chrome/installer/util/conditional_work_item_list.h

   1 // Copyright (c) 2011 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 CHROME_INSTALLER_UTIL_CONDITIONAL_WORK_ITEM_LIST_H_
   6 #define CHROME_INSTALLER_UTIL_CONDITIONAL_WORK_ITEM_LIST_H_
   7
   8 #include "chrome/installer/util/work_item_list.h"
   9
  10 #include "base/files/file_path.h"
  11 #include "base/memory/scoped_ptr.h"
  12
  13 // A WorkItemList subclass that permits conditionally executing a set of
  14 // WorkItems.
  15 class ConditionalWorkItemList : public WorkItemList {
  16  public:
  17   explicit ConditionalWorkItemList(Condition* condition);
  18   virtual ~ConditionalWorkItemList();
  19
  20   // If condition_->ShouldRun() returns true, then execute the items in this
  21   // list and return true iff they all succeed. If condition_->ShouldRun()
  22   // returns false, does nothing and returns true.
  23   virtual bool Do();
  24
  25   // Does a rollback of the items (if any) that were run in Do.
  26   virtual void Rollback();
  27
  28  protected:
  29   // Pointer to a Condition that is used to determine whether to run this
  30   // WorkItemList.
  31   scoped_ptr<Condition> condition_;
  32 };
  33
  34
  35 // Pre-defined conditions:
  36 //------------------------------------------------------------------------------
  37 class ConditionRunIfFileExists : public WorkItem::Condition {
  38  public:
  39   explicit ConditionRunIfFileExists(const base::FilePath& key_path)
  40       : key_path_(key_path) {}
  41   bool ShouldRun() const;
  42
  43  private:
  44   base::FilePath key_path_;
  45 };
  46
  47 // Condition class that inverts the ShouldRun result of another Condition.
  48 // This class assumes ownership of original_condition.
  49 class Not : public WorkItem::Condition {
  50  public:
  51    explicit Not(WorkItem::Condition* original_condition)
  52      : original_condition_(original_condition) {}
  53   bool ShouldRun() const;
  54
  55  private:
  56   scoped_ptr<WorkItem::Condition> original_condition_;
  57 };
  58
  59
  60 #endif  // CHROME_INSTALLER_UTIL_CONDITIONAL_WORK_ITEM_LIST_H_