"{ Encoding: utf8 }"
"
COPYRIGHT (c) 1997 by Claus Gittinger
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.
"
"{ Package: 'stx:libbasic' }"
"{ NameSpace: Smalltalk }"
WeakIdentityDictionary subclass:#WeakDependencyDictionary
instanceVariableNames:''
classVariableNames:''
poolDictionaries:''
category:'Collections-Weak'
!
!WeakDependencyDictionary class methodsFor:'documentation'!
copyright
"
COPYRIGHT (c) 1997 by Claus Gittinger
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.
"
!
documentation
"
A specialized WeakIdentityDictionary, which 'knowns' how
to get rid of obsolete entries. This is only used with the
dependency mechanism.
[author:]
Claus Gittinger
[See also:]
WeakArray WeakIdentityDictionary WeakValueDictionary WeakIdentitySet
"
! !
!WeakDependencyDictionary methodsFor:'private'!
keyContainerOfSize:n
"return a container for keys of size n.
use WeakArrays here, but don't make me a dependent of it."
^ WeakArray new:n.
"Modified: / 07-01-1997 / 17:01:15 / stefan"
"Modified: / 04-08-2012 / 14:55:53 / cg"
! !
!WeakDependencyDictionary methodsFor:'special dependency support'!
removeEmptyDependencyValues
"special entry for dependency management:
remove any empty (due to finalization) value WeakArray elements."
|index t wasBlocked deps o key originalKeyArray|
"/ careful: this is sent by the finalizer at low prio.
"/ be prepared for the receiver to change while we walk over
"/ the value array here ...
"/ 'removeEmptyDependencyValues ...' printCR.
originalKeyArray := keyArray.
index := 1.
[index <= keyArray size] whileTrue:[
"/ get the size again - it could have changed
wasBlocked := OperatingSystem blockInterrupts.
keyArray ~~ originalKeyArray ifTrue:[
index := 1. "/ start over
"/ 'restart removeEmpty' infoPrintCR.
originalKeyArray := keyArray.
].
index <= keyArray size ifTrue:[
key := keyArray basicAt:index.
key class == SmallInteger ifTrue:[
"/ that one is gone
key := DeletedEntry.
keyArray basicAt:index put:key.
valueArray basicAt:index put:nil.
tally := tally - 1.
].
(key notNil and:[key ~~ DeletedEntry]) ifTrue:[
deps := valueArray basicAt:index.
deps notNil ifTrue:[
"/ is it an empty WeakArray ?
(deps isMemberOf:WeakArray) ifTrue:[
t := deps findFirst:[:el | el notNil and:[el ~~ 0]].
t == 0 ifTrue:[
"/ yes - nil it
valueArray basicAt:index put:nil.
keyArray basicAt:index put:DeletedEntry.
tally := tally - 1.
]
] ifFalse:[
"/ is it an empty WeakIdSet ?
(deps isMemberOf:WeakIdentitySet) ifTrue:[
(t := deps size) == 0 ifTrue:[
"/ yes - nil it
valueArray basicAt:index put:nil.
keyArray basicAt:index put:DeletedEntry.
tally := tally - 1.
"/ ] ifFalse:[
"/ t == 1 ifTrue:[
"/ "/ careful - it could actually be empty
"/ o := deps firstIfEmpty:nil.
"/ o notNil ifTrue:[
"/ "/ the set lost an object, and shrunk to size 1
"/ "/ can now use a WeakArray
"/ valueArray basicAt:index put:(WeakArray with:o)
"/ ] ifFalse:[
"/ key notNil ifTrue:[
"/ keyArray basicAt:index put:DeletedEntry.
"/ tally := tally - 1.
"/ ]
"/ ]
"/ ]
]
]
]
] ifFalse:[
"/ 'oops: nil value for key' infoPrint. key infoPrintCR.
keyArray basicAt:index put:DeletedEntry.
tally := tally - 1.
]
]
].
wasBlocked ifFalse:[OperatingSystem unblockInterrupts].
index := index + 1.
].
"/ 'done' printCR.
"
Dependencies removeEmptyDependencyValues
"
"Created: 9.1.1997 / 00:00:28 / cg"
"Modified: 27.3.1997 / 15:55:12 / cg"
! !
!WeakDependencyDictionary class methodsFor:'documentation'!
version
^ '$Header$'
! !