reg: Simplify root key search.

programs/reg/reg.c

@@ -22,6 +22,32 @@
 
 #define ARRAY_SIZE(A) (sizeof(A)/sizeof(*A))
 
+static const WCHAR short_hklm[] = {'H','K','L','M',0};
+static const WCHAR short_hkcu[] = {'H','K','C','U',0};
+static const WCHAR short_hkcr[] = {'H','K','C','R',0};
+static const WCHAR short_hku[] = {'H','K','U',0};
+static const WCHAR short_hkcc[] = {'H','K','C','C',0};
+static const WCHAR long_hklm[] = {'H','K','E','Y','_','L','O','C','A','L','_','M','A','C','H','I','N','E',0};
+static const WCHAR long_hkcu[] = {'H','K','E','Y','_','C','U','R','R','E','N','T','_','U','S','E','R',0};
+static const WCHAR long_hkcr[] = {'H','K','E','Y','_','C','L','A','S','S','E','S','_','R','O','O','T',0};
+static const WCHAR long_hku[] = {'H','K','E','Y','_','U','S','E','R','S',0};
+static const WCHAR long_hkcc[] = {'H','K','E','Y','_','C','U','R','R','E','N','T','_','C','O','N','F','I','G',0};
+
+static const struct
+{
+    HKEY key;
+    const WCHAR *short_name;
+    const WCHAR *long_name;
+}
+root_rels[] =
+{
+    {HKEY_LOCAL_MACHINE, short_hklm, long_hklm},
+    {HKEY_CURRENT_USER, short_hkcu, long_hkcu},
+    {HKEY_CLASSES_ROOT, short_hkcr, long_hkcr},
+    {HKEY_USERS, short_hku, long_hku},
+    {HKEY_CURRENT_CONFIG, short_hkcc, long_hkcc},
+};
+
 static const WCHAR type_none[] = {'R','E','G','_','N','O','N','E',0};
 static const WCHAR type_sz[] = {'R','E','G','_','S','Z',0};
 static const WCHAR type_expand_sz[] = {'R','E','G','_','E','X','P','A','N','D','_','S','Z',0};
@@ -95,51 +121,26 @@ static int reg_message(int msg)
     return reg_printfW(formatW, msg_buffer);
 }
 
-static int reg_StrCmpNIW(LPCWSTR str, LPCWSTR comp, int len)
+static inline BOOL path_rootname_cmp(const WCHAR *input_path, const WCHAR *rootkey_name)
 {
-    int i;
+    DWORD length = strlenW(rootkey_name);
 
-    for (i = 0; i < len; i++)
-    {
-        if (!str[i])
-        {
-            len = i + 1;
-            break;
-        }
-    }
-
-    return CompareStringW(CP_ACP, NORM_IGNORECASE, str, len, comp, len) - CSTR_EQUAL;
+    return (!strncmpiW(input_path, rootkey_name, length) &&
+            (input_path[length] == 0 || input_path[length] == '\\'));
 }
 
-static HKEY get_rootkey(LPWSTR key)
+static HKEY path_get_rootkey(const WCHAR *path)
 {
-    static const WCHAR szHKLM[] = {'H','K','L','M',0};
-    static const WCHAR szHKEY_LOCAL_MACHINE[] = {'H','K','E','Y','_','L','O','C','A','L','_','M','A','C','H','I','N','E',0};
-    static const WCHAR szHKCU[] = {'H','K','C','U',0};
-    static const WCHAR szHKEY_CURRENT_USER[] = {'H','K','E','Y','_','C','U','R','R','E','N','T','_','U','S','E','R',0};
-    static const WCHAR szHKCR[] = {'H','K','C','R',0};
-    static const WCHAR szHKEY_CLASSES_ROOT[] = {'H','K','E','Y','_','C','L','A','S','S','E','S','_','R','O','O','T',0};
-    static const WCHAR szHKU[] = {'H','K','U',0};
-    static const WCHAR szHKEY_USERS[] = {'H','K','E','Y','_','U','S','E','R','S',0};
-    static const WCHAR szHKCC[] = {'H','K','C','C',0};
-    static const WCHAR szHKEY_CURRENT_CONFIG[] = {'H','K','E','Y','_','C','U','R','R','E','N','T','_','C','O','N','F','I','G',0};
-
-    if (!reg_StrCmpNIW(key, szHKLM, 4) ||
-        !reg_StrCmpNIW(key, szHKEY_LOCAL_MACHINE, 18))
-        return HKEY_LOCAL_MACHINE;
-    else if (!reg_StrCmpNIW(key, szHKCU, 4) ||
-             !reg_StrCmpNIW(key, szHKEY_CURRENT_USER, 17))
-        return HKEY_CURRENT_USER;
-    else if (!reg_StrCmpNIW(key, szHKCR, 4) ||
-             !reg_StrCmpNIW(key, szHKEY_CLASSES_ROOT, 17))
-        return HKEY_CLASSES_ROOT;
-    else if (!reg_StrCmpNIW(key, szHKU, 3) ||
-             !reg_StrCmpNIW(key, szHKEY_USERS, 10))
-        return HKEY_USERS;
-    else if (!reg_StrCmpNIW(key, szHKCC, 4) ||
-             !reg_StrCmpNIW(key, szHKEY_CURRENT_CONFIG, 19))
-        return HKEY_CURRENT_CONFIG;
-    else return NULL;
+    DWORD i;
+
+    for (i = 0; i < ARRAY_SIZE(root_rels); i++)
+    {
+        if (path_rootname_cmp(path, root_rels[i].short_name) ||
+            path_rootname_cmp(path, root_rels[i].long_name))
+            return root_rels[i].key;
+    }
+
+    return NULL;
 }
 
 static DWORD wchar_get_type(const WCHAR *type_name)
@@ -280,7 +281,7 @@ static int reg_add(WCHAR *key_name, WCHAR *value_name, BOOL value_empty,
     }
     p++;
 
-    root = get_rootkey(key_name);
+    root = path_get_rootkey(key_name);
     if (!root)
     {
         reg_message(STRING_INVALID_KEY);
@@ -350,7 +351,7 @@ static int reg_delete(WCHAR *key_name, WCHAR *value_name, BOOL value_empty,
     }
     p++;
 
-    root = get_rootkey(key_name);
+    root = path_get_rootkey(key_name);
     if (!root)
     {
         reg_message(STRING_INVALID_KEY);