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/* -*- 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 */
#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> {
~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;
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() {
mIsMarkedForBytecodeEncoding = true;
// Convenience methods to call into the module loader for this request.
void CancelDynamicImport(nsresult aResult) {
mLoader->CancelDynamicImport(this, aResult);
#ifdef DEBUG
bool IsRegisteredDynamicImport() const {
return IsDynamicImport() && mLoader->HasDynamicImport(this);
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); }
void LoadFinished();
void CancelImports();
void CheckModuleDependenciesLoaded();
void AssertAllImportsReady() const;
void AssertAllImportsCancelled() const;
// 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