[ES6 modules] Introduce ModulatorImpl

third_party/WebKit/Source/core/dom/ModulatorImpl.cpp

+// 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.
+
+#include "core/dom/ModulatorImpl.h"
+
+#include "core/dom/Document.h"
+#include "core/dom/ExecutionContext.h"
+#include "core/dom/ModuleMap.h"
+#include "core/dom/ModuleScript.h"
+#include "core/dom/ScriptModuleResolverImpl.h"
+#include "core/dom/TaskRunnerHelper.h"
+#include "core/frame/LocalFrame.h"
+#include "core/loader/modulescript/ModuleScriptFetchRequest.h"
+#include "core/loader/modulescript/ModuleScriptLoaderRegistry.h"
+#include "platform/loader/fetch/ResourceFetcher.h"
+
+namespace blink {
+
+ModulatorImpl* ModulatorImpl::Create(RefPtr<ScriptState> script_state,
+                                     Document& document) {
+  return new ModulatorImpl(
+      std::move(script_state),
+      TaskRunnerHelper::Get(TaskType::kNetworking, &document),
+      document.Fetcher());
+}
+
+ModulatorImpl::ModulatorImpl(RefPtr<ScriptState> script_state,
+                             RefPtr<WebTaskRunner> task_runner,
+                             ResourceFetcher* fetcher)
+    : script_state_(std::move(script_state)),
+      task_runner_(std::move(task_runner)),
+      fetcher_(fetcher),
+      map_(this, ModuleMap::Create(this)),
+      loader_registry_(ModuleScriptLoaderRegistry::Create()),
+      script_module_resolver_(ScriptModuleResolverImpl::Create(this)) {
+  DCHECK(script_state_);
+  DCHECK(task_runner_);
+  DCHECK(fetcher_);
+}
+
+ModulatorImpl::~ModulatorImpl() {}
+
+ReferrerPolicy ModulatorImpl::GetReferrerPolicy() {
+  return GetExecutionContext()->GetReferrerPolicy();
+}
+
+SecurityOrigin* ModulatorImpl::GetSecurityOrigin() {
+  return GetExecutionContext()->GetSecurityOrigin();
+}
+
+void ModulatorImpl::FetchTree(const ModuleScriptFetchRequest& request,
+                              ModuleTreeClient* client) {
+  // Step 1. Perform the internal module script graph fetching procedure given
+  // url, settings object, destination, cryptographic nonce, parser state,
+  // credentials mode, settings object, a new empty list, "client", and with the
+  // top-level module fetch flag set. If the caller of this algorithm specified
+  // custom perform the fetch steps, pass those along as well.
+
+  // Note: "Fetch a module script graph" algorithm doesn't have "referrer" as
+  // its argument.
+  DCHECK(request.GetReferrer().IsNull());
+
+  AncestorList empty_ancestor_list;
+  FetchTreeInternal(request, empty_ancestor_list,
+                    ModuleGraphLevel::kTopLevelModuleFetch, client);
+
+  // Step 2. When the internal module script graph fetching procedure
+  // asynchronously completes with result, asynchronously complete this
+  // algorithm with result.
+  // Note: We delegate to ModuleTreeLinker to notify ModuleTreeClient.
+}
+
+void ModulatorImpl::FetchTreeInternal(const ModuleScriptFetchRequest& request,
+                                      const AncestorList& ancestor_list,
+                                      ModuleGraphLevel level,
+                                      ModuleTreeClient* client) {
+  NOTIMPLEMENTED();
+}
+
+void ModulatorImpl::FetchSingle(const ModuleScriptFetchRequest& request,
+                                ModuleGraphLevel level,
+                                SingleModuleClient* client) {
+  map_->FetchSingleModuleScript(request, level, client);
+}
+
+void ModulatorImpl::FetchNewSingleModule(
+    const ModuleScriptFetchRequest& request,
+    ModuleGraphLevel level,
+    ModuleScriptLoaderClient* client) {
+  loader_registry_->Fetch(request, level, this, fetcher_.Get(), client);
+}
+
+ModuleScript* ModulatorImpl::GetFetchedModuleScript(const KURL& url) {
+  return map_->GetFetchedModuleScript(url);
+}
+
+ScriptModule ModulatorImpl::CompileModule(
+    const String& provided_source,
+    const String& url_str,
+    AccessControlStatus access_control_status) {
+  // Implements Steps 3-6 of
+  // https://html.spec.whatwg.org/multipage/webappapis.html#creating-a-module-script
+
+  // Step 3. Let realm be the provided environment settings object's Realm.
+  // Note: Realm is v8::Context.
+
+  // Step 4. If scripting is disabled for the given environment settings
+  // object's responsible browsing context, then let script source be the empty
+  // string. Otherwise, let script source be the provided script source.
+  String script_source;
+  if (GetExecutionContext()->CanExecuteScripts(kAboutToExecuteScript))
+    script_source = provided_source;
+
+  // Step 5. Let result be ParseModule(script source, realm, script).
+  // Step 6. If result is a List of errors, report the exception given by the
+  // first element of result for script, return null, and abort these steps.
+  // Note: reporting is routed via V8Initializer::messageHandlerInMainThread.
+  ScriptState::Scope scope(script_state_.Get());
+  return ScriptModule::Compile(script_state_->GetIsolate(), script_source,
+                               url_str, access_control_status);
+}
+
+ScriptValue ModulatorImpl::InstantiateModule(ScriptModule script_module) {
+  ScriptState::Scope scope(script_state_.Get());
+  return script_module.Instantiate(script_state_.Get());
+}
+
+Vector<String> ModulatorImpl::ModuleRequestsFromScriptModule(
+    ScriptModule script_module) {
+  ScriptState::Scope scope(script_state_.Get());
+  return script_module.ModuleRequests(script_state_.Get());
+}
+
+inline ExecutionContext* ModulatorImpl::GetExecutionContext() const {
+  return ExecutionContext::From(script_state_.Get());
+}
+
+DEFINE_TRACE(ModulatorImpl) {
+  Modulator::Trace(visitor);
+  visitor->Trace(fetcher_);
+  visitor->Trace(map_);
+  visitor->Trace(loader_registry_);
+  visitor->Trace(script_module_resolver_);
+}
+
+DEFINE_TRACE_WRAPPERS(ModulatorImpl) {
+  visitor->TraceWrappers(map_);
+}
+
+}  // namespace blink