/* 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 js_loader_LoadedScript_h #define js_loader_LoadedScript_h #include "mozilla/dom/SRIMetadata.h" // mozilla::dom::SRIMetadata #include "mozilla/Maybe.h" #include "mozilla/MaybeOneOf.h" #include "mozilla/MemoryReporting.h" #include "mozilla/RefPtr.h" #include "mozilla/UniquePtr.h" // mozilla::UniquePtr #include "mozilla/Utf8.h" // mozilla::Utf8Unit #include "mozilla/Variant.h" #include "mozilla/Vector.h" #include "jsapi.h" #include "nsCOMPtr.h" #include "nsCycleCollectionParticipant.h" #include "nsICacheInfoChannel.h" // nsICacheInfoChannel #include "ResolvedModuleSet.h" #include "ScriptFetchOptions.h" #include "ScriptKind.h" #include "js/AllocPolicy.h" #include "js/experimental/JSStencil.h" #include "js/Transcoding.h" class nsIURI; namespace JS::loader { class ScriptLoadRequest; using Utf8Unit = mozilla::Utf8Unit; void HostAddRefScriptFetchInfo(const Value& aPrivate); void HostReleaseScriptFetchInfo(const Value& aPrivate); class ClassicScript; class LoadedModuleScript; class LoadContextBase; // Information required to fetch scripts or module graphs. // // This class is separated than LoadedScript or ScriptLoadRequest, in order to // store it into the script private and module private, to propagate the // information to the module imports performed later. // // The fields are initialized from the request, and then updated from the // responses. class ScriptFetchInfo : public nsISupports { public: ScriptFetchInfo(ScriptKind aKind, mozilla::dom::ReferrerPolicy aReferrerPolicy, ScriptFetchOptions* aFetchOptions, nsIURI* aURI); NS_DECL_ISUPPORTS size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const; bool IsForModulePreload() const { return mIsForModulePreload; } void SetForModulePreload(bool aValue) { mIsForModulePreload = aValue; } bool IsForModuleScript() const { return mKind == ScriptKind::eModule; } bool IsForEvent() const { return mKind == ScriptKind::eEvent; } mozilla::dom::ReferrerPolicy ReferrerPolicy() const { return mReferrerPolicy; } void UpdateReferrerPolicy(mozilla::dom::ReferrerPolicy aReferrerPolicy) { mReferrerPolicy = aReferrerPolicy; } ScriptFetchOptions* FetchOptions() const { return mFetchOptions; } nsIURI* BaseURL() const { return mBaseURL; } void SetBaseURL(nsIURI* aBaseURL) { mBaseURL = aBaseURL; } /* * Set the mBaseURL, based on aChannel. * aOriginalURI is the result of aChannel->GetOriginalURI. */ void SetBaseURLFromChannelAndOriginalURI(nsIChannel* aChannel, nsIURI* aOriginalURI); void AssociateWithScript(JSScript* aScript); void AssociateWithModule(JSObject* aModuleRecord); protected: virtual ~ScriptFetchInfo() = default; private: // Set to true if this is for a module imported as part of preload. // // This field can be overwritten based on the module import processing. bool mIsForModulePreload = false; // This should match the LoadedScript::mKind. ScriptKind mKind; // The referrer policy used for fetching this script, and going to be used for // fetching imported modules. // // This field can be overwritten based on the response. mozilla::dom::ReferrerPolicy mReferrerPolicy; // The fetch option used for fetching this script, and going to be used for // fetching imported modules. // This field is constant, and never overwritten from the response. RefPtr mFetchOptions; // The base URL used for resolving relative module imports. // This field is unused for Event script, and in that case the loader's base // URL should be used. // // This field can be overwritten based on the response. nsCOMPtr mBaseURL; }; // A LoadedScript is a place where the Script is stored once it is loaded. It is // not unique to a load, and can be shared across loads as long as it is // properly ref-counted by each load instance. // // When