v8 Namespace Reference

Data Structures
class	AccessorSignature
class	ActivityControl
class	AlignOfHelper
class	AllocationProfile
class	Array
class	ArrayBuffer
class	ArrayBufferView
class	BigInt
class	BigInt64Array
class	BigIntObject
class	BigUint64Array
class	Boolean
class	BooleanObject
class	CodeEvent
class	CodeEventHandler
class	Context
class	ConvertableToTraceFormat
struct	CopyablePersistentTraits
class	CpuProfile
struct	CpuProfileDeoptFrame
struct	CpuProfileDeoptInfo
class	CpuProfileNode
class	CpuProfiler
class	Data
class	DataView
class	Date
class	DefaultGlobalMapTraits
class	DefaultPersistentValueMapTraits
class	DefaultPersistentValueVectorTraits
struct	DeserializeInternalFieldsCallback
class	EmbedderGraph
class	EmbedderHeapTracer
class	EscapableHandleScope
class	Eternal
class	Exception
class	Extension
class	ExtensionConfiguration
class	External
class	ExternalOneByteStringResourceImpl
class	ExternalResourceVisitor
class	Float32Array
class	Float64Array
class	Function
class	FunctionCallbackInfo
class	FunctionTemplate
class	Global
class	GlobalValueMap
class	HandleScope
class	HeapCodeStatistics
class	HeapGraphEdge
class	HeapGraphNode
class	HeapObjectStatistics
class	HeapProfiler
class	HeapSnapshot
class	HeapSpaceStatistics
class	HeapStatistics
struct	HeapStatsUpdate
class	IdleTask
struct	IndexedPropertyHandlerConfiguration
class	Int16Array
class	Int32
class	Int32Array
class	Int8Array
class	Integer
class	Isolate
struct	JitCodeEvent
class	JSON
class	Local
class	Location
class	Locker
class	Map
class	Maybe
class	Maybe< void >
class	MaybeLocal
class	Message
class	MicrotasksScope
class	Module
class	Name
struct	NamedPropertyHandlerConfiguration
class	NonCopyablePersistentTraits
class	Number
class	NumberObject
class	Object
class	ObjectTemplate
class	OutputStream
class	PageAllocator
class	Persistent
class	PersistentBase
class	PersistentHandleVisitor
class	PersistentValueMap
class	PersistentValueMapBase
class	PersistentValueVector
class	Platform
class	Primitive
class	PrimitiveArray
class	Private
class	Promise
class	PromiseRejectMessage
class	PropertyCallbackInfo
class	PropertyDescriptor
class	Proxy
class	RegExp
struct	RegisterState
class	ResourceConstraints
class	RetainedObjectInfo
class	ReturnValue
struct	SampleInfo
class	Script
class	ScriptCompiler
class	ScriptOrigin
class	ScriptOriginOptions
class	ScriptOrModule
class	SealHandleScope
struct	SerializeInternalFieldsCallback
class	Set
class	SharedArrayBuffer
class	Signature
class	SnapshotCreator
class	StackFrame
class	StackTrace
class	StartupData
class	StdGlobalValueMap
class	StdMapTraits
class	StdPersistentValueMap
class	String
class	StringObject
class	Symbol
class	SymbolObject
class	Task
class	TaskRunner
class	Template
class	Testing
struct	TickSample
class	TracingController
class	TracingCpuProfiler
class	TryCatch
class	TypedArray
class	Uint16Array
class	Uint32
class	Uint32Array
class	Uint8Array
class	Uint8ClampedArray
class	UnboundModuleScript
class	UnboundScript
class	Unlocker
class	V8
class	Value
class	ValueDeserializer
class	ValueSerializer
class	WasmCompiledModule
class	WasmModuleObjectBuilderStreaming
class	WasmStreaming
class	WeakCallbackInfo
class	WeakCallbackObject

