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      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_BROWSER_PREFS_PREF_VALUE_MAP_H_
      6 #define CHROME_BROWSER_PREFS_PREF_VALUE_MAP_H_
      7 #pragma once
      8 
      9 #include <map>
     10 #include <string>
     11 #include <vector>
     12 
     13 #include "base/basictypes.h"
     14 
     15 class Value;
     16 
     17 // A generic string to value map used by the PrefStore implementations.
     18 class PrefValueMap {
     19  public:
     20   typedef std::map<std::string, Value*>::iterator iterator;
     21   typedef std::map<std::string, Value*>::const_iterator const_iterator;
     22 
     23   PrefValueMap();
     24   virtual ~PrefValueMap();
     25 
     26   // Gets the value for |key| and stores it in |value|. Ownership remains with
     27   // the map. Returns true if a value is present. If not, |value| is not
     28   // touched.
     29   bool GetValue(const std::string& key, const Value** value) const;
     30   bool GetValue(const std::string& key, Value** value);
     31 
     32   // Sets a new |value| for |key|. Takes ownership of |value|, which must be
     33   // non-NULL. Returns true if the value changed.
     34   bool SetValue(const std::string& key, Value* value);
     35 
     36   // Removes the value for |key| from the map. Returns true if a value was
     37   // removed.
     38   bool RemoveValue(const std::string& key);
     39 
     40   // Clears the map.
     41   void Clear();
     42 
     43   iterator begin();
     44   iterator end();
     45   const_iterator begin() const;
     46   const_iterator end() const;
     47 
     48   // Gets a boolean value for |key| and stores it in |value|. Returns true if
     49   // the value was found and of the proper type.
     50   bool GetBoolean(const std::string& key, bool* value) const;
     51 
     52   // Gets a string value for |key| and stores it in |value|. Returns true if
     53   // the value was found and of the proper type.
     54   bool GetString(const std::string& key, std::string* value) const;
     55 
     56   // Sets the value for |key| to the string |value|.
     57   void SetString(const std::string& key, const std::string& value);
     58 
     59   // Compares this value map against |other| and stores all key names that have
     60   // different values in |differing_keys|. This includes keys that are present
     61   // only in one of the maps.
     62   void GetDifferingKeys(const PrefValueMap* other,
     63                         std::vector<std::string>* differing_keys) const;
     64 
     65  private:
     66   typedef std::map<std::string, Value*> Map;
     67 
     68   Map prefs_;
     69 
     70   DISALLOW_COPY_AND_ASSIGN(PrefValueMap);
     71 };
     72 
     73 #endif  // CHROME_BROWSER_PREFS_PREF_VALUE_MAP_H_
     74