On 3 October 2010 03:13, Henrik Sperre Johansen
<henrik.s.johan...@veloxit.no> wrote:
> On 02.10.2010 19:01, Igor Stasenko wrote:
>>
>> On 2 October 2010 19:47, Stéphane Ducasse<stephane.duca...@inria.fr>
>> wrote:
>>>
>>> Hi igor
>>>
>>> do you understand why the previous definition was
>>>
>>> cachedDefinitions
>>> Definitions ifNil: [Definitions := WeakIdentityKeyDictionary new.
>>> WeakArray addWeakDependent: Definitions].
>>> ^ Definitions
>>>
>> i don't. :)
>>
>> It just a way to free memory as fast as possible.
>> But its really not worth spending so much CPU in order to save few
>> bytes of memory.
>
> Without registering the dict for finalization, the values won't ever be
> removed with the current implementation.
They are removed. After each package load/unload operation.
I don't see a reason to do this more often.
> Which can be somewhat hampering to performance once you have lots of
> nil-keyed elements all stashed from index 1 and onwards after a rehash.
>
In Pharo, weak dict knows how to reuse expired associations:
at: key put: anObject
"Set the value at key to be anObject. If key is not found, create a new
entry for key and set is value to anObject. Answer anObject."
| index element |
key isNil ifTrue:[^anObject].
index := self scanForEmpty: key.
"There should always be room."
index = 0 ifTrue: [ self error: 'No space left in dictionary' ].
element := array at: index.
element == nil
ifTrue: [self atNewIndex: index put: (WeakKeyAssociation key:
key
value: anObject)]
ifFalse: [
element expired ifTrue: [ tally := tally + 1].
element key: key.
element value: anObject.
self fullCheck.
].
^ anObject
> Cheers,
> Henry
>
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--
Best regards,
Igor Stasenko AKA sig.
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