Typedefs
typedef uint32_t	SnapshotObjectId
typedef uintptr_t	PersistentContainerValue
template<class T >
using	Handle = Local< T >
template<class T >
using	UniquePersistent = Global< T >
typedef void(*	AccessorGetterCallback) (Local< String > property, const PropertyCallbackInfo< Value > &info)
typedef void(*	AccessorNameGetterCallback) (Local< Name > property, const PropertyCallbackInfo< Value > &info)
typedef void(*	AccessorSetterCallback) (Local< String > property, Local< Value > value, const PropertyCallbackInfo< void > &info)
typedef void(*	AccessorNameSetterCallback) (Local< Name > property, Local< Value > value, const PropertyCallbackInfo< void > &info)
typedef void(*	FunctionCallback) (const FunctionCallbackInfo< Value > &info)
typedef void(*	NamedPropertyGetterCallback) (Local< String > property, const PropertyCallbackInfo< Value > &info)
typedef void(*	NamedPropertySetterCallback) (Local< String > property, Local< Value > value, const PropertyCallbackInfo< Value > &info)
typedef void(*	NamedPropertyQueryCallback) (Local< String > property, const PropertyCallbackInfo< Integer > &info)
typedef void(*	NamedPropertyDeleterCallback) (Local< String > property, const PropertyCallbackInfo< Boolean > &info)
typedef void(*	NamedPropertyEnumeratorCallback) (const PropertyCallbackInfo< Array > &info)
typedef void(*	GenericNamedPropertyGetterCallback) (Local< Name > property, const PropertyCallbackInfo< Value > &info)
typedef void(*	GenericNamedPropertySetterCallback) (Local< Name > property, Local< Value > value, const PropertyCallbackInfo< Value > &info)
typedef void(*	GenericNamedPropertyQueryCallback) (Local< Name > property, const PropertyCallbackInfo< Integer > &info)
typedef void(*	GenericNamedPropertyDeleterCallback) (Local< Name > property, const PropertyCallbackInfo< Boolean > &info)
typedef void(*	GenericNamedPropertyEnumeratorCallback) (const PropertyCallbackInfo< Array > &info)
typedef void(*	GenericNamedPropertyDefinerCallback) (Local< Name > property, const PropertyDescriptor &desc, const PropertyCallbackInfo< Value > &info)
typedef void(*	GenericNamedPropertyDescriptorCallback) (Local< Name > property, const PropertyCallbackInfo< Value > &info)
typedef void(*	IndexedPropertyGetterCallback) (uint32_t index, const PropertyCallbackInfo< Value > &info)
typedef void(*	IndexedPropertySetterCallback) (uint32_t index, Local< Value > value, const PropertyCallbackInfo< Value > &info)
typedef void(*	IndexedPropertyQueryCallback) (uint32_t index, const PropertyCallbackInfo< Integer > &info)
typedef void(*	IndexedPropertyDeleterCallback) (uint32_t index, const PropertyCallbackInfo< Boolean > &info)
typedef void(*	IndexedPropertyEnumeratorCallback) (const PropertyCallbackInfo< Array > &info)
typedef void(*	IndexedPropertyDefinerCallback) (uint32_t index, const PropertyDescriptor &desc, const PropertyCallbackInfo< Value > &info)
typedef void(*	IndexedPropertyDescriptorCallback) (uint32_t index, const PropertyCallbackInfo< Value > &info)
typedef bool(*	AccessCheckCallback) (Local< Context > accessing_context, Local< Object > accessed_object, Local< Value > data)
typedef void(*	FatalErrorCallback) (const char *location, const char *message)
typedef void(*	OOMErrorCallback) (const char *location, bool is_heap_oom)
typedef void(*	DcheckErrorCallback) (const char *file, int line, const char *message)
typedef void(*	MessageCallback) (Local< Message > message, Local< Value > data)
typedef void(*	LogEventCallback) (const char *name, int event)
typedef int *(*	CounterLookupCallback) (const char *name)
typedef void *(*	CreateHistogramCallback) (const char *name, int min, int max, size_t buckets)
typedef void(*	AddHistogramSampleCallback) (void *histogram, int sample)
typedef void(*	BeforeCallEnteredCallback) (Isolate *)
typedef void(*	CallCompletedCallback) (Isolate *)
typedef void(*	DeprecatedCallCompletedCallback) ()
typedef MaybeLocal< Promise >(*	HostImportModuleDynamicallyCallback) (Local< Context > context, Local< ScriptOrModule > referrer, Local< String > specifier)
typedef void(*	HostInitializeImportMetaObjectCallback) (Local< Context > context, Local< Module > module, Local< Object > meta)
typedef void(*	PromiseHook) (PromiseHookType type, Local< Promise > promise, Local< Value > parent)
typedef void(*	PromiseRejectCallback) (PromiseRejectMessage message)
typedef void(*	MicrotasksCompletedCallback) (Isolate *)
typedef void(*	MicrotaskCallback) (void *data)
typedef void(*	FailedAccessCheckCallback) (Local< Object > target, AccessType type, Local< Value > data)
typedef bool(*	AllowCodeGenerationFromStringsCallback) (Local< Context > context, Local< String > source)
typedef bool(*	ExtensionCallback) (const FunctionCallbackInfo< Value > &)
typedef bool(*	AllowWasmCodeGenerationCallback) (Local< Context > context, Local< String > source)
typedef void(*	ApiImplementationCallback) (const FunctionCallbackInfo< Value > &)
typedef void(*	WasmStreamingCallback) (const FunctionCallbackInfo< Value > &)
typedef void(*	GCCallback) (GCType type, GCCallbackFlags flags)
typedef void(*	InterruptCallback) (Isolate *isolate, void *data)
typedef size_t(*	NearHeapLimitCallback) (void *data, size_t current_heap_limit, size_t initial_heap_limit)
typedef void(*	FunctionEntryHook) (uintptr_t function, uintptr_t return_addr_location)
typedef void(*	JitCodeEventHandler) (const JitCodeEvent *event)
typedef SerializeInternalFieldsCallback	SerializeEmbedderFieldsCallback
typedef DeserializeInternalFieldsCallback	DeserializeEmbedderFieldsCallback
typedef bool(*	EntropySource) (unsigned char *buffer, size_t length)
typedef uintptr_t(*	ReturnAddressLocationResolver) (uintptr_t return_addr_location)

