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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 "js/RootingAPI.h"
#include "js/Value.h"
#include "nsURIHashKey.h"
#include "nsTHashtable.h"
namespace JS::loader {
class LoadedScript;
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() {
MOZ_ASSERT(mAwaitingImports == 0);
ModuleLoadRequest(const ModuleLoadRequest& aOther) = delete;
ModuleLoadRequest(ModuleLoadRequest&& aOther) = delete;
using SRIMetadata = mozilla::dom::SRIMetadata;
ModuleLoadRequest(nsIURI* aURI, mozilla::dom::ReferrerPolicy aReferrerPolicy,
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 SetDynamicImport(LoadedScript* aReferencingScript,
JS::Handle<JSString*> aSpecifier,
JS::Handle<JSObject*> aPromise);
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 ChildLoadComplete(bool aSuccess);
void LoadFinished();
void CancelImports();
void CheckModuleDependenciesLoaded();
void ChildModuleUnlinked();
void AssertAllImportsFinished() 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;
// Array of imported modules.
nsTArray<RefPtr<ModuleLoadRequest>> mImports;
// Parent module (i.e. importer of this module) that is waiting for this
// module and its dependencies to load, or null.
RefPtr<ModuleLoadRequest> mWaitingParentRequest;
// Number of child modules (i.e. imported modules) that this module is waiting
// for.
size_t mAwaitingImports = 0;
// 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.
RefPtr<LoadedScript> mDynamicReferencingScript;
JS::Heap<JSString*> mDynamicSpecifier;
JS::Heap<JSObject*> mDynamicPromise;
} // namespace JS::loader
#endif // js_loader_ModuleLoadRequest_h