extensions/renderer/v8_schema_registry.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "extensions/renderer/v8_schema_registry.h"
   6
   7 #include "base/logging.h"
   8 #include "base/values.h"
   9 #include "content/public/child/v8_value_converter.h"
  10 #include "extensions/common/extension_api.h"
  11 #include "extensions/renderer/object_backed_native_handler.h"
  12 #include "extensions/renderer/script_context.h"
  13
  14 using content::V8ValueConverter;
  15
  16 namespace extensions {
  17
  18 namespace {
  19
  20 class SchemaRegistryNativeHandler : public ObjectBackedNativeHandler {
  21  public:
  22   SchemaRegistryNativeHandler(V8SchemaRegistry* registry,
  23                               scoped_ptr<ScriptContext> context)
  24       : ObjectBackedNativeHandler(context.get()),
  25         context_(context.Pass()),
  26         registry_(registry) {
  27     RouteFunction("GetSchema",
  28                   base::Bind(&SchemaRegistryNativeHandler::GetSchema,
  29                              base::Unretained(this)));
  30   }
  31
  32  private:
  33   void GetSchema(const v8::FunctionCallbackInfo<v8::Value>& args) {
  34     args.GetReturnValue().Set(
  35         registry_->GetSchema(*v8::String::Utf8Value(args[0])));
  36   }
  37
  38   scoped_ptr<ScriptContext> context_;
  39   V8SchemaRegistry* registry_;
  40 };
  41
  42 }  // namespace
  43
  44 V8SchemaRegistry::V8SchemaRegistry() {
  45 }
  46
  47 V8SchemaRegistry::~V8SchemaRegistry() {
  48 }
  49
  50 scoped_ptr<NativeHandler> V8SchemaRegistry::AsNativeHandler() {
  51   scoped_ptr<ScriptContext> context(
  52       new ScriptContext(GetOrCreateContext(v8::Isolate::GetCurrent()),
  53                         NULL,  // no frame
  54                         NULL,  // no extension
  55                         Feature::UNSPECIFIED_CONTEXT,
  56                         NULL,  // no effective extension
  57                         Feature::UNSPECIFIED_CONTEXT));
  58   return scoped_ptr<NativeHandler>(
  59       new SchemaRegistryNativeHandler(this, context.Pass()));
  60 }
  61
  62 v8::Handle<v8::Array> V8SchemaRegistry::GetSchemas(
  63     const std::vector<std::string>& apis) {
  64   v8::Isolate* isolate = v8::Isolate::GetCurrent();
  65   v8::EscapableHandleScope handle_scope(isolate);
  66   v8::Context::Scope context_scope(GetOrCreateContext(isolate));
  67
  68   v8::Local<v8::Array> v8_apis(v8::Array::New(isolate, apis.size()));
  69   size_t api_index = 0;
  70   for (std::vector<std::string>::const_iterator i = apis.begin();
  71        i != apis.end();
  72        ++i) {
  73     v8_apis->Set(api_index++, GetSchema(*i));
  74   }
  75   return handle_scope.Escape(v8_apis);
  76 }
  77
  78 v8::Handle<v8::Object> V8SchemaRegistry::GetSchema(const std::string& api) {
  79   if (schema_cache_ != NULL) {
  80     v8::Local<v8::Object> cached_schema = schema_cache_->Get(api);
  81     if (!cached_schema.IsEmpty()) {
  82       return cached_schema;
  83     }
  84   }
  85
  86   // Slow path: Need to build schema first.
  87
  88   v8::Isolate* isolate = v8::Isolate::GetCurrent();
  89   v8::EscapableHandleScope handle_scope(isolate);
  90   v8::Handle<v8::Context> context = GetOrCreateContext(isolate);
  91   v8::Context::Scope context_scope(context);
  92
  93   const base::DictionaryValue* schema =
  94       ExtensionAPI::GetSharedInstance()->GetSchema(api);
  95   CHECK(schema) << api;
  96   scoped_ptr<V8ValueConverter> v8_value_converter(V8ValueConverter::create());
  97   v8::Handle<v8::Value> value = v8_value_converter->ToV8Value(schema, context);
  98   CHECK(!value.IsEmpty());
  99
 100   v8::Local<v8::Object> v8_schema(v8::Handle<v8::Object>::Cast(value));
 101   schema_cache_->Set(api, v8_schema);
 102
 103   return handle_scope.Escape(v8_schema);
 104 }
 105
 106 v8::Handle<v8::Context> V8SchemaRegistry::GetOrCreateContext(
 107     v8::Isolate* isolate) {
 108   // It's ok to create local handles in this function, since this is only called
 109   // when we have a HandleScope.
 110   if (!context_holder_) {
 111     context_holder_.reset(new gin::ContextHolder(isolate));
 112     context_holder_->SetContext(v8::Context::New(isolate));
 113     schema_cache_.reset(new SchemaCache(isolate));
 114     return context_holder_->context();
 115   }
 116   return context_holder_->context();
 117 }
 118
 119 }  // namespace extensions