the load is not performed, the URI represents the resource to be loaded, // and it is replaced by the absolute resource location once loaded. // // As the LoadedScript can be shared, using the SharedSubResourceCache, it is // exposed to the memory reporter such that sharing might be accounted for // properly. class LoadedScript final : public nsISupports { ~LoadedScript() = default; public: LoadedScript(ScriptKind aKind, nsIURI* aURI); size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const; public: NS_DECL_ISUPPORTS uint16_t ClampedRefCountForTelemetry() const { uintptr_t count = mRefCnt.get(); if (count > 100) { return 100; } return uint16_t(count); } bool IsClassicScript() const { return mKind == ScriptKind::eClassic; } bool IsModuleScript() const { return mKind == ScriptKind::eModule; } bool IsImportMapScript() const { return mKind == ScriptKind::eImportMap; } bool IsSpeculationRulesScript() const { return mKind == ScriptKind::eSpeculationRules; } nsIURI* GetURI() const { return mURI; } nsIURI* CachedBaseURL() const { return mCachedBaseURL; } mozilla::dom::ReferrerPolicy CachedReferrerPolicy() const { return mCachedReferrerPolicy; } public: // =========================================================================== // Encoding of the content provided by the network, or refined by the JS // engine. template using Variant = mozilla::Variant; template using VariantType = mozilla::VariantType; // Type of data this instance holds, which is either provided by the nsChannel // or retrieved from the cache. enum class DataType : uint8_t { // This script haven't yet received the data. eUnknown, // This script is received as a plain text from the channel. // mScriptData holds the text source, and mStencil holds the compiled // stencil. // mSRIAndSerializedStencil holds the SRI. eTextSource, // This script is received as a serialized stencil from the channel, // mSRIAndSerializedStencil holds the SRI and the serialized stencil, and // mCachedStencil is unused. eSerializedStencil, // This script is cached from the previous load. // mCachedStencil holds the cached stencil. mScriptData is unused. // // mSRIAndSerializedStencil can contain SRI only if this script is going to // be saved to disk: // * If this was retrieved as eTextSource and then converted to // eCachedStencil: // * If this script is going to be saved to disk, // mSRIAndSerializedStencil holds the SRI // * If this script was already saved to disk, // mSRIAndSerializedStencil was cleared before save, and is unused // * If this script is not going to be saved to disk, // mSRIAndSerializedStencil is unused // * If this was retrieved as eSerializedStencil and then converted to // eCachedStencil, the decoded stencil should not borrow the buffer. // mSRIAndSerializedStencil was cleared on conversion, is unused eCachedStencil, // This was eCachedStencil, but the stencil reference is cleared // for the memory pressure. // Other fields are still valid. eInvalidatedCachedStencil, // This is a wasm module, which is used when the response mime type essence // is application/wasm. // mScriptData holds the wasm source as uint8_t from the channel. // mCachedStencil and mSRIAndSerializedStencil are unused. eWasmBytes, }; // 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 using ScriptTextBuffer = mozilla::Vector; using MaybeSourceText = mozilla::MaybeOneOf, SourceText>; // ==== Methods to query the data type ==== bool IsUnknownDataType() const { return mDataType == DataType::eUnknown; } bool IsTextSource() const { return mDataType == DataType::eTextSource; } bool IsSerializedStencil() const { return mDataType == DataType::eSerializedStencil; } bool IsCachedStencil() const { return mDataType == DataType::eCachedStencil; } bool IsInvalidatedCachedStencil() const { return mDataType == DataType::eInvalidatedCachedStencil; } bool IsWasmBytes() const { return mDataType == DataType::eWasmBytes; } // ==== Methods to convert the data type ==== void SetUnknownDataType() { mDataType = DataType::eUnknown; mScriptData.reset(); } void SetTextSource(LoadContextBase* maybeLoadContext) { MOZ_ASSERT(IsUnknownDataType()); mDataType = DataType::eTextSource; mScriptData.emplace(VariantType>()); } void SetSerializedStencil() { MOZ_ASSERT(IsUnknownDataType()); mDataType = DataType::eSerializedStencil; } void ConvertToCachedStencil(JS::Stencil* aStencil, mozilla::dom::ReferrerPolicy aReferrerPolicy, nsIURI* aBaseURL) { if (IsTextSource()) { // The text source is no longer necessary, given it's already compiled. // The SRI is still necessary in order to save it to the disk cache. ClearScriptText(); } else { // The serialized stencil is no longer necessary, given it's already // decoded, without borrowing. // The SRI is also unnecessary given we don't save serialized stencil // again. MOZ_ASSERT(IsSerializedStencil()); MOZ_ASSERT(!JS::StencilIsBorrowed(aStencil)); DropSRIOrSRIAndSerializedStencil(); } SetUnknownDataType(); mDataType = DataType::eCachedStencil; mCachedStencil = aStencil; mCachedReferrerPolicy = aReferrerPolicy; mCachedBaseURL = aBaseURL; } void InvalidateCachedStencil() { MOZ_ASSERT(IsCachedStencil()); mDataType = DataType::eInvalidatedCachedStencil; mCachedStencil = nullptr; } void SetWasmBytes() { MOZ_ASSERT(IsUnknownDataType()); mDataType = DataType::eWasmBytes; mScriptData.emplace(VariantType>()); } bool IsUTF16Text() const { return mScriptData->is>(); } bool IsUTF8Text() const { return mScriptData->is>(); } // ==== Methods to access the text source ==== template const ScriptTextBuffer& ScriptText() const { MOZ_ASSERT(IsTextSource()); return mScriptData->as>(); } template ScriptTextBuffer& ScriptText() { MOZ_ASSERT(IsTextSource()); return mScriptData->as>(); } ScriptTextBuffer& WasmBytes() { MOZ_ASSERT(IsWasmBytes()); return mScriptData->as>(); } size_t ScriptTextLength() const { MOZ_ASSERT(IsTextSource()); return IsUTF16Text() ? ScriptText().length() : ScriptText().length(); } // Get source text. On success |aMaybeSource| will contain either UTF-8 or // UTF-16 source; on failure it will remain in its initial state. nsresult GetScriptSource(JSContext* aCx, MaybeSourceText* aMaybeSource, LoadContextBase* aMaybeLoadContext); void ClearScriptText() { MOZ_ASSERT(IsTextSource()); return IsUTF16Text() ? ScriptText().clearAndFree() : ScriptText().clearAndFree(); } size_t ReceivedScriptTextLength() const { MOZ_ASSERT(IsTextSource()); return mReceivedScriptTextLength; } void SetReceivedScriptTextLength(size_t aLength) { MOZ_ASSERT(IsTextSource()); mReceivedScriptTextLength = aLength; } // ==== Methods to access the serialized data or the SRI part ==== // mSRIAndSerializedStencil field is shared between two separate consumers. // See mSRIAndSerializedStencil comment for more info. // ---- For SRI-only consumers ---- bool CanHaveSRIOnly() const { return IsTextSource() || IsCachedStencil() || IsInvalidatedCachedStencil(); } bool HasSRI() const { MOZ_ASSERT(CanHaveSRIOnly()); return !mSRIAndSerializedStencil.empty(); } TranscodeBuffer& SRI() { MOZ_ASSERT(CanHaveSRIOnly()); return mSRIAndSerializedStencil; } void DropSRI() { MOZ_ASSERT(CanHaveSRIOnly()); mSRIAndSerializedStencil.clearAndFree(); } // ---- For SRI and serialized Stencil consumers --- bool CanHaveSRIAndSerializedStencil() const { return IsSerializedStencil(); } TranscodeBuffer& SRIAndSerializedStencil() { MOZ_ASSERT(CanHaveSRIAndSerializedStencil()); return mSRIAndSerializedStencil; } TranscodeRange SerializedStencil() const { MOZ_ASSERT(CanHaveSRIAndSerializedStencil()); const auto& buf = mSRIAndSerializedStencil; auto offset = mSerializedStencilOffset; return TranscodeRange(buf.begin() + offset, buf.length() - offset); } // ---- Methods shared between both consumers ---- size_t GetSRILength() const { MOZ_ASSERT(CanHaveSRIOnly() || CanHaveSRIAndSerializedStencil()); return mSerializedStencilOffset; } void SetSRILength(size_t sriLength) { MOZ_ASSERT(CanHaveSRIOnly() || CanHaveSRIAndSerializedStencil()); mSerializedStencilOffset = AlignTranscodingBytecodeOffset(sriLength); } bool HasNoSRIOrSRIAndSerializedStencil() const { MOZ_ASSERT(CanHaveSRIOnly() || CanHaveSRIAndSerializedStencil()); return mSRIAndSerializedStencil.empty(); } void DropSRIOrSRIAndSerializedStencil() { MOZ_ASSERT(CanHaveSRIOnly() || CanHaveSRIAndSerializedStencil()); mSRIAndSerializedStencil.clearAndFree(); } // ==== Methods to access the stencil ==== Stencil* GetCachedStencil() const { MOZ_ASSERT(IsCachedStencil()); return mCachedStencil; } // ==== Methods to access the disk cache reference ==== // Check the reference to the cache info channel, which is used by the disk // cache. bool HasDiskCacheReference() const { return !!mCacheEntry; } // Drop the reference to the cache info channel. void DropDiskCacheReference() { mCacheEntry = nullptr; } void DropDiskCacheReferenceAndSRI() { DropDiskCacheReference(); if (IsTextSource()) { DropSRI(); } } // ==== Other methods ==== void SetTookLongInPreviousRuns() { mTookLongInPreviousRuns = true; } bool TookLongInPreviousRuns() const { return mTookLongInPreviousRuns; } void SetIsEverHitFromMemoryCache() { mIsEverHitFromMemoryCache = true; } bool IsEverHitFromMemoryCache() const { return mIsEverHitFromMemoryCache; } bool IsDirty() const { return mIsDirty; } void SetDirty() { MOZ_ASSERT(HasCacheEntryId()); mIsDirty = true; } void UnsetDirty() { MOZ_ASSERT(HasCacheEntryId()); mIsDirty = false; } bool HasCacheEntryId() const { return mCacheEntryId != InvalidCacheEntryId; } uint64_t CacheEntryId() const { MOZ_ASSERT(HasCacheEntryId()); return mCacheEntryId; } void SetCacheEntryId(uint64_t aId) { mCacheEntryId = aId; // mCacheEntryId is 48bits. Verify no overflow happened. MOZ_ASSERT(mCacheEntryId == aId); } void AddFetchCount() { if (mFetchCount < UINT8_MAX) { mFetchCount++; } } void SetSRIMetadata(const mozilla::dom::SRIMetadata& aSRIMetadata); // Returns true if this script has compatible SRI metadata as the provided // one. bool IsSRIMetadataReusableBy(const mozilla::dom::SRIMetadata& aSRIMetadata); public: // Fields. // Determine whether the mScriptData or mSRIAndSerializedStencil is used. // See DataType description for more info. DataType mDataType; // The consumer-defined number of times that this loaded script is used. // // In DOM ScriptLoader, this is used for counting the number of times that // the in-memory-cached script is used, clamped at UINT8_MAX. uint8_t mFetchCount = 0; private: const ScriptKind mKind; // The final ScriptFetchInfo::mReferrerPolicy value o the // initial request. // This field is set before this LoadedScript is stored into the // SharedScriptCache, and then propagated to the ScriptFetchInfo // for the request that uses this cache. mozilla::dom::ReferrerPolicy mCachedReferrerPolicy; public: // Offset of the serialized Stencil in mSRIAndSerializedStencil. uint32_t mSerializedStencilOffset; private: static constexpr uint64_t InvalidCacheEntryId = 0; // The cache entry ID of this script. // // 0 if the response doesn't have the corresponding cache entry, // or any other failure happened. // // This value comes from mozilla::net::CacheEntry::mCacheEntryId, // which comes from mozilla::net::CacheEntry::GetNextId. // It generates sequential IDs from 1 (thus 0 is treated as invalid value), // and the ID is valid within single browser session. // // In order to pack this field with mIsDirty below, we use shorter bits than // the original mozilla::net::CacheEntry::mCacheEntryId type (uint64_t). // // As long as the per-session sequential ID is the sole source of this value, // 48 bits should be sufficient. 