gecko-dev/dom/script/ScriptLoader.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_ScriptLoader_h
#define mozilla_dom_ScriptLoader_h
#include "nsCOMPtr.h"
#include "nsRefPtrHashtable.h"
#include "mozilla/Encoding.h"
#include "nsIScriptElement.h"
#include "nsCOMArray.h"
#include "nsCycleCollectionParticipant.h"
#include "nsTArray.h"
#include "nsAutoPtr.h"
#include "nsICacheInfoChannel.h"
#include "nsIDocument.h"
#include "nsIIncrementalStreamLoader.h"
#include "nsURIHashKey.h"
#include "mozilla/CORSMode.h"
#include "mozilla/dom/ScriptLoadRequest.h"
#include "mozilla/dom/SRIMetadata.h"
#include "mozilla/dom/SRICheck.h"
#include "mozilla/MozPromise.h"
#include "mozilla/net/ReferrerPolicy.h"
#include "mozilla/Vector.h"
class nsIURI;
namespace JS {
class SourceBufferHolder;
} // namespace JS
namespace mozilla {
namespace dom {
class AutoJSAPI;
class ModuleLoadRequest;
class ModuleScript;
class ScriptLoadHandler;
class ScriptRequestProcessor;
//////////////////////////////////////////////////////////////
// Script loader implementation
//////////////////////////////////////////////////////////////
class ScriptLoader final : public nsISupports
{
class MOZ_STACK_CLASS AutoCurrentScriptUpdater
{
public:
AutoCurrentScriptUpdater(ScriptLoader* aScriptLoader,
nsIScriptElement* aCurrentScript)
: mOldScript(aScriptLoader->mCurrentScript)
, mScriptLoader(aScriptLoader)
{
mScriptLoader->mCurrentScript = aCurrentScript;
}
~AutoCurrentScriptUpdater()
{
mScriptLoader->mCurrentScript.swap(mOldScript);
}
private:
nsCOMPtr<nsIScriptElement> mOldScript;
ScriptLoader* mScriptLoader;
};
friend class ModuleLoadRequest;
friend class ScriptRequestProcessor;
friend class ScriptLoadHandler;
friend class AutoCurrentScriptUpdater;
public:
explicit ScriptLoader(nsIDocument* aDocument);
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_CLASS(ScriptLoader)
/**
* The loader maintains a weak reference to the document with
* which it is initialized. This call forces the reference to
* be dropped.
*/
void DropDocumentReference()
{
mDocument = nullptr;
}
/**
* Add an observer for all scripts loaded through this loader.
*
* @param aObserver observer for all script processing.
*/
nsresult AddObserver(nsIScriptLoaderObserver* aObserver)
{
return mObservers.AppendObject(aObserver) ? NS_OK :
NS_ERROR_OUT_OF_MEMORY;
}
/**
* Remove an observer.
*
* @param aObserver observer to be removed
*/
void RemoveObserver(nsIScriptLoaderObserver* aObserver)
{
mObservers.RemoveObject(aObserver);
}
/**
* Process a script element. This will include both loading the
* source of the element if it is not inline and evaluating
* the script itself.
*
* If the script is an inline script that can be executed immediately
* (i.e. there are no other scripts pending) then ScriptAvailable
* and ScriptEvaluated will be called before the function returns.
*
* If true is returned the script could not be executed immediately.
* In this case ScriptAvailable is guaranteed to be called at a later
* point (as well as possibly ScriptEvaluated).
*
* @param aElement The element representing the script to be loaded and
* evaluated.
*/
bool ProcessScriptElement(nsIScriptElement* aElement);
/**
* Gets the currently executing script. This is useful if you want to
* generate a unique key based on the currently executing script.
*/
nsIScriptElement* GetCurrentScript()
{
return mCurrentScript;
}
nsIScriptElement* GetCurrentParserInsertedScript()
{
return mCurrentParserInsertedScript;
}
/**
* Whether the loader is enabled or not.
