summaryrefslogtreecommitdiffstats
path: root/dom/script/ScriptLoadContext.h
diff options
context:
space:
mode:
Diffstat (limited to 'dom/script/ScriptLoadContext.h')
-rw-r--r--dom/script/ScriptLoadContext.h253
1 files changed, 253 insertions, 0 deletions
diff --git a/dom/script/ScriptLoadContext.h b/dom/script/ScriptLoadContext.h
new file mode 100644
index 0000000000..74f7c6fe4f
--- /dev/null
+++ b/dom/script/ScriptLoadContext.h
@@ -0,0 +1,253 @@
+/* -*- 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_ScriptLoadContext_h
+#define mozilla_dom_ScriptLoadContext_h
+
+#include "js/AllocPolicy.h"
+#include "js/ColumnNumber.h" // JS::ColumnNumberOneOrigin
+#include "js/CompileOptions.h" // JS::OwningCompileOptions
+#include "js/experimental/JSStencil.h" // JS::FrontendContext, JS::Stencil, JS::InstantiationStorage
+#include "js/RootingAPI.h"
+#include "js/SourceText.h"
+#include "js/Transcoding.h" // JS::TranscodeResult
+#include "js/TypeDecls.h"
+#include "js/loader/LoadContextBase.h"
+#include "js/loader/ScriptKind.h"
+#include "mozilla/AlreadyAddRefed.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/MaybeOneOf.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/PreloaderBase.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/StaticPrefs_dom.h"
+#include "mozilla/TaskController.h" // mozilla::Task
+#include "mozilla/Utf8.h" // mozilla::Utf8Unit
+#include "mozilla/Variant.h"
+#include "mozilla/Vector.h"
+#include "nsCOMPtr.h"
+#include "nsCycleCollectionParticipant.h"
+#include "nsIScriptElement.h"
+
+class nsICacheInfoChannel;
+struct JSContext;
+
+namespace mozilla::dom {
+
+class Element;
+
+/*
+ * DOM specific ScriptLoadContext.
+ *
+ * ScriptLoadContexts augment the loading of a ScriptLoadRequest. They
+ * describe how a ScriptLoadRequests loading and evaluation needs to be
+ * augmented, based on the information provided by the loading context. In
+ * the case of the DOM, the ScriptLoadContext is used to identify how a script
+ * should be loaded according to information found in the HTML document into
+ * which it will be loaded. The following fields describe how the
+ * ScriptLoadRequest will be loaded.
+ *
+ * * mScriptMode
+ * stores the mode (Async, Sync, Deferred), and preload, which
+ * allows the ScriptLoader to decide if the script should be pushed
+ * offThread, or if the preloaded request should be used.
+ * * mScriptFromHead
+ * Set when the script tag is in the head, and should be treated as
+ * a blocking script
+ * * mIsInline
+ * Set for scripts whose bodies are inline in the html. In this case,
+ * the script does not need to be fetched first.
+ * * mIsXSLT
+ * Set if we are in an XSLT request.
+ * * mIsPreload
+ * Set for scripts that are preloaded in a
+ * <link rel="preload" as="script"> or <link rel="modulepreload">
+ * element.
+ *
+ * In addition to describing how the ScriptLoadRequest will be loaded by the
+ * DOM ScriptLoader, the ScriptLoadContext contains fields that facilitate
+ * those custom behaviors, including support for offthread parsing and preload
+ * element specific controls.
+ *
+ */
+
+// Base class for the off-thread compile or off-thread decode tasks.
+class CompileOrDecodeTask : public mozilla::Task {
+ protected:
+ CompileOrDecodeTask();
+ virtual ~CompileOrDecodeTask();
+
+ nsresult InitFrontendContext();
+
+ void DidRunTask(const MutexAutoLock& aProofOfLock,
+ RefPtr<JS::Stencil>&& aStencil);
+
+ bool IsCancelled(const MutexAutoLock& aProofOfLock) const {
+ return mIsCancelled;
+ }
+
+ public:
+ // Returns the result of the compilation or decode if it was successful.
+ // Returns nullptr otherwise, and sets pending exception on JSContext.
+ //
+ // aInstantiationStorage receives the storage allocated off main thread
+ // on successful case.
