js/loader/ModuleLoadRequest.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef js_loader_ModuleLoadRequest_h
   8 #define js_loader_ModuleLoadRequest_h
   9
  10 #include "LoadContextBase.h"
  11 #include "ScriptLoadRequest.h"
  12 #include "ModuleLoaderBase.h"
  13 #include "mozilla/Assertions.h"
  14 #include "js/RootingAPI.h"
  15 #include "js/Value.h"
  16 #include "nsURIHashKey.h"
  17 #include "nsTHashtable.h"
  18
  19 namespace JS::loader {
  20
  21 class LoadedScript;
  22 class ModuleScript;
  23 class ModuleLoaderBase;
  24
  25 // A reference counted set of URLs we have visited in the process of loading a
  26 // module graph.
  27 class VisitedURLSet : public nsTHashtable<nsURIHashKey> {
  28   NS_INLINE_DECL_REFCOUNTING(VisitedURLSet)
  29
  30  private:
  31   ~VisitedURLSet() = default;
  32 };
  33
  34 // A load request for a module, created for every top level module script and
  35 // every module import.  Load request can share an ModuleScript if there are
  36 // multiple imports of the same module.
  37
  38 class ModuleLoadRequest final : public ScriptLoadRequest {
  39   ~ModuleLoadRequest() {
  40     MOZ_ASSERT(!mWaitingParentRequest);
  41     MOZ_ASSERT(mAwaitingImports == 0);
  42   }
  43
  44   ModuleLoadRequest(const ModuleLoadRequest& aOther) = delete;
  45   ModuleLoadRequest(ModuleLoadRequest&& aOther) = delete;
  46
  47  public:
  48   NS_DECL_ISUPPORTS_INHERITED
  49   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(ModuleLoadRequest,
  50                                                          ScriptLoadRequest)
  51   using SRIMetadata = mozilla::dom::SRIMetadata;
  52
  53   ModuleLoadRequest(nsIURI* aURI, mozilla::dom::ReferrerPolicy aReferrerPolicy,
  54                     ScriptFetchOptions* aFetchOptions,
  55                     const SRIMetadata& aIntegrity, nsIURI* aReferrer,
  56                     LoadContextBase* aContext, bool aIsTopLevel,
  57                     bool aIsDynamicImport, ModuleLoaderBase* aLoader,
  58                     VisitedURLSet* aVisitedSet, ModuleLoadRequest* aRootModule);
  59
  60   static VisitedURLSet* NewVisitedSetForTopLevelImport(nsIURI* aURI);
  61
  62   bool IsTopLevel() const override { return mIsTopLevel; }
  63
  64   bool IsDynamicImport() const { return mIsDynamicImport; }
  65
  66   bool IsErrored() const;
  67
  68   nsIGlobalObject* GetGlobalObject();
  69
  70   void SetReady() override;
  71   void Cancel() override;
  72   void ClearDynamicImport();
  73
  74   void ModuleLoaded();
  75   void ModuleErrored();
  76   void DependenciesLoaded();
  77   void LoadFailed();
  78
  79   ModuleLoadRequest* GetRootModule() {
  80     if (!mRootModule) {
  81       return this;
  82     }
  83     return mRootModule;
  84   }
  85
  86   bool IsModuleMarkedForBytecodeEncoding() const {
  87     return mIsMarkedForBytecodeEncoding;
  88   }
  89   void MarkModuleForBytecodeEncoding() {
  90     MOZ_ASSERT(!IsModuleMarkedForBytecodeEncoding());
  91     mIsMarkedForBytecodeEncoding = true;
  92   }
  93
  94   // Convenience methods to call into the module loader for this request.
  95
  96   void CancelDynamicImport(nsresult aResult) {
  97     MOZ_ASSERT(IsDynamicImport());
  98     mLoader->CancelDynamicImport(this, aResult);
  99   }
 100 #ifdef DEBUG
 101   bool IsRegisteredDynamicImport() const {
 102     return IsDynamicImport() && mLoader->HasDynamicImport(this);
 103   }
 104 #endif
 105   nsresult StartModuleLoad() { return mLoader->StartModuleLoad(this); }
 106   nsresult RestartModuleLoad() { return mLoader->RestartModuleLoad(this); }
 107   nsresult OnFetchComplete(nsresult aRv) {
 108     return mLoader->OnFetchComplete(this, aRv);
 109   }
 110   bool InstantiateModuleGraph() {
 111     return mLoader->InstantiateModuleGraph(this);
 112   }
 113   nsresult EvaluateModule() { return mLoader->EvaluateModule(this); }
 114   void StartDynamicImport() { mLoader->StartDynamicImport(this); }
 115   void ProcessDynamicImport() { mLoader->ProcessDynamicImport(this); }
 116
 117   void ChildLoadComplete(bool aSuccess);
 118
 119  private:
 120   void LoadFinished();
 121   void CancelImports();
 122   void CheckModuleDependenciesLoaded();
 123
 124   void AssertAllImportsFinished() const;
 125   void AssertAllImportsCancelled() const;
 126
 127  public:
 128   // Is this a request for a top level module script or an import?
 129   const bool mIsTopLevel;
 130
 131   // Is this the top level request for a dynamic module import?
 132   const bool mIsDynamicImport;
 133
 134   // True if this module is planned to be saved in the bytecode cache.
 135   // ModuleLoadRequest doesn't use ScriptLoadRequest::mScriptForBytecodeEncoding
 136   // field because the JSScript reference isn't always avaialble for module.
 137   bool mIsMarkedForBytecodeEncoding = false;
 138
 139   // Pointer to the script loader, used to trigger actions when the module load
 140   // finishes.
 141   RefPtr<ModuleLoaderBase> mLoader;
 142
 143   // Pointer to the top level module of this module graph, nullptr if this is a
 144   // top level module
 145   RefPtr<ModuleLoadRequest> mRootModule;
 146
 147   // Set to a module script object after a successful load or nullptr on
 148   // failure.
 149   RefPtr<ModuleScript> mModuleScript;
 150
 151   // Array of imported modules.
 152   nsTArray<RefPtr<ModuleLoadRequest>> mImports;
 153
 154   // Parent module (i.e. importer of this module) that is waiting for this
 155   // module and its dependencies to load, or null.
 156   RefPtr<ModuleLoadRequest> mWaitingParentRequest;
 157
 158   // Number of child modules (i.e. imported modules) that this module is waiting
 159   // for.
 160   size_t mAwaitingImports = 0;
 161
 162   // Set of module URLs visited while fetching the module graph this request is
 163   // part of.
 164   RefPtr<VisitedURLSet> mVisitedSet;
 165
 166   // For dynamic imports, the details to pass to FinishDynamicImport.
 167   RefPtr<LoadedScript> mDynamicReferencingScript;
 168   JS::Heap<JSString*> mDynamicSpecifier;
 169   JS::Heap<JSObject*> mDynamicPromise;
 170 };
 171
 172 }  // namespace JS::loader
 173
 174 #endif  // js_loader_ModuleLoadRequest_h