Lazily load API schemas from resource files and convert all APIs to features

chrome/common/extensions/features/base_feature_provider.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 "chrome/common/extensions/features/base_feature_provider.h"
 
 #include "base/json/json_reader.h"
 #include "base/lazy_instance.h"
 #include "chrome/common/extensions/features/api_feature.h"
 #include "chrome/common/extensions/features/complex_feature.h"
@@ skipping 18 matching lines @@
                       int resource_id)
       : name_(name),
         factory_(factory),
         resource_id_(resource_id) {
   }
 
   virtual Feature* GetFeature(const std::string& name) OVERRIDE {
     return GetBaseFeatureProvider()->GetFeature(name);
   }
 
-  virtual std::set<std::string> GetAllFeatureNames() OVERRIDE {
+  virtual std::vector<std::string> GetAllFeatureNames() OVERRIDE {
     return GetBaseFeatureProvider()->GetAllFeatureNames();
   }
 
  private:
   BaseFeatureProvider* GetBaseFeatureProvider() {
     if (!features_)
       features_ = LoadProvider();
     return features_.get();
   }
 
@@ skipping 48 matching lines @@
     LazyFeatureProviderMap::iterator it = lazy_feature_providers.find(name);
     CHECK(it != lazy_feature_providers.end());
     return it->second.get();
   }
 
   LazyFeatureProviderMap lazy_feature_providers;
 };
 
 base::LazyInstance<Static> g_static = LAZY_INSTANCE_INITIALIZER;
 
-bool ParseFeature(const DictionaryValue* value,
+bool ParseFeature(const DictionaryValue& root,
+                  const DictionaryValue* value,
                   const std::string& name,
                   SimpleFeature* feature) {
+  std::string error;
+  std::string parent_name;
+  if (value->GetString("parent", &parent_name)) {
+    const DictionaryValue* parent = NULL;
+    CHECK(root.GetDictionaryWithoutPathExpansion(parent_name, &parent));
+    scoped_ptr<DictionaryValue> value_with_parent(parent->DeepCopy());
+    value_with_parent->MergeDictionary(value);
+    error = feature->Parse(value_with_parent.get());
+  } else {
+    error = feature->Parse(value);
+  }
   feature->set_name(name);
-  std::string error = feature->Parse(value);
   if (!error.empty())
     LOG(ERROR) << error;
   return error.empty();
 }
 
 }  // namespace
 
 BaseFeatureProvider::BaseFeatureProvider(const DictionaryValue& root,
                                          FeatureFactory factory)
     : factory_(factory ? factory :
                static_cast<FeatureFactory>(&CreateFeature<SimpleFeature>)) {
   for (DictionaryValue::Iterator iter(root); !iter.IsAtEnd(); iter.Advance()) {
     if (iter.value().GetType() == Value::TYPE_DICTIONARY) {
       linked_ptr<SimpleFeature> feature((*factory_)());
 
-      if (!ParseFeature(static_cast<const DictionaryValue*>(&iter.value()),
+      if (!ParseFeature(root,
+                        static_cast<const DictionaryValue*>(&iter.value()),
                         iter.key(),
-                        feature.get()))
+                        feature.get())) {
         continue;
+      }
 
       features_[iter.key()] = feature;
     } else if (iter.value().GetType() == Value::TYPE_LIST) {
       // This is a complex feature.
       const ListValue* list = static_cast<const ListValue*>(&iter.value());
       CHECK_GT(list->GetSize(), 0UL);
 
       scoped_ptr<ComplexFeature::FeatureList> features(
           new ComplexFeature::FeatureList());
 
       // Parse and add all SimpleFeatures from the list.
       for (ListValue::const_iterator list_iter = list->begin();
            list_iter != list->end(); ++list_iter) {
         if ((*list_iter)->GetType() != Value::TYPE_DICTIONARY) {
           LOG(ERROR) << iter.key() << ": Feature rules must be dictionaries.";
           continue;
         }
 
         scoped_ptr<SimpleFeature> feature((*factory_)());
-        if (!ParseFeature(static_cast<const DictionaryValue*>(*list_iter),
+        if (!ParseFeature(root,
+                          static_cast<const DictionaryValue*>(*list_iter),
                           iter.key(),
-                          feature.get()))
+                          feature.get())) {
           continue;
+        }
 
         features->push_back(feature.release());
       }
 
       linked_ptr<ComplexFeature> feature(new ComplexFeature(features.Pass()));
       feature->set_name(iter.key());
 
       features_[iter.key()] = feature;
     } else {
       LOG(ERROR) << iter.key() << ": Feature description must be dictionary or"
                  << " list of dictionaries.";
     }
   }
 }
 
 BaseFeatureProvider::~BaseFeatureProvider() {
 }
 
 // static
 FeatureProvider* BaseFeatureProvider::GetByName(
     const std::string& name) {
   return g_static.Get().LazyGetFeatures(name);
 }
 
-std::set<std::string> BaseFeatureProvider::GetAllFeatureNames() {
-  std::set<std::string> result;
-  for (FeatureMap::const_iterator iter = features_.begin();
-       iter != features_.end(); ++iter) {
-    result.insert(iter->first);
+std::vector<std::string> BaseFeatureProvider::GetAllFeatureNames() {
+  if (feature_names_.empty()) {
+    for (FeatureMap::const_iterator iter = features_.begin();
+         iter != features_.end(); ++iter) {
+      feature_names_.push_back(iter->first);
+    }
   }
-  return result;
+  return feature_names_;
 }
 
 Feature* BaseFeatureProvider::GetFeature(const std::string& name) {
   FeatureMap::iterator iter = features_.find(name);
   if (iter != features_.end())
     return iter->second.get();
   else
     return NULL;
 }
 
 }  // namespace