1 // Copyright 2013 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_POLICY_CORE_COMMON_REGISTRY_DICT_H_
6 #define COMPONENTS_POLICY_CORE_COMMON_REGISTRY_DICT_H_
7 
8 #include <map>
9 #include <memory>
10 #include <string>
11 
12 #include "base/macros.h"
13 #include "base/optional.h"
14 #include "base/strings/string16.h"
15 #include "components/policy/policy_export.h"
16 
17 #if defined(OS_WIN)
18 #include <windows.h>
19 #endif
20 
21 namespace base {
22 class Value;
23 }
24 
25 namespace policy {
26 
27 class Schema;
28 
29 // Converts a value (as read from the registry) to meet |schema|, converting
30 // types as necessary. Unconvertible types will show up as null values in the
31 // result.
32 base::Optional<base::Value> POLICY_EXPORT
33 ConvertRegistryValue(const base::Value& value, const Schema& schema);
34 
35 // A case-insensitive string comparison functor.
36 struct POLICY_EXPORT CaseInsensitiveStringCompare {
37   bool operator()(const std::string& a, const std::string& b) const;
38 };
39 
40 // In-memory representation of a registry subtree. Using a
41 // base::DictionaryValue directly seems tempting, but that doesn't handle the
42 // registry's case-insensitive-but-case-preserving semantics properly.
43 class POLICY_EXPORT RegistryDict {
44  public:
45   using KeyMap = std::map<std::string,
46                           std::unique_ptr<RegistryDict>,
47                           CaseInsensitiveStringCompare>;
48   using ValueMap = std::map<std::string,
49                             std::unique_ptr<base::Value>,
50                             CaseInsensitiveStringCompare>;
51 
52   RegistryDict();
53   ~RegistryDict();
54 
55   // Returns a pointer to an existing key, NULL if not present.
56   RegistryDict* GetKey(const std::string& name);
57   const RegistryDict* GetKey(const std::string& name) const;
58   // Sets a key. If |dict| is NULL, clears that key.
59   void SetKey(const std::string& name, std::unique_ptr<RegistryDict> dict);
60   // Removes a key. If the key doesn't exist, NULL is returned.
61   std::unique_ptr<RegistryDict> RemoveKey(const std::string& name);
62   // Clears all keys.
63   void ClearKeys();
64 
65   // Returns a pointer to a value, NULL if not present.
66   base::Value* GetValue(const std::string& name);
67   const base::Value* GetValue(const std::string& name) const;
68   // Sets a value. If |value| is NULL, removes the value.
69   void SetValue(const std::string& name, std::unique_ptr<base::Value> value);
70   // Removes a value. If the value doesn't exist, NULL is returned.
71   std::unique_ptr<base::Value> RemoveValue(const std::string& name);
72   // Clears all values.
73   void ClearValues();
74 
75   // Merge keys and values from |other|, giving precedence to |other|.
76   void Merge(const RegistryDict& other);
77 
78   // Swap with |other|.
79   void Swap(RegistryDict* other);
80 
81 #if defined(OS_WIN)
82   // Read a Windows registry subtree into this registry dictionary object.
83   void ReadRegistry(HKEY hive, const base::string16& root);
84 
85   // Converts the dictionary to base::Value representation. For key/value name
86   // collisions, the key wins. |schema| is used to determine the expected type
87   // for each policy.
88   // The returned object is either a base::DictionaryValue or a base::ListValue.
89   std::unique_ptr<base::Value> ConvertToJSON(const class Schema& schema) const;
90 #endif
91 
keys()92   const KeyMap& keys() const { return keys_; }
values()93   const ValueMap& values() const { return values_; }
94 
95  private:
96   KeyMap keys_;
97   ValueMap values_;
98 
99   DISALLOW_COPY_AND_ASSIGN(RegistryDict);
100 };
101 
102 }  // namespace policy
103 
104 #endif  // COMPONENTS_POLICY_CORE_COMMON_REGISTRY_DICT_H_
105