Enumerations
enum	CpuProfilingMode { kLeafNodeLineNumbers, kCallerLineNumbers }
enum	CodeEventType { kUnknownType }
enum	PersistentContainerCallbackType { kNotWeak, kWeakWithParameter, kWeakWithInternalFields, kWeak = kWeakWithParameter }
enum	WeakCallbackType { kParameter, kInternalFields, kFinalizer }
enum	StateTag {   JS, GC, PARSER, BYTECODE_COMPILER,   COMPILER, OTHER, EXTERNAL, IDLE }
enum	NewStringType { NewStringType::kNormal, NewStringType::kInternalized }
enum	PropertyAttribute { None = 0, ReadOnly = 1 << 0, DontEnum = 1 << 1, DontDelete = 1 << 2 }
enum	AccessControl { DEFAULT = 0, ALL_CAN_READ = 1, ALL_CAN_WRITE = 1 << 1, PROHIBITS_OVERWRITING = 1 << 2 }
enum	PropertyFilter {   ALL_PROPERTIES = 0, ONLY_WRITABLE = 1, ONLY_ENUMERABLE = 2, ONLY_CONFIGURABLE = 4,   SKIP_STRINGS = 8, SKIP_SYMBOLS = 16 }
enum	SideEffectType { kHasSideEffect, kHasNoSideEffect }
enum	KeyCollectionMode { kOwnOnly, kIncludePrototypes }
enum	IndexFilter { kIncludeIndices, kSkipIndices }
enum	KeyConversionMode { kConvertToString, kKeepNumbers }
enum	IntegrityLevel { kFrozen, kSealed }
enum	ConstructorBehavior { kThrow, kAllow }
enum	ArrayBufferCreationMode { kInternalized, kExternalized }
enum	Intrinsic
enum	AccessType {   ACCESS_GET, ACCESS_SET, ACCESS_HAS, ACCESS_DELETE,   ACCESS_KEYS }
enum	PropertyHandlerFlags {   PropertyHandlerFlags::kNone = 0, PropertyHandlerFlags::kAllCanRead = 1, PropertyHandlerFlags::kNonMasking = 1 << 1, PropertyHandlerFlags::kOnlyInterceptStrings = 1 << 2,   PropertyHandlerFlags::kHasNoSideEffect = 1 << 3 }
enum	PromiseHookType { kInit, kResolve, kBefore, kAfter }
enum	PromiseRejectEvent { kPromiseRejectWithNoHandler = 0, kPromiseHandlerAddedAfterReject = 1, kPromiseRejectAfterResolved = 2, kPromiseResolveAfterResolved = 3 }
enum	MicrotasksPolicy { kExplicit, kScoped, kAuto }
enum	GCType {   kGCTypeScavenge = 1 << 0, kGCTypeMarkSweepCompact = 1 << 1, kGCTypeIncrementalMarking = 1 << 2, kGCTypeProcessWeakCallbacks = 1 << 3,   kGCTypeAll }
enum	GCCallbackFlags {   kNoGCCallbackFlags = 0, kGCCallbackFlagConstructRetainedObjectInfos = 1 << 1, kGCCallbackFlagForced = 1 << 2, kGCCallbackFlagSynchronousPhantomCallbackProcessing = 1 << 3,   kGCCallbackFlagCollectAllAvailableGarbage = 1 << 4, kGCCallbackFlagCollectAllExternalMemory = 1 << 5, kGCCallbackScheduleIdleGarbageCollection = 1 << 6 }
enum	RAILMode { PERFORMANCE_RESPONSE, PERFORMANCE_ANIMATION, PERFORMANCE_IDLE, PERFORMANCE_LOAD }
enum	JitCodeEventOptions { kJitCodeEventDefault = 0, kJitCodeEventEnumExisting = 1 }
enum	MemoryPressureLevel { kNone, kModerate, kCritical }

