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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
#ifndef js_loader_LoadedScript_h
#define js_loader_LoadedScript_h
#include "js/AllocPolicy.h"
#include "js/Transcoding.h"
#include "mozilla/Maybe.h"
#include "mozilla/MaybeOneOf.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/Utf8.h" // mozilla::Utf8Unit
#include "mozilla/Variant.h"
#include "mozilla/Vector.h"
#include "nsCOMPtr.h"
#include "nsCycleCollectionParticipant.h"
#include "nsIMemoryReporter.h"
#include "jsapi.h"
#include "ScriptKind.h"
#include "ScriptFetchOptions.h"
class nsIURI;
namespace JS::loader {
class ScriptLoadRequest;
using Utf8Unit = mozilla::Utf8Unit;
void HostAddRefTopLevelScript(const JS::Value& aPrivate);
void HostReleaseTopLevelScript(const JS::Value& aPrivate);
class ClassicScript;
class ModuleScript;
class EventScript;
class LoadContextBase;
// 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 : public nsIMemoryReporter {
ScriptKind mKind;
const mozilla::dom::ReferrerPolicy mReferrerPolicy;
RefPtr<ScriptFetchOptions> mFetchOptions;
nsCOMPtr<nsIURI> mURI;
nsCOMPtr<nsIURI> mBaseURL;
protected:
LoadedScript(ScriptKind aKind, mozilla::dom::ReferrerPolicy aReferrerPolicy,
ScriptFetchOptions* aFetchOptions, nsIURI* aURI);
virtual ~LoadedScript();
public:
// When the memory should be reported, register it using RegisterMemoryReport,
// and make sure to call SizeOfIncludingThis in the enclosing container.
//
// Each reported script would be listed under
// `explicit/js/script/loaded-script/<kind>`.
void RegisterMemoryReport();
size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
public:
NS_DECL_CYCLE_COLLECTING_ISUPPORTS;
NS_DECL_NSIMEMORYREPORTER;
NS_DECL_CYCLE_COLLECTION_CLASS(LoadedScript)
bool IsClassicScript() const { return mKind == ScriptKind::eClassic; }
bool IsModuleScript() const { return mKind == ScriptKind::eModule; }
bool IsEventScript() const { return mKind == ScriptKind::eEvent; }
inline ClassicScript* AsClassicScript();
inline ModuleScript* AsModuleScript();
inline EventScript* AsEventScript();
// Used to propagate Fetch Options to child modules
ScriptFetchOptions* GetFetchOptions() const { return mFetchOptions; }
mozilla::dom::ReferrerPolicy ReferrerPolicy() const {
return mReferrerPolicy;
}
nsIURI* GetURI() const { return mURI; }
void SetBaseURL(nsIURI* aBaseURL) {
MOZ_ASSERT(!mBaseURL);
mBaseURL = aBaseURL;
}
nsIURI* BaseURL() const { return mBaseURL; }
void AssociateWithScript(JSScript* aScript);
public:
// ===========================================================================
// Encoding of the content provided by the network, or refined by the JS
// engine.
template <typename... Ts>
using Variant = mozilla::Variant<Ts...>;
template <typename... Ts>
using VariantType = mozilla::VariantType<Ts...>;
// Type of data provided by the nsChannel.
