com.oracle.truffle.api.frame

Class FrameDescriptor

java.lang.Object

com.oracle.truffle.api.frame.FrameDescriptor

All Implemented Interfaces:

Cloneable

public final class FrameDescriptor
extends Object
implements Cloneable

Descriptor of the slots of frame objects. Multiple frame instances are associated with one such descriptor. The FrameDescriptor is thread-safe.

Since:

0.8 or earlier

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FrameDescriptor.Builder Builder API for frame descriptors with indexed slots.

Constructor Summary

Constructors

Constructor and Description
FrameDescriptor() Constructs empty descriptor.
FrameDescriptor(Object defaultValue) Constructs new descriptor with specified FrameDescriptor.getDefaultValue().

Method Summary

Modifier and Type	Method and Description
FrameDescriptor	copy() Deeper copy of the descriptor.
void	disableAuxiliarySlot(Object key) Disables the auxiliary slot with the given key, so that subsequently created Frame instances may avoid allocating storage for it.
int	findOrAddAuxiliarySlot(Object key) Find or adds an auxiliary slot to this frame descriptor.
Map<Object,Integer>	getAuxiliarySlots() Returns all currently active auxiliary slots along with their indexes.
Object	getDefaultValue() Default value for the created slots.
Object	getInfo()
int	getNumberOfAuxiliarySlots()
int	getNumberOfSlots()
Object	getSlotInfo(int slot) Queries the info object for a given indexed slot.
FrameSlotKind	getSlotKind(int slot) Returns the FrameSlotKind associated with the given indexed slot.
Object	getSlotName(int slot) Queries the name for a given indexed slot.
static FrameDescriptor.Builder	newBuilder() Builds a new frame descriptor with index-based frame slots.
static FrameDescriptor.Builder	newBuilder(int capacity) Builds a new frame descriptor with index-based frame slots.
void	setSlotKind(int slot, FrameSlotKind kind) Sets the FrameSlotKind of the given indexed slot.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

FrameDescriptor

public FrameDescriptor()

Constructs empty descriptor. The FrameDescriptor.getDefaultValue() is null.

Since:

0.8 or earlier

FrameDescriptor

public FrameDescriptor(Object defaultValue)

Constructs new descriptor with specified FrameDescriptor.getDefaultValue().

Parameters:

defaultValue - to be returned from FrameDescriptor.getDefaultValue()

Since:

0.8 or earlier

Method Detail

copy

public FrameDescriptor copy()

Deeper copy of the descriptor. Copies all slots in the descriptor, but only their identifier and info but not their kind!

Returns:

new instance of a descriptor with copies of values from this one

Since:

0.8 or earlier

getDefaultValue

public Object getDefaultValue()

Default value for the created slots.

Returns:

value provided to FrameDescriptor.FrameDescriptor(java.lang.Object)

Since:

0.8 or earlier

toString

public String toString()

Overrides:

toString in class Object

Since:

0.8 or earlier

getNumberOfSlots

public int getNumberOfSlots()

Returns:

the number of indexed slots in this frame descriptor

Since:

22.0

getSlotKind

public FrameSlotKind getSlotKind(int slot)

Returns the FrameSlotKind associated with the given indexed slot.

Parameters:

slot - index of the slot

Returns:

a non-null FrameSlotKind

Since:

22.0

setSlotKind

public void setSlotKind(int slot,
                        FrameSlotKind kind)

Sets the FrameSlotKind of the given indexed slot.

Parameters:

slot - index of the slot

kind - new non-null FrameSlotKind

Since:

22.0

getSlotName

public Object getSlotName(int slot)

Queries the name for a given indexed slot.

Parameters:

slot - index of the slot

Returns:

the name of the slot (may be null)

Since:

22.0

getSlotInfo

public Object getSlotInfo(int slot)

Queries the info object for a given indexed slot.

Parameters:

slot - index of the slot

Returns:

the info object of the slot (may be null)

Since:

22.0

findOrAddAuxiliarySlot

public int findOrAddAuxiliarySlot(Object key)

Find or adds an auxiliary slot to this frame descriptor. Returns an integer index that can be used to access the auxiliary slot in the frame.

Parameters:

key - used as a hash map entry

Returns:

an integer that can be used to access the auxiliary slot in the frame

Since:

22.0

disableAuxiliarySlot

public void disableAuxiliarySlot(Object key)

Disables the auxiliary slot with the given key, so that subsequently created Frame instances may avoid allocating storage for it. Depending on the internal storage layout, it may not be possible to remove the storage for individual slots, so it is important to disable _all_ unused slots.

Parameters:

key - the key, as passed to FrameDescriptor.findOrAddAuxiliarySlot(Object)

Since:

22.0

getAuxiliarySlots

public Map<Object,Integer> getAuxiliarySlots()

Returns all currently active auxiliary slots along with their indexes. This is a slow operation that returns a data structure that is not backed by the frame descriptor, i.e., which does not reflect changes to the set of active auxiliary slots in either direction.

Since:

22.0

getNumberOfAuxiliarySlots

public int getNumberOfAuxiliarySlots()

Returns:

the current number of auxiliary slots in this frame descriptor

Since:

22.0

getInfo

public Object getInfo()

Returns:

the user-defined info object associated with this frame descriptor

Since:

22.1

newBuilder

public static FrameDescriptor.Builder newBuilder()

Builds a new frame descriptor with index-based frame slots.

Since:

22.0

newBuilder

public static FrameDescriptor.Builder newBuilder(int capacity)

Builds a new frame descriptor with index-based frame slots.

Parameters:

capacity - the expected number of index-based frame slots (taken as a hint when allocating internal data structures)

Since:

22.0