Functions
constexpr uint32_t	CurrentValueSerializerFormatVersion ()
	V8_DEPRECATE_SOON ("Implementation detail", class ExternalOneByteStringResourceImpl)
void V8_EXPORT	RegisterExtension (Extension *extension)
V8_INLINE Local< Primitive >	Undefined (Isolate *isolate)
V8_INLINE Local< Primitive >	Null (Isolate *isolate)
V8_INLINE Local< Boolean >	True (Isolate *isolate)
V8_INLINE Local< Boolean >	False (Isolate *isolate)
template<class T >
Maybe< T >	Nothing ()
template<class T >
Maybe< T >	Just (const T &t)
Maybe< void >	JustVoid ()

Detailed Description

Profiler support for the V8 JavaScript engine.

Testing support for the V8 JavaScript engine.

Support for Persistent containers.

C++11 embedders can use STL containers with Global values, but pre-C++11 does not support the required move semantic and hence may want these container classes.

Compile-time constants.

This header provides access to information about the value serializer at compile time, without declaring or defining any symbols that require linking to V8.

The v8 JavaScript engine.

Typedef Documentation

AccessCheckCallback

typedef bool(* v8::AccessCheckCallback) (Local< Context > accessing_context, Local< Object > accessed_object, Local< Value > data)

Returns true if the given context should be allowed to access the given object.

AccessorGetterCallback

typedef void(* v8::AccessorGetterCallback) (Local< String > property, const PropertyCallbackInfo< Value > &info)

Accessor[Getter|Setter] are used as callback functions when setting|getting a particular property. See Object and ObjectTemplate's method SetAccessor.

AllowCodeGenerationFromStringsCallback

typedef bool(* v8::AllowCodeGenerationFromStringsCallback) (Local< Context > context, Local< String > source)

Callback to check if code generation from strings is allowed. See Context::AllowCodeGenerationFromStrings.

EntropySource

typedef bool(* v8::EntropySource) (unsigned char *buffer, size_t length)

EntropySource is used as a callback function when v8 needs a source of entropy.

FunctionEntryHook

typedef void(* v8::FunctionEntryHook) (uintptr_t function, uintptr_t return_addr_location)

FunctionEntryHook is the type of the profile entry hook called at entry to any generated function when function-level profiling is enabled.

Parameters

function	the address of the function that's being entered.
return_addr_location	points to a location on stack where the machine return address resides. This can be used to identify the caller of function, and/or modified to divert execution when function exits.

Note

the entry hook must not cause garbage collection.

