Introduce UpdateActiveSetupVersionWorkItem

chrome/installer/setup/update_active_setup_version_work_item.h

+// Copyright 2015 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_INSTALLER_SETUP_UPDATE_ACTIVE_SETUP_VERSION_WORK_ITEM_H_
+#define CHROME_INSTALLER_SETUP_UPDATE_ACTIVE_SETUP_VERSION_WORK_ITEM_H_
+
+#include "base/macros.h"
+#include "base/strings/string16.h"
+#include "chrome/installer/util/set_reg_value_work_item.h"
+#include "chrome/installer/util/work_item.h"
+
+// A WorkItem that updates (or installs if not present) the Active Setup
+// "Version" field in the registry. Optionally bumping the OS_UPGRADES component
+// on demand. This WorkItem is only viable on machine-wide installs.
+class UpdateActiveSetupVersionWorkItem : public WorkItem {
+ public:
+  // The operation to be performed by this UpdateActiveSetupVersionWorkItem.
+  enum Operation {
+    // Update (or install if not present) the Active Setup "Version" in the
+    // registry.
+    UPDATE,
+    // Also bump the OS_UPGRADES component on top of updating the version
+    // (will default to 1 if the version was absent or invalid).
+    UPDATE_AND_BUMP_OS_UPGRADES_COMPONENT,
+  };
+
+  // Constructs an UpdateActiveSetupVersionWorkItem that will perform
+  // |operation| on the |active_setup_path| key in the registry. This key needs
+  // to exist when this WorkItem is ran.
+  UpdateActiveSetupVersionWorkItem(const base::string16& active_setup_path,
+                                   Operation operation);
+
+  // Overriden from WorkItem.
+  bool Do() override;
+  void Rollback() override;
+
+ private:
+  // The components of the Active Setup Version entry, in order.
+  enum ActiveSetupVersionComponent {
+    // The major version.
+    MAJOR,
+    // Unused component, always 0 for now.
+    UNUSED1,
+    // Number of OS upgrades handled since original install.
+    OS_UPGRADES,
+    // Unused component, always 0 for now.
+    UNUSED2,
+  };
+
+  // Returns the updated Active Setup version to be used based on the
+  // |existing_version|.
+  base::string16 GetUpdatedActiveSetupVersion(
+      const base::string16& existing_version);
+
+  // The underlying WorkItem re-used to operate forward and backward on the
+  // registry.
+  SetRegValueWorkItem set_reg_value_work_item_;
+
+  // The Operation to be performed by this WorkItem when executed.
+  const Operation operation_;
+
+  DISALLOW_COPY_AND_ASSIGN(UpdateActiveSetupVersionWorkItem);
+};
+
+#endif  // CHROME_INSTALLER_SETUP_UPDATE_ACTIVE_SETUP_VERSION_WORK_ITEM_H_