[WIP Prototype] ES6 https://html.spec.whatwg.org/#fetch-a-single-module-script implementation

third_party/WebKit/Source/core/loader/modulescript/ModuleScriptLoader.h

+// Copyright 2017 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.
+
+#ifndef ModuleScriptLoader_h
+#define ModuleScriptLoader_h
+
+#include "core/CoreExport.h"
+#include "core/fetch/ResourceOwner.h"
+#include "core/loader/resource/ScriptResource.h"
+#include "platform/heap/Handle.h"
+#include "platform/weborigin/KURL.h"
+
+namespace blink {
+
+class ModuleController;
+class ModuleScript;
+class ModuleScriptLoaderRegistry;
+class ModuleScriptLoaderClient;
+
+// A ModuleScriptLoader is responsible for loading a new single ModuleScript.
+//
+// A ModuleScriptLoader constructs and emit FetchRequest to RequestFetcher (via
+// ScriptResource::fetch).
+// Then, it keeps track of the fetch progress by being a ScriptResourceClient.
+// Finally, it return its client a compiled ModuleScript.
+//
+// ModuleLoaders should only be used via Modulator and its ModuleMap.
+class CORE_EXPORT ModuleScriptLoader final
+    : public GarbageCollectedFinalized<ModuleScriptLoader>,
+      public ResourceOwner<ScriptResource> {
+  WTF_MAKE_NONCOPYABLE(ModuleScriptLoader);
+  USING_GARBAGE_COLLECTED_MIXIN(ModuleScriptLoader);
+
+  enum class State {
+    Initial,
+    // FetchRequest is being processed, and ModuleScriptLoader hasn't
+    // notifyFinished().
+    Fetching,
+    // Finished successfully or w/ error.
+    Finished,
+  };
+
+ public:
+  static ModuleScriptLoader* create(const KURL& url,
+                                    const KURL& baseURL,
+                                    ModuleController* moduleController,
+                                    ModuleScriptLoaderRegistry* registry,
+                                    ModuleScriptLoaderClient* client) {
+    return new ModuleScriptLoader(url, baseURL, moduleController, registry,
+                                  client);
+  }
+
+  virtual ~ModuleScriptLoader();
+
+  void fetch(ResourceFetcher*);
+
+  bool isInitialState() const { return m_state == State::Initial; }
+  bool hasFinished() const { return m_state == State::Finished; }
+
+  DECLARE_TRACE();
+
+ private:
+  explicit ModuleScriptLoader(const KURL&,
+                              const KURL& baseURL,
+                              ModuleController*,
+                              ModuleScriptLoaderRegistry*,
+                              ModuleScriptLoaderClient*);
+
+  void advanceState(State newState);
+
+  // Implements ScriptResourceClient
+  void notifyFinished(Resource*) override;
+  String debugName() const override { return "ModuleScriptLoader"; }
+
+  // TODO(kouhei): May be this method should live in ModuleResource? or should
+  // it be here to consolidate the spec impl code in ModuleMap.cpp?
+  static bool wasModuleLoadSuccessful(Resource*);
+
+  KURL m_url;
+  KURL m_baseURL;
+  Member<ModuleController> m_moduleController;
+  State m_state = State::Initial;
+  Member<ModuleScript> m_moduleScript;
+  Member<ModuleScriptLoaderRegistry> m_registry;
+  Member<ModuleScriptLoaderClient> m_client;
+};
+
+}  // namespace blink
+
+#endif