(false),
      diff_update_failed(false),
      error_category(0),
      error_code(0),
      extra_code1(0),
      diff_error_category(0),
      diff_error_code(0),
      diff_extra_code1(0) {
}

CrxUpdateItem::~CrxUpdateItem() {
}

CrxComponent::CrxComponent()
    : installer(NULL),
      observer(NULL),
      allow_background_download(true) {
}

CrxComponent::~CrxComponent() {
}

CrxComponentInfo::CrxComponentInfo() {
}

CrxComponentInfo::~CrxComponentInfo() {
}

///////////////////////////////////////////////////////////////////////////////
// In charge of blocking url requests until the |crx_id| component has been
// updated. This class is touched solely from the IO thread. The UI thread
// can post tasks to it via weak pointers. By default the request is blocked
// unless the CrxUpdateService calls Unblock().
// The lifetime is controlled by Chrome's resource loader so the component
// updater cannot touch objects from this class except via weak pointers.
class CUResourceThrottle
    : public content::ResourceThrottle,
      public base::SupportsWeakPtr<CUResourceThrottle> {
 public:
  explicit CUResourceThrottle(const net::URLRequest* request);
  virtual ~CUResourceThrottle();

  // Overriden from ResourceThrottle.
  virtual void WillStartRequest(bool* defer) OVERRIDE;
  virtual void WillRedirectRequest(const GURL& new_url, bool* defer) OVERRIDE;
  virtual const char* GetNameForLogging() const OVERRIDE;

  // Component updater calls this function via PostTask to unblock the request.
  void Unblock();

  typedef std::vector<base::WeakPtr<CUResourceThrottle> > WeakPtrVector;

 private:
  enum State {
    NEW,
    BLOCKED,
    UNBLOCKED
  };

  State state_;
};

void UnblockResourceThrottle(base::WeakPtr<CUResourceThrottle> rt) {
  BrowserThread::PostTask(
      BrowserThread::IO,
      FROM_HERE,
      base::Bind(&CUResourceThrottle::Unblock, rt));
}

void UnblockandReapAllThrottles(CUResourceThrottle::WeakPtrVector* throttles) {
  CUResourceThrottle::WeakPtrVector::iterator it;
  for (it = throttles->begin(); it != throttles->end(); ++it)
    UnblockResourceThrottle(*it);
  throttles->clear();
}

//////////////////////////////////////////////////////////////////////////////
// The one and only implementation of the ComponentUpdateService interface. In
// charge of running the show. The main method is ProcessPendingItems() which
// is called periodically to do the upgrades/installs or the update checks.
// An important consideration here is to be as "low impact" as we can to the
// rest of the browser, so even if we have many components registered and
// eligible for update, we only do one thing at a time with pauses in between
// the tasks. Also when we do network requests there is only one |url_fetcher_|
// in flight at a time.
// There are no locks in this code, the main structure |work_items_| is mutated
// only from the UI thread. The unpack and installation is done in a blocking
// pool thread. The network requests are done in the IO thread or in the file
// thread.
class CrxUpdateService : public ComponentUpdateService {
 public:
  explicit CrxUpdateService(ComponentUpdateService::Configurator* config);
  virtual ~CrxUpdateService();

  // Overrides for ComponentUpdateService.
  virtual Status Start() OVERRIDE;
  virtual Status Stop() OVERRIDE;
  virtual Status RegisterComponent(const CrxComponent& component) OVERRIDE;
  virtual Status OnDemandUpdate(const std::string& component_id) OVERRIDE;
  virtual void GetComponents(
      std::vector<CrxComponentInfo>* components) OVERRIDE;
  virtual content::ResourceThrottle* GetOnDemandResourceThrottle(
      net::URLRequest* request, const std::string& crx_id) OVERRIDE;