* When disabled, processing of new script elements is disabled.
* Any call to ProcessScriptElement() will return false. Note that
* this DOES NOT disable currently loading or executing scripts.
*/
bool GetEnabled()
{
return mEnabled;
}
void SetEnabled(bool aEnabled)
{
if (!mEnabled && aEnabled) {
ProcessPendingRequestsAsync();
}
mEnabled = aEnabled;
}
/**
* Add/remove a blocker for parser-blocking scripts (and XSLT
* scripts). Blockers will stop such scripts from executing, but not from
* loading.
*/
void AddParserBlockingScriptExecutionBlocker()
{
++mParserBlockingBlockerCount;
}
void RemoveParserBlockingScriptExecutionBlocker()
{
if (!--mParserBlockingBlockerCount && ReadyToExecuteScripts()) {
ProcessPendingRequestsAsync();
}
}
/**
* Add/remove a blocker for execution of all scripts. Blockers will stop
* scripts from executing, but not from loading.
*/
void AddExecuteBlocker()
{
++mBlockerCount;
}
void RemoveExecuteBlocker()
{
MOZ_ASSERT(mBlockerCount);
if (!--mBlockerCount) {
ProcessPendingRequestsAsync();
}
}
/**
* Convert the given buffer to a UTF-16 string.
* @param aChannel Channel corresponding to the data. May be null.
* @param aData The data to convert
* @param aLength Length of the data
* @param aHintCharset Hint for the character set (e.g., from a charset
* attribute). May be the empty string.
* @param aDocument Document which the data is loaded for. Must not be
* null.
* @param aBufOut [out] char16_t array allocated by ConvertToUTF16 and
* containing data converted to unicode. Caller must
* js_free() this data when no longer needed.
* @param aLengthOut [out] Length of array returned in aBufOut in number
* of char16_t code units.
*/
static nsresult ConvertToUTF16(nsIChannel* aChannel, const uint8_t* aData,
uint32_t aLength,
const nsAString& aHintCharset,
nsIDocument* aDocument,
char16_t*& aBufOut, size_t& aLengthOut);
static inline nsresult
ConvertToUTF16(nsIChannel* aChannel, const uint8_t* aData,
uint32_t aLength, const nsAString& aHintCharset,
nsIDocument* aDocument,
JS::UniqueTwoByteChars& aBufOut, size_t& aLengthOut)
{
char16_t* bufOut;
nsresult rv = ConvertToUTF16(aChannel, aData, aLength, aHintCharset,
aDocument, bufOut, aLengthOut);
if (NS_SUCCEEDED(rv)) {
aBufOut.reset(bufOut);
}
return rv;
};
/**
* Handle the completion of a stream. This is called by the
* ScriptLoadHandler object which observes the IncrementalStreamLoader
* loading the script. The streamed content is expected to be stored on the
* aRequest argument.
*/
nsresult OnStreamComplete(nsIIncrementalStreamLoader* aLoader,
ScriptLoadRequest* aRequest,
nsresult aChannelStatus,
nsresult aSRIStatus,
SRICheckDataVerifier* aSRIDataVerifier);
/**
* Returns wether any request is queued, and not executed yet.
*/
bool HasPendingRequests();
/**
* Processes any pending requests that are ready for processing.
*/
void ProcessPendingRequests();
/**
* Starts deferring deferred scripts and puts them in the mDeferredRequests
* queue instead.
*/
void BeginDeferringScripts()
{
mDeferEnabled = true;
if (mDocument) {
mDocument->BlockOnload();
}
}
/**
* Notifies the script loader that parsing is done. If aTerminated is true,
* this will drop any pending scripts that haven't run yet. Otherwise, it
* will stops deferring scripts and immediately processes the
* mDeferredRequests queue.
*
* WARNING: This function will synchronously execute content scripts, so be
* prepared that the world might change around you.
*/
void ParsingComplete(bool aTerminated);
/**
* Returns the number of pending scripts, deferred or not.
