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

third_party/WebKit/Source/core/dom/Modulator.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 Modulator_h
 #define Modulator_h
 
 #include "core/CoreExport.h"
+#include "core/dom/AncestorList.h"
 #include "platform/heap/Handle.h"
 #include "platform/weborigin/KURL.h"
+#include "platform/weborigin/ReferrerPolicy.h"
+#include "wtf/text/WTFString.h"
 
 namespace blink {
 
+class ExecutionContext;
 class LocalFrame;
+class ModuleScript;
+class ModuleScriptLoaderClient;
+class ScriptModule;
+class ScriptModuleResolver;
+class ScriptValue;
+class WebTaskRunner;
+class ModuleScriptFetchRequest;
+
+// A SingleModuleClient is notified when single module script node (node as in a
+// module tree graph) load is complete and its corresponding entry is created in
+// module map.
+class SingleModuleClient : public GarbageCollectedMixin {
+ public:
+  virtual void notifyModuleLoadFinished(ModuleScript*) = 0;
+};
+
+// A ModuleTreeClient is notified when a module script and its whole descendent
+// tree load is complete.
+class ModuleTreeClient : public GarbageCollectedMixin {
+ public:
+  virtual void notifyModuleTreeLoadFinished(ModuleScript*) = 0;
+};
+
+// spec: "top-level module fetch flag"
+enum class ModuleGraphLevel { TopLevelModuleFetch, DependentModuleFetch };
 
 // A Modulator is an interface for "environment settings object" concept for
 // module scripts.
 // https://html.spec.whatwg.org/#environment-settings-object
 //
 // A Modulator also serves as an entry point for various module spec algorithms.
 class CORE_EXPORT Modulator : public GarbageCollectedMixin {
  public:
   static Modulator* from(LocalFrame*);
 
+  virtual ScriptModuleResolver* scriptModuleResolver() = 0;
+  virtual WebTaskRunner* taskRunner() = 0;
+  virtual ExecutionContext* executionContext() = 0;
+  virtual ReferrerPolicy referrerPolicy() = 0;
+
+  // https://html.spec.whatwg.org/multipage/webappapis.html#fetch-a-module-script-tree
+  virtual void fetchTree(const ModuleScriptFetchRequest&,
+                         ModuleTreeClient*) = 0;
+
+  // https://html.spec.whatwg.org/#internal-module-script-graph-fetching-procedure
+  virtual void fetchTreeInternal(const ModuleScriptFetchRequest&,
+                                 const AncestorList&,
+                                 ModuleGraphLevel,
+                                 ModuleTreeClient*) = 0;
+
+  // Asynchronously retrieve a module script from the module map, or fetch it
+  // and put it in the map if it's not there already.
+  // https://html.spec.whatwg.org/#fetch-a-single-module-script
+  virtual void fetchSingle(const ModuleScriptFetchRequest&,
+                           ModuleGraphLevel,
+                           SingleModuleClient*) = 0;
+
+  // Synchronously retrieves a single module script from existing module map
+  // entry.
+  virtual ModuleScript* retrieveFetchedModuleScript(const KURL&) = 0;
+
   // https://html.spec.whatwg.org/#resolve-a-module-specifier
   static KURL resolveModuleSpecifier(const String& moduleRequest,
                                      const KURL& baseURL);
+
+  // TODO(kouhei): script should be a ScriptSourceCode.
+  virtual ScriptModule compileModule(const String& script,
+                                     const String& urlStr) = 0;
+
+  virtual ScriptValue instantiateModule(ScriptModule) = 0;
+
+  virtual Vector<String> moduleRequestsFromScriptModule(ScriptModule) = 0;
+
+  virtual void executeModule(ScriptModule) = 0;
+
+ private:
+  friend class ModuleMap;
+
+  // Asynchronously fetches a single module script.
+  // This is triggered from fetchSingle() implementation (which is ModuleMap) if
+  // the cached entry doesn't exist.
+  virtual void fetchNewSingleModule(const ModuleScriptFetchRequest&,
+                                    ModuleGraphLevel,
+                                    ModuleScriptLoaderClient*) = 0;
 };
 
 }  // namespace blink
 
 #endif