   // Context for a crx download url request.
   struct CRXContext {
     ComponentInstaller* installer;
     std::vector<uint8> pk_hash;
     std::string id;
     std::string fingerprint;
     CRXContext() : installer(NULL) {}
   };

 private:
  enum ErrorCategory {
    kErrorNone = 0,
    kNetworkError,
    kUnpackError,
    kInstallError,
  };

  enum StepDelayInterval {
    kStepDelayShort = 0,
    kStepDelayMedium,
    kStepDelayLong,
  };

  void UpdateCheckComplete(int error,
                           const std::string& error_message,
                           const UpdateResponse::Results& results);
  void OnUpdateCheckSucceeded(const UpdateResponse::Results& results);
  void OnUpdateCheckFailed(int error, const std::string& error_message);

  void DownloadComplete(
      scoped_ptr<CRXContext> crx_context,
      const CrxDownloader::Result& download_result);

  Status OnDemandUpdateInternal(CrxUpdateItem* item);

  void ProcessPendingItems();

  // Find a component that is ready to update.
  CrxUpdateItem* FindReadyComponent() const;

  // Prepares the components for an update check and initiates the request.
  // Returns true if an update check request has been made. Returns false if
  // no update check was needed or an error occured.
  bool CheckForUpdates();

  void UpdateComponent(CrxUpdateItem* workitem);

  void ScheduleNextRun(StepDelayInterval step_delay);

  void ParseResponse(const std::string& xml);

  void Install(scoped_ptr<CRXContext> context, const base::FilePath& crx_path);

  void EndUnpacking(const std::string& component_id,
                    const base::FilePath& crx_path,
                    ComponentUnpacker::Error error,
                    int extended_error);

  void DoneInstalling(const std::string& component_id,
                      ComponentUnpacker::Error error,
                      int extended_error);

  void ChangeItemState(CrxUpdateItem* item, CrxUpdateItem::Status to);

  size_t ChangeItemStatus(CrxUpdateItem::Status from,
                          CrxUpdateItem::Status to);

  CrxUpdateItem* FindUpdateItemById(const std::string& id);

  void NotifyComponentObservers(ComponentObserver::Events event,
                                int extra) const;

  bool HasOnDemandItems() const;

  void OnNewResourceThrottle(base::WeakPtr<CUResourceThrottle> rt,
                             const std::string& crx_id);

  scoped_ptr<ComponentUpdateService::Configurator> config_;

  scoped_ptr<UpdateChecker> update_checker_;

  scoped_ptr<PingManager> ping_manager_;

  scoped_refptr<ComponentUnpacker> unpacker_;

  scoped_ptr<CrxDownloader> crx_downloader_;

  // A collection of every work item.
  typedef std::vector<CrxUpdateItem*> UpdateItems;
  UpdateItems work_items_;

  base::OneShotTimer<CrxUpdateService> timer_;

  scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;

  const Version chrome_version_;

  bool running_;

  DISALLOW_COPY_AND_ASSIGN(CrxUpdateService);
};

//////////////////////////////////////////////////////////////////////////////

CrxUpdateService::CrxUpdateService(ComponentUpdateService::Configurator* config)
    : config_(config),
      ping_manager_(new PingManager(config->PingUrl(),
                                    config->RequestContext())),
      blocking_task_runner_(BrowserThread::GetBlockingPool()->
          GetSequencedTaskRunnerWithShutdownBehavior(
              BrowserThread::GetBlockingPool()->GetSequenceToken(),
              base::SequencedWorkerPool::SKIP_ON_SHUTDOWN)),
      chrome_version_(chrome::VersionInfo().Version()),
      running_(false) {
}

CrxUpdateService::~CrxUpdateService() {
  // Because we are a singleton, at this point only the UI thread should be
  // alive, this simplifies the management of the work that could be in
  // flight in other threads.
  Stop();
  STLDeleteElements(&work_items_);
}

ComponentUpdateService::Status CrxUpdateService::Start() {
  // Note that RegisterComponent will call Start() when the first
  // component is registered, so it can be called twice. This way
  // we avoid scheduling the timer if there is no work to do.
  running_ = true;
  if (work_items_.empty())
    return kOk;

  NotifyComponentObservers(ComponentObserver::COMPONENT_UPDATER_STARTED, 0);

  timer_.Start(FROM_HERE, base::TimeDelta::FromSeconds(config_->InitialDelay()),
               this, &CrxUpdateService::ProcessPendingItems);
  return kOk;
}

