Package org.mozilla.javascript

Class HashSlotMap

java.lang.Object

org.mozilla.javascript.HashSlotMap

All Implemented Interfaces:

Iterable<Slot>, SlotMap

public class HashSlotMap
extends Object
implements SlotMap

This class implements the SlotMap interface using a java.util.HashMap. This class has more overhead than EmbeddedSlotMap, especially because it puts each "Slot" inside an intermediate object. However it is much more resistant to large number of hash collisions than EmbeddedSlotMap and therefore we use this implementation when an object gains a large number of properties.

Nested Class Summary

Nested classes/interfaces inherited from interface org.mozilla.javascript.SlotMap

SlotMap.SlotComputer<S extends Slot>

Constructor Summary

Constructors

Constructor	Description
HashSlotMap()
HashSlotMap(SlotMap oldMap)

Method Summary

Modifier and Type	Method	Description
void	add(Slot newSlot)	Insert a new slot to the map.
<S extends Slot> S	compute(Object key, int index, SlotMap.SlotComputer<S> c)	Replace the value of key with the slot computed by the "compute" method.
boolean	isEmpty()	Return whether the map is empty.
Iterator<Slot>	iterator()
Slot	modify(Object key, int index, int attributes)	Return the Slot that matches EITHER "key" or "index".
Slot	query(Object key, int index)	Retrieve the slot at EITHER key or index, or return null if the slot cannot be found.
int	size()	Return the size of the map.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Details

HashSlotMap

public HashSlotMap()

HashSlotMap

public HashSlotMap(SlotMap oldMap)

Method Details

size

public int size()

Description copied from interface: SlotMap

Return the size of the map.

Specified by:

size in interface SlotMap

isEmpty

public boolean isEmpty()

Description copied from interface: SlotMap

Return whether the map is empty.

Specified by:

isEmpty in interface SlotMap

query

public Slot query(Object key,
 int index)

Description copied from interface: SlotMap

Retrieve the slot at EITHER key or index, or return null if the slot cannot be found.

Specified by:

query in interface SlotMap

Parameters:

key - The key for the slot, which should be a String or a Symbol.

index - if key is zero, then this will be used as the key instead.

Returns:

either the Slot that matched the key and index, or null

modify

public Slot modify(Object key,
 int index,
 int attributes)

Description copied from interface: SlotMap

Return the Slot that matches EITHER "key" or "index". (It will use "key" if it is not null, and otherwise "index".) If no slot exists, then create a default slot class.

Specified by:

modify in interface SlotMap

Parameters:

key - The key for the slot, which should be a String or a Symbol.

index - if key is zero, then this will be used as the key instead.

attributes - the attributes to be set on the slot if a new slot is created. Existing slots will not be modified.

Returns:

a Slot, which will be created anew if no such slot exists.

compute

public <S extends Slot> S compute(Object key,
 int index,
 SlotMap.SlotComputer<S> c)

Description copied from interface: SlotMap

Replace the value of key with the slot computed by the "compute" method. If "compute" throws an exception, make no change. If "compute" returns null, remove the mapping, otherwise, replace any existing mapping with the result of "compute", and create a new mapping if none exists. This is equivalent to the "compute" method on the Map interface, which simplifies code and is more efficient than making multiple calls to this interface. In order to allow use of multiple Slot subclasses, this function is templatized.

Specified by:

compute in interface SlotMap

add

public void add(Slot newSlot)

Description copied from interface: SlotMap

Insert a new slot to the map. Both "name" and "indexOrHash" must be populated. Note that ScriptableObject generally adds slots via the "modify" method.

Specified by:

add in interface SlotMap

iterator

public Iterator<Slot> iterator()

Specified by:

iterator in interface Iterable<Slot>