*/
uint32_t HasPendingOrCurrentScripts()
{
return mCurrentScript || mParserBlockingRequest;
}
/**
* Adds aURI to the preload list and starts loading it.
*
* @param aURI The URI of the external script.
* @param aCharset The charset parameter for the script.
* @param aType The type parameter for the script.
* @param aCrossOrigin The crossorigin attribute for the script.
* Void if not present.
* @param aIntegrity The expect hash url, if avail, of the request
* @param aScriptFromHead Whether or not the script was a child of head
*/
virtual void PreloadURI(nsIURI* aURI,
const nsAString& aCharset,
const nsAString& aType,
const nsAString& aCrossOrigin,
const nsAString& aIntegrity,
bool aScriptFromHead,
bool aAsync,
bool aDefer,
bool aNoModule,
const mozilla::net::ReferrerPolicy aReferrerPolicy);
/**
* Process a request that was deferred so that the script could be compiled
* off thread.
*/
nsresult ProcessOffThreadRequest(ScriptLoadRequest* aRequest);
bool AddPendingChildLoader(ScriptLoader* aChild)
{
return mPendingChildLoaders.AppendElement(aChild) != nullptr;
}
mozilla::dom::DocGroup* GetDocGroup() const
{
return mDocument->GetDocGroup();
}
/**
* Register the fact that we saw the load event, and that we need to save the
* bytecode at the next loop cycle unless new scripts are waiting in the
* pipeline.
*/
void LoadEventFired();
/**
* Destroy and prevent the ScriptLoader or the ScriptLoadRequests from owning
* any references to the JSScript or to the Request which might be used for
* caching the encoded bytecode.
*/
void Destroy()
{
GiveUpBytecodeEncoding();
}
private:
virtual ~ScriptLoader();
ScriptLoadRequest* CreateLoadRequest(ScriptKind aKind,
nsIURI* aURI,
nsIScriptElement* aElement,
mozilla::CORSMode aCORSMode,
const SRIMetadata& aIntegrity,
mozilla::net::ReferrerPolicy aReferrerPolicy);
/**
* Unblocks the creator parser of the parser-blocking scripts.
*/
void UnblockParser(ScriptLoadRequest* aParserBlockingRequest);
/**
* Asynchronously resumes the creator parser of the parser-blocking scripts.
*/
void ContinueParserAsync(ScriptLoadRequest* aParserBlockingRequest);
bool ProcessExternalScript(nsIScriptElement* aElement,
ScriptKind aScriptKind,
nsAutoString aTypeAttr,
nsIContent* aScriptContent);
bool ProcessInlineScript(nsIScriptElement* aElement,
ScriptKind aScriptKind);
ScriptLoadRequest* LookupPreloadRequest(nsIScriptElement* aElement,
ScriptKind aScriptKind);
void GetSRIMetadata(const nsAString& aIntegrityAttr,
SRIMetadata *aMetadataOut);
/**
* Helper function to check the content policy for a given request.
*/
static nsresult CheckContentPolicy(nsIDocument* aDocument,
nsISupports* aContext,
nsIURI* aURI,
const nsAString& aType,
bool aIsPreLoad);
/**
* Start a load for aRequest's URI.
*/
nsresult StartLoad(ScriptLoadRequest* aRequest);
/**
* Abort the current stream, and re-start with a new load request from scratch
* without requesting any alternate data. Returns NS_BINDING_RETARGETED on
* success, as this error code is used to abort the input stream.
*/
nsresult RestartLoad(ScriptLoadRequest* aRequest);
void HandleLoadError(ScriptLoadRequest *aRequest, nsresult aResult);
/**
* Process any pending requests asynchronously (i.e. off an event) if there
* are any. Note that this is a no-op if there aren't any currently pending
* requests.
*
* This function is virtual to allow cross-library calls to SetEnabled()
*/
virtual void ProcessPendingRequestsAsync();
/**
* If true, the loader is ready to execute parser-blocking scripts, and so are
* all its ancestors. If the loader itself is ready but some ancestor is not,
* this function will add an execute blocker and ask the ancestor to remove it
* once it becomes ready.
