Class: WeakValueIdentityDictionary

• Inheritance
• Description
• Instance protocol
  • adding & removing
  • element disposal
  • private
  • queries
  • testing

Inheritance:

   Object
   |
   +--Collection
      |
      +--Set
         |
         +--Dictionary
            |
            +--IdentityDictionary
               |
               +--WeakValueIdentityDictionary

Package:

stx:libbasic

Category:

Collections-Weak

Version:

rev: 1.11 date: 2022/01/17 11:27:32

user: stefan

file: WeakValueIdentityDictionary.st directory: libbasic

module: stx stc-classLibrary: libbasic

Description:

WeakValueIdentityDictionaries behave like IdentityDictionaries, 
as long as the values are still referenced by some 
other (non-weak) object.
However, once the last non-weak reference ceases to exist,
the Dictionary will return nil for the value at position key.
(with some delay: it will be removed after the next garbage collect).

copyright
COPYRIGHT (c) 1999 by eXept Software AG
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

Instance protocol:

 at: key put: anObject

add the argument anObject under key, aKey to the receiver.
Return anObject (sigh).
Redefined to block interrupts, to avoid trouble when dependencies
are added within interrupting high prio processes.

 removeKey: aKey ifAbsent: aBlock

remove the association under aKey from the collection,
return the value previously stored there.
If it was not in the collection return the result
from evaluating aBlock.

Redefined to avoid synchronization problems, in case
of interrupts (otherwise, there could be some other operation
on the receiver done by another process, which garbles my contents).

 removeValue: aKey ifAbsent: aBlock

remove the association under aValue from the collection,
return the key previously stored there.
If it was not in the collection return the result
from evaluating aBlock.

Redefined to avoid synchronization problems, in case
of interrupts (otherwise, there could be some other operation
on the receiver done by another process, which garbles my contents).

 update: something with: aParameter from: changedObject

an element (either key or value) died - clear out slots for
disposed keys.

 valueContainerOfSize: n

return a container for values of size n.
use WeakArrays here.

 includes: anObject

redefined to block interrupts
(avoid change of the dictionary while accessing)

 includesKey: key

redefined to block interrupts
(avoid change of the dictionary while accessing)

 isWeak

return true if the receiver has weak references to its elements.

 isWeakCollection

return true, if the receiver has weak references to its elements.