js/loader/ModuleLoadRequest.cpp

   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 #include "ModuleLoadRequest.h"
   8
   9 #include "mozilla/HoldDropJSObjects.h"
  10 #include "mozilla/dom/ScriptLoadContext.h"
  11
  12 #include "LoadedScript.h"
  13 #include "LoadContextBase.h"
  14 #include "ModuleLoaderBase.h"
  15
  16 namespace JS::loader {
  17
  18 #undef LOG
  19 #define LOG(args)                                                           \
  20   MOZ_LOG(ModuleLoaderBase::gModuleLoaderBaseLog, mozilla::LogLevel::Debug, \
  21           args)
  22
  23 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ModuleLoadRequest)
  24 NS_INTERFACE_MAP_END_INHERITING(ScriptLoadRequest)
  25
  26 NS_IMPL_CYCLE_COLLECTION_MULTI_ZONE_JSHOLDER_CLASS(ModuleLoadRequest)
  27
  28 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(ModuleLoadRequest,
  29                                                 ScriptLoadRequest)
  30   NS_IMPL_CYCLE_COLLECTION_UNLINK(mLoader, mModuleScript, mImports, mRootModule)
  31   tmp->ClearDynamicImport();
  32 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
  33
  34 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(ModuleLoadRequest,
  35                                                   ScriptLoadRequest)
  36   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mLoader, mModuleScript, mImports,
  37                                     mRootModule)
  38 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
  39
  40 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(ModuleLoadRequest,
  41                                                ScriptLoadRequest)
  42   NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mDynamicReferencingPrivate)
  43   NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mDynamicSpecifier)
  44   NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mDynamicPromise)
  45 NS_IMPL_CYCLE_COLLECTION_TRACE_END
  46
  47 NS_IMPL_ADDREF_INHERITED(ModuleLoadRequest, ScriptLoadRequest)
  48 NS_IMPL_RELEASE_INHERITED(ModuleLoadRequest, ScriptLoadRequest)
  49
  50 /* static */
  51 VisitedURLSet* ModuleLoadRequest::NewVisitedSetForTopLevelImport(nsIURI* aURI) {
  52   auto set = new VisitedURLSet();
  53   set->PutEntry(aURI);
  54   return set;
  55 }
  56
  57 ModuleLoadRequest::ModuleLoadRequest(
  58     nsIURI* aURI, ScriptFetchOptions* aFetchOptions,
  59     const mozilla::dom::SRIMetadata& aIntegrity, nsIURI* aReferrer,
  60     LoadContextBase* aContext, bool aIsTopLevel, bool aIsDynamicImport,
  61     ModuleLoaderBase* aLoader, VisitedURLSet* aVisitedSet,
  62     ModuleLoadRequest* aRootModule)
  63     : ScriptLoadRequest(ScriptKind::eModule, aURI, aFetchOptions, aIntegrity,
  64                         aReferrer, aContext),
  65       mIsTopLevel(aIsTopLevel),
  66       mIsDynamicImport(aIsDynamicImport),
  67       mLoader(aLoader),
  68       mRootModule(aRootModule),
  69       mVisitedSet(aVisitedSet) {
  70   MOZ_ASSERT(mLoader);
  71 }
  72
  73 nsIGlobalObject* ModuleLoadRequest::GetGlobalObject() {
  74   return mLoader->GetGlobalObject();
  75 }
  76
  77 void ModuleLoadRequest::Cancel() {
  78   ScriptLoadRequest::Cancel();
  79   mModuleScript = nullptr;
  80   CancelImports();
  81   mReady.RejectIfExists(NS_ERROR_DOM_ABORT_ERR, __func__);
  82 }
  83
  84 void ModuleLoadRequest::CancelImports() {
  85   for (size_t i = 0; i < mImports.Length(); i++) {
  86     mImports[i]->Cancel();
  87   }
  88 }
  89
  90 void ModuleLoadRequest::SetReady() {
  91   // Mark a module as ready to execute. This means that this module and all it
  92   // dependencies have had their source loaded, parsed as a module and the
  93   // modules instantiated.