// Stop the main check + update loop. In flight operations will be
// completed.
ComponentUpdateService::Status CrxUpdateService::Stop() {
  running_ = false;
  timer_.Stop();
  return kOk;
}

bool CrxUpdateService::HasOnDemandItems() const {
  class Helper {
   public:
    static bool IsOnDemand(CrxUpdateItem* item) {
      return item->on_demand;
    }
  };
  return std::find_if(work_items_.begin(),
                      work_items_.end(),
                      Helper::IsOnDemand) != work_items_.end();
}

// This function sets the timer which will call ProcessPendingItems() or
// ProcessRequestedItem() if there is an on_demand item.  There
// are three kinds of waits:
//  - a short delay, when there is immediate work to be done.
//  - a medium delay, when there are updates to be applied within the current
//    update cycle, or there are components that are still unchecked.
//  - a long delay when a full check/update cycle has completed for all
//    components.
void CrxUpdateService::ScheduleNextRun(StepDelayInterval step_delay) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(!update_checker_);
  CHECK(!timer_.IsRunning());
  // It could be the case that Stop() had been called while a url request
  // or unpacking was in flight, if so we arrive here but |running_| is
  // false. In that case do not loop again.
  if (!running_)
    return;

  // Keep the delay short if in the middle of an update (step_delay),
  // or there are new requested_work_items_ that have not been processed yet.
  int64 delay_seconds = 0;
  if (!HasOnDemandItems()) {
    switch (step_delay) {
      case kStepDelayShort:
        delay_seconds = config_->StepDelay();
        break;
      case kStepDelayMedium:
        delay_seconds = config_->StepDelayMedium();
        break;
      case kStepDelayLong:
        delay_seconds = config_->NextCheckDelay();
        break;
    }
  } else {
    delay_seconds = config_->StepDelay();
  }

  if (step_delay != kStepDelayShort) {
    NotifyComponentObservers(ComponentObserver::COMPONENT_UPDATER_SLEEPING, 0);

    // Zero is only used for unit tests.
    if (0 == delay_seconds)
      return;
  }

  timer_.Start(FROM_HERE, base::TimeDelta::FromSeconds(delay_seconds),
               this, &CrxUpdateService::ProcessPendingItems);
}

// Given a extension-like component id, find the associated component.
CrxUpdateItem* CrxUpdateService::FindUpdateItemById(const std::string& id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  CrxUpdateItem::FindById finder(id);
  UpdateItems::iterator it = std::find_if(work_items_.begin(),
                                          work_items_.end(),
                                          finder);
  return it != work_items_.end() ? *it : NULL;
}

// Changes a component's status, clearing on_demand and firing notifications as
// necessary. By convention, this is the only function that can change a
// CrxUpdateItem's |status|.
// TODO(waffles): Do we want to add DCHECKS for valid state transitions here?
void CrxUpdateService::ChangeItemState(CrxUpdateItem* item,
                                       CrxUpdateItem::Status to) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (to == CrxUpdateItem::kNoUpdate ||
      to == CrxUpdateItem::kUpdated ||
      to == CrxUpdateItem::kUpToDate) {
    item->on_demand = false;
  }

  item->status = to;

  ComponentObserver* observer = item->component.observer;
  if (observer) {
    switch (to) {
      case CrxUpdateItem::kCanUpdate:
        observer->OnEvent(ComponentObserver::COMPONENT_UPDATE_FOUND, 0);
        break;
      case CrxUpdateItem::kUpdatingDiff:
      case CrxUpdateItem::kUpdating:
        observer->OnEvent(ComponentObserver::COMPONENT_UPDATE_READY, 0);
        break;
      case CrxUpdateItem::kUpdated:
        observer->OnEvent(ComponentObserver::COMPONENT_UPDATED, 0);
        break;
      case CrxUpdateItem::kUpToDate:
      case CrxUpdateItem::kNoUpdate:
        observer->OnEvent(ComponentObserver::COMPONENT_NOT_UPDATED, 0);
        break;
      case CrxUpdateItem::kNew:
      case CrxUpdateItem::kChecking:
      case CrxUpdateItem::kDownloading:
      case CrxUpdateItem::kDownloadingDiff:
      case CrxUpdateItem::kLastStatus:
        // No notification for these states.
        break;
    }
  }