GenericNamedPropertyDefinerCallback

typedef void(* v8::GenericNamedPropertyDefinerCallback) (Local< Name > property, const PropertyDescriptor &desc, const PropertyCallbackInfo< Value > &info)

Interceptor for defineProperty requests on an object.

Use info.GetReturnValue() to indicate whether the request was intercepted or not. If the definer successfully intercepts the request, i.e., if the request should not be further executed, call info.GetReturnValue().Set(value). If the definer did not intercept the request, i.e., if the request should be handled as if no interceptor is present, do not not call Set().

Parameters

property	The name of the property for which the request was intercepted.
desc	The property descriptor which is used to define the property if the request is not intercepted.
info	Information about the intercepted request, such as isolate, receiver, return value, or whether running in ‘'use strict’mode. SeePropertyCallbackInfo`.

See also ObjectTemplate::SetHandler.

GenericNamedPropertyDeleterCallback

typedef void(* v8::GenericNamedPropertyDeleterCallback) (Local< Name > property, const PropertyCallbackInfo< Boolean > &info)

Interceptor for delete requests on an object.

Use info.GetReturnValue() to indicate whether the request was intercepted or not. If the deleter successfully intercepts the request, i.e., if the request should not be further executed, call info.GetReturnValue().Set(value) with a boolean value. The value is used as the return value of delete.

Parameters

property	The name of the property for which the request was intercepted.
info	Information about the intercepted request, such as isolate, receiver, return value, or whether running in ‘'use strict’mode. SeePropertyCallbackInfo`.

Note

If you need to mimic the behavior of delete, i.e., throw in strict mode instead of returning false, use info.ShouldThrowOnError() to determine if you are in strict mode.

See also ObjectTemplate::SetHandler.

GenericNamedPropertyDescriptorCallback

typedef void(* v8::GenericNamedPropertyDescriptorCallback) (Local< Name > property, const PropertyCallbackInfo< Value > &info)

Interceptor for getOwnPropertyDescriptor requests on an object.

Use info.GetReturnValue().Set() to set the return value of the intercepted request. The return value must be an object that can be converted to a PropertyDescriptor, e.g., a v8::value returned from v8::Object::getOwnPropertyDescriptor.

Parameters

property

The name of the property for which the request was intercepted. Information about the intercepted request, such as isolate, receiver, return value, or whether running in ‘'use strict’mode. SeePropertyCallbackInfo`.

Note

If GetOwnPropertyDescriptor is intercepted, it will always return true, i.e., indicate that the property was found.

See also ObjectTemplate::SetHandler.

GenericNamedPropertyEnumeratorCallback

typedef void(* v8::GenericNamedPropertyEnumeratorCallback) (const PropertyCallbackInfo< Array > &info)

Returns an array containing the names of the properties the named property getter intercepts.

Note: The values in the array must be of type v8::Name.

GenericNamedPropertyGetterCallback

typedef void(* v8::GenericNamedPropertyGetterCallback) (Local< Name > property, const PropertyCallbackInfo< Value > &info)

Interceptor for get requests on an object.

Use info.GetReturnValue().Set() to set the return value of the intercepted get request.

Parameters

property	The name of the property for which the request was intercepted.
info	Information about the intercepted request, such as isolate, receiver, return value, or whether running in 'use strict' mode. See PropertyCallbackInfo.

void GetterCallback(
  Local<Name> name,
  const v8::PropertyCallbackInfo<v8::Value>& info) {
    info.GetReturnValue().Set(v8_num(42));
}

v8::Local<v8::FunctionTemplate> templ =
    v8::FunctionTemplate::New(isolate);
templ->InstanceTemplate()->SetHandler(
    v8::NamedPropertyHandlerConfiguration(GetterCallback));
LocalContext env;
env->Global()
    ->Set(env.local(), v8_str("obj"), templ->GetFunction(env.local())
                                           .ToLocalChecked()
                                           ->NewInstance(env.local())
                                           .ToLocalChecked())
    .FromJust();
v8::Local<v8::Value> result = CompileRun("obj.a = 17; obj.a");
CHECK(v8_num(42)->Equals(env.local(), result).FromJust());

See also ObjectTemplate::SetHandler.

