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 <stdint.h>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/compiler_specific.h"
  13 #include "base/macros.h"
  14 #include "base/memory/ref_counted.h"
  15 #include "base/memory/scoped_ptr.h"
  16 #include "base/threading/thread_checker.h"
  17 #include "base/values.h"
  18 #include "base/version.h"
  19 #include "components/component_updater/component_updater_service.h"
  20
  21 namespace base {
  22 class FilePath;
  23 class SequencedTaskRunner;
  24 class SingleThreadTaskRunner;
  25 }  // namespace base
  26
  27 namespace component_updater {
  28
  29 // Components should use a DefaultComponentInstaller by defining a class that
  30 // implements the members of ComponentInstallerTraits, and then registering a
  31 // DefaultComponentInstaller that has been constructed with an instance of that
  32 // class.
  33 class ComponentInstallerTraits {
  34  public:
  35   virtual ~ComponentInstallerTraits();
  36
  37   // Verifies that a working installation resides within the directory specified
  38   // by |dir|. |dir| is of the form <base directory>/<version>.
  39   // Called only from a thread belonging to a blocking thread pool.
  40   // The implementation of this function must be efficient since the function
  41   // can be called when Chrome starts.
  42   virtual bool VerifyInstallation(const base::FilePath& dir) const = 0;
  43
  44   // Returns true if the component can be automatically updated. Called once
  45   // during component registration from the UI thread.
  46   virtual bool CanAutoUpdate() const = 0;
  47
  48   // OnCustomInstall is called during the installation process. Components that
  49   // require custom installation operations should implement them here.
  50   // Returns false if a custom operation failed, and true otherwise.
  51   // Called only from a thread belonging to a blocking thread pool.
  52   virtual bool OnCustomInstall(const base::DictionaryValue& manifest,
  53                                const base::FilePath& install_dir) = 0;
  54
  55   // ComponentReady is called in two cases:
  56   //   1) After an installation is successfully completed.
  57   //   2) During component registration if the component is already installed.
  58   // In both cases the install is verified before this is called. This method
  59   // is guaranteed to be called before any observers of the component are
  60   // notified of a successful install, and is meant to support follow-on work
  61   // such as updating paths elsewhere in Chrome. Called on the UI thread.
  62   // |version| is the version of the component.
  63   // |install_dir| is the path to the install directory for this version.
  64   // |manifest| is the manifest for this version of the component.
  65   virtual void ComponentReady(const base::Version& version,
  66                               const base::FilePath& install_dir,
  67                               scoped_ptr<base::DictionaryValue> manifest) = 0;
  68
  69   // Returns the directory that the installer will place versioned installs of
  70   // the component into.
  71   virtual base::FilePath GetBaseDirectory() const = 0;
  72
  73   // Returns the component's SHA2 hash as raw bytes.
  74   virtual void GetHash(std::vector<uint8_t>* hash) const = 0;
  75
  76   // Returns the human-readable name of the component.
  77   virtual std::string GetName() const = 0;
  78 };
  79
  80 // A DefaultComponentInstaller is intended to be final, and not derived from.
  81 // Customization must be provided by passing a ComponentInstallerTraits object
  82 // to the constructor.
  83 class DefaultComponentInstaller : public ComponentInstaller {
  84  public:
  85   DefaultComponentInstaller(
  86       scoped_ptr<ComponentInstallerTraits> installer_traits);
  87
  88   // Registers the component for update checks and installs.
  89   void Register(ComponentUpdateService* cus);
  90
  91   // Overridden from ComponentInstaller:
  92   virtual void OnUpdateError(int error) OVERRIDE;
  93   virtual bool Install(const base::DictionaryValue& manifest,
  94                        const base::FilePath& unpack_path) OVERRIDE;
  95   virtual bool GetInstalledFile(const std::string& file,
  96                                 base::FilePath* installed_file) OVERRIDE;
  97
  98   virtual ~DefaultComponentInstaller();
  99
 100  private:
 101   base::FilePath GetInstallDirectory();
 102   bool InstallHelper(const base::DictionaryValue& manifest,
 103                      const base::FilePath& unpack_path,
 104                      const base::FilePath& install_path);
 105   void StartRegistration(ComponentUpdateService* cus);
 106   void FinishRegistration(ComponentUpdateService* cus);
 107
 108   base::Version current_version_;
 109   std::string current_fingerprint_;
 110   scoped_ptr<base::DictionaryValue> current_manifest_;
 111   scoped_ptr<ComponentInstallerTraits> installer_traits_;
 112   scoped_refptr<base::SequencedTaskRunner> task_runner_;
 113
 114   // Used to post responses back to the main thread. Initialized on the main
 115   // loop but accessed from the task runner.
 116   scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
 117
 118   base::ThreadChecker thread_checker_;
 119
 120   DISALLOW_COPY_AND_ASSIGN(DefaultComponentInstaller);
 121 };
 122
 123 }  // namespace component_updater
 124
 125 #endif  // COMPONENTS_COMPONENT_UPDATER_DEFAULT_COMPONENT_INSTALLER_H_