Shape

java.lang.Object
- com.oracle.truffle.api.object.Shape

```
public abstract class Shape
extends Object
```
Shape objects create a mapping of Property objects to Locations. Shapes are immutable; adding or deleting a property yields a new Shape which links to the old one. This allows inline caching to simply check the identity of an object's Shape to determine if the cache is valid. There is one exception to this immutability, the transition map, but that is used simply to assure that an identical series of property additions and deletions will yield the same Shape object.

Since:

0.8 or earlier

See Also:

DynamicObject, Property, Location

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`Shape.Allocator` Utility class to allocate locations in an object layout.
`static interface`	`Shape.Pred<T>` Represents a predicate (boolean-valued function) of one argument.

Constructor Summary

Constructors
Modifier Constructor and Description

protected Shape()
Constructor for subclasses.

Constructors
Modifier	Constructor and Description
`protected`	`Shape()` Constructor for subclasses.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`abstract Shape`	`addProperty(Property property)` Add a new property in the map, yielding a new or cached Shape object.
`abstract Shape.Allocator`	`allocator()` Obtain an `Shape.Allocator` instance for the purpose of allocating locations.
`abstract Shape`	`append(Property oldProperty)` Append the property, relocating it to the next allocated location.
`abstract Shape`	`changeType(ObjectType newOps)` Change the shape's type, yielding a new shape.
`abstract boolean`	`check(DynamicObject subject)` Check whether this shape is identical to the given shape.
`abstract DynamicObjectFactory`	`createFactory()` Create a `DynamicObjectFactory` for creating instances of this shape.
`abstract Shape`	`createSeparateShape(Object sharedData)` Clone off a separate shape with new shared data.
`abstract Shape`	`defineProperty(Object key, Object value, int flags)` Add or change property in the map, yielding a new or cached Shape object.
`abstract Shape`	`defineProperty(Object key, Object value, int flags, LocationFactory locationFactory)` Add or change property in the map, yielding a new or cached Shape object.
`abstract int`	`getId()`
`abstract List<Object>`	`getKeyList()` Get a list of all property keys in insertion order.
`abstract List<Object>`	`getKeyList(Shape.Pred<Property> filter)` Get a filtered list of property keys in insertion order.
`abstract Iterable<Object>`	`getKeys()` Get all property keys in insertion order.
`abstract Property`	`getLastProperty()` Get the last added property.
`abstract Layout`	`getLayout()` Get the shape's layout.
`abstract Assumption`	`getLeafAssumption()` Get an assumption that the shape is a leaf.
`abstract Object`	`getMutex()` Get mutex object shared by related shapes, i.e.
`abstract ObjectType`	`getObjectType()` Get the shape's operations.
`abstract Shape`	`getParent()`
`abstract Iterable<Property>`	`getProperties()` An `Iterable` over the shape's properties in insertion order.
`abstract Property`	`getProperty(Object key)` Get a property entry by key.
`abstract int`	`getPropertyCount()` Get number of properties in this shape.
`abstract List<Property>`	`getPropertyList()` Get a list of all properties that this Shape stores.
`abstract List<Property>`	`getPropertyList(Shape.Pred<Property> filter)` Get a list of properties that this Shape stores.
`abstract List<Property>`	`getPropertyListInternal(boolean ascending)` Returns all (also hidden) property objects in this shape.
`abstract Shape`	`getRoot()` Get the root shape.
`abstract Object`	`getSharedData()` Get the shape's shared data.
`abstract Assumption`	`getValidAssumption()` Get an assumption that the shape is valid.
`abstract boolean`	`hasProperty(Object key)` Check whether the shape has a property with the given key.
`abstract boolean`	`hasTransitionWithKey(Object key)` Query whether the shape has a transition with the given key.
`abstract boolean`	`isLeaf()` Check whether this shape is a leaf in the transition graph, i.e.
`abstract boolean`	`isRelated(Shape other)` Are these two shapes related, i.e.
`boolean`	`isShared()` Whether this shape is `shared`.
`abstract boolean`	`isValid()` Check whether this shape is valid.
`Shape`	`makeSharedShape()` Make a shared variant of this shape, to allow safe usage of this object between threads.
`abstract DynamicObject`	`newInstance()` Create a new `DynamicObject` instance with this shape.
`abstract Shape`	`removeProperty(Property property)` Remove the given property from the shape.
`abstract Shape`	`replaceProperty(Property oldProperty, Property newProperty)` Replace a property in the shape.
`abstract Shape`	`reservePrimitiveExtensionArray()` Reserve the primitive extension array field.
`abstract Shape`	`tryMerge(Shape other)` Try to merge two related shapes to a more general shape that has the same properties and can store at least the values of both shapes.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - Shape
```
protected Shape()
```
    Constructor for subclasses.
    
