Componentize component_updater: Move over a bunch of files to the component.

chrome/browser/component_updater/component_updater_service.h

-// 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.
-
-#ifndef CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_
-#define CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_
-
-#include <string>
-#include <vector>
-
-#include "base/callback_forward.h"
-#include "base/gtest_prod_util.h"
-#include "base/memory/ref_counted.h"
-#include "base/version.h"
-#include "url/gurl.h"
-
-class ComponentsUI;
-
-namespace base {
-class DictionaryValue;
-class FilePath;
-class SequencedTaskRunner;
-}
-
-namespace net {
-class URLRequestContextGetter;
-class URLRequest;
-}
-
-namespace content {
-class ResourceThrottle;
-}
-
-namespace component_updater {
-
-class Configurator;
-class OnDemandUpdater;
-
-// Component specific installers must derive from this class and implement
-// OnUpdateError() and Install(). A valid instance of this class must be
-// given to ComponentUpdateService::RegisterComponent().
-class ComponentInstaller {
- public:
-  // Called by the component updater on the main thread when there was a
-  // problem unpacking or verifying the component. |error| is a non-zero
-  // value which is only meaningful to the component updater.
-  virtual void OnUpdateError(int error) = 0;
-
-  // Called by the component updater when a component has been unpacked
-  // and is ready to be installed. |manifest| contains the CRX manifest
-  // json dictionary and |unpack_path| contains the temporary directory
-  // with all the unpacked CRX files. This method may be called from
-  // a thread other than the main thread.
-  virtual bool Install(const base::DictionaryValue& manifest,
-                       const base::FilePath& unpack_path) = 0;
-
-  // Set |installed_file| to the full path to the installed |file|. |file| is
-  // the filename of the file in this component's CRX. Returns false if this is
-  // not possible (the file has been removed or modified, or its current
-  // location is unknown). Otherwise, returns true.
-  virtual bool GetInstalledFile(const std::string& file,
-                                base::FilePath* installed_file) = 0;
-
-  virtual ~ComponentInstaller() {}
-};
-
-// Describes a particular component that can be installed or updated. This
-// structure is required to register a component with the component updater.
-// |pk_hash| is the SHA256 hash of the component's public key. If the component
-// is to be installed then version should be "0" or "0.0", else it should be
-// the current version. |fingerprint|, and |name| are optional.
-// |allow_background_download| specifies that the component can be background
-// downloaded in some cases. The default for this value is |true| and the value
-// can be overriden at the registration time. This is a temporary change until
-// the issue 340448 is resolved.
-struct CrxComponent {
-  std::vector<uint8> pk_hash;
-  ComponentInstaller* installer;
-  Version version;
-  std::string fingerprint;
-  std::string name;
-  bool allow_background_download;
-  CrxComponent();
-  ~CrxComponent();
-};
-
-struct CrxUpdateItem;
-
-// The component update service is in charge of installing or upgrading
-// select parts of chrome. Each part is called a component and managed by
-// instances of CrxComponent registered using RegisterComponent(). On the
-// server, each component is packaged as a CRX which is the same format used
-// to package extensions. To the update service each component is identified
-// by its public key hash (CrxComponent::pk_hash). If there is an update
-// available and its version is bigger than (CrxComponent::version), it will
-// be downloaded, verified and unpacked. Then component-specific installer
-// ComponentInstaller::Install (of CrxComponent::installer) will be called.
-//
-// During the normal operation of the component updater some specific
-// notifications are fired, like COMPONENT_UPDATER_STARTED and
-// COMPONENT_UPDATE_FOUND. See notification_type.h for more details.
-//
-// All methods are safe to call ONLY from the browser's main thread.
-class ComponentUpdateService {
- public:
-  enum Status { kOk, kReplaced, kInProgress, kError };
-
-  // Defines an interface to observe ComponentUpdateService. It provides
-  // notifications when state changes occur for the service or for the
-  // registered components.
-  class Observer {
-   public:
-    enum Events {
-      // Sent when the component updater starts doing update checks.
-      COMPONENT_UPDATER_STARTED,
-
-      // Sent when the component updater is going to take a long nap.
-      COMPONENT_UPDATER_SLEEPING,
-
-      // Sent when there is a new version of a registered component. After
-      // the notification is sent the component will be downloaded.
