#include <v8-profiler.h>

Data Structures
class	ObjectNameResolver

Public Types
typedef RetainedObjectInfo (	WrapperInfoCallback) (uint16_t class_id, Local< Value > wrapper)

Public Member Functions
int	GetSnapshotCount ()

const HeapSnapshot *	GetHeapSnapshot (int index)

SnapshotObjectId	GetObjectId (Local< Value > value)

Local< Value >	FindObjectById (SnapshotObjectId id)

void	ClearObjectIds ()

const HeapSnapshot *	TakeHeapSnapshot (ActivityControl control=NULL, ObjectNameResolver global_object_name_resolver=NULL)

void	StartTrackingHeapObjects (bool track_allocations=false)

SnapshotObjectId	GetHeapStats (OutputStream stream, int64_t timestamp_us=NULL)

void	StopTrackingHeapObjects ()

void	DeleteAllHeapSnapshots ()

void	SetWrapperClassInfoProvider (uint16_t class_id, WrapperInfoCallback callback)

size_t	GetProfilerMemorySize ()

void	SetRetainedObjectInfo (UniqueId id, RetainedObjectInfo *info)

Static Public Attributes
static const SnapshotObjectId	kUnknownObjectId = 0

static const uint16_t	kPersistentHandleNoClassId = 0

Detailed Description

Interface for controlling heap profiling. Instance of the profiler can be retrieved using v8::Isolate::GetHeapProfiler.

Definition at line 425 of file v8-profiler.h.

Member Typedef Documentation

◆ WrapperInfoCallback

typedef RetainedObjectInfo*(* WrapperInfoCallback) (uint16_t class_id, Local< Value > wrapper)

Callback function invoked for obtaining RetainedObjectInfo for the given JavaScript wrapper object. It is prohibited to enter V8 while the callback is running: only getters on the handle and GetPointerFromInternalField on the objects are allowed.

Definition at line 433 of file v8-profiler.h.

Member Function Documentation

◆ ClearObjectIds()

void ClearObjectIds ( )

Clears internal map from SnapshotObjectId to heap object. The new objects will not be added into it unless a heap snapshot is taken or heap object tracking is kicked off.

◆ DeleteAllHeapSnapshots()

void DeleteAllHeapSnapshots ( )

Deletes all snapshots taken. All previously returned pointers to snapshots and their contents become invalid after this call.

◆ FindObjectById()

Local<Value> FindObjectById ( SnapshotObjectId id )

Returns heap object with given SnapshotObjectId if the object is alive, otherwise empty handle is returned.

◆ GetHeapSnapshot()

const HeapSnapshot* GetHeapSnapshot ( int index )

Returns a snapshot by index.

◆ GetHeapStats()

SnapshotObjectId GetHeapStats	(	OutputStream *	stream,
		int64_t *	timestamp_us = `NULL`
	)

Adds a new time interval entry to the aggregated statistics array. The time interval entry contains information on the current heap objects population size. The method also updates aggregated statistics and reports updates for all previous time intervals via the OutputStream object. Updates on each time interval are provided as a stream of the HeapStatsUpdate structure instances. If |timestamp_us| is supplied, timestamp of the new entry will be written into it. The return value of the function is the last seen heap object Id.

StartTrackingHeapObjects must be called before the first call to this method.

◆ GetObjectId()

SnapshotObjectId GetObjectId ( Local< Value > value )

Returns SnapshotObjectId for a heap object referenced by |value| if it has been seen by the heap profiler, kUnknownObjectId otherwise.

◆ GetProfilerMemorySize()

size_t GetProfilerMemorySize ( )

Returns memory used for profiler internal data and snapshots.

◆ GetSnapshotCount()

int GetSnapshotCount ( )

Returns the number of snapshots taken.

◆ SetRetainedObjectInfo()

void SetRetainedObjectInfo	(	UniqueId	id,
		RetainedObjectInfo *	info
	)

Sets a RetainedObjectInfo for an object group (see V8::SetObjectGroupId).

◆ SetWrapperClassInfoProvider()

void SetWrapperClassInfoProvider	(	uint16_t	class_id,
		WrapperInfoCallback	callback
	)

Binds a callback to embedder's class ID.

◆ StartTrackingHeapObjects()

void StartTrackingHeapObjects ( bool track_allocations = false )

Starts tracking of heap objects population statistics. After calling this method, all heap objects relocations done by the garbage collector are being registered.

|track_allocations| parameter controls whether stack trace of each allocation in the heap will be recorded and reported as part of HeapSnapshot.

◆ StopTrackingHeapObjects()

void StopTrackingHeapObjects ( )

Stops tracking of heap objects population statistics, cleans up all collected data. StartHeapObjectsTracking must be called again prior to calling GetHeapStats next time.

◆ TakeHeapSnapshot()

const HeapSnapshot* TakeHeapSnapshot	(	ActivityControl *	control = `NULL`,
		ObjectNameResolver *	global_object_name_resolver = `NULL`
	)

Takes a heap snapshot and returns it.

Field Documentation

◆ kPersistentHandleNoClassId

const uint16_t kPersistentHandleNoClassId = 0

static

Default value of persistent handle class ID. Must not be used to define a class. Can be used to reset a class of a persistent handle.

Definition at line 540 of file v8-profiler.h.

◆ kUnknownObjectId

const SnapshotObjectId kUnknownObjectId = 0