GenericNamedPropertyQueryCallback

typedef void(* v8::GenericNamedPropertyQueryCallback) (Local< Name > property, const PropertyCallbackInfo< Integer > &info)

Intercepts all requests that query the attributes of the property, e.g., getOwnPropertyDescriptor(), propertyIsEnumerable(), and defineProperty().

Use info.GetReturnValue().Set(value) to set the property attributes. The value is an integer encoding a v8::PropertyAttribute.

Parameters

property	The name of the property for which the request was intercepted.
info	Information about the intercepted request, such as isolate, receiver, return value, or whether running in ‘'use strict’mode. SeePropertyCallbackInfo`.

Note

Some functions query the property attributes internally, even though they do not return the attributes. For example, hasOwnProperty() can trigger this interceptor depending on the state of the object.

See also ObjectTemplate::SetHandler.

GenericNamedPropertySetterCallback

typedef void(* v8::GenericNamedPropertySetterCallback) (Local< Name > property, Local< Value > value, const PropertyCallbackInfo< Value > &info)

Interceptor for set requests on an object.

Use info.GetReturnValue() to indicate whether the request was intercepted or not. If the setter successfully intercepts the request, i.e., if the request should not be further executed, call info.GetReturnValue().Set(value). If the setter did not intercept the request, i.e., if the request should be handled as if no interceptor is present, do not not call Set().

Parameters

property	The name of the property for which the request was intercepted.
value	The value which the property will have if the request is not intercepted.
info	Information about the intercepted request, such as isolate, receiver, return value, or whether running in ‘'use strict’mode. SeePropertyCallbackInfo`.

See also ObjectTemplate::SetHandler.

HostImportModuleDynamicallyCallback

typedef MaybeLocal<Promise>(* v8::HostImportModuleDynamicallyCallback) (Local< Context > context, Local< ScriptOrModule > referrer, Local< String > specifier)

HostImportModuleDynamicallyCallback is called when we require the embedder to load a module. This is used as part of the dynamic import syntax.

The referrer contains metadata about the script/module that calls import.

The specifier is the name of the module that should be imported.

The embedder must compile, instantiate, evaluate the Module, and obtain it's namespace object.

The Promise returned from this function is forwarded to userland JavaScript. The embedder must resolve this promise with the module namespace object. In case of an exception, the embedder must reject this promise with the exception. If the promise creation itself fails (e.g. due to stack overflow), the embedder must propagate that exception by returning an empty MaybeLocal.

HostInitializeImportMetaObjectCallback

typedef void(* v8::HostInitializeImportMetaObjectCallback) (Local< Context > context, Local< Module > module, Local< Object > meta)

HostInitializeImportMetaObjectCallback is called the first time import.meta is accessed for a module. Subsequent access will reuse the same value.

The method combines two implementation-defined abstract operations into one: HostGetImportMetaProperties and HostFinalizeImportMeta.

The embedder should use v8::Object::CreateDataProperty to add properties on the meta object.

IndexedPropertyDefinerCallback

typedef void(* v8::IndexedPropertyDefinerCallback) (uint32_t index, const PropertyDescriptor &desc, const PropertyCallbackInfo< Value > &info)

See v8::GenericNamedPropertyDefinerCallback.

IndexedPropertyDeleterCallback

typedef void(* v8::IndexedPropertyDeleterCallback) (uint32_t index, const PropertyCallbackInfo< Boolean > &info)

See v8::GenericNamedPropertyDeleterCallback.

IndexedPropertyDescriptorCallback

typedef void(* v8::IndexedPropertyDescriptorCallback) (uint32_t index, const PropertyCallbackInfo< Value > &info)

See v8::GenericNamedPropertyDescriptorCallback.

IndexedPropertyEnumeratorCallback

typedef void(* v8::IndexedPropertyEnumeratorCallback) (const PropertyCallbackInfo< Array > &info)

Returns an array containing the indices of the properties the indexed property getter intercepts.

Note: The values in the array must be uint32_t.

IndexedPropertyGetterCallback

typedef void(* v8::IndexedPropertyGetterCallback) (uint32_t index, const PropertyCallbackInfo< Value > &info)

See v8::GenericNamedPropertyGetterCallback.