  // Free possible pending network requests.
  if ((to == CrxUpdateItem::kUpdated) ||
      (to == CrxUpdateItem::kUpToDate) ||
      (to == CrxUpdateItem::kNoUpdate)) {
    UnblockandReapAllThrottles(&item->throttles);
  }
}

// Changes all the components in |work_items_| that have |from| status to
// |to| status and returns how many have been changed.
size_t CrxUpdateService::ChangeItemStatus(CrxUpdateItem::Status from,
                                          CrxUpdateItem::Status to) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  size_t count = 0;
  for (UpdateItems::iterator it = work_items_.begin();
       it != work_items_.end(); ++it) {
    CrxUpdateItem* item = *it;
    if (item->status == from) {
      ChangeItemState(item, to);
      ++count;
    }
  }
  return count;
}

// Adds a component to be checked for upgrades. If the component exists it
// it will be replaced and the return code is kReplaced.
ComponentUpdateService::Status CrxUpdateService::RegisterComponent(
    const CrxComponent& component) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (component.pk_hash.empty() ||
      !component.version.IsValid() ||
      !component.installer)
    return kError;

  std::string id(GetCrxComponentID(component));
  CrxUpdateItem* uit = FindUpdateItemById(id);
  if (uit) {
    uit->component = component;
    return kReplaced;
  }

  uit = new CrxUpdateItem;
  uit->id.swap(id);
  uit->component = component;

  work_items_.push_back(uit);
  // If this is the first component registered we call Start to
  // schedule the first timer.
  if (running_ && (work_items_.size() == 1))
    Start();

  return kOk;
}

// Start the process of checking for an update, for a particular component
// that was previously registered.
// |component_id| is a value returned from GetCrxComponentID().
ComponentUpdateService::Status CrxUpdateService::OnDemandUpdate(
    const std::string& component_id) {
  return OnDemandUpdateInternal(FindUpdateItemById(component_id));
}

ComponentUpdateService::Status CrxUpdateService::OnDemandUpdateInternal(
    CrxUpdateItem* uit) {
  if (!uit)
    return kError;

  // Check if the request is too soon.
  base::TimeDelta delta = base::Time::Now() - uit->last_check;
  if (delta < base::TimeDelta::FromSeconds(config_->OnDemandDelay()))
    return kError;

  switch (uit->status) {
    // If the item is already in the process of being updated, there is
    // no point in this call, so return kInProgress.
    case CrxUpdateItem::kChecking:
    case CrxUpdateItem::kCanUpdate:
    case CrxUpdateItem::kDownloadingDiff:
    case CrxUpdateItem::kDownloading:
    case CrxUpdateItem::kUpdatingDiff:
    case CrxUpdateItem::kUpdating:
      return kInProgress;
    // Otherwise the item was already checked a while back (or it is new),
    // set its status to kNew to give it a slightly higher priority.
    case CrxUpdateItem::kNew:
    case CrxUpdateItem::kUpdated:
    case CrxUpdateItem::kUpToDate:
    case CrxUpdateItem::kNoUpdate:
      ChangeItemState(uit, CrxUpdateItem::kNew);
      uit->on_demand = true;
      break;
    case CrxUpdateItem::kLastStatus:
      NOTREACHED() << uit->status;
  }

  // In case the current delay is long, set the timer to a shorter value
  // to get the ball rolling.
  if (timer_.IsRunning()) {
    timer_.Stop();
    timer_.Start(FROM_HERE, base::TimeDelta::FromSeconds(config_->StepDelay()),
                 this, &CrxUpdateService::ProcessPendingItems);
  }

  return kOk;
}

void CrxUpdateService::GetComponents(
    std::vector<CrxComponentInfo>* components) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  for (UpdateItems::const_iterator it = work_items_.begin();
       it != work_items_.end(); ++it) {
    const CrxUpdateItem* item = *it;
    CrxComponentInfo info;
    info.id = GetCrxComponentID(item->component);
    info.version = item->component.version.GetString();
    info.name = item->component.name;
    components->push_back(info);
  }
}

