org.mozilla.javascript.SlotMap Maven / Gradle / Ivy
Show all versions of rhino-runtime Show documentation
/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.javascript;
/**
* 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.
*/
public interface SlotMap extends Iterable {
/** Return the size of the map. */
int size();
/** Return whether the map is empty. */
boolean isEmpty();
/**
* 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.
*
* @param key The key for the slot, which should be a String or a Symbol.
* @param index if key is zero, then this will be used as the key instead.
* @param attributes the attributes to be set on the slot if a new slot is created. Existing
* slots will not be modified.
* @return a Slot, which will be created anew if no such slot exists.
*/
Slot modify(Object key, int index, int attributes);
/**
* Retrieve the slot at EITHER key or index, or return null if the slot cannot be found.
*
* @param key The key for the slot, which should be a String or a Symbol.
* @param index if key is zero, then this will be used as the key instead.
* @return either the Slot that matched the key and index, or null
*/
Slot query(Object key, int index);
/** Replace "slot" with a new slot. This is used to change slot types. */
void replace(Slot oldSlot, 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.
*/
void add(Slot newSlot);
/**
* Remove the slot at either "key" or "index".
*
* @param key The key for the slot, which should be a String or a Symbol.
* @param index if key is zero, then this will be used as the key instead.
*/
void remove(Object key, int index);
}