components/component_updater/default_component_installer.h

   1 // Copyright 2014 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 #ifndef COMPONENTS_COMPONENT_UPDATER_DEFAULT_COMPONENT_INSTALLER_H_
   6 #define COMPONENTS_COMPONENT_UPDATER_DEFAULT_COMPONENT_INSTALLER_H_
   7
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/compiler_specific.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/threading/thread_checker.h"
  15 #include "base/values.h"
  16 #include "base/version.h"
  17 #include "components/component_updater/component_updater_service.h"
  18
  19 namespace base {
  20 class FilePath;
  21 class SequencedTaskRunner;
  22 class SingleThreadTaskRunner;
  23 }  // namespace base
  24
  25 namespace component_updater {
  26
  27 // Components should use a DefaultComponentInstaller by defining a class that
  28 // implements the members of ComponentInstallerTraits, and then registering a
  29 // DefaultComponentInstaller that has been constructed with an instance of that
  30 // class.
  31 class ComponentInstallerTraits {
  32  public:
  33   virtual ~ComponentInstallerTraits();
  34
  35   // Verifies that a working installation resides within the directory specified
  36   // by |dir|. |dir| is of the form <base directory>/<version>.
  37   // Called only from a thread belonging to a blocking thread pool.
  38   // The implementation of this function must be efficient since the function
  39   // can be called when Chrome starts.
  40   virtual bool VerifyInstallation(const base::FilePath& dir) const = 0;
  41
  42   // Returns true if the component can be automatically updated. Called once
  43   // during component registration from the UI thread.
  44   virtual bool CanAutoUpdate() const = 0;
  45
  46   // OnCustomInstall is called during the installation process. Components that
  47   // require custom installation operations should implement them here.
  48   // Returns false if a custom operation failed, and true otherwise.
  49   // Called only from a thread belonging to a blocking thread pool.
  50   virtual bool OnCustomInstall(const base::DictionaryValue& manifest,
  51                                const base::FilePath& install_dir) = 0;
  52
  53   // ComponentReady is called in two cases:
  54   //   1) After an installation is successfully completed.
  55   //   2) During component registration if the component is already installed.
  56   // In both cases the install is verified before this is called. This method
  57   // is guaranteed to be called before any observers of the component are
  58   // notified of a successful install, and is meant to support follow-on work
  59   // such as updating paths elsewhere in Chrome. Called on the UI thread.
  60   // |version| is the version of the component.
  61   // |install_dir| is the path to the install directory for this version.
  62   // |manifest| is the manifest for this version of the component.
  63   virtual void ComponentReady(const base::Version& version,
  64                               const base::FilePath& install_dir,
  65                               scoped_ptr<base::DictionaryValue> manifest) = 0;
  66
  67   // Returns the directory that the installer will place versioned installs of
  68   // the component into.
  69   virtual base::FilePath GetBaseDirectory() const = 0;
  70
  71   // Returns the component's SHA2 hash as raw bytes.
  72   virtual void GetHash(std::vector<uint8>* hash) const = 0;
  73
  74   // Returns the human-readable name of the component.
  75   virtual std::string GetName() const = 0;
  76 };
  77
  78 // A DefaultComponentInstaller is intended to be final, and not derived from.
  79 // Customization must be provided by passing a ComponentInstallerTraits object
  80 // to the constructor.
  81 class DefaultComponentInstaller : public ComponentInstaller {
  82  public:
  83   DefaultComponentInstaller(
  84       scoped_ptr<ComponentInstallerTraits> installer_traits);
  85
  86   // Registers the component for update checks and installs.
  87   void Register(ComponentUpdateService* cus);
  88
  89   // Overridden from ComponentInstaller:
  90   virtual void OnUpdateError(int error) OVERRIDE;
  91   virtual bool Install(const base::DictionaryValue& manifest,
  92                        const base::FilePath& unpack_path) OVERRIDE;
  93   virtual bool GetInstalledFile(const std::string& file,
  94                                 base::FilePath* installed_file) OVERRIDE;
  95
  96   virtual ~DefaultComponentInstaller();
  97
  98  private:
  99   base::FilePath GetInstallDirectory();
 100   bool InstallHelper(const base::DictionaryValue& manifest,
 101                      const base::FilePath& unpack_path,
 102                      const base::FilePath& install_path);
 103   void StartRegistration(ComponentUpdateService* cus);
 104   void FinishRegistration(ComponentUpdateService* cus);
 105
 106   base::Version current_version_;
 107   std::string current_fingerprint_;
 108   scoped_ptr<base::DictionaryValue> current_manifest_;
 109   scoped_ptr<ComponentInstallerTraits> installer_traits_;
 110   scoped_refptr<base::SequencedTaskRunner> task_runner_;
 111
 112   // Used to post responses back to the main thread. Initialized on the main
 113   // loop but accessed from the task runner.
 114   scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
 115
 116   base::ThreadChecker thread_checker_;
 117
 118   DISALLOW_COPY_AND_ASSIGN(DefaultComponentInstaller);
 119 };
 120
 121 }  // namespace component_updater
 122
 123 #endif  // COMPONENTS_COMPONENT_UPDATER_DEFAULT_COMPONENT_INSTALLER_H_