// This is the main loop of the component updater. It updates one component
// at a time if updates are available. Otherwise, it does an update check or
// takes a long sleep until the loop runs again.
void CrxUpdateService::ProcessPendingItems() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  CrxUpdateItem* ready_upgrade = FindReadyComponent();
  if (ready_upgrade) {
    UpdateComponent(ready_upgrade);
    return;
  }

  if (!CheckForUpdates())
    ScheduleNextRun(kStepDelayLong);
}

CrxUpdateItem* CrxUpdateService::FindReadyComponent() const {
  class Helper {
   public:
    static bool IsReadyOnDemand(CrxUpdateItem* item) {
      return item->on_demand && IsReady(item);
    }
    static bool IsReady(CrxUpdateItem* item) {
      return item->status == CrxUpdateItem::kCanUpdate;
    }
  };

  std::vector<CrxUpdateItem*>::const_iterator it = std::find_if(
      work_items_.begin(), work_items_.end(), Helper::IsReadyOnDemand);
  if (it != work_items_.end())
    return *it;
  it = std::find_if(work_items_.begin(), work_items_.end(), Helper::IsReady);
  if (it != work_items_.end())
    return *it;
  return NULL;
}

// Prepares the components for an update check and initiates the request.
// On demand components are always included in the update check request.
// Otherwise, only include components that have not been checked recently.
bool CrxUpdateService::CheckForUpdates() {
  const base::TimeDelta minimum_recheck_wait_time =
      base::TimeDelta::FromSeconds(config_->MinimumReCheckWait());
  const base::Time now(base::Time::Now());

  std::vector<CrxUpdateItem*> items_to_check;
  for (size_t i = 0; i != work_items_.size(); ++i) {
    CrxUpdateItem* item = work_items_[i];
    DCHECK(item->status == CrxUpdateItem::kNew ||
           item->status == CrxUpdateItem::kNoUpdate ||
           item->status == CrxUpdateItem::kUpToDate ||
           item->status == CrxUpdateItem::kUpdated);

    const base::TimeDelta time_since_last_checked(now - item->last_check);

    if (!item->on_demand &&
        time_since_last_checked < minimum_recheck_wait_time) {
      continue;
    }

    ChangeItemState(item, CrxUpdateItem::kChecking);

    item->last_check = now;
    item->crx_urls.clear();
    item->crx_diffurls.clear();
    item->previous_version = item->component.version;
    item->next_version = Version();
    item->previous_fp = item->component.fingerprint;
    item->next_fp.clear();
    item->diff_update_failed = false;
    item->error_category = 0;
    item->error_code = 0;
    item->extra_code1 = 0;
    item->diff_error_category = 0;
    item->diff_error_code = 0;
    item->diff_extra_code1 = 0;
    item->download_metrics.clear();

    items_to_check.push_back(item);
  }

  if (items_to_check.empty())
    return false;

  update_checker_ = UpdateChecker::Create(
      config_->UpdateUrl(),
      config_->RequestContext(),
      base::Bind(&CrxUpdateService::UpdateCheckComplete,
                 base::Unretained(this))).Pass();
  return update_checker_->CheckForUpdates(items_to_check,
                                          config_->ExtraRequestParams());
}

void CrxUpdateService::UpdateComponent(CrxUpdateItem* workitem) {
  scoped_ptr<CRXContext> crx_context(new CRXContext);
  crx_context->pk_hash = workitem->component.pk_hash;
  crx_context->id = workitem->id;
  crx_context->installer = workitem->component.installer;
  crx_context->fingerprint = workitem->next_fp;
  const std::vector<GURL>* urls = NULL;
  bool allow_background_download = false;
  if (CanTryDiffUpdate(workitem, *config_)) {
    urls = &workitem->crx_diffurls;
    ChangeItemState(workitem, CrxUpdateItem::kDownloadingDiff);
  } else {
    // Background downloads are enabled only for selected components and
    // only for full downloads (see issue 340448).
    allow_background_download = workitem->component.allow_background_download;
    urls = &workitem->crx_urls;
    ChangeItemState(workitem, CrxUpdateItem::kDownloading);
  }