1000 new IDs per second for 365 days // becomes 0x7_57b1_2c00, which is 35 bits. uint64_t mCacheEntryId : 48; // Set to true in the following situation: // * this is cached in SharedScriptCache // * A behavior around the network request is modified, and // the cache needs validation on the necko side // // NOTE: In order to pack this with the mCacheEntryId above on windows, // this must be uint64_t. uint64_t mIsDirty : 1; // Set to true if executing the top-level script takes long. // This can be used for scheduling the script execution in subsequent loads. // The threshold of "takes long" is user-defined. // See dom::ScriptLoader::EvaluateScript for the example case // // TODO: Move this into JS::Stencil, and save to the disk cache (bug 2005128) uint64_t mTookLongInPreviousRuns : 1; // Set to true if this entry is ever used in the current process. uint64_t mIsEverHitFromMemoryCache : 1; nsCOMPtr mURI; // The final ScriptFetchInfo::mBaseURL value of the // initial request. // This field is set before this LoadedScript is stored into the // SharedScriptCache, and then propagated to the ScriptFetchInfo // for the request that uses this cache. nsCOMPtr mCachedBaseURL; // An optional field to store the SRI metadata used by the request that // first creates this instance. // nullptr if the SRI metadata was empty, or not yet set. mozilla::UniquePtr mSRIMetadata; public: // Holds script source data for non-inline scripts, or raw bytes for wasm // modules. mozilla::Maybe, ScriptTextBuffer, ScriptTextBuffer>> 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 mReceivedScriptTextLength; // Holds either of the following for non-inline scripts: // * The SRI serialized hash and the paddings, which is calculated when // receiving the source text // * The SRI, padding, and the serialized Stencil, which is received // from necko. The data is laid out according to ScriptBytecodeDataLayout // or, if compression is enabled, ScriptBytecodeCompressedDataLayout. TranscodeBuffer mSRIAndSerializedStencil; // Holds the stencil for the script, cached for the subsequent requests. RefPtr mCachedStencil; // The cache info channel used when saving the serialized Stencil to the // necko cache. // // This field is populated if the cache is enabled and this is either // IsTextSource() or IsCachedStencil(), and it's cleared after saving to the // necko cache, and thus, this field is used only once. nsCOMPtr mCacheEntry; }; // Provide accessors for any classes `Derived` which is providing the // `getLoadedScript` function as interface. The accessors are meant to be // inherited by the `Derived` class. template class LoadedScriptDelegate { private: // Use a static_cast instead of declaring virtual functions. This is // meant to avoid relying on virtual table, and improve inlining for non-final // classes. const LoadedScript* GetLoadedScript() const { return static_cast(this)->getLoadedScript(); } LoadedScript* GetLoadedScript() { return static_cast(this)->getLoadedScript(); } public: template using ScriptTextBuffer = LoadedScript::ScriptTextBuffer; using MaybeSourceText = LoadedScript::MaybeSourceText; nsIURI* URI() const { return GetLoadedScript()->GetURI(); } bool IsUnknownDataType() const { return GetLoadedScript()->IsUnknownDataType(); } bool IsWasmBytes() const { return GetLoadedScript()->IsWasmBytes(); } void SetUnknownDataType() { GetLoadedScript()->SetUnknownDataType(); } void SetTextSource(LoadContextBase* maybeLoadContext) { GetLoadedScript()->SetTextSource(maybeLoadContext); } void