#include <v8-local-handle.h>

Public Member Functions
V8_INLINE	Local ()

template<class S >
V8_INLINE	Local (Local< S > that)

V8_INLINE bool	IsEmpty () const

V8_INLINE void	Clear ()

V8_INLINE T *	operator-> () const

V8_INLINE T *	operator* () const

template<class S >
V8_INLINE bool	operator== (const Local< S > &that) const

template<class S >
V8_INLINE bool	operator== (const PersistentBase< S > &that) const

template<class S >
V8_INLINE bool	operator!= (const Local< S > &that) const

template<class S >
V8_INLINE bool	operator!= (const Persistent< S > &that) const

template<class S >
V8_INLINE Local< S >	As () const

Static Public Member Functions
template<class S >
static V8_INLINE Local< T >	Cast (Local< S > that)

static V8_INLINE Local< T >	New (Isolate *isolate, Local< T > that)

static V8_INLINE Local< T >	New (Isolate *isolate, const PersistentBase< T > &that)

static V8_INLINE Local< T >	New (Isolate *isolate, const BasicTracedReference< T > &that)

Friends
class	TracedReferenceBase

class	Utils

template<class F >
class	Eternal

template<class F >
class	PersistentBase

template<class F , class M >
class	Persistent

template<class F >
class	Local

template<class F >
class	MaybeLocal

template<class F >
class	FunctionCallbackInfo

template<class F >
class	PropertyCallbackInfo

class	String

class	Object

class	Context

class	Isolate

class	Private

template<class F >
class	internal::CustomArguments

class	HandleScope

class	EscapableHandleScope

template<class F1 , class F2 , class F3 >
class	PersistentValueMapBase

template<class F1 , class F2 >
class	PersistentValueVector

template<class F >
class	ReturnValue

template<class F >
class	Traced

template<class F >
class	BasicTracedReference

template<class F >
class	TracedReference

Local< Primitive >	Undefined (Isolate *isolate)

Local< Primitive >	Null (Isolate *isolate)

Local< Boolean >	True (Isolate *isolate)

Local< Boolean >	False (Isolate *isolate)

Detailed Description

template<class T>
class v8::Local< T >

An object reference managed by the v8 garbage collector.

All objects returned from v8 have to be tracked by the garbage collector so that it knows that the objects are still alive. Also, because the garbage collector may move objects, it is unsafe to point directly to an object. Instead, all objects are stored in handles which are known by the garbage collector and updated whenever an object moves. Handles should always be passed by value (except in cases like out-parameters) and they should never be allocated on the heap.

There are two types of handles: local and persistent handles.

Local handles are light-weight and transient and typically used in local operations. They are managed by HandleScopes. That means that a HandleScope must exist on the stack when they are created and that they are only valid inside of the HandleScope active during their creation. For passing a local handle to an outer HandleScope, an EscapableHandleScope and its Escape() method must be used.

Persistent handles can be used when storing objects across several independent operations and have to be explicitly deallocated when they're no longer used.

It is safe to extract the object stored in the handle by dereferencing the handle (for instance, to extract the Object* from a Local<Object>); the value will still be governed by a handle behind the scenes and the same rules apply to these values as to their handles.

Definition at line 155 of file v8-local-handle.h.

Constructor & Destructor Documentation

◆ Local() [1/2]

template<class T >

V8_INLINE Local ( )

inline

Definition at line 157 of file v8-local-handle.h.

◆ Local() [2/2]

template<class T >

template<class S >

V8_INLINE Local ( Local< S > that )

inline

This check fails when trying to convert between incompatible handles. For example, converting from a Local<String> to a Local<Number>.

Definition at line 159 of file v8-local-handle.h.

Member Function Documentation

◆ As()

template<class T >

template<class S >

V8_INLINE Local< S > As ( ) const

inline

Calling this is equivalent to Local<S>::Cast(). In particular, this is only valid if the handle actually refers to a value of the target type.

Definition at line 251 of file v8-local-handle.h.

References Local< T >::Cast().

◆ Cast()

template<class T >

template<class S >

static V8_INLINE Local< T > Cast ( Local< S > that )

inlinestatic

Cast a handle to a subclass, e.g. Local<Value> to Local<Object>. This is only valid if the handle actually refers to a value of the target type.

Definition at line 236 of file v8-local-handle.h.

References Local< T >::IsEmpty().

Referenced by Local< T >::As().

