[Vm-dev] Re: SmallInetger as methods was not ready yet....now
siguctua at gmail.com
Sat Dec 4 05:12:20 UTC 2010
On 4 December 2010 02:21, Andreas Raab <andreas.raab at gmx.de> wrote:
> On 12/3/2010 4:18 PM, Eliot Miranda wrote:
>> BTW, Mariano's use of SmallIntegers rather than wrappers is an attempt
>> to get a very compact image and seems a reasonable experiment. Using
>> wrappers would defeat his use-as-little-memory-as-possible purpose.
> Not at all. The design of objects-as-methods was deliberately done such that
> one could use a single wrapper for multiple methods. The only thing you need
> is to map from selector to method being executed. For example:
> MethodSwapper>>run: aSelector with: argsArray in: aReceiver
> "Execute the given method"
> method:= methodMap at: aSelector.
> ^aReceiver withArgs: argsArray executeMethod: method
> Then you install a single MethodSwapper instance like here:
> swapper := MethodSwapper new.
> Morph selectorsAndMethodsDo:[:sel :meth| swapper methodMap at: sel put:
> Morph selectorsDo:[:sel| Morph addSelector: sel withMethod: swapper].
> At this point the only overhead you have is what's in the (single)
> MethodSwapper instance and even with a most naive implementation (looking up
> the index by selector) you'd have 8 bytes per method in your image which I
> suspect is well below 5% of the image size.
> And then of course you can start *really* looking at getting the size down.
> Did you know that Dan once did a very neat hack where he replaced all
> symbols with integers? Works great and if you do that you not only reclaim
> the space for the symbols but also don't need a lookup at all :-)
don't need a lookup? how?
you still have a method dictionaries, and keys there are not ordered
nor sequential ( yes, you can make selectors in a single class
to be sequential , like 1 , 2 ,3 ,4 , then you don't need to do a
lookup for a single given class, but for the rest of classes which
obviously contain different set of selectors, you won't be able to do
> - Andreas
Igor Stasenko AKA sig.
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