org.htmlunit.corejs.javascript

Interface SlotMap

All Superinterfaces:

Iterable<Slot>

All Known Implementing Classes:

EmbeddedSlotMap, HashSlotMap

public interface SlotMap
extends Iterable<Slot>

A SlotMap is an interface to the main data structure that contains all the "Slots" that back a ScriptableObject. It is the primary property map in Rhino. It is Iterable but does not implement java.util.Map because that comes with a bunch of overhead that we do not need.

This class generally has a bit of a strange interface, and its interactions with ScriptableObject are complex. Many attempts to make this interface more elegant have resulted in substantial performance regressions so we are doing the best that we can.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	SlotMap.SlotComputer<S extends Slot>

Method Summary

Modifier and Type	Method and Description
void	add(Slot newSlot) Insert a new slot to the map.
<S extends Slot> S	compute(Object key, int index, SlotMap.SlotComputer<S> compute) Replace the value of key with the slot computed by the "compute" method.
boolean	isEmpty() Return whether the map is empty.
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 interface java.lang.Iterable

forEach, iterator, spliterator

Method Detail

size

int size()

Return the size of the map.

isEmpty

boolean isEmpty()

Return whether the map is empty.

modify

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

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.

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.

query

Slot query(Object key,
           int index)

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

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

compute

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

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.

add

void add(Slot newSlot)

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