+ already_AddRefed<JS::Stencil> StealResult(
+ JSContext* aCx, JS::InstantiationStorage* aInstantiationStorage);
+
+ // Cancel the task.
+ // If the task is already running, this waits for the task to finish.
+ void Cancel();
+
+ protected:
+ // This mutex is locked during running the task or cancelling task.
+ mozilla::Mutex mMutex;
+
+ // The result of decode task, to distinguish throwing case and decode error.
+ JS::TranscodeResult mResult = JS::TranscodeResult::Ok;
+
+ // An option used to compile the code, or the equivalent for decode.
+ // This holds the filename pointed by errors reported to JS::FrontendContext.
+ JS::OwningCompileOptions mOptions;
+
+ // Owning-pointer for the context associated with the script compilation.
+ //
+ // The context is allocated on main thread in InitFrontendContext method,
+ // and is freed on any thread in the destructor.
+ JS::FrontendContext* mFrontendContext = nullptr;
+
+ bool mIsCancelled = false;
+
+ private:
+ // The result of the compilation or decode.
+ RefPtr<JS::Stencil> mStencil;
+
+ JS::InstantiationStorage mInstantiationStorage;
+};
+
+class ScriptLoadContext : public JS::loader::LoadContextBase,
+ public PreloaderBase {
+ protected:
+ virtual ~ScriptLoadContext();
+
+ public:
+ explicit ScriptLoadContext();
+
+ NS_DECL_ISUPPORTS_INHERITED
+ NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(ScriptLoadContext,
+ JS::loader::LoadContextBase)
+
+ static void PrioritizeAsPreload(nsIChannel* aChannel);
+
+ bool IsPreload() const;
+
+ bool CompileStarted() const;
+
+ bool IsTracking() const { return mIsTracking; }
+ void SetIsTracking() {
+ MOZ_ASSERT(!mIsTracking);
+ mIsTracking = true;
+ }
+
+ void BlockOnload(Document* aDocument);
+
+ void MaybeUnblockOnload();
+
+ enum class ScriptMode : uint8_t {
+ eBlocking,
+ eDeferred,
+ eAsync,
+ eLinkPreload // this is a load initiated by <link rel="preload"
+ // as="script"> or <link rel="modulepreload"> 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; }
+
+ nsIScriptElement* GetScriptElement() const;
+
+ // Make this request a preload (speculative) request.
+ void SetIsPreloadRequest() {
+ MOZ_ASSERT(!GetScriptElement());
+ MOZ_ASSERT(!IsPreload());
+ 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();
+ }
+
+ // Used to output a string for the Gecko Profiler.
+ void GetProfilerLabel(nsACString& aOutString) override;
+
+ void MaybeCancelOffThreadScript();
+
+ // Finish the off-main-thread compilation and return the result, or
+ // convert the compilation error to runtime error.
+ already_AddRefed<JS::Stencil> StealOffThreadResult(
+ JSContext* aCx, JS::InstantiationStorage* aInstantiationStorage);
+
+ ScriptMode mScriptMode; // Whether this is a blocking, defer or async script.
+ 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 mInCompilingList; // True if we are in mOffThreadCompilingRequests.
+ bool mIsTracking; // True if the script comes from a source on our
+ // tracking protection list.
+ bool mWasCompiledOMT; // True if the script has been compiled off main
+ // thread.
+
+ // Task that performs off-thread compilation or off-thread decode.
+ // This field is used to take the result of the task, or cancel the task.
+ //
+ // Set to non-null on the task creation, and set to null when taking the
+ // result or cancelling the task.
+ RefPtr<CompileOrDecodeTask> mCompileOrDecodeTask;
+
+ uint32_t mLineNo;
+ JS::ColumnNumberOneOrigin mColumnNo;
+
+ // Set on scripts and top level modules.
+ bool mIsPreload;
+
+ // Non-null if there is a document that this request is blocking from loading.
+ RefPtr<Document> mLoadBlockedDocument;
+
+ // For preload requests, we defer reporting errors to the console until the
+ // request is used.
+ nsresult mUnreportedPreloadError;
+};
+
+} // namespace mozilla::dom
+
+#endif // mozilla_dom_ScriptLoadContext_h