Improve perforance for component IME extensions initialization by using map instead of vector in Co…

chromeos/ime/extension_ime_util.cc

 // Copyright 2013 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.
 
 #include "chromeos/ime/extension_ime_util.h"
 
 #include "base/strings/string_util.h"
 
 namespace chromeos {
 
@@ skipping 21 matching lines @@
 
 std::string GetComponentInputMethodID(const std::string& extension_id,
                                       const std::string& engine_id) {
   DCHECK(!extension_id.empty());
   DCHECK(!engine_id.empty());
   return kComponentExtensionIMEPrefix + extension_id + engine_id;
 }
 
 std::string GetExtensionIDFromInputMethodID(
     const std::string& input_method_id) {
-  if (IsExtensionIME(input_method_id) &&
-      input_method_id.size() >= kExtensionIMEPrefixLength +
-                                kExtensionIdLength) {
+  if (IsExtensionIME(input_method_id)) {
     return input_method_id.substr(kExtensionIMEPrefixLength,
                                   kExtensionIdLength);
   }
-  if (IsComponentExtensionIME(input_method_id) &&
-      input_method_id.size() >= kComponentExtensionIMEPrefixLength +
-                                kExtensionIdLength) {
+  if (IsComponentExtensionIME(input_method_id)) {
     return input_method_id.substr(kComponentExtensionIMEPrefixLength,
                                   kExtensionIdLength);
   }
   return "";
 }
 
 std::string GetComponentIDByInputMethodID(const std::string& input_method_id) {
   if (IsComponentExtensionIME(input_method_id))
     return input_method_id.substr(kComponentExtensionIMEPrefixLength +
                                   kExtensionIdLength);
@@ skipping 31 matching lines @@
   }
   if (engine_id.find("-t-i0-") != std::string::npos)
     return GetComponentInputMethodID(kT13nExtensionId, engine_id);
 
   return engine_id;
 }
 
 bool IsExtensionIME(const std::string& input_method_id) {
   return StartsWithASCII(input_method_id,
                          kExtensionIMEPrefix,
-                         true);  // Case sensitive.
+                         true /* Case sensitive */) &&
+      input_method_id.size() > kExtensionIMEPrefixLength +
+          kExtensionIdLength;
 }
 
 bool IsComponentExtensionIME(const std::string& input_method_id) {
   return StartsWithASCII(input_method_id,
                          kComponentExtensionIMEPrefix,
-                         true);  // Case sensitive.
+                         true /* Case sensitive */) &&
+      input_method_id.size() > kComponentExtensionIMEPrefixLength +
+          kExtensionIdLength;
 }
 
 bool IsMemberOfExtension(const std::string& input_method_id,
                          const std::string& extension_id) {
   return StartsWithASCII(input_method_id,
                          kExtensionIMEPrefix + extension_id,
-                         true);  // Case sensitive.
+                         true /* Case sensitive */);
 }
 
 bool IsKeyboardLayoutExtension(const std::string& input_method_id) {
   std::string prefix = kComponentExtensionIMEPrefix;
   return StartsWithASCII(input_method_id, prefix + kXkbExtensionId, true);
 }
 
 std::string MaybeGetLegacyXkbId(const std::string& input_method_id) {
   if (IsKeyboardLayoutExtension(input_method_id))
     return GetComponentIDByInputMethodID(input_method_id);
   return input_method_id;
 }
 
 }  // namespace extension_ime_util
 }  // namespace chromeos