  94   //
  95   // The mReady promise is used to ensure that when all dependencies of a module
  96   // have become ready, DependenciesLoaded is called on that module
  97   // request. This is set up in StartFetchingModuleDependencies.
  98
  99 #ifdef DEBUG
 100   for (size_t i = 0; i < mImports.Length(); i++) {
 101     MOZ_ASSERT(mImports[i]->IsReadyToRun());
 102   }
 103 #endif
 104
 105   ScriptLoadRequest::SetReady();
 106   mReady.ResolveIfExists(true, __func__);
 107 }
 108
 109 void ModuleLoadRequest::ModuleLoaded() {
 110   // A module that was found to be marked as fetching in the module map has now
 111   // been loaded.
 112
 113   LOG(("ScriptLoadRequest (%p): Module loaded", this));
 114
 115   mModuleScript = mLoader->GetFetchedModule(mURI);
 116   if (!mModuleScript || mModuleScript->HasParseError()) {
 117     ModuleErrored();
 118     return;
 119   }
 120
 121   mLoader->StartFetchingModuleDependencies(this);
 122 }
 123
 124 void ModuleLoadRequest::ModuleErrored() {
 125   if (IsCanceled()) {
 126     return;
 127   }
 128
 129   LOG(("ScriptLoadRequest (%p): Module errored", this));
 130
 131   CheckModuleDependenciesLoaded();
 132   MOZ_ASSERT(!mModuleScript || mModuleScript->HasParseError());
 133
 134   CancelImports();
 135   SetReady();
 136   LoadFinished();
 137 }
 138
 139 void ModuleLoadRequest::DependenciesLoaded() {
 140   if (IsCanceled()) {
 141     return;
 142   }
 143
 144   // The module and all of its dependencies have been successfully fetched and
 145   // compiled.
 146
 147   LOG(("ScriptLoadRequest (%p): Module dependencies loaded", this));
 148
 149   MOZ_ASSERT(mModuleScript);
 150
 151   CheckModuleDependenciesLoaded();
 152   SetReady();
 153   LoadFinished();
 154 }
 155
 156 void ModuleLoadRequest::CheckModuleDependenciesLoaded() {
 157   LOG(("ScriptLoadRequest (%p): Check dependencies loaded", this));
 158
 159   if (!mModuleScript || mModuleScript->HasParseError()) {
 160     return;
 161   }
 162   for (const auto& childRequest : mImports) {
 163     ModuleScript* childScript = childRequest->mModuleScript;
 164     if (!childScript) {
 165       mModuleScript = nullptr;
 166       LOG(("ScriptLoadRequest (%p):   %p failed (load error)", this,
 167            childRequest.get()));
 168       return;
 169     }
 170   }
 171
 172   LOG(("ScriptLoadRequest (%p):   all ok", this));
 173 }
 174
 175 void ModuleLoadRequest::LoadFailed() {
 176   // We failed to load the source text or an error occurred unrelated to the
 177   // content of the module (e.g. OOM).
 178
 179   LOG(("ScriptLoadRequest (%p): Module load failed", this));
 180
 181   MOZ_ASSERT(!mModuleScript);
 182
 183   Cancel();
 184   LoadFinished();
 185 }
 186
 187 void ModuleLoadRequest::LoadFinished() {
 188   RefPtr<ModuleLoadRequest> request(this);
 189   if (IsTopLevel() && IsDynamicImport()) {
 190     mLoader->RemoveDynamicImport(request);
 191   }
 192
 193   mLoader->OnModuleLoadComplete(request);
 194 }
 195
 196 void ModuleLoadRequest::ClearDynamicImport() {
 197   mDynamicReferencingPrivate = JS::UndefinedValue();
 198   mDynamicSpecifier = nullptr;
 199   mDynamicPromise = nullptr;
 200 }
 201
 202 }  // namespace JS::loader