-      COMPONENT_UPDATE_FOUND,
-
-      // Sent when the new component has been downloaded and an installation
-      // or upgrade is about to be attempted.
-      COMPONENT_UPDATE_READY,
-
-      // Sent when a component has been successfully updated.
-      COMPONENT_UPDATED,
-
-      // Sent when a component has not been updated following an update check:
-      // either there was no update available, or an update failed.
-      COMPONENT_NOT_UPDATED,
-
-      // Sent when component bytes are being downloaded.
-      COMPONENT_UPDATE_DOWNLOADING,
-    };
-
-    virtual ~Observer() {}
-
-    // The component updater service will call this function when an interesting
-    // state change happens. If the |id| is specified, then the event is fired
-    // on behalf of a specific component. The implementors of this interface are
-    // expected to filter the relevant events based on the component id.
-    virtual void OnEvent(Events event, const std::string& id) = 0;
-  };
-
-  // Adds an observer for this class. An observer should not be added more
-  // than once. The caller retains the ownership of the observer object.
-  virtual void AddObserver(Observer* observer) = 0;
-
-  // Removes an observer. It is safe for an observer to be removed while
-  // the observers are being notified.
-  virtual void RemoveObserver(Observer* observer) = 0;
-
-  // Start doing update checks and installing new versions of registered
-  // components after Configurator::InitialDelay() seconds.
-  virtual Status Start() = 0;
-
-  // Stop doing update checks. In-flight requests and pending installations
-  // will not be canceled.
-  virtual Status Stop() = 0;
-
-  // Add component to be checked for updates. You can call this method
-  // before calling Start().
-  virtual Status RegisterComponent(const CrxComponent& component) = 0;
-
-  // Returns a list of registered components.
-  virtual std::vector<std::string> GetComponentIDs() const = 0;
-
-  // Returns an interface for on-demand updates. On-demand updates are
-  // proactively triggered outside the normal component update service schedule.
-  virtual OnDemandUpdater& GetOnDemandUpdater() = 0;
-
-  // This method is used to trigger an on-demand update for component |crx_id|.
-  // This can be used when loading a resource that depends on this component.
-  //
-  // |callback| is called on the main thread once the on-demand update is
-  // complete, regardless of success. |callback| may be called immediately
-  // within the method body.
-  //
-  // Additionally, this function implements an embedder-defined cooldown
-  // interval between on demand update attempts. This behavior is intended
-  // to be defensive against programming bugs, usually triggered by web fetches,
-  // where the on-demand functionality is invoked too often. If this function
-  // is called while still on cooldown, |callback| will be called immediately.
-  virtual void MaybeThrottle(const std::string& crx_id,
-                             const base::Closure& callback) = 0;
-
-  // Returns a task runner suitable for use by component installers.
-  virtual scoped_refptr<base::SequencedTaskRunner> GetSequencedTaskRunner() = 0;
-
-  virtual ~ComponentUpdateService() {}
-
- private:
-  // Returns details about registered component in the |item| parameter. The
-  // function returns true in case of success and false in case of errors.
-  virtual bool GetComponentDetails(const std::string& component_id,
-                                   CrxUpdateItem* item) const = 0;
-
-  friend class ::ComponentsUI;
-};
-
-typedef ComponentUpdateService::Observer ServiceObserver;
-
-class OnDemandUpdater {
- public:
-  virtual ~OnDemandUpdater() {}
-
- private:
-  friend class OnDemandTester;
-  friend class ::ComponentsUI;
-
-  // Triggers an update check for a component. |component_id| is a value
-  // returned by GetCrxComponentID(). If an update for this component is already
-  // in progress, the function returns |kInProgress|. If an update is available,
-  // the update will be applied. The caller can subscribe to component update
-  // service notifications to get an indication about the outcome of the
-  // on-demand update. The function does not implement any cooldown interval.
-  virtual ComponentUpdateService::Status OnDemandUpdate(
-      const std::string& component_id) = 0;
-};
-
-// Creates the component updater. You must pass a valid |config| allocated on
-// the heap which the component updater will own.
-ComponentUpdateService* ComponentUpdateServiceFactory(Configurator* config);
-
-}  // namespace component_updater
-
-#endif  // CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_