Making structure for ContentSettings and its corresponding strings.

components/content_settings/core/browser/content_settings_utils.cc

 // Copyright (c) 2012 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 "components/content_settings/core/browser/content_settings_utils.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/pref_registry.h"
 #include "base/strings/string_split.h"
 #include "base/values.h"
 #include "components/content_settings/core/browser/content_settings_provider.h"
 #include "components/content_settings/core/browser/content_settings_rule.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/content_settings/core/browser/website_settings_info.h"
 #include "components/content_settings/core/browser/website_settings_registry.h"
 #include "components/content_settings/core/common/content_settings_pattern.h"
 #include "components/pref_registry/pref_registry_syncable.h"
 #include "url/gurl.h"
 
 namespace {
 
 const char kPatternSeparator[] = ",";
 
+struct ContentSettingsStringMapping {
+  ContentSetting content_setting;
+  const char* content_setting_str;
+};
+const ContentSettingsStringMapping kContentSettingsStringMapping[] = {
+    {CONTENT_SETTING_DEFAULT, "default"},
+    {CONTENT_SETTING_ALLOW, "allow"},
+    {CONTENT_SETTING_BLOCK, "block"},
+    {CONTENT_SETTING_ASK, "ask"},
+    {CONTENT_SETTING_SESSION_ONLY, "session_only"},
+    {CONTENT_SETTING_DETECT_IMPORTANT_CONTENT, "detect_important_content"},
+};
+static_assert(arraysize(kContentSettingsStringMapping) ==
+                  CONTENT_SETTING_NUM_SETTINGS,
+              "kContentSettingsToFromString should have "
+              "CONTENT_SETTING_NUM_SETTINGS elements");
 }  // namespace
 
 namespace content_settings {
 
 std::string ContentSettingToString(ContentSetting setting) {
-  switch (setting) {
-    case CONTENT_SETTING_ALLOW:
-      return "allow";
-    case CONTENT_SETTING_ASK:
-      return "ask";
-    case CONTENT_SETTING_BLOCK:
-      return "block";
-    case CONTENT_SETTING_SESSION_ONLY:
-      return "session";
-    case CONTENT_SETTING_DETECT_IMPORTANT_CONTENT:
-      return "detect";
-    case CONTENT_SETTING_DEFAULT:
-      return "default";
-    case CONTENT_SETTING_NUM_SETTINGS:
-      NOTREACHED();
-  }
-
-  return ResourceIdentifier();
+  DCHECK_GE(setting, CONTENT_SETTING_DEFAULT);
+  DCHECK_LT(setting, CONTENT_SETTING_NUM_SETTINGS);
+  DCHECK_EQ(kContentSettingsStringMapping[setting].content_setting, setting);
+  return kContentSettingsStringMapping[setting].content_setting_str;
 }
 
-ContentSetting ContentSettingFromString(const std::string& name) {
-  if (name == "allow")
-    return CONTENT_SETTING_ALLOW;
-  if (name == "ask")
-    return CONTENT_SETTING_ASK;
-  if (name == "block")
-    return CONTENT_SETTING_BLOCK;
-  if (name == "session")
-    return CONTENT_SETTING_SESSION_ONLY;
-  if (name == "detect")
-    return CONTENT_SETTING_DETECT_IMPORTANT_CONTENT;
-
+bool ContentSettingFromString(const std::string& name,
+                              ContentSetting* setting) {
+  // We are starting the index from 1, as |CONTENT_SETTING_DEFAULT| is not
+  // a recognized content setting.
+  for (size_t i = 1; i < arraysize(kContentSettingsStringMapping); ++i) {
+    if (name == kContentSettingsStringMapping[i].content_setting_str) {
+      *setting = kContentSettingsStringMapping[i].content_setting;
+      return true;
+    }
+  }
   NOTREACHED() << name << " is not a recognized content setting.";

[Bernhard Bauer, 2015/10/07 09:32:04]

Remove this. Passing an invalid string is now acceptable, and the method is
supposed to return false in that case. This is the reason why we added the
DCHECK at the callsites instead.

[Deepak, 2015/10/07 11:12:24]

Done.

-  return CONTENT_SETTING_DEFAULT;
+  *setting = CONTENT_SETTING_DEFAULT;
+  return false;
 }
 
 std::string CreatePatternString(
     const ContentSettingsPattern& item_pattern,
     const ContentSettingsPattern& top_level_frame_pattern) {
   return item_pattern.ToString()
          + std::string(kPatternSeparator)
          + top_level_frame_pattern.ToString();
 }
 
@@ skipping 112 matching lines @@
       CONTENT_SETTINGS_TYPE_IMAGES,
       ResourceIdentifier(),
       &(rules->image_rules));
   map->GetSettingsForOneType(
       CONTENT_SETTINGS_TYPE_JAVASCRIPT,
       ResourceIdentifier(),
       &(rules->script_rules));
 }
 
 }  // namespace content_settings