*/
bool ReadyToExecuteParserBlockingScripts();
/**
* Return whether just this loader is ready to execute parser-blocking
* scripts.
*/
bool SelfReadyToExecuteParserBlockingScripts()
{
return ReadyToExecuteScripts() && !mParserBlockingBlockerCount;
}
/**
* Return whether this loader is ready to execute scripts in general.
*/
bool ReadyToExecuteScripts()
{
return mEnabled && !mBlockerCount;
}
nsresult VerifySRI(ScriptLoadRequest *aRequest,
nsIIncrementalStreamLoader* aLoader,
nsresult aSRIStatus,
SRICheckDataVerifier* aSRIDataVerifier) const;
nsresult SaveSRIHash(ScriptLoadRequest *aRequest,
SRICheckDataVerifier* aSRIDataVerifier) const;
void ReportErrorToConsole(ScriptLoadRequest *aRequest, nsresult aResult) const;
nsresult AttemptAsyncScriptCompile(ScriptLoadRequest* aRequest);
nsresult ProcessRequest(ScriptLoadRequest* aRequest);
nsresult CompileOffThreadOrProcessRequest(ScriptLoadRequest* aRequest);
void FireScriptAvailable(nsresult aResult,
ScriptLoadRequest* aRequest);
void FireScriptEvaluated(nsresult aResult,
ScriptLoadRequest* aRequest);
nsresult EvaluateScript(ScriptLoadRequest* aRequest);
/**
* Queue the current script load request to be saved, when the page
* initialization ends. The page initialization end is defined as being the
* time when the load event got received, and when no more scripts are waiting
* to be executed.
*/
void RegisterForBytecodeEncoding(ScriptLoadRequest* aRequest);
/**
* Check if all conditions are met, i-e that the onLoad event fired and that
* no more script have to be processed. If all conditions are met, queue an
* event to encode all the bytecode and save them on the cache.
*/
void MaybeTriggerBytecodeEncoding();
/**
* Iterate over all script load request and save the bytecode of executed
* functions on the cache provided by the channel.
*/
void EncodeBytecode();
void EncodeRequestBytecode(JSContext* aCx, ScriptLoadRequest* aRequest);
void GiveUpBytecodeEncoding();
already_AddRefed<nsIScriptGlobalObject> GetScriptGlobalObject();
nsresult FillCompileOptionsForRequest(const mozilla::dom::AutoJSAPI& jsapi,
ScriptLoadRequest* aRequest,
JS::Handle<JSObject*> aScopeChain,
JS::CompileOptions* aOptions);
uint32_t NumberOfProcessors();
nsresult PrepareLoadedRequest(ScriptLoadRequest* aRequest,
nsIIncrementalStreamLoader* aLoader,
nsresult aStatus);
void AddDeferRequest(ScriptLoadRequest* aRequest);
void AddAsyncRequest(ScriptLoadRequest* aRequest);
bool MaybeRemovedDeferRequests();
void MaybeMoveToLoadedList(ScriptLoadRequest* aRequest);
JS::SourceBufferHolder GetScriptSource(ScriptLoadRequest* aRequest,
nsAutoString& inlineData);
void SetModuleFetchStarted(ModuleLoadRequest *aRequest);
void SetModuleFetchFinishedAndResumeWaitingRequests(ModuleLoadRequest* aRequest,
nsresult aResult);
bool IsFetchingModule(ModuleLoadRequest* aRequest) const;
bool ModuleMapContainsURL(nsIURI* aURL) const;
RefPtr<mozilla::GenericPromise> WaitForModuleFetch(nsIURI* aURL);
ModuleScript* GetFetchedModule(nsIURI* aURL) const;
friend bool
HostResolveImportedModule(JSContext* aCx, unsigned argc, JS::Value* vp);
// Returns wether we should save the bytecode of this script after the
// execution of the script.
