// Copyright (c) 2012 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 BASE_WIN_REGISTRY_H_ #define BASE_WIN_REGISTRY_H_ #include #include #include #include "base/base_export.h" #include "base/basictypes.h" #include "base/stl_util.h" namespace base { namespace win { // Utility class to read, write and manipulate the Windows Registry. // Registry vocabulary primer: a "key" is like a folder, in which there // are "values", which are pairs, with an associated data type. // // Note: // ReadValue family of functions guarantee that the return arguments // are not touched in case of failure. class BASE_EXPORT RegKey { public: RegKey(); explicit RegKey(HKEY key); RegKey(HKEY rootkey, const wchar_t* subkey, REGSAM access); ~RegKey(); LONG Create(HKEY rootkey, const wchar_t* subkey, REGSAM access); LONG CreateWithDisposition(HKEY rootkey, const wchar_t* subkey, DWORD* disposition, REGSAM access); // Creates a subkey or open it if it already exists. LONG CreateKey(const wchar_t* name, REGSAM access); // Opens an existing reg key. LONG Open(HKEY rootkey, const wchar_t* subkey, REGSAM access); // Opens an existing reg key, given the relative key name. LONG OpenKey(const wchar_t* relative_key_name, REGSAM access); // Closes this reg key. void Close(); // Replaces the handle of the registry key and takes ownership of the handle. void Set(HKEY key); // Transfers ownership away from this object. HKEY Take(); // Returns false if this key does not have the specified value, of if an error // occurrs while attempting to access it. bool HasValue(const wchar_t* value_name) const; // Returns the number of values for this key, of 0 if the number cannot be // determined. DWORD GetValueCount() const; // Determine the nth value's name. LONG GetValueNameAt(int index, std::wstring* name) const; // True while the key is valid. bool Valid() const { return key_ != NULL; } // Kill a key and everything that live below it; please be careful when using // it. LONG DeleteKey(const wchar_t* name); // Deletes a single value within the key. LONG DeleteValue(const wchar_t* name); // Getters: // Returns an int32 value. If |name| is NULL or empty, returns the default // value, if any. LONG ReadValueDW(const wchar_t* name, DWORD* out_value) const; // Returns an int64 value. If |name| is NULL or empty, returns the default // value, if any. LONG ReadInt64(const wchar_t* name, int64* out_value) const; // Returns a string value. If |name| is NULL or empty, returns the default // value, if any. LONG ReadValue(const wchar_t* name, std::wstring* out_value) const; // Reads a REG_MULTI_SZ registry field into a vector of strings. Clears // |values| initially and adds further strings to the list. Returns // ERROR_CANTREAD if type is not REG_MULTI_SZ. LONG ReadValues(const wchar_t* name, std::vector* values); // Returns raw data. If |name| is NULL or empty, returns the default // value, if any. LONG ReadValue(const wchar_t* name, void* data, DWORD* dsize, DWORD* dtype) const; // Setters: // Sets an int32 value. LONG WriteValue(const wchar_t* name, DWORD in_value); // Sets a string value. LONG WriteValue(const wchar_t* name, const wchar_t* in_value); // Sets raw data, including type. LONG WriteValue(const wchar_t* name, const void* data, DWORD dsize, DWORD dtype); // Starts watching the key to see if any of its values have changed. // The key must have been opened with the KEY_NOTIFY access privilege. LONG StartWatching(); // If StartWatching hasn't been called, always returns false. // Otherwise, returns true if anything under the key has changed. // This can't be const because the |watch_event_| may be refreshed. bool HasChanged(); // Will automatically be called by destructor if not manually called // beforehand. Returns true if it was watching, false otherwise. LONG StopWatching(); inline bool IsWatching() const { return watch_event_ != 0; } HANDLE watch_event() const { return watch_event_; } HKEY Handle() const { return key_; } private: HKEY key_; // The registry key being iterated. HANDLE watch_event_; DISALLOW_COPY_AND_ASSIGN(RegKey); }; // Iterates the entries found in a particular folder on the registry. class BASE_EXPORT RegistryValueIterator { public: RegistryValueIterator(HKEY root_key, const wchar_t* folder_key); ~RegistryValueIterator(); DWORD ValueCount() const; // True while the iterator is valid. bool Valid() const; // Advances to the next registry entry. void operator++(); const wchar_t* Name() const { return name_.c_str(); } const wchar_t* Value() const { return vector_as_array(&value_); } // ValueSize() is in bytes. DWORD ValueSize() const { return value_size_; } DWORD Type() const { return type_; } int Index() const { return index_; } private: // Read in the current values. bool Read(); // The registry key being iterated. HKEY key_; // Current index of the iteration. int index_; // Current values. std::wstring name_; std::vector value_; DWORD value_size_; DWORD type_; DISALLOW_COPY_AND_ASSIGN(RegistryValueIterator); }; class BASE_EXPORT RegistryKeyIterator { public: RegistryKeyIterator(HKEY root_key, const wchar_t* folder_key); ~RegistryKeyIterator(); DWORD SubkeyCount() const; // True while the iterator is valid. bool Valid() const; // Advances to the next entry in the folder. void operator++(); const wchar_t* Name() const { return name_; } int Index() const { return index_; } private: // Read in the current values. bool Read(); // The registry key being iterated. HKEY key_; // Current index of the iteration. int index_; wchar_t name_[MAX_PATH]; DISALLOW_COPY_AND_ASSIGN(RegistryKeyIterator); }; } // namespace win } // namespace base #endif // BASE_WIN_REGISTRY_H_