    Since:
    
    0.8 or earlier
- Method Detail
  - getProperty
```
public abstract Property getProperty(Object key)
```
    Get a property entry by key.
    
    Parameters:
    
    key - the identifier to look up
    
    Returns:
    
    a Property object, or null if not found
    
    Since:
    
    0.8 or earlier
  - addProperty
```
public abstract Shape addProperty(Property property)
```
    Add a new property in the map, yielding a new or cached Shape object.
    
    Parameters:
    
    property - the property to add
    
    Returns:
    
    the new Shape
    
    Since:
    
    0.8 or earlier
  - defineProperty
```
public abstract Shape defineProperty(Object key,
                                     Object value,
                                     int flags)
```
    Add or change property in the map, yielding a new or cached Shape object.
    
    Returns:
    
    the shape after defining the property
    
    Since:
    
    0.8 or earlier
  - defineProperty
```
public abstract Shape defineProperty(Object key,
                                     Object value,
                                     int flags,
                                     LocationFactory locationFactory)
```
    Add or change property in the map, yielding a new or cached Shape object.
    
    Returns:
    
    the shape after defining the property
    
    Since:
    
    0.8 or earlier
  - getProperties
```
public abstract Iterable<Property> getProperties()
```
    An Iterable over the shape's properties in insertion order.
    
    Since:
    
    0.8 or earlier
  - getPropertyList
```
public abstract List<Property> getPropertyList(Shape.Pred<Property> filter)
```
    Get a list of properties that this Shape stores.
    
    Returns:
    
    list of properties
    
    Since:
    
    0.8 or earlier
  - getPropertyList
```
public abstract List<Property> getPropertyList()
```
    Get a list of all properties that this Shape stores.
    
    Returns:
    
    list of properties
    
    Since:
    
    0.8 or earlier
  - getPropertyListInternal
```
public abstract List<Property> getPropertyListInternal(boolean ascending)
```
    Returns all (also hidden) property objects in this shape.
    
    Parameters:
    
    ascending - desired order (true for insertion order, false for reverse insertion order)
    
    Since:
    
    0.8 or earlier
  - getKeyList
```
public abstract List<Object> getKeyList(Shape.Pred<Property> filter)
```
    Get a filtered list of property keys in insertion order.
    
    Since:
    
    0.8 or earlier
  - getKeyList
```
public abstract List<Object> getKeyList()
```
    Get a list of all property keys in insertion order.
    
    Since:
    
    0.8 or earlier
  - getKeys
```
public abstract Iterable<Object> getKeys()
```
    Get all property keys in insertion order.
    
    Since:
    
    0.8 or earlier
  - getValidAssumption
```
public abstract Assumption getValidAssumption()
```
    Get an assumption that the shape is valid.
    
    Since:
    
    0.8 or earlier
  - isValid
```
public abstract boolean isValid()
```
    Check whether this shape is valid.
    
    Since:
    
    0.8 or earlier
  - getLeafAssumption
```
public abstract Assumption getLeafAssumption()
```
    Get an assumption that the shape is a leaf.
    
    Since:
    
    0.8 or earlier
  - isLeaf
```
public abstract boolean isLeaf()
```
    Check whether this shape is a leaf in the transition graph, i.e. transitionless.
    
    Since:
    
    0.8 or earlier
  - getParent
```
public abstract Shape getParent()
```
    Returns:
    
    the parent shape or null if none.
    
    Since:
    
    0.8 or earlier
  - hasProperty
```
public abstract boolean hasProperty(Object key)
```
    Check whether the shape has a property with the given key.
    
    Since:
    
    0.8 or earlier
  - removeProperty
```
public abstract Shape removeProperty(Property property)
```
    Remove the given property from the shape.
    
    Since:
    
    0.8 or earlier
  - replaceProperty
```
public abstract Shape replaceProperty(Property oldProperty,
                                      Property newProperty)
```
    Replace a property in the shape.
    
    Since:
    
    0.8 or earlier
  - getLastProperty
```
public abstract Property getLastProperty()
```
    Get the last added property.
    
