1 files changed, 169 insertions, 0 deletions
diff --git a/js/loader/ModuleLoadRequest.h b/js/loader/ModuleLoadRequest.h
new file mode 100644
index 0000000000..4a4d5c8bed
--- /dev/null
+++ b/js/loader/ModuleLoadRequest.h
@@ -0,0 +1,169 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef js_loader_ModuleLoadRequest_h
+#define js_loader_ModuleLoadRequest_h
+
+#include "LoadContextBase.h"
+#include "ScriptLoadRequest.h"
+#include "ModuleLoaderBase.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/MozPromise.h"
+#include "js/RootingAPI.h"
+#include "js/Value.h"
+#include "nsURIHashKey.h"
+#include "nsTHashtable.h"
+
+namespace JS::loader {
+
+class ModuleScript;
+class ModuleLoaderBase;
+
+// A reference counted set of URLs we have visited in the process of loading a
+// module graph.
+class VisitedURLSet : public nsTHashtable<nsURIHashKey> {
+  NS_INLINE_DECL_REFCOUNTING(VisitedURLSet)
+
+ private:
+  ~VisitedURLSet() = default;
+};
+
+// A load request for a module, created for every top level module script and
+// every module import.  Load request can share an ModuleScript if there are
+// multiple imports of the same module.
+
+class ModuleLoadRequest final : public ScriptLoadRequest {
+  ~ModuleLoadRequest() = default;
+
+  ModuleLoadRequest(const ModuleLoadRequest& aOther) = delete;
+  ModuleLoadRequest(ModuleLoadRequest&& aOther) = delete;
+
+ public:
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(ModuleLoadRequest,
+                                                         ScriptLoadRequest)
+  using SRIMetadata = mozilla::dom::SRIMetadata;
+
+  template <typename T>
+  using MozPromiseHolder = mozilla::MozPromiseHolder<T>;
+  using GenericPromise = mozilla::GenericPromise;
+
+  ModuleLoadRequest(nsIURI* aURI, ScriptFetchOptions* aFetchOptions,
+                    const SRIMetadata& aIntegrity, nsIURI* aReferrer,
+                    LoadContextBase* aContext, bool aIsTopLevel,
+                    bool aIsDynamicImport, ModuleLoaderBase* aLoader,
+                    VisitedURLSet* aVisitedSet, ModuleLoadRequest* aRootModule);
+
+  static VisitedURLSet* NewVisitedSetForTopLevelImport(nsIURI* aURI);
+
+  bool IsTopLevel() const override { return mIsTopLevel; }
+
+  bool IsDynamicImport() const { return mIsDynamicImport; }
+
+  bool IsErrored() const;
+
+  nsIGlobalObject* GetGlobalObject();
+
+  void SetReady() override;
+  void Cancel() override;
+  void ClearDynamicImport();
+
+  void ModuleLoaded();
+  void ModuleErrored();
+  void DependenciesLoaded();
+  void LoadFailed();
+
+  ModuleLoadRequest* GetRootModule() {
+    if (!mRootModule) {
+      return this;
+    }
+    return mRootModule;
+  }
+
+  bool IsModuleMarkedForBytecodeEncoding() const {
+    return mIsMarkedForBytecodeEncoding;
+  }
+  void MarkModuleForBytecodeEncoding() {
+    MOZ_ASSERT(!IsModuleMarkedForBytecodeEncoding());
+    mIsMarkedForBytecodeEncoding = true;
+  }
+
+  // Convenience methods to call into the module loader for this request.
+
+  void CancelDynamicImport(nsresult aResult) {
+    MOZ_ASSERT(IsDynamicImport());
+    mLoader->CancelDynamicImport(this, aResult);
+  }
+#ifdef DEBUG
+  bool IsRegisteredDynamicImport() const {
+    return IsDynamicImport() && mLoader->HasDynamicImport(this);
+  }
+#endif
+  nsresult StartModuleLoad() { return mLoader->StartModuleLoad(this); }
+  nsresult RestartModuleLoad() { return mLoader->RestartModuleLoad(this); }
+  nsresult OnFetchComplete(nsresult aRv) {
+    return mLoader->OnFetchComplete(this, aRv);
+  }
+  bool InstantiateModuleGraph() {
+    return mLoader->InstantiateModuleGraph(this);
+  }
+  nsresult EvaluateModule() { return mLoader->EvaluateModule(this); }
+  void StartDynamicImport() { mLoader->StartDynamicImport(this); }
+  void ProcessDynamicImport() { mLoader->ProcessDynamicImport(this); }
+
+ private:
+  void LoadFinished();
+  void CancelImports();
+  void CheckModuleDependenciesLoaded();
+
+  void AssertAllImportsReady() const;
+  void AssertAllImportsCancelled() const;
+
+ public:
+  // Is this a request for a top level module script or an import?
+  const bool mIsTopLevel;
+
+  // Is this the top level request for a dynamic module import?
+  const bool mIsDynamicImport;
+
+  // True if this module is planned to be saved in the bytecode cache.
+  // ModuleLoadRequest doesn't use ScriptLoadRequest::mScriptForBytecodeEncoding
+  // field because the JSScript reference isn't always avaialble for module.
+  bool mIsMarkedForBytecodeEncoding = false;
+
+  // Pointer to the script loader, used to trigger actions when the module load
+  // finishes.
+  RefPtr<ModuleLoaderBase> mLoader;
+
+  // Pointer to the top level module of this module graph, nullptr if this is a
+  // top level module
+  RefPtr<ModuleLoadRequest> mRootModule;
+
+  // Set to a module script object after a successful load or nullptr on
+  // failure.
+  RefPtr<ModuleScript> mModuleScript;
+
+  // A promise that is completed on successful load of this module and all of
+  // its dependencies, indicating that the module is ready for instantiation and
+  // evaluation.
+  MozPromiseHolder<GenericPromise> mReady;
+
+  // Array of imported modules.
+  nsTArray<RefPtr<ModuleLoadRequest>> mImports;
+
+  // Set of module URLs visited while fetching the module graph this request is
+  // part of.
+  RefPtr<VisitedURLSet> mVisitedSet;
+
+  // For dynamic imports, the details to pass to FinishDynamicImport.
+  JS::Heap<JS::Value> mDynamicReferencingPrivate;
+  JS::Heap<JSString*> mDynamicSpecifier;
+  JS::Heap<JSObject*> mDynamicPromise;
+};
+
+}  // namespace JS::loader
+
+#endif  // js_loader_ModuleLoadRequest_h