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/callback_forward.h"
  13 #include "base/compiler_specific.h"
  14 #include "base/macros.h"
  15 #include "base/memory/ref_counted.h"
  16 #include "base/memory/scoped_ptr.h"
  17 #include "base/threading/thread_checker.h"
  18 #include "base/values.h"
  19 #include "base/version.h"
  20 #include "components/update_client/update_client.h"
  21
  22 namespace base {
  23 class FilePath;
  24 class SequencedTaskRunner;
  25 class SingleThreadTaskRunner;
  26 }  // namespace base
  27
  28 namespace component_updater {
  29
  30 class ComponentUpdateService;
  31
  32 // Components should use a DefaultComponentInstaller by defining a class that
  33 // implements the members of ComponentInstallerTraits, and then registering a
  34 // DefaultComponentInstaller that has been constructed with an instance of that
  35 // class.
  36 class ComponentInstallerTraits {
  37  public:
  38   virtual ~ComponentInstallerTraits();
  39
  40   // Verifies that a working installation resides within the directory specified
  41   // by |install_dir|. |install_dir| is of the form <base directory>/<version>.
  42   // |manifest| should have been read from the manifest file in |install_dir|.
  43   // Called only from a thread belonging to a blocking thread pool.
  44   // The implementation of this function must be efficient since the function
  45   // can be called when Chrome starts.
  46   virtual bool VerifyInstallation(const base::DictionaryValue& manifest,
  47                                   const base::FilePath& install_dir) const = 0;
  48
  49   // Returns true if the component can be automatically updated. Called once
  50   // during component registration from the UI thread.
  51   virtual bool CanAutoUpdate() const = 0;
  52
  53   // OnCustomInstall is called during the installation process. Components that
  54   // require custom installation operations should implement them here.
  55   // Returns false if a custom operation failed, and true otherwise.
  56   // Called only from a thread belonging to a blocking thread pool.
  57   virtual bool OnCustomInstall(const base::DictionaryValue& manifest,
  58                                const base::FilePath& install_dir) = 0;
  59
  60   // ComponentReady is called in two cases:
  61   //   1) After an installation is successfully completed.
  62   //   2) During component registration if the component is already installed.
  63   // In both cases the install is verified before this is called. This method
  64   // is guaranteed to be called before any observers of the component are
  65   // notified of a successful install, and is meant to support follow-on work
  66   // such as updating paths elsewhere in Chrome. Called on the UI thread.
  67   // |version| is the version of the component.
  68   // |install_dir| is the path to the install directory for this version.
  69   // |manifest| is the manifest for this version of the component.
  70   virtual void ComponentReady(const base::Version& version,
  71                               const base::FilePath& install_dir,
  72                               scoped_ptr<base::DictionaryValue> manifest) = 0;
  73
  74   // Returns the directory that the installer will place versioned installs of
  75   // the component into.
  76   virtual base::FilePath GetBaseDirectory() const = 0;
  77
  78   // Returns the component's SHA2 hash as raw bytes.
  79   virtual void GetHash(std::vector<uint8_t>* hash) const = 0;
  80
  81   // Returns the human-readable name of the component.
  82   virtual std::string GetName() const = 0;
  83 };
  84
  85 // A DefaultComponentInstaller is intended to be final, and not derived from.
  86 // Customization must be provided by passing a ComponentInstallerTraits object
  87 // to the constructor.
  88 class DefaultComponentInstaller : public update_client::ComponentInstaller {
  89  public:
  90   DefaultComponentInstaller(
  91       scoped_ptr<ComponentInstallerTraits> installer_traits);
  92
  93   // Registers the component for update checks and installs.
  94   // The passed |callback| will be called once the initial check for installed
  95   // versions is done and the component has been registered.
  96   void Register(ComponentUpdateService* cus, const base::Closure& callback);
  97
  98   // Overridden from ComponentInstaller:
  99   void OnUpdateError(int error) override;
 100   bool Install(const base::DictionaryValue& manifest,
 101                const base::FilePath& unpack_path) override;
 102   bool GetInstalledFile(const std::string& file,
 103                         base::FilePath* installed_file) override;
 104   bool Uninstall() override;
 105
 106  private:
 107   ~DefaultComponentInstaller() override;
 108
 109   base::FilePath GetInstallDirectory();
 110   bool InstallHelper(const base::DictionaryValue& manifest,
 111                      const base::FilePath& unpack_path,
 112                      const base::FilePath& install_path);
 113   void StartRegistration(ComponentUpdateService* cus);
 114   void FinishRegistration(ComponentUpdateService* cus,
 115                           const base::Closure& callback);
 116   void ComponentReady(scoped_ptr<base::DictionaryValue> manifest);
 117   void UninstallOnTaskRunner();
 118
 119   base::Version current_version_;
 120   std::string current_fingerprint_;
 121   scoped_ptr<base::DictionaryValue> current_manifest_;
 122   scoped_ptr<ComponentInstallerTraits> installer_traits_;
 123   scoped_refptr<base::SequencedTaskRunner> task_runner_;
 124
 125   // Used to post responses back to the main thread. Initialized on the main
 126   // loop but accessed from the task runner.
 127   scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
 128
 129   base::ThreadChecker thread_checker_;
 130
 131   DISALLOW_COPY_AND_ASSIGN(DefaultComponentInstaller);
 132 };
 133
 134 }  // namespace component_updater
 135
 136 #endif  // COMPONENTS_COMPONENT_UPDATER_DEFAULT_COMPONENT_INSTALLER_H_