  // On demand component updates are always downloaded in foreground.
  const bool is_background_download =
      !workitem->on_demand && allow_background_download &&
      config_->UseBackgroundDownloader();

  crx_downloader_.reset(CrxDownloader::Create(
      is_background_download,
      config_->RequestContext(),
      blocking_task_runner_,
      base::Bind(&CrxUpdateService::DownloadComplete,
                 base::Unretained(this),
                 base::Passed(&crx_context))));
  crx_downloader_->StartDownload(*urls);
}

void CrxUpdateService::UpdateCheckComplete(
    int error,
    const std::string& error_message,
    const UpdateResponse::Results& results) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  update_checker_.reset();
  if (!error)
    OnUpdateCheckSucceeded(results);
  else
    OnUpdateCheckFailed(error, error_message);
}

// Handles a valid Omaha update check response by matching the results with
// the registered components which were checked for updates.
// If updates are found, prepare the components for the actual version upgrade.
// One of these components will be drafted for the upgrade next time
// ProcessPendingItems is called.
void CrxUpdateService::OnUpdateCheckSucceeded(
    const UpdateResponse::Results& results) {
  size_t num_updates_pending = 0;
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  std::vector<UpdateResponse::Result>::const_iterator it;
  for (it = results.list.begin(); it != results.list.end(); ++it) {
    CrxUpdateItem* crx = FindUpdateItemById(it->extension_id);
    if (!crx)
      continue;

    if (crx->status != CrxUpdateItem::kChecking) {
      NOTREACHED();
      continue;  // Not updating this component now.
    }

    if (it->manifest.version.empty()) {
      // No version means no update available.
      ChangeItemState(crx, CrxUpdateItem::kNoUpdate);
      continue;
    }

    if (!IsVersionNewer(crx->component.version, it->manifest.version)) {
      // The component is up to date.
      ChangeItemState(crx, CrxUpdateItem::kUpToDate);
      continue;
    }

    if (!it->manifest.browser_min_version.empty()) {
      if (IsVersionNewer(chrome_version_, it->manifest.browser_min_version)) {
        // The component is not compatible with this Chrome version.
        ChangeItemState(crx, CrxUpdateItem::kNoUpdate);
        continue;
      }
    }

    if (it->manifest.packages.size() != 1) {
      // Assume one and only one package per component.
      ChangeItemState(crx, CrxUpdateItem::kNoUpdate);
      continue;
    }

    // Parse the members of the result and queue an upgrade for this component.
    crx->next_version = Version(it->manifest.version);

    typedef UpdateResponse::Result::Manifest::Package Package;
    const Package& package(it->manifest.packages[0]);
    crx->next_fp = package.fingerprint;

    // Resolve the urls by combining the base urls with the package names.
    for (size_t i = 0; i != it->crx_urls.size(); ++i) {
      const GURL url(it->crx_urls[i].Resolve(package.name));
      if (url.is_valid())
         crx->crx_urls.push_back(url);
    }
    for (size_t i = 0; i != it->crx_diffurls.size(); ++i) {
      const GURL url(it->crx_diffurls[i].Resolve(package.namediff));
      if (url.is_valid())
         crx->crx_diffurls.push_back(url);
    }

    ChangeItemState(crx, CrxUpdateItem::kCanUpdate);
    ++num_updates_pending;
  }

  // All components that are not included in the update response are
  // considered up to date.
  ChangeItemStatus(CrxUpdateItem::kChecking, CrxUpdateItem::kUpToDate);

  // If there are updates pending we do a short wait, otherwise we take
  // a longer delay until we check the components again.
  ScheduleNextRun(num_updates_pending > 0 ? kStepDelayShort : kStepDelayLong);
}

// TODO: record UMA stats.
void CrxUpdateService::OnUpdateCheckFailed(int error,
                                           const std::string& error_message) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(error);
  size_t count = ChangeItemStatus(CrxUpdateItem::kChecking,
                                  CrxUpdateItem::kNoUpdate);
  DCHECK_GT(count, 0ul);
  ScheduleNextRun(kStepDelayLong);
}