enum class DataType : uint8_t { eUnknown, eTextSource, eBytecode };
// 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 = mozilla::Vector<Unit, 0, js::MallocAllocPolicy>;
using MaybeSourceText =
mozilla::MaybeOneOf<JS::SourceText<char16_t>, JS::SourceText<Utf8Unit>>;
bool IsUnknownDataType() const { return mDataType == DataType::eUnknown; }
bool IsTextSource() const { return mDataType == DataType::eTextSource; }
bool IsSource() const { return IsTextSource(); }
bool IsBytecode() const { return mDataType == DataType::eBytecode; }
void SetUnknownDataType() {
mDataType = DataType::eUnknown;
mScriptData.reset();
}
void SetTextSource(LoadContextBase* maybeLoadContext) {
MOZ_ASSERT(IsUnknownDataType());
mDataType = DataType::eTextSource;
mScriptData.emplace(VariantType<ScriptTextBuffer<Utf8Unit>>());
}
void SetBytecode() {
MOZ_ASSERT(IsUnknownDataType());
mDataType = DataType::eBytecode;
}
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>>();
}
size_t ScriptTextLength() const {
MOZ_ASSERT(IsTextSource());
return IsUTF16Text() ? ScriptText<char16_t>().length()
: ScriptText<Utf8Unit>().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 ClearScriptSource() {
if (IsTextSource()) {
ClearScriptText();
}
}
void ClearScriptText() {
MOZ_ASSERT(IsTextSource());
return IsUTF16Text() ? ScriptText<char16_t>().clearAndFree()
: ScriptText<Utf8Unit>().clearAndFree();
}
size_t ReceivedScriptTextLength() const { return mReceivedScriptTextLength; }
void SetReceivedScriptTextLength(size_t aLength) {
mReceivedScriptTextLength = aLength;
}
JS::TranscodeBuffer& SRIAndBytecode() {
// Note: SRIAndBytecode might be called even if the IsSource() returns true,
// as we want to be able to save the bytecode content when we are loading
// from source.
MOZ_ASSERT(IsBytecode() || IsSource());
return mScriptBytecode;
}
JS::TranscodeRange Bytecode() const {
MOZ_ASSERT(IsBytecode());
const auto& bytecode = mScriptBytecode;
auto offset = mBytecodeOffset;
return JS::TranscodeRange(bytecode.begin() + offset,
bytecode.length() - offset);
}
size_t GetSRILength() const {
MOZ_ASSERT(IsBytecode() || IsSource());
return mBytecodeOffset;
}
void SetSRILength(size_t sriLength) {
MOZ_ASSERT(IsBytecode() || IsSource());
mBytecodeOffset = JS::AlignTranscodingBytecodeOffset(sriLength);
}
void DropBytecode() {
MOZ_ASSERT(IsBytecode() || IsSource());
mScriptBytecode.clearAndFree();
}
// Determine whether the mScriptData or mScriptBytecode is used.
DataType mDataType;
// Holds script source data for non-inline scripts.
mozilla::Maybe<
Variant<ScriptTextBuffer<char16_t>, ScriptTextBuffer<Utf8Unit>>>
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 the SRI serialized hash and the script bytecode for non-inline
// scripts. The data is laid out according to ScriptBytecodeDataLayout
// or, if compression is enabled, ScriptBytecodeCompressedDataLayout.
JS::TranscodeBuffer mScriptBytecode;
uint32_t mBytecodeOffset; // Offset of the bytecode in mScriptBytecode
};
// 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 <typename Derived>
class LoadedScriptDelegate {
private:
// Use a static_cast<Derived> 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<const Derived*>(this)->getLoadedScript();
}
LoadedScript* GetLoadedScript() {
return static_cast<Derived*>(this)->getLoadedScript();
}
public:
template <typename Unit>
using ScriptTextBuffer = LoadedScript::ScriptTextBuffer<Unit>;
using MaybeSourceText = LoadedScript::MaybeSourceText;
bool IsModuleScript() const { return GetLoadedScript()->IsModuleScript(); }
bool IsEventScript() const { return GetLoadedScript()->IsEventScript(); }
bool IsUnknownDataType() const {
return GetLoadedScript()->IsUnknownDataType();
}
bool IsTextSource() const { return GetLoadedScript()->IsTextSource(); }
