1 files changed, 409 insertions, 0 deletions
diff --git a/dom/script/ScriptLoadRequest.h b/dom/script/ScriptLoadRequest.h
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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 http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_ScriptLoadRequest_h
+#define mozilla_dom_ScriptLoadRequest_h
+
+#include "js/AllocPolicy.h"
+#include "js/RootingAPI.h"
+#include "js/TypeDecls.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/CORSMode.h"
+#include "mozilla/dom/SRIMetadata.h"
+#include "mozilla/LinkedList.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/PreloaderBase.h"
+#include "mozilla/Utf8.h"  // mozilla::Utf8Unit
+#include "mozilla/Variant.h"
+#include "mozilla/Vector.h"
+#include "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsIScriptElement.h"
+#include "ScriptKind.h"
+
+class nsICacheInfoChannel;
+
+namespace JS {
+class OffThreadToken;
+}
+
+namespace mozilla {
+namespace dom {
+
+class Element;
+class ModuleLoadRequest;
+class ScriptLoadRequestList;
+
+/*
+ * Some options used when fetching script resources. This only loosely
+ * corresponds to HTML's "script fetch options".
+ *
+ * These are common to all modules in a module graph, and hence a single
+ * instance is shared by all ModuleLoadRequest objects in a graph.
+ */
+
+class ScriptFetchOptions {
+  ~ScriptFetchOptions();
+
+ public:
+  NS_INLINE_DECL_CYCLE_COLLECTING_NATIVE_REFCOUNTING(ScriptFetchOptions)
+  NS_DECL_CYCLE_COLLECTION_NATIVE_CLASS(ScriptFetchOptions)
+
+  ScriptFetchOptions(mozilla::CORSMode aCORSMode,
+                     enum ReferrerPolicy aReferrerPolicy, Element* aElement,
+                     nsIPrincipal* aTriggeringPrincipal);
+
+  const mozilla::CORSMode mCORSMode;
+  const enum ReferrerPolicy mReferrerPolicy;
+  bool mIsPreload;
+  nsCOMPtr<Element> mElement;
+  nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
+};
+
+/*
+ * A class that handles loading and evaluation of <script> elements.
+ */
+
+class ScriptLoadRequest
+    : public PreloaderBase,
+      private mozilla::LinkedListElement<ScriptLoadRequest> {
+  typedef LinkedListElement<ScriptLoadRequest> super;
+
+  // Allow LinkedListElement<ScriptLoadRequest> to cast us to itself as needed.
+  friend class mozilla::LinkedListElement<ScriptLoadRequest>;
+  friend class ScriptLoadRequestList;
+
+ protected:
+  virtual ~ScriptLoadRequest();
+
+ public:
+  ScriptLoadRequest(ScriptKind aKind, nsIURI* aURI,
+                    ScriptFetchOptions* aFetchOptions,
+                    const SRIMetadata& aIntegrity, nsIURI* aReferrer);
+
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(ScriptLoadRequest)
+
+  // PreloaderBase
+  static void PrioritizeAsPreload(nsIChannel* aChannel);
+  virtual void PrioritizeAsPreload() override;
+
+  bool IsModuleRequest() const { return mKind == ScriptKind::eModule; }
+
+  ModuleLoadRequest* AsModuleRequest();
+
+#ifdef MOZ_GECKO_PROFILER
+  TimeStamp mOffThreadParseStartTime;
+  TimeStamp mOffThreadParseStopTime;
+#endif
+
+  void FireScriptAvailable(nsresult aResult) {
+    bool isInlineClassicScript = mIsInline && !IsModuleRequest();
+    GetScriptElement()->ScriptAvailable(aResult, GetScriptElement(),
+                                        isInlineClassicScript, mURI, mLineNo);
+  }
+  void FireScriptEvaluated(nsresult aResult) {
+    GetScriptElement()->ScriptEvaluated(aResult, GetScriptElement(), mIsInline);
+  }
+
+  bool IsPreload() const {
+    MOZ_ASSERT_IF(mFetchOptions->mIsPreload, !GetScriptElement());
+    return mFetchOptions->mIsPreload;
+  }
+
+  virtual void Cancel();
+
+  bool IsCanceled() const { return mIsCanceled; }
+
+  virtual void SetReady();
+
+  JS::OffThreadToken** OffThreadTokenPtr() {
+    return mOffThreadToken ? &mOffThreadToken : nullptr;
+  }
+
+  bool IsTracking() const { return mIsTracking; }
+  void SetIsTracking() {
+    MOZ_ASSERT(!mIsTracking);
+    mIsTracking = true;
+  }
+
+  void BlockOnload(Document* aDocument);
+
+  void MaybeUnblockOnload();
+
+  enum class Progress : uint8_t {
+    eLoading,         // Request either source or bytecode
+    eLoading_Source,  // Explicitly Request source stream
+    eCompiling,
+    eFetchingImports,
+    eReady
+  };
+
+  bool IsReadyToRun() const { return mProgress == Progress::eReady; }
+  bool IsLoading() const {
+    return mProgress == Progress::eLoading ||
+           mProgress == Progress::eLoading_Source;
+  }
+  bool IsLoadingSource() const {
+    return mProgress == Progress::eLoading_Source;
+  }
+  bool InCompilingStage() const {
+    return mProgress == Progress::eCompiling ||
+           (IsReadyToRun() && mWasCompiledOMT);
+  }
+
+  // Type of data provided by the nsChannel.
