"Preallocate objects, so we won't count gc time." n := 1000000. objects := Array new: n streamContents: [ :stream | n timesRepeat: [ stream nextPut: Object new ] ].
set := IdentitySet new: n. Smalltalk garbageCollect. [1 to: n do: [ :i | set add: (objects at: i) ] ] timeToRun. "4949"
set := LargeIdentitySet new. Smalltalk garbageCollect. [1 to: n do: [ :i | set add: (objects at: i) ] ] timeToRun. "331"
set := (PluggableSet new: n) hashBlock: [ :object | object identityHash * 4096 + object class identityHash * 64 ]; "Change this to #basicIdentityHash in Pharo" equalBlock: [ :a :b | a == b ]; yourself. Smalltalk garbageCollect. [1 to: n do: [ :i | set add: (objects at: i) ] ] timeToRun. "5511"
I also have a LargeIdentityDictionary, which is relatively fast, but not as fast as LargeIdentitySet, because (for some unknown reason) we don't have a primitive that could support it. If we had a primitive like primitive 132 which would return the index of the element if found or 0 if not, then we could have a really fast LargeIdentityDictionary.
Eliot do you think we could provide such a primitive? Thanks
Levente
Cheers, Henry
-- Mariano http://marianopeck.wordpress.com