// Called when the CRX package has been downloaded to a temporary location.
// Here we fire the notifications and schedule the component-specific installer
// to be called in the file thread.
void CrxUpdateService::DownloadComplete(
    scoped_ptr<CRXContext> crx_context,
    const CrxDownloader::Result& download_result) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  CrxUpdateItem* crx = FindUpdateItemById(crx_context->id);
  DCHECK(crx->status == CrxUpdateItem::kDownloadingDiff ||
         crx->status == CrxUpdateItem::kDownloading);

  AppendDownloadMetrics(crx_downloader_->download_metrics(),
                        &crx->download_metrics);

  if (download_result.error) {
    if (crx->status == CrxUpdateItem::kDownloadingDiff) {
      crx->diff_error_category = kNetworkError;
      crx->diff_error_code = download_result.error;
      crx->diff_update_failed = true;
      size_t count = ChangeItemStatus(CrxUpdateItem::kDownloadingDiff,
                                      CrxUpdateItem::kCanUpdate);
      DCHECK_EQ(count, 1ul);
      crx_downloader_.reset();

      ScheduleNextRun(kStepDelayShort);
      return;
    }
    crx->error_category = kNetworkError;
    crx->error_code = download_result.error;
    size_t count = ChangeItemStatus(CrxUpdateItem::kDownloading,
                                    CrxUpdateItem::kNoUpdate);
    DCHECK_EQ(count, 1ul);
    crx_downloader_.reset();

    // At this point, since both the differential and the full downloads failed,
    // the update for this component has finished with an error.
    ping_manager_->OnUpdateComplete(crx);

    // Move on to the next update, if there is one available.
    ScheduleNextRun(kStepDelayMedium);
  } else {
    size_t count = 0;
    if (crx->status == CrxUpdateItem::kDownloadingDiff) {
      count = ChangeItemStatus(CrxUpdateItem::kDownloadingDiff,
                               CrxUpdateItem::kUpdatingDiff);
    } else {
      count = ChangeItemStatus(CrxUpdateItem::kDownloading,
                               CrxUpdateItem::kUpdating);
    }
    DCHECK_EQ(count, 1ul);
    crx_downloader_.reset();

    // Why unretained? See comment at top of file.
    blocking_task_runner_->PostDelayedTask(
        FROM_HERE,
        base::Bind(&CrxUpdateService::Install,
                   base::Unretained(this),
                   base::Passed(&crx_context),
                   download_result.response),
        base::TimeDelta::FromMilliseconds(config_->StepDelay()));
  }
}

// Install consists of digital signature verification, unpacking and then
// calling the component specific installer. All that is handled by the
// |unpacker_|. If there is an error this function is in charge of deleting
// the files created.
void CrxUpdateService::Install(scoped_ptr<CRXContext> context,
                               const base::FilePath& crx_path) {
  // This function owns the file at |crx_path| and the |context| object.
  unpacker_ = new ComponentUnpacker(context->pk_hash,
                                    crx_path,
                                    context->fingerprint,
                                    context->installer,
                                    config_->InProcess(),
                                    blocking_task_runner_);
  unpacker_->Unpack(base::Bind(&CrxUpdateService::EndUnpacking,
                               base::Unretained(this),
                               context->id,
                               crx_path));
}

void CrxUpdateService::EndUnpacking(const std::string& component_id,
                                    const base::FilePath& crx_path,
                                    ComponentUnpacker::Error error,
                                    int extended_error) {
  if (!DeleteFileAndEmptyParentDirectory(crx_path))
    NOTREACHED() << crx_path.value();
  BrowserThread::PostDelayedTask(
      BrowserThread::UI,
      FROM_HERE,
      base::Bind(&CrxUpdateService::DoneInstalling, base::Unretained(this),
                 component_id, error, extended_error),
      base::TimeDelta::FromMilliseconds(config_->StepDelay()));
  // Reset the unpacker last, otherwise we free our own arguments.
  unpacker_ = NULL;
}

// Installation has been completed. Adjust the component status and
// schedule the next check. Schedule a short delay before trying the full
// update when the differential update failed.
void CrxUpdateService::DoneInstalling(const std::string& component_id,
                                      ComponentUnpacker::Error error,
                                      int extra_code) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  ErrorCategory error_category = kErrorNone;
  switch (error) {
    case ComponentUnpacker::kNone:
      break;
    case ComponentUnpacker::kInstallerError:
      error_category = kInstallError;
      break;
    default:
      error_category = kUnpackError;
      break;
  }

  const bool is_success = error == ComponentUnpacker::kNone;