SetWasmBytes() { GetLoadedScript()->SetWasmBytes(); } void SetSerializedStencil() { GetLoadedScript()->SetSerializedStencil(); } bool IsUTF16Text() const { return GetLoadedScript()->IsUTF16Text(); } bool IsUTF8Text() const { return GetLoadedScript()->IsUTF8Text(); } template const ScriptTextBuffer& ScriptText() const { const LoadedScript* loader = GetLoadedScript(); return loader->ScriptText(); } template ScriptTextBuffer& ScriptText() { LoadedScript* loader = GetLoadedScript(); return loader->ScriptText(); } ScriptTextBuffer& WasmBytes() { LoadedScript* loader = GetLoadedScript(); return loader->WasmBytes(); } size_t ScriptTextLength() const { return GetLoadedScript()->ScriptTextLength(); } size_t ReceivedScriptTextLength() const { return GetLoadedScript()->ReceivedScriptTextLength(); } void SetReceivedScriptTextLength(size_t aLength) { GetLoadedScript()->SetReceivedScriptTextLength(aLength); } // Get source text. On success |aMaybeSource| will contain either UTF-8 or // UTF-16 source; on failure it will remain in its initial state. nsresult GetScriptSource(JSContext* aCx, MaybeSourceText* aMaybeSource, LoadContextBase* aLoadContext) { return GetLoadedScript()->GetScriptSource(aCx, aMaybeSource, aLoadContext); } bool HasNoSRIOrSRIAndSerializedStencil() const { return GetLoadedScript()->HasNoSRIOrSRIAndSerializedStencil(); } TranscodeBuffer& SRI() { return GetLoadedScript()->SRI(); } TranscodeBuffer& SRIAndSerializedStencil() { return GetLoadedScript()->SRIAndSerializedStencil(); } TranscodeRange SerializedStencil() const { return GetLoadedScript()->SerializedStencil(); } size_t GetSRILength() const { return GetLoadedScript()->GetSRILength(); } void SetSRILength(size_t sriLength) { GetLoadedScript()->SetSRILength(sriLength); } void SetTookLongInPreviousRuns() { GetLoadedScript()->SetTookLongInPreviousRuns(); } bool TookLongInPreviousRuns() const { return GetLoadedScript()->TookLongInPreviousRuns(); } }; // A single module script. May be used to satisfy multiple load requests. class ModuleScript final : public nsISupports { // Those fields are used only after instantiated, and they're reset to // null and false when stored into the cache as LoadedScript instance. Heap mModuleRecord; Heap mParseError; Heap mErrorToRethrow; // A copy of ScriptLoadRequest::mFetchInfo, to read and update the // ScriptFetchInfo::mIsForModulePreload field. RefPtr mFetchInfoForAccessingPreloadFlag; bool mHadImportMap = false; mozilla::UniquePtr mPreloadedResolvedSet; ~ModuleScript(); public: NS_DECL_CYCLE_COLLECTING_ISUPPORTS_FINAL NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(ModuleScript) explicit ModuleScript(ScriptFetchInfo* aFetchInfo); void SetModuleRecord(Handle aModuleRecord); void SetParseError(const Value& aError); void SetErrorToRethrow(const Value& aError); void SetForPreload(bool aValue); void SetHadImportMap(bool aValue); JSObject* ModuleRecord() const { return mModuleRecord; } Value ParseError() const { return mParseError; } Value ErrorToRethrow() const { return mErrorToRethrow; } bool HasParseError() const { return !mParseError.isUndefined(); } bool HasErrorToRethrow() const { return !mErrorToRethrow.isUndefined(); } bool ForPreload() const { return mFetchInfoForAccessingPreloadFlag->IsForModulePreload(); } bool HadImportMap() const { return mHadImportMap; } // This is used to reset the module graph information which happened during // preload. void ResetPreload(); void Shutdown(); friend void CheckModuleScriptPrivate(LoadedScript*, const Value&); bool HasPreloadedResolvedSet() { return !!mPreloadedResolvedSet; } ResolvedModuleSet* GetPreloadedResolvedSet(); void ReleasePreloadedResolvedSet() { mPreloadedResolvedSet = nullptr; } }; } // namespace JS::loader #endif // js_loader_LoadedScript_h