base/win: small improvement to RegKey API.

- Rename ValueExists() to HasValue().
- Rename ValueCount()  to GetValueCount().
- Rename ReadName()    to GetValueNameAt().

R=maruel@chromium.org,willchan@chromium.org

Review URL: http://codereview.chromium.org/8337006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@106074 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 45 insertions, 38 deletions

diff --git a/base/win/registry.cc b/base/win/registry.cc
index d105a4c..fa8f422 100644
--- a/base/win/registry.cc
+++ b/base/win/registry.cc
@@ -56,15 +56,6 @@ LONG RegKey::CreateWithDisposition(HKEY rootkey, const wchar_t* subkey,
   return result;
 }
 
-LONG RegKey::Open(HKEY rootkey, const wchar_t* subkey, REGSAM access) {
-  base::ThreadRestrictions::AssertIOAllowed();
-  DCHECK(rootkey && subkey && access);
-  Close();
-
-  LONG result = RegOpenKeyEx(rootkey, subkey, 0, access, &key_);
-  return result;
-}
-
 LONG RegKey::CreateKey(const wchar_t* name, REGSAM access) {
   base::ThreadRestrictions::AssertIOAllowed();
   DCHECK(name && access);
@@ -78,13 +69,24 @@ LONG RegKey::CreateKey(const wchar_t* name, REGSAM access) {
   return result;
 }
 
-LONG RegKey::OpenKey(const wchar_t* name, REGSAM access) {
+LONG RegKey::Open(HKEY rootkey, const wchar_t* subkey, REGSAM access) {
   base::ThreadRestrictions::AssertIOAllowed();
-  DCHECK(name && access);
+  DCHECK(rootkey && subkey && access);
+  Close();
+
+  LONG result = RegOpenKeyEx(rootkey, subkey, 0, access, &key_);
+  return result;
+}
+
+LONG RegKey::OpenKey(const wchar_t* relative_key_name, REGSAM access) {
+  base::ThreadRestrictions::AssertIOAllowed();
+  DCHECK(relative_key_name && access);
 
   HKEY subkey = NULL;
-  LONG result = RegOpenKeyEx(key_, name, 0, access, &subkey);
+  LONG result = RegOpenKeyEx(key_, relative_key_name, 0, access, &subkey);
 
+  // We have to close the current opened key before replacing it with the new
+  // one.
   Close();
 
   key_ = subkey;
@@ -100,15 +102,20 @@ void RegKey::Close() {
   }
 }
 
-DWORD RegKey::ValueCount() const {
+bool RegKey::HasValue(const wchar_t* name) const {
+  base::ThreadRestrictions::AssertIOAllowed();
+  return RegQueryValueEx(key_, name, 0, NULL, NULL, NULL) == ERROR_SUCCESS;
+}
+
+DWORD RegKey::GetValueCount() const {
   base::ThreadRestrictions::AssertIOAllowed();
   DWORD count = 0;
   LONG result = RegQueryInfoKey(key_, NULL, 0, NULL, NULL, NULL, NULL, &count,
                                 NULL, NULL, NULL, NULL);
-  return (result != ERROR_SUCCESS) ? 0 : count;
+  return (result == ERROR_SUCCESS) ? count : 0;
 }
 
-LONG RegKey::ReadName(int index, std::wstring* name) const {
+LONG RegKey::GetValueNameAt(int index, std::wstring* name) const {
   base::ThreadRestrictions::AssertIOAllowed();
   wchar_t buf[256];
   DWORD bufsize = arraysize(buf);
@@ -135,12 +142,6 @@ LONG RegKey::DeleteValue(const wchar_t* value_name) {
   return result;
 }
 
-bool RegKey::ValueExists(const wchar_t* name) const {
-  base::ThreadRestrictions::AssertIOAllowed();
-  LONG result = RegQueryValueEx(key_, name, 0, NULL, NULL, NULL);
-  return result == ERROR_SUCCESS;
-}
-
 LONG RegKey::ReadValue(const wchar_t* name, void* data, DWORD* dsize,
                        DWORD* dtype) const {
   base::ThreadRestrictions::AssertIOAllowed();
diff --git a/base/win/registry.h b/base/win/registry.h
index 078e6e0..33052ff 100644
--- a/base/win/registry.h
+++ b/base/win/registry.h
@@ -33,20 +33,28 @@ class BASE_EXPORT RegKey {
   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; }
@@ -58,8 +66,6 @@ class BASE_EXPORT RegKey {
   // 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;
diff --git a/base/win/registry_unittest.cc b/base/win/registry_unittest.cc
index a7961e9..1737786 100644
--- a/base/win/registry_unittest.cc
+++ b/base/win/registry_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -60,10 +60,10 @@ TEST_F(RegistryTest, ValueTest) {
     ASSERT_EQ(ERROR_SUCCESS, key.WriteValue(kDWORDValueName, kDWORDData));
     ASSERT_EQ(ERROR_SUCCESS, key.WriteValue(kInt64ValueName, &kInt64Data,
                                             sizeof(kInt64Data), REG_QWORD));
-    EXPECT_EQ(3U, key.ValueCount());
-    EXPECT_TRUE(key.ValueExists(kStringValueName));
-    EXPECT_TRUE(key.ValueExists(kDWORDValueName));
-    EXPECT_TRUE(key.ValueExists(kInt64ValueName));
+    EXPECT_EQ(3U, key.GetValueCount());
+    EXPECT_TRUE(key.HasValue(kStringValueName));
+    EXPECT_TRUE(key.HasValue(kDWORDValueName));
+    EXPECT_TRUE(key.HasValue(kInt64ValueName));
 
     // Test Read
     std::wstring string_value;
@@ -89,10 +89,10 @@ TEST_F(RegistryTest, ValueTest) {
     ASSERT_EQ(ERROR_SUCCESS, key.DeleteValue(kStringValueName));
     ASSERT_EQ(ERROR_SUCCESS, key.DeleteValue(kDWORDValueName));
     ASSERT_EQ(ERROR_SUCCESS, key.DeleteValue(kInt64ValueName));
-    EXPECT_EQ(0U, key.ValueCount());
-    EXPECT_FALSE(key.ValueExists(kStringValueName));
-    EXPECT_FALSE(key.ValueExists(kDWORDValueName));
-    EXPECT_FALSE(key.ValueExists(kInt64ValueName));
+    EXPECT_EQ(0U, key.GetValueCount());
+    EXPECT_FALSE(key.HasValue(kStringValueName));
+    EXPECT_FALSE(key.HasValue(kDWORDValueName));
+    EXPECT_FALSE(key.HasValue(kInt64ValueName));
   }
 }