  CrxUpdateItem* item = FindUpdateItemById(component_id);
  if (item->status == CrxUpdateItem::kUpdatingDiff && !is_success) {
    item->diff_error_category = error_category;
    item->diff_error_code = error;
    item->diff_extra_code1 = extra_code;
    item->diff_update_failed = true;
    size_t count = ChangeItemStatus(CrxUpdateItem::kUpdatingDiff,
                                    CrxUpdateItem::kCanUpdate);
    DCHECK_EQ(count, 1ul);
    ScheduleNextRun(kStepDelayShort);
    return;
    }

  if (is_success) {
    ChangeItemState(item, CrxUpdateItem::kUpdated);
    item->component.version = item->next_version;
    item->component.fingerprint = item->next_fp;
  } else {
    ChangeItemState(item, CrxUpdateItem::kNoUpdate);
    item->error_category = error_category;
    item->error_code = error;
    item->extra_code1 = extra_code;
  }

  ping_manager_->OnUpdateComplete(item);

  // Move on to the next update, if there is one available.
  ScheduleNextRun(kStepDelayMedium);
}

void CrxUpdateService::NotifyComponentObservers(
    ComponentObserver::Events event, int extra) const {
  for (UpdateItems::const_iterator it = work_items_.begin();
       it != work_items_.end(); ++it) {
    ComponentObserver* observer = (*it)->component.observer;
    if (observer)
      observer->OnEvent(event, 0);
  }
}

content::ResourceThrottle* CrxUpdateService::GetOnDemandResourceThrottle(
     net::URLRequest* request, const std::string& crx_id) {
  // We give the raw pointer to the caller, who will delete it at will
  // and we keep for ourselves a weak pointer to it so we can post tasks
  // from the UI thread without having to track lifetime directly.
  CUResourceThrottle* rt = new CUResourceThrottle(request);
  BrowserThread::PostTask(
      BrowserThread::UI,
      FROM_HERE,
      base::Bind(&CrxUpdateService::OnNewResourceThrottle,
                 base::Unretained(this),
                 rt->AsWeakPtr(),
                 crx_id));
  return rt;
}

void CrxUpdateService::OnNewResourceThrottle(
    base::WeakPtr<CUResourceThrottle> rt, const std::string& crx_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  // Check if we can on-demand update, else unblock the request anyway.
  CrxUpdateItem* item = FindUpdateItemById(crx_id);
  Status status = OnDemandUpdateInternal(item);
  if (status == kOk || status == kInProgress) {
    item->throttles.push_back(rt);
    return;
  }
  UnblockResourceThrottle(rt);
}

///////////////////////////////////////////////////////////////////////////////

CUResourceThrottle::CUResourceThrottle(const net::URLRequest* request)
    : state_(NEW) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
}

CUResourceThrottle::~CUResourceThrottle() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
}

void CUResourceThrottle::WillStartRequest(bool* defer) {
  if (state_ != UNBLOCKED) {
    state_ = BLOCKED;
    *defer = true;
  } else {
    *defer = false;
  }
}

void CUResourceThrottle::WillRedirectRequest(const GURL& new_url, bool* defer) {
  WillStartRequest(defer);
}

const char* CUResourceThrottle::GetNameForLogging() const {
  return "ComponentUpdateResourceThrottle";
}

void CUResourceThrottle::Unblock() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  if (state_ == BLOCKED)
    controller()->Resume();
  state_ = UNBLOCKED;
}

// The component update factory. Using the component updater as a singleton
// is the job of the browser process.
ComponentUpdateService* ComponentUpdateServiceFactory(
    ComponentUpdateService::Configurator* config) {
  DCHECK(config);
  return new CrxUpdateService(config);
}

}  // namespace component_updater
/* [<][>][^][v][top][bottom][index][help] */
root/chrome/browser/component_updater/component_updater_service.cc

DEFINITIONS