◆ Clear()

template<class T >

V8_INLINE void Clear ( )

inline

Sets the handle to be empty. IsEmpty() will then return true.

Definition at line 176 of file v8-local-handle.h.

◆ IsEmpty()

template<class T >

V8_INLINE bool IsEmpty ( ) const

inline

Returns true if the handle is empty.

Definition at line 171 of file v8-local-handle.h.

Referenced by Local< T >::Cast(), PersistentBase< T >::Reset(), TracedReference< T >::Reset(), and ReturnValue< T >::Set().

◆ New() [1/3]

template<class T >

static V8_INLINE Local< T > New	(	Isolate *	isolate,
		const BasicTracedReference< T > &	that
	)

inlinestatic

Definition at line 269 of file v8-local-handle.h.

References Local< T >::New().

◆ New() [2/3]

template<class T >

static V8_INLINE Local< T > New	(	Isolate *	isolate,
		const PersistentBase< T > &	that
	)

inlinestatic

Definition at line 264 of file v8-local-handle.h.

References Local< T >::New().

◆ New() [3/3]

template<class T >

static V8_INLINE Local< T > New	(	Isolate *	isolate,
		Local< T >	that
	)

inlinestatic

Create a local handle for the content of another handle. The referee is kept alive by the local handle even when the original handle is destroyed/disposed.

Definition at line 260 of file v8-local-handle.h.

References Local< T >::New().

Referenced by PersistentValueMapBase< K, V, Traits >::Get(), PersistentBase< T >::Get(), BasicTracedReference< T >::Get(), PersistentValueVector< V, Traits >::Get(), TracedReferenceBase::Get(), Local< T >::New(), Local< T >::New(), Local< T >::New(), and PersistentValueMapBase< K, V, Traits >::PersistentValueReference::NewLocal().

◆ operator!=() [1/2]

template<class T >

template<class S >

V8_INLINE bool operator!= ( const Local< S > & that ) const

inline

Checks whether two handles are different. Returns true if only one of the handles is empty, or if the objects to which they refer are different.

If both handles refer to JS objects, this is the same as strict non-equality. For primitives, such as numbers or strings, a true return value does not indicate that the values aren't equal in the JavaScript sense. Use Value::StrictEquals() to check primitives for equality.

Definition at line 221 of file v8-local-handle.h.

References Local< T >::operator==().

◆ operator!=() [2/2]

template<class T >

template<class S >

V8_INLINE bool operator!= ( const Persistent< S > & that ) const

inline

Definition at line 226 of file v8-local-handle.h.

References Local< T >::operator==().

◆ operator*()

template<class T >

V8_INLINE T * operator* ( ) const

inline

Definition at line 180 of file v8-local-handle.h.

◆ operator->()

template<class T >

V8_INLINE T * operator-> ( ) const

inline

Definition at line 178 of file v8-local-handle.h.

◆ operator==() [1/2]

template<class T >

template<class S >

V8_INLINE bool operator== ( const Local< S > & that ) const

inline

Checks whether two handles are the same. Returns true if both are empty, or if the objects to which they refer are identical.

If both handles refer to JS objects, this is the same as strict equality. For primitives, such as numbers or strings, a false return value does not indicate that the values aren't equal in the JavaScript sense. Use Value::StrictEquals() to check primitives for equality.

Definition at line 193 of file v8-local-handle.h.

Referenced by Local< T >::operator!=(), and Local< T >::operator!=().

◆ operator==() [2/2]

template<class T >

template<class S >

V8_INLINE bool operator== ( const PersistentBase< S > & that ) const

inline

Definition at line 202 of file v8-local-handle.h.

Friends And Related Symbol Documentation

◆ BasicTracedReference

template<class T >

template<class F >

friend class BasicTracedReference

friend

Definition at line 313 of file v8-local-handle.h.

◆ Context

template<class T >

friend class Context

friend

Definition at line 293 of file v8-local-handle.h.

◆ EscapableHandleScope

template<class T >

friend class EscapableHandleScope

friend

Definition at line 303 of file v8-local-handle.h.

◆ Eternal

template<class T >

template<class F >

friend class Eternal

friend

Definition at line 278 of file v8-local-handle.h.

◆ False

template<class T >

Local< Boolean > False ( Isolate * isolate )

friend

Definition at line 852 of file v8-primitive.h.

◆ FunctionCallbackInfo

template<class T >

template<class F >

friend class FunctionCallbackInfo

friend

Definition at line 288 of file v8-local-handle.h.

