Package org.mozilla.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
    Description
    static interface 
    SlotMap.SlotComputer<S extends Slot>
     

  • 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> 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 Details

    • 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.