BackingStore Class Reference

#include <v8.h>

Inheritance diagram for BackingStore:

Collaboration diagram for BackingStore:

Public Types
using	DeleterCallback = void(*)(void *data, size_t length, void *deleter_data)

Public Member Functions
	~BackingStore ()
void *	Data () const
size_t	ByteLength () const
bool	IsShared () const
void	operator delete (void *ptr)

Static Public Member Functions
static std::unique_ptr< BackingStore >	Reallocate (v8::Isolate *isolate, std::unique_ptr< BackingStore > backing_store, size_t byte_length)
static void	EmptyDeleter (void *data, size_t length, void *deleter_data)

Detailed Description

A wrapper around the backing store (i.e. the raw memory) of an array buffer. See a document linked in http://crbug.com/v8/9908 for more information.

The allocation and destruction of backing stores is generally managed by V8. Clients should always use standard C++ memory ownership types (i.e. std::unique_ptr and std::shared_ptr) to manage lifetimes of backing stores properly, since V8 internal objects may alias backing stores.

This object does not keep the underlying |ArrayBuffer::Allocator| alive by default. Use Isolate::CreateParams::array_buffer_allocator_shared when creating the Isolate to make it hold a reference to the allocator itself.

Definition at line 5291 of file v8.h.

Member Typedef Documentation

DeleterCallback

using DeleterCallback = void (*)(void* data, size_t length, void* deleter_data)

This callback is used only if the memory block for a BackingStore cannot be allocated with an ArrayBuffer::Allocator. In such cases the destructor of the BackingStore invokes the callback to free the memory block.

Definition at line 5334 of file v8.h.

Constructor & Destructor Documentation

~BackingStore()

~BackingStore

(

)

Member Function Documentation

ByteLength()

size_t ByteLength

(

)

const

The length (in bytes) of this backing store.

Data()

void* Data

(

)

const

Return a pointer to the beginning of the memory block for this backing store. The pointer is only valid as long as this backing store object lives.

EmptyDeleter()

static void EmptyDeleter ( void *  data, size_t  length, void *  deleter_data  )

static

If the memory block of a BackingStore is static or is managed manually, then this empty deleter along with nullptr deleter_data can be passed to ArrayBuffer::NewBackingStore to indicate that.

The manually managed case should be used with caution and only when it is guaranteed that the memory block freeing happens after detaching its ArrayBuffer.

IsShared()

bool IsShared

(

)

const

Indicates whether the backing store was created for an ArrayBuffer or a SharedArrayBuffer.

operator delete()

void operator delete ( void *  ptr )

inline

Prevent implicit instantiation of operator delete with size_t argument. The size_t argument would be incorrect because ptr points to the internal BackingStore object.

Definition at line 5318 of file v8.h.

Reallocate()

static std::unique_ptr<BackingStore> Reallocate ( v8::Isolate *  isolate, std::unique_ptr< BackingStore >  backing_store, size_t  byte_length  )

static

Wrapper around ArrayBuffer::Allocator::Reallocate that preserves IsShared. Assumes that the backing_store was allocated by the ArrayBuffer allocator of the given isolate.

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

• include/v8.h