IndexedPropertyQueryCallback

typedef void(* v8::IndexedPropertyQueryCallback) (uint32_t index, const PropertyCallbackInfo< Integer > &info)

See v8::GenericNamedPropertyQueryCallback.

IndexedPropertySetterCallback

typedef void(* v8::IndexedPropertySetterCallback) (uint32_t index, Local< Value > value, const PropertyCallbackInfo< Value > &info)

See v8::GenericNamedPropertySetterCallback.

JitCodeEventHandler

typedef void(* v8::JitCodeEventHandler) (const JitCodeEvent *event)

Callback function passed to SetJitCodeEventHandler.

Parameters

event

code add, move or removal event.

NamedPropertyDeleterCallback

typedef void(* v8::NamedPropertyDeleterCallback) (Local< String > property, const PropertyCallbackInfo< Boolean > &info)

Returns a non-empty handle if the deleter intercepts the request. The return value is true if the property could be deleted and false otherwise.

NamedPropertyEnumeratorCallback

typedef void(* v8::NamedPropertyEnumeratorCallback) (const PropertyCallbackInfo< Array > &info)

Returns an array containing the names of the properties the named property getter intercepts.

Note: The values in the array must be of type v8::Name.

NamedPropertyGetterCallback

typedef void(* v8::NamedPropertyGetterCallback) (Local< String > property, const PropertyCallbackInfo< Value > &info)

NamedProperty[Getter|Setter] are used as interceptors on object. See ObjectTemplate::SetNamedPropertyHandler.

NamedPropertyQueryCallback

typedef void(* v8::NamedPropertyQueryCallback) (Local< String > property, const PropertyCallbackInfo< Integer > &info)

Returns a non-empty handle if the interceptor intercepts the request. The result is an integer encoding property attributes (like v8::None, v8::DontEnum, etc.)

NamedPropertySetterCallback

typedef void(* v8::NamedPropertySetterCallback) (Local< String > property, Local< Value > value, const PropertyCallbackInfo< Value > &info)

Returns the value if the setter intercepts the request. Otherwise, returns an empty handle.

NearHeapLimitCallback

typedef size_t(* v8::NearHeapLimitCallback) (void *data, size_t current_heap_limit, size_t initial_heap_limit)

This callback is invoked when the heap size is close to the heap limit and V8 is likely to abort with out-of-memory error. The callback can extend the heap limit by returning a value that is greater than the current_heap_limit. The initial heap limit is the limit that was set after heap setup.

ReturnAddressLocationResolver

typedef uintptr_t(* v8::ReturnAddressLocationResolver) (uintptr_t return_addr_location)

ReturnAddressLocationResolver is used as a callback function when v8 is resolving the location of a return address on the stack. Profilers that change the return address on the stack can use this to resolve the stack location to wherever the profiler stashed the original return address.

Parameters

return_addr_location

A location on stack where a machine return address resides.

Returns

Either return_addr_location, or else a pointer to the profiler's copy of the original return address.

Note

The resolver function must not cause garbage collection.

Enumeration Type Documentation

AccessControl

enum v8::AccessControl

Access control specifications.

Some accessors should be accessible across contexts. These accessors have an explicit access control parameter which specifies the kind of cross-context access that should be allowed.

TODO(dcarney): Remove PROHIBITS_OVERWRITING as it is now unused.

AccessType

enum v8::AccessType

Access type specification.

CodeEventType

enum v8::CodeEventType

Note that this enum may be extended in the future. Please include a default case if this enum is used in a switch statement.

GCCallbackFlags

enum v8::GCCallbackFlags

GCCallbackFlags is used to notify additional information about the GC callback.

• kGCCallbackFlagConstructRetainedObjectInfos: The GC callback is for constructing retained object infos.
• kGCCallbackFlagForced: The GC callback is for a forced GC for testing.
• kGCCallbackFlagSynchronousPhantomCallbackProcessing: The GC callback is called synchronously without getting posted to an idle task.
• kGCCallbackFlagCollectAllAvailableGarbage: The GC callback is called in a phase where V8 is trying to collect all available garbage (e.g., handling a low memory notification).
• kGCCallbackScheduleIdleGarbageCollection: The GC callback is called to trigger an idle garbage collection.