static bool
ShouldCacheBytecode(ScriptLoadRequest* aRequest);
nsresult CreateModuleScript(ModuleLoadRequest* aRequest);
nsresult ProcessFetchedModuleSource(ModuleLoadRequest* aRequest);
void CheckModuleDependenciesLoaded(ModuleLoadRequest* aRequest);
void ProcessLoadedModuleTree(ModuleLoadRequest* aRequest);
bool InstantiateModuleTree(ModuleLoadRequest* aRequest);
JS::Value FindFirstParseError(ModuleLoadRequest* aRequest);
void StartFetchingModuleDependencies(ModuleLoadRequest* aRequest);
RefPtr<mozilla::GenericPromise>
StartFetchingModuleAndDependencies(ModuleLoadRequest* aParent, nsIURI* aURI);
nsIDocument* mDocument; // [WEAK]
nsCOMArray<nsIScriptLoaderObserver> mObservers;
ScriptLoadRequestList mNonAsyncExternalScriptInsertedRequests;
// mLoadingAsyncRequests holds async requests while they're loading; when they
// have been loaded they are moved to mLoadedAsyncRequests.
ScriptLoadRequestList mLoadingAsyncRequests;
ScriptLoadRequestList mLoadedAsyncRequests;
ScriptLoadRequestList mDeferRequests;
ScriptLoadRequestList mXSLTRequests;
RefPtr<ScriptLoadRequest> mParserBlockingRequest;
// List of script load request that are holding a buffer which has to be saved
// on the cache.
ScriptLoadRequestList mBytecodeEncodingQueue;
// In mRequests, the additional information here is stored by the element.
struct PreloadInfo
{
RefPtr<ScriptLoadRequest> mRequest;
nsString mCharset;
};
friend void ImplCycleCollectionUnlink(ScriptLoader::PreloadInfo& aField);
friend void ImplCycleCollectionTraverse(nsCycleCollectionTraversalCallback& aCallback,
ScriptLoader::PreloadInfo& aField,
const char* aName, uint32_t aFlags);
struct PreloadRequestComparator
{
bool Equals(const PreloadInfo& aPi, ScriptLoadRequest* const& aRequest) const
{
return aRequest == aPi.mRequest;
}
};
struct PreloadURIComparator
{
bool Equals(const PreloadInfo& aPi, nsIURI* const &aURI) const;
};
nsTArray<PreloadInfo> mPreloads;
nsCOMPtr<nsIScriptElement> mCurrentScript;
nsCOMPtr<nsIScriptElement> mCurrentParserInsertedScript;
nsTArray< RefPtr<ScriptLoader> > mPendingChildLoaders;
uint32_t mParserBlockingBlockerCount;
uint32_t mBlockerCount;
uint32_t mNumberOfProcessors;
bool mEnabled;
bool mDeferEnabled;
bool mDocumentParsingDone;
bool mBlockingDOMContentLoaded;
bool mLoadEventFired;
bool mGiveUpEncoding;
// Module map
nsRefPtrHashtable<nsURIHashKey, mozilla::GenericPromise::Private> mFetchingModules;
nsRefPtrHashtable<nsURIHashKey, ModuleScript> mFetchedModules;
nsCOMPtr<nsIConsoleReportCollector> mReporter;
// Logging
static LazyLogModule gCspPRLog;
static LazyLogModule gScriptLoaderLog;
};
class nsAutoScriptLoaderDisabler
{
public:
explicit nsAutoScriptLoaderDisabler(nsIDocument* aDoc)
{
mLoader = aDoc->ScriptLoader();
mWasEnabled = mLoader->GetEnabled();
if (mWasEnabled) {
mLoader->SetEnabled(false);
}
}
~nsAutoScriptLoaderDisabler()
{
if (mWasEnabled) {
mLoader->SetEnabled(true);
}
}
bool mWasEnabled;
RefPtr<ScriptLoader> mLoader;
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_ScriptLoader_h