chrome/installer/mini_installer/regkey.h

   1 // Copyright (c) 2012 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_MINI_INSTALLER_REGKEY_H_
   6 #define CHROME_INSTALLER_MINI_INSTALLER_REGKEY_H_
   7
   8 #include <windows.h>
   9
  10 namespace mini_installer {
  11
  12 // A helper class used to manipulate the Windows registry.  Typically, members
  13 // return Windows last-error codes a la Win32 registry API.
  14 class RegKey {
  15  public:
  16   RegKey() : key_(NULL) { }
  17   ~RegKey() { Close(); }
  18
  19   // Opens the key named |sub_key| with given |access| rights.  Returns
  20   // ERROR_SUCCESS or some other error.
  21   LONG Open(HKEY key, const wchar_t* sub_key, REGSAM access);
  22
  23   // Returns true if a key is open.
  24   bool is_valid() const { return key_ != NULL; }
  25
  26   // Read a value from the registry into the memory indicated by |value|
  27   // (of |value_size| wchar_t units).  Returns ERROR_SUCCESS,
  28   // ERROR_FILE_NOT_FOUND, ERROR_MORE_DATA, or some other error.  |value| is
  29   // guaranteed to be null-terminated on success.
  30   LONG ReadSZValue(const wchar_t* value_name,
  31                    wchar_t* value,
  32                    size_t value_size) const;
  33   LONG ReadDWValue(const wchar_t* value_name, DWORD* value) const;
  34
  35   // Write a value to the registry.  SZ |value| must be null-terminated.
  36   // Returns ERROR_SUCCESS or an error code.
  37   LONG WriteSZValue(const wchar_t* value_name, const wchar_t* value);
  38   LONG WriteDWValue(const wchar_t* value_name, DWORD value);
  39
  40   // Closes the key if it was open.
  41   void Close();
  42
  43   // Helper function to read a value from registry.  Returns true if value
  44   // is read successfully and stored in parameter value. Returns false
  45   // otherwise. |size| is measured in wchar_t units.
  46   static bool ReadSZValue(HKEY root_key, const wchar_t *sub_key,
  47                           const wchar_t *value_name, wchar_t *value,
  48                           size_t value_size);
  49
  50  private:
  51   RegKey(const RegKey&);
  52   RegKey& operator=(const RegKey&);
  53
  54   HKEY key_;
  55 };  // class RegKey
  56
  57
  58 // Helper function to get the RegKey associated with the "client state" of
  59 // the given |app_guid|.
  60 bool OpenClientStateKey(HKEY root_key, const wchar_t* app_guid,
  61                         REGSAM access, RegKey* key);
  62
  63 }  // namespace mini_installer
  64
  65 #endif  // CHROME_INSTALLER_MINI_INSTALLER_REGKEY_H_