+  enum class DataType : uint8_t {
+    eUnknown,
+    eTextSource,
+    eBinASTSource,
+    eBytecode
+  };
+
+  bool IsUnknownDataType() const { return mDataType == DataType::eUnknown; }
+  bool IsTextSource() const { return mDataType == DataType::eTextSource; }
+  bool IsBinASTSource() const { return false; }
+  bool IsSource() const { return IsTextSource() || IsBinASTSource(); }
+  bool IsBytecode() const { return mDataType == DataType::eBytecode; }
+
+  void SetUnknownDataType();
+  void SetTextSource();
+  void SetBinASTSource();
+  void SetBytecode();
+
+  // Use a vector backed by the JS allocator for script text so that contents
+  // can be transferred in constant time to the JS engine, not copied in linear
+  // time.
+  template <typename Unit>
+  using ScriptTextBuffer = Vector<Unit, 0, js::MallocAllocPolicy>;
+
+  // BinAST data isn't transferred to the JS engine, so it doesn't need to use
+  // the JS allocator.
+  using BinASTSourceBuffer = Vector<uint8_t>;
+
+  bool IsUTF16Text() const {
+    return mScriptData->is<ScriptTextBuffer<char16_t>>();
+  }
+  bool IsUTF8Text() const {
+    return mScriptData->is<ScriptTextBuffer<Utf8Unit>>();
+  }
+
+  template <typename Unit>
+  const ScriptTextBuffer<Unit>& ScriptText() const {
+    MOZ_ASSERT(IsTextSource());
+    return mScriptData->as<ScriptTextBuffer<Unit>>();
+  }
+  template <typename Unit>
+  ScriptTextBuffer<Unit>& ScriptText() {
+    MOZ_ASSERT(IsTextSource());
+    return mScriptData->as<ScriptTextBuffer<Unit>>();
+  }
+
+  const BinASTSourceBuffer& ScriptBinASTData() const {
+    MOZ_ASSERT(IsBinASTSource());
+    return mScriptData->as<BinASTSourceBuffer>();
+  }
+  BinASTSourceBuffer& ScriptBinASTData() {
+    MOZ_ASSERT(IsBinASTSource());
+    return mScriptData->as<BinASTSourceBuffer>();
+  }
+
+  size_t ScriptTextLength() const {
+    MOZ_ASSERT(IsTextSource());
+    return IsUTF16Text() ? ScriptText<char16_t>().length()
+                         : ScriptText<Utf8Unit>().length();
+  }
+
+  void ClearScriptText() {
+    MOZ_ASSERT(IsTextSource());
+    return IsUTF16Text() ? ScriptText<char16_t>().clearAndFree()
+                         : ScriptText<Utf8Unit>().clearAndFree();
+  }
+
+  enum class ScriptMode : uint8_t {
+    eBlocking,
+    eDeferred,
+    eAsync,
+    eLinkPreload  // this is a load initiated by <link rel="preload"
+                  // as="script"> tag
+  };
+
+  void SetScriptMode(bool aDeferAttr, bool aAsyncAttr, bool aLinkPreload);
+
+  bool IsLinkPreloadScript() const {
+    return mScriptMode == ScriptMode::eLinkPreload;
+  }
+
+  bool IsBlockingScript() const { return mScriptMode == ScriptMode::eBlocking; }
+
+  bool IsDeferredScript() const { return mScriptMode == ScriptMode::eDeferred; }
+
+  bool IsAsyncScript() const { return mScriptMode == ScriptMode::eAsync; }
+
+  virtual bool IsTopLevel() const {
+    // Classic scripts are always top level.
+    return true;
+  }
+
+  mozilla::CORSMode CORSMode() const { return mFetchOptions->mCORSMode; }
+  enum ReferrerPolicy ReferrerPolicy() const {
+    return mFetchOptions->mReferrerPolicy;
+  }
+  nsIScriptElement* GetScriptElement() const;
+  nsIPrincipal* TriggeringPrincipal() const {
+    return mFetchOptions->mTriggeringPrincipal;
+  }
+
+  // Make this request a preload (speculative) request.
+  void SetIsPreloadRequest() {
+    MOZ_ASSERT(!GetScriptElement());
+    MOZ_ASSERT(!IsPreload());
+    mFetchOptions->mIsPreload = true;
+  }
+
+  // Make a preload request into an actual load request for the given element.
+  void SetIsLoadRequest(nsIScriptElement* aElement);
+
+  FromParser GetParserCreated() const {
+    nsIScriptElement* element = GetScriptElement();
+    if (!element) {
+      return NOT_FROM_PARSER;
+    }
+    return element->GetParserCreated();
+  }
+
+  bool ShouldAcceptBinASTEncoding() const;
+
+  void ClearScriptSource();
+
+  void SetScript(JSScript* aScript);
+
+  void MaybeCancelOffThreadScript();
+  void DropBytecodeCacheReferences();
+
+  using super::getNext;
+  using super::isInList;
+
+  const ScriptKind mKind;  // Whether this is a classic script or a module
+                           // script.