    Since:
    
    0.8 or earlier
  - getId
```
public abstract int getId()
```
    Since:
    
    0.8 or earlier
  - append
```
public abstract Shape append(Property oldProperty)
```
    Append the property, relocating it to the next allocated location.
    
    Since:
    
    0.8 or earlier
  - allocator
```
public abstract Shape.Allocator allocator()
```
    Obtain an Shape.Allocator instance for the purpose of allocating locations.
    
    Since:
    
    0.8 or earlier
  - getPropertyCount
```
public abstract int getPropertyCount()
```
    Get number of properties in this shape.
    
    Since:
    
    0.8 or earlier
  - getObjectType
```
public abstract ObjectType getObjectType()
```
    Get the shape's operations.
    
    Since:
    
    0.8 or earlier
  - getRoot
```
public abstract Shape getRoot()
```
    Get the root shape.
    
    Since:
    
    0.8 or earlier
  - check
```
public abstract boolean check(DynamicObject subject)
```
    Check whether this shape is identical to the given shape.
    
    Since:
    
    0.8 or earlier
  - getLayout
```
public abstract Layout getLayout()
```
    Get the shape's layout.
    
    Since:
    
    0.8 or earlier
  - getSharedData
```
public abstract Object getSharedData()
```
    Get the shape's shared data.
    
    Since:
    
    0.8 or earlier
  - hasTransitionWithKey
```
public abstract boolean hasTransitionWithKey(Object key)
```
    Query whether the shape has a transition with the given key.
    
    Since:
    
    0.8 or earlier
  - createSeparateShape
```
public abstract Shape createSeparateShape(Object sharedData)
```
    Clone off a separate shape with new shared data.
    
    Since:
    
    0.8 or earlier
  - changeType
```
public abstract Shape changeType(ObjectType newOps)
```
    Change the shape's type, yielding a new shape.
    
    Since:
    
    0.8 or earlier
  - reservePrimitiveExtensionArray
```
public abstract Shape reservePrimitiveExtensionArray()
```
    Reserve the primitive extension array field.
    
    Since:
    
    0.8 or earlier
  - newInstance
```
public abstract DynamicObject newInstance()
```
    Create a new DynamicObject instance with this shape.
    
    Since:
    
    0.8 or earlier
  - createFactory
```
public abstract DynamicObjectFactory createFactory()
```
    Create a DynamicObjectFactory for creating instances of this shape.
    
    Since:
    
    0.8 or earlier
  - getMutex
```
public abstract Object getMutex()
```
    Get mutex object shared by related shapes, i.e. shapes with a common root.
    
    Since:
    
    0.8 or earlier
  - isRelated
```
public abstract boolean isRelated(Shape other)
```
    Are these two shapes related, i.e. do they have the same root?
    
    Parameters:
    
    other - Shape to compare to
    
    Returns:
    
    true if one shape is an upcast of the other, or the Shapes are equal
    
    Since:
    
    0.8 or earlier
  - tryMerge
```
public abstract Shape tryMerge(Shape other)
```
    Try to merge two related shapes to a more general shape that has the same properties and can store at least the values of both shapes.
    
    Returns:
    
    this, other, or a new shape that is compatible with both shapes
    
    Since:
    
    0.8 or earlier
  - isShared
```
public boolean isShared()
```
    Whether this shape is shared.
    
    Since:
    
    0.18
  - makeSharedShape
```
public Shape makeSharedShape()
```
    Make a shared variant of this shape, to allow safe usage of this object between threads. Shared shapes will not reuse storage locations for other fields. In combination with careful synchronization on writes, this can prevent reading out-of-thin-air values.
    
    Returns:
    
    a cached and shared variant of this shape
    
    Since:
    
    0.18

Class Shape

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Shape

Method Detail

getProperty

addProperty

defineProperty

defineProperty

getProperties

getPropertyList

getPropertyList

getPropertyListInternal

getKeyList

getKeyList

getKeys

getValidAssumption

isValid

getLeafAssumption

isLeaf

getParent

hasProperty

removeProperty

replaceProperty

getLastProperty

getId

append

allocator

getPropertyCount

getObjectType

getRoot

check

getLayout

getSharedData

hasTransitionWithKey

createSeparateShape

changeType

reservePrimitiveExtensionArray

newInstance

createFactory

getMutex

isRelated

tryMerge

isShared

makeSharedShape