base/win: small improvement to RegKey API.

base/win/registry.h

 // Copyright (c) 2011 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_
 #pragma once
 
 #include <windows.h>
 #include <string>
@@ skipping 15 matching lines @@
  public:
   RegKey();
   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);
 
-  LONG Open(HKEY rootkey, const wchar_t* subkey, REGSAM access);
-
   // Creates a subkey or open it if it already exists.
   LONG CreateKey(const wchar_t* name, REGSAM access);
 
-  // Opens a subkey
-  LONG OpenKey(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();
 
-  DWORD ValueCount() const;
+  // 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 ReadName(int index, std::wstring* name) const;
+  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);
 
-  bool ValueExists(const wchar_t* name) const;
-
   LONG ReadValue(const wchar_t* name, void* data, DWORD* dsize,
                  DWORD* dtype) const;
   LONG ReadValue(const wchar_t* name, std::wstring* value) const;
   LONG ReadValueDW(const wchar_t* name, DWORD* value) const;
   LONG ReadInt64(const wchar_t* name, int64* value) const;
 
   LONG WriteValue(const wchar_t* name, const void* data, DWORD dsize,
                   DWORD dtype);
   LONG WriteValue(const wchar_t* name, const wchar_t* value);
   LONG WriteValue(const wchar_t* name, DWORD value);
@@ skipping 96 matching lines @@
 
   wchar_t name_[MAX_PATH];
 
   DISALLOW_COPY_AND_ASSIGN(RegistryKeyIterator);
 };
 
 }  // namespace win
 }  // namespace base
 
 #endif  // BASE_WIN_REGISTRY_H_