◆ HandleScope

template<class T >

friend class HandleScope

friend

Definition at line 302 of file v8-local-handle.h.

◆ internal::CustomArguments

template<class T >

template<class F >

friend class internal::CustomArguments

friend

Definition at line 297 of file v8-local-handle.h.

◆ Isolate

template<class T >

friend class Isolate

friend

Definition at line 294 of file v8-local-handle.h.

◆ Local

template<class T >

template<class F >

friend class Local

friend

Definition at line 284 of file v8-local-handle.h.

◆ MaybeLocal

template<class T >

template<class F >

friend class MaybeLocal

friend

Definition at line 286 of file v8-local-handle.h.

◆ Null

template<class T >

Local< Primitive > Null ( Isolate * isolate )

friend

Definition at line 836 of file v8-primitive.h.

◆ Object

template<class T >

friend class Object

friend

Definition at line 292 of file v8-local-handle.h.

◆ Persistent

template<class T >

template<class F , class M >

friend class Persistent

friend

Persistent is a way to create a strong pointer from an off-heap object to another on-heap object. As long as the Persistent handle is alive the GC will keep the object pointed to alive. The Persistent handle is always a GC root from the point of view of the GC. Persistent must be constructed and destructed in the same thread.

Definition at line 282 of file v8-local-handle.h.

◆ PersistentBase

template<class T >

template<class F >

friend class PersistentBase

friend

Definition at line 280 of file v8-local-handle.h.

◆ PersistentValueMapBase

template<class T >

template<class F1 , class F2 , class F3 >

friend class PersistentValueMapBase

friend

Definition at line 305 of file v8-local-handle.h.

◆ PersistentValueVector

template<class T >

template<class F1 , class F2 >

friend class PersistentValueVector

friend

Definition at line 307 of file v8-local-handle.h.

◆ Private

template<class T >

friend class Private

friend

Definition at line 295 of file v8-local-handle.h.

◆ PropertyCallbackInfo

template<class T >

template<class F >

friend class PropertyCallbackInfo

friend

Definition at line 290 of file v8-local-handle.h.

◆ ReturnValue

template<class T >

template<class F >

friend class ReturnValue

friend

Definition at line 309 of file v8-local-handle.h.

◆ String

template<class T >

friend class String

friend

Definition at line 291 of file v8-local-handle.h.

◆ Traced

template<class T >

template<class F >

friend class Traced

friend

Definition at line 311 of file v8-local-handle.h.

◆ TracedReference

template<class T >

template<class F >

friend class TracedReference

friend

Definition at line 315 of file v8-local-handle.h.

◆ TracedReferenceBase

template<class T >

friend class TracedReferenceBase

friend

Definition at line 275 of file v8-local-handle.h.

◆ True

template<class T >

Local< Boolean > True ( Isolate * isolate )

friend

Definition at line 844 of file v8-primitive.h.

◆ Undefined

template<class T >

Local< Primitive > Undefined ( Isolate * isolate )

friend

Definition at line 828 of file v8-primitive.h.

◆ Utils

template<class T >

friend class Utils

friend

Definition at line 276 of file v8-local-handle.h.

The documentation for this class was generated from the following files:

include/v8-internal.h
include/v8-local-handle.h

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Constructor & Destructor Documentation

◆ Local() [1/2]

◆ Local() [2/2]

Member Function Documentation

◆ As()

◆ Cast()

◆ Clear()

◆ IsEmpty()

◆ New() [1/3]

◆ New() [2/3]

◆ New() [3/3]

◆ operator!=() [1/2]

◆ operator!=() [2/2]

◆ operator*()

◆ operator->()

◆ operator==() [1/2]

◆ operator==() [2/2]

Friends And Related Symbol Documentation

◆ BasicTracedReference

◆ Context

◆ EscapableHandleScope

◆ Eternal

◆ False

◆ FunctionCallbackInfo

◆ HandleScope

◆ internal::CustomArguments

◆ Isolate

◆ Local

◆ MaybeLocal

◆ Null

◆ Object

◆ Persistent

◆ PersistentBase

◆ PersistentValueMapBase

◆ PersistentValueVector

◆ Private

◆ PropertyCallbackInfo

◆ ReturnValue

◆ String

◆ Traced

◆ TracedReference

◆ TracedReferenceBase

◆ True

◆ Undefined

◆ Utils