+  ScriptMode mScriptMode;  // Whether this is a blocking, defer or async script.
+  Progress mProgress;      // Are we still waiting for a load to complete?
+  DataType mDataType;      // Does this contain Source or Bytecode?
+  bool mScriptFromHead;    // Synchronous head script block loading of other non
+                           // js/css content.
+  bool mIsInline;          // Is the script inline or loaded?
+  bool mInDeferList;       // True if we live in mDeferRequests.
+  bool mInAsyncList;       // True if we live in mLoadingAsyncRequests or
+                           // mLoadedAsyncRequests.
+  bool mIsNonAsyncScriptInserted;  // True if we live in
+                                   // mNonAsyncExternalScriptInsertedRequests
+  bool mIsXSLT;                    // True if we live in mXSLTRequests.
+  bool mIsCanceled;                // True if we have been explicitly canceled.
+  bool mWasCompiledOMT;  // True if the script has been compiled off main
+                         // thread.
+  bool mIsTracking;      // True if the script comes from a source on our
+                         // tracking protection list.
+
+  RefPtr<ScriptFetchOptions> mFetchOptions;
+
+  JS::OffThreadToken* mOffThreadToken;  // Off-thread parsing token.
+  Maybe<nsString> mSourceMapURL;  // Holds source map url for loaded scripts
+
+  Atomic<Runnable*> mRunnable;  // Runnable created when dispatching off thread
+                                // compile. Tracked here so that it can be
+                                // properly released during cancellation.
+
+  // Holds the top-level JSScript that corresponds to the current source, once
+  // it is parsed, and planned to be saved in the bytecode cache.
+  JS::Heap<JSScript*> mScript;
+
+  // Holds script source data for non-inline scripts.
+  Maybe<Variant<ScriptTextBuffer<char16_t>, ScriptTextBuffer<Utf8Unit>,
+                BinASTSourceBuffer>>
+      mScriptData;
+
+  // The length of script source text, set when reading completes. This is used
+  // since mScriptData is cleared when the source is passed to the JS engine.
+  size_t mScriptTextLength;
+
+  // Holds the SRI serialized hash and the script bytecode for non-inline
+  // scripts.
+  mozilla::Vector<uint8_t> mScriptBytecode;
+  uint32_t mBytecodeOffset;  // Offset of the bytecode in mScriptBytecode
+
+  const nsCOMPtr<nsIURI> mURI;
+  nsCOMPtr<nsIPrincipal> mOriginPrincipal;
+  nsAutoCString
+      mURL;  // Keep the URI's filename alive during off thread parsing.
+  int32_t mLineNo;
+  const SRIMetadata mIntegrity;
+  const nsCOMPtr<nsIURI> mReferrer;
+
+  // Non-null if there is a document that this request is blocking from loading.
+  RefPtr<Document> mLoadBlockedDocument;
+
+  // Holds the Cache information, which is used to register the bytecode
+  // on the cache entry, such that we can load it the next time.
+  nsCOMPtr<nsICacheInfoChannel> mCacheInfo;
+
+  // The base URL used for resolving relative module imports.
+  nsCOMPtr<nsIURI> mBaseURL;
+
+  // For preload requests, we defer reporting errors to the console until the
+  // request is used.
+  nsresult mUnreportedPreloadError;
+};
+
+class ScriptLoadRequestList : private mozilla::LinkedList<ScriptLoadRequest> {
+  typedef mozilla::LinkedList<ScriptLoadRequest> super;
+
+ public:
+  ~ScriptLoadRequestList();
+
+  void Clear();
+
+#ifdef DEBUG
+  bool Contains(ScriptLoadRequest* aElem) const;
+#endif  // DEBUG
+
+  using super::getFirst;
+  using super::isEmpty;
+
+  void AppendElement(ScriptLoadRequest* aElem) {
+    MOZ_ASSERT(!aElem->isInList());
+    NS_ADDREF(aElem);
+    insertBack(aElem);
+  }
+
+  MOZ_MUST_USE
+  already_AddRefed<ScriptLoadRequest> Steal(ScriptLoadRequest* aElem) {
+    aElem->removeFrom(*this);
+    return dont_AddRef(aElem);
+  }
+
+  MOZ_MUST_USE
+  already_AddRefed<ScriptLoadRequest> StealFirst() {
+    MOZ_ASSERT(!isEmpty());
+    return Steal(getFirst());
+  }
+
+  void Remove(ScriptLoadRequest* aElem) {
+    aElem->removeFrom(*this);
+    NS_RELEASE(aElem);
+  }
+};
+
+void ImplCycleCollectionUnlink(ScriptLoadRequestList& aField);
+
+void ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
+                                 ScriptLoadRequestList& aField,
+                                 const char* aName, uint32_t aFlags);
+
+}  // namespace dom
+}  // namespace mozilla
+
+#endif  // mozilla_dom_ScriptLoadRequest_h