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 BASE_WIN_REGISTRY_H_ 6 #define BASE_WIN_REGISTRY_H_ 7 #pragma once 8 9 #include <windows.h> 10 #include <string> 11 12 #include "base/base_api.h" 13 #include "base/basictypes.h" 14 15 namespace base { 16 namespace win { 17 18 // Utility class to read, write and manipulate the Windows Registry. 19 // Registry vocabulary primer: a "key" is like a folder, in which there 20 // are "values", which are <name, data> pairs, with an associated data type. 21 // 22 // Note: 23 // ReadValue family of functions guarantee that the return arguments 24 // are not touched in case of failure. 25 class BASE_API RegKey { 26 public: 27 RegKey(); 28 RegKey(HKEY rootkey, const wchar_t* subkey, REGSAM access); 29 ~RegKey(); 30 31 LONG Create(HKEY rootkey, const wchar_t* subkey, REGSAM access); 32 33 LONG CreateWithDisposition(HKEY rootkey, const wchar_t* subkey, 34 DWORD* disposition, REGSAM access); 35 36 LONG Open(HKEY rootkey, const wchar_t* subkey, REGSAM access); 37 38 // Creates a subkey or open it if it already exists. 39 LONG CreateKey(const wchar_t* name, REGSAM access); 40 41 // Opens a subkey 42 LONG OpenKey(const wchar_t* name, REGSAM access); 43 44 void Close(); 45 46 DWORD ValueCount() const; 47 48 // Determine the nth value's name. 49 LONG ReadName(int index, std::wstring* name) const; 50 51 // True while the key is valid. 52 bool Valid() const { return key_ != NULL; } 53 54 // Kill a key and everything that live below it; please be careful when using 55 // it. 56 LONG DeleteKey(const wchar_t* name); 57 58 // Deletes a single value within the key. 59 LONG DeleteValue(const wchar_t* name); 60 61 bool ValueExists(const wchar_t* name) const; 62 63 LONG ReadValue(const wchar_t* name, void* data, DWORD* dsize, 64 DWORD* dtype) const; 65 LONG ReadValue(const wchar_t* name, std::wstring* value) const; 66 LONG ReadValueDW(const wchar_t* name, DWORD* value) const; 67 LONG ReadInt64(const wchar_t* name, int64* value) const; 68 69 LONG WriteValue(const wchar_t* name, const void* data, DWORD dsize, 70 DWORD dtype); 71 LONG WriteValue(const wchar_t* name, const wchar_t* value); 72 LONG WriteValue(const wchar_t* name, DWORD value); 73 74 // Starts watching the key to see if any of its values have changed. 75 // The key must have been opened with the KEY_NOTIFY access privilege. 76 LONG StartWatching(); 77 78 // If StartWatching hasn't been called, always returns false. 79 // Otherwise, returns true if anything under the key has changed. 80 // This can't be const because the |watch_event_| may be refreshed. 81 bool HasChanged(); 82 83 // Will automatically be called by destructor if not manually called 84 // beforehand. Returns true if it was watching, false otherwise. 85 LONG StopWatching(); 86 87 inline bool IsWatching() const { return watch_event_ != 0; } 88 HANDLE watch_event() const { return watch_event_; } 89 HKEY Handle() const { return key_; } 90 91 private: 92 HKEY key_; // The registry key being iterated. 93 HANDLE watch_event_; 94 95 DISALLOW_COPY_AND_ASSIGN(RegKey); 96 }; 97 98 // Iterates the entries found in a particular folder on the registry. 99 // For this application I happen to know I wont need data size larger 100 // than MAX_PATH, but in real life this wouldn't neccessarily be 101 // adequate. 102 class BASE_API RegistryValueIterator { 103 public: 104 RegistryValueIterator(HKEY root_key, const wchar_t* folder_key); 105 106 ~RegistryValueIterator(); 107 108 DWORD ValueCount() const; 109 110 // True while the iterator is valid. 111 bool Valid() const; 112 113 // Advances to the next registry entry. 114 void operator++(); 115 116 const wchar_t* Name() const { return name_; } 117 const wchar_t* Value() const { return value_; } 118 DWORD ValueSize() const { return value_size_; } 119 DWORD Type() const { return type_; } 120 121 int Index() const { return index_; } 122 123 private: 124 // Read in the current values. 125 bool Read(); 126 127 // The registry key being iterated. 128 HKEY key_; 129 130 // Current index of the iteration. 131 int index_; 132 133 // Current values. 134 wchar_t name_[MAX_PATH]; 135 wchar_t value_[MAX_PATH]; 136 DWORD value_size_; 137 DWORD type_; 138 139 DISALLOW_COPY_AND_ASSIGN(RegistryValueIterator); 140 }; 141 142 class BASE_API RegistryKeyIterator { 143 public: 144 RegistryKeyIterator(HKEY root_key, const wchar_t* folder_key); 145 146 ~RegistryKeyIterator(); 147 148 DWORD SubkeyCount() const; 149 150 // True while the iterator is valid. 151 bool Valid() const; 152 153 // Advances to the next entry in the folder. 154 void operator++(); 155 156 const wchar_t* Name() const { return name_; } 157 158 int Index() const { return index_; } 159 160 private: 161 // Read in the current values. 162 bool Read(); 163 164 // The registry key being iterated. 165 HKEY key_; 166 167 // Current index of the iteration. 168 int index_; 169 170 wchar_t name_[MAX_PATH]; 171 172 DISALLOW_COPY_AND_ASSIGN(RegistryKeyIterator); 173 }; 174 175 } // namespace win 176 } // namespace base 177 178 #endif // BASE_WIN_REGISTRY_H_ 179
