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.

Field Summary

Fields

Modifier and Type	Field	Description
private final LinkedHashMap<Object,Slot>	map

Constructor Summary

Constructors

Constructor	Description
HashSlotMap()

Method Summary

Modifier and Type	Method	Description
void	add(Slot newSlot)	Insert a new slot to the map.
private Slot	createSlot(Object key, int index, int attributes)
boolean	isEmpty()	Return whether the map is empty.
Iterator<Slot>	iterator()
private Object	makeKey(Object name, int index)
private Object	makeKey(Slot slot)
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.
void	remove(Object key, int index)	Remove the slot at either "key" or "index".
void	replace(Slot oldSlot, Slot newSlot)	Replace "slot" with a new slot.
int	size()	Return the size of the map.

Methods inherited from class Object

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

Methods inherited from interface Iterable

forEach, spliterator

Field Details

map

private final LinkedHashMap<Object,Slot> map

Constructor Details

HashSlotMap

public HashSlotMap()

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.

replace

public void replace(Slot oldSlot,
 Slot newSlot)

Description copied from interface: SlotMap

Replace "slot" with a new slot. This is used to change slot types.

Specified by:

replace in interface SlotMap

createSlot

private Slot createSlot(Object key,
 int index,
 int attributes)

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

remove

public void remove(Object key,
 int index)

Description copied from interface: SlotMap

Remove the slot at either "key" or "index".

Specified by:

remove 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.

iterator

public Iterator<Slot> iterator()

Specified by:

iterator in interface Iterable<Slot>

makeKey

private Object makeKey(Object name,
 int index)

makeKey

private Object makeKey(Slot slot)