GCType

enum v8::GCType

Applications can register callback functions which will be called before and after certain garbage collection operations. Allocations are not allowed in the callback functions, you therefore cannot manipulate objects (set or delete properties for example) since it is possible such operations will result in the allocation of objects.

IndexFilter

enum v8::IndexFilter

strong

kIncludesIndices allows for integer indices to be collected, while kSkipIndices will exclude integer indices from being collected.

IntegrityLevel

enum v8::IntegrityLevel

strong

Integrity level for objects.

JitCodeEventOptions

enum v8::JitCodeEventOptions

Option flags passed to the SetJitCodeEventHandler function.

KeyCollectionMode

enum v8::KeyCollectionMode

strong

Keys/Properties filter enums:

KeyCollectionMode limits the range of collected properties. kOwnOnly limits the collected properties to the given Object only. kIncludesPrototypes will include all keys of the objects's prototype chain as well.

KeyConversionMode

enum v8::KeyConversionMode

strong

kConvertToString will convert integer indices to strings. kKeepNumbers will return numbers for integer indices.

MemoryPressureLevel

enum v8::MemoryPressureLevel

strong

Memory pressure level for the MemoryPressureNotification. kNone hints V8 that there is no memory pressure. kModerate hints V8 to speed up incremental garbage collection at the cost of of higher latency due to garbage collection pauses. kCritical hints V8 to free memory as soon as possible. Garbage collection pauses at this level will be large.

MicrotasksPolicy

enum v8::MicrotasksPolicy

strong

Policy for running microtasks:

• explicit: microtasks are invoked with Isolate::RunMicrotasks() method;
• scoped: microtasks invocation is controlled by MicrotasksScope objects;
• auto: microtasks are invoked when the script call depth decrements to zero.

NewStringType

enum v8::NewStringType

strong

A flag describing different modes of string creation.

Aside from performance implications there are no differences between the two creation modes.

Enumerator
kNormal	Create a new string, always allocating new storage memory.
kInternalized	Acts as a hint that the string should be created in the old generation heap space and be deduplicated if an identical string already exists.

PromiseHookType

enum v8::PromiseHookType

strong

PromiseHook with type kInit is called when a new promise is created. When a new promise is created as part of the chain in the case of Promise.then or in the intermediate promises created by Promise.{race, all}/AsyncFunctionAwait, we pass the parent promise otherwise we pass undefined.

PromiseHook with type kResolve is called at the beginning of resolve or reject function defined by CreateResolvingFunctions.

PromiseHook with type kBefore is called at the beginning of the PromiseReactionJob.

PromiseHook with type kAfter is called right at the end of the PromiseReactionJob.

PropertyAttribute

enum v8::PropertyAttribute

PropertyAttribute.

Enumerator
None	None.
ReadOnly	ReadOnly, i.e., not writable.
DontEnum	DontEnum, i.e., not enumerable.
DontDelete	DontDelete, i.e., not configurable.

PropertyFilter

enum v8::PropertyFilter

Property filter bits. They can be or'ed to build a composite filter.

PropertyHandlerFlags

enum v8::PropertyHandlerFlags

strong

Configuration flags for v8::NamedPropertyHandlerConfiguration or v8::IndexedPropertyHandlerConfiguration.

Enumerator
kNone	None.
kAllCanRead	See ALL_CAN_READ above.
kNonMasking	Will not call into interceptor for properties on the receiver or prototype chain, i.e., only call into interceptor for properties that do not exist. Currently only valid for named interceptors.
kOnlyInterceptStrings	Will not call into interceptor for symbol lookup. Only meaningful for named interceptors.
kHasNoSideEffect	The getter, query, enumerator callbacks do not produce side effects.

RAILMode

enum v8::RAILMode

Option flags passed to the SetRAILMode function. See documentation https://developers.google.com/web/tools/chrome-devtools/ profile/evaluate-performance/rail

SideEffectType

enum v8::SideEffectType

strong

Options for marking whether callbacks may trigger JS-observable side effects. Side-effect-free callbacks are whitelisted during debug evaluation with throwOnSideEffect. It applies when calling a Function, FunctionTemplate, or an Accessor's getter callback. For Interceptors, please see PropertyHandlerFlags's kHasNoSideEffect.