bool IsSource() const { return GetLoadedScript()->IsSource(); }
bool IsBytecode() const { return GetLoadedScript()->IsBytecode(); }
void SetUnknownDataType() { GetLoadedScript()->SetUnknownDataType(); }
void SetTextSource(LoadContextBase* maybeLoadContext) {
GetLoadedScript()->SetTextSource(maybeLoadContext);
}
void SetBytecode() { GetLoadedScript()->SetBytecode(); }
bool IsUTF16Text() const { return GetLoadedScript()->IsUTF16Text(); }
bool IsUTF8Text() const { return GetLoadedScript()->IsUTF8Text(); }
template <typename Unit>
const ScriptTextBuffer<Unit>& ScriptText() const {
const LoadedScript* loader = GetLoadedScript();
return loader->ScriptText<Unit>();
}
template <typename Unit>
ScriptTextBuffer<Unit>& ScriptText() {
LoadedScript* loader = GetLoadedScript();
return loader->ScriptText<Unit>();
}
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);
}
void ClearScriptSource() { GetLoadedScript()->ClearScriptSource(); }
void ClearScriptText() { GetLoadedScript()->ClearScriptText(); }
JS::TranscodeBuffer& SRIAndBytecode() {
return GetLoadedScript()->SRIAndBytecode();
}
JS::TranscodeRange Bytecode() const { return GetLoadedScript()->Bytecode(); }
size_t GetSRILength() const { return GetLoadedScript()->GetSRILength(); }
void SetSRILength(size_t sriLength) {
GetLoadedScript()->SetSRILength(sriLength);
}
void DropBytecode() { GetLoadedScript()->DropBytecode(); }
};
class ClassicScript final : public LoadedScript {
~ClassicScript() = default;
private:
// Scripts can be created only by ScriptLoadRequest::NoCacheEntryFound.
ClassicScript(mozilla::dom::ReferrerPolicy aReferrerPolicy,
ScriptFetchOptions* aFetchOptions, nsIURI* aURI);
friend class ScriptLoadRequest;
};
class EventScript final : public LoadedScript {
~EventScript() = default;
public:
EventScript(mozilla::dom::ReferrerPolicy aReferrerPolicy,
ScriptFetchOptions* aFetchOptions, nsIURI* aURI);
};
// A single module script. May be used to satisfy multiple load requests.
class ModuleScript final : public LoadedScript {
JS::Heap<JSObject*> mModuleRecord;
JS::Heap<JS::Value> mParseError;
JS::Heap<JS::Value> mErrorToRethrow;
bool mForPreload;
bool mHadImportMap;
bool mDebuggerDataInitialized;
~ModuleScript();
public:
NS_DECL_ISUPPORTS_INHERITED
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(ModuleScript,
LoadedScript)
private:
// Scripts can be created only by ScriptLoadRequest::NoCacheEntryFound.
ModuleScript(mozilla::dom::ReferrerPolicy aReferrerPolicy,
ScriptFetchOptions* aFetchOptions, nsIURI* aURI);
friend class ScriptLoadRequest;
public:
void SetModuleRecord(JS::Handle<JSObject*> aModuleRecord);
void SetParseError(const JS::Value& aError);
void SetErrorToRethrow(const JS::Value& aError);
void SetForPreload(bool aValue);
void SetHadImportMap(bool aValue);
void SetDebuggerDataInitialized();
JSObject* ModuleRecord() const { return mModuleRecord; }
JS::Value ParseError() const { return mParseError; }
JS::Value ErrorToRethrow() const { return mErrorToRethrow; }
bool HasParseError() const { return !mParseError.isUndefined(); }
bool HasErrorToRethrow() const { return !mErrorToRethrow.isUndefined(); }
bool ForPreload() const { return mForPreload; }
bool HadImportMap() const { return mHadImportMap; }
bool DebuggerDataInitialized() const { return mDebuggerDataInitialized; }
void Shutdown();
void UnlinkModuleRecord();
friend void CheckModuleScriptPrivate(LoadedScript*, const JS::Value&);
};
ClassicScript* LoadedScript::AsClassicScript() {
MOZ_ASSERT(!IsModuleScript());
return static_cast<ClassicScript*>(this);
}
ModuleScript* LoadedScript::AsModuleScript() {
MOZ_ASSERT(IsModuleScript());
return static_cast<ModuleScript*>(this);
}
} // namespace JS::loader
#endif // js_loader_LoadedScript_h