0001632: [ENH] BehaviorHashEnh

Notes
(0002207 - 56 - 78 - 78 - 78 - 78 - 78) KenCausey 08-08-05 21:54	karl.ramberg@chello.se: "[er][et][sm][cd] looks good"

(0002208 - 841 - 1484 - 1484 - 1484 - 1484 - 1484) KenCausey 08-08-05 21:56	ducasse@iam.unibe.ch: "can somebody else have a look at this enh. I run the "tests" \| allClasses allClassesSet block \| allClasses := Smalltalk allClasses. block _ [allClassesSet _ allClasses asSet. [allClasses do: [:class \| allClassesSet remove: class]] timeToRun]. {block value. block value. block value} before and after filing in this cs. To see the problem again just doIt \| allClasses allClassesSet block \| allClasses := Smalltalk allClasses. block _ [allClassesSet _ allClasses asIdentitySet. [allClasses do: [:class \| allClassesSet remove: class]] timeToRun]. {block value. block value. block value}. after loading I got -> #(64 57 63) To see the problem again just doIt -> #(34 33 39) So I'm confused because I thought this would be the opposite so I may be too tired."

(0002209 - 429 - 683 - 725 - 725 - 725 - 725) KenCausey 08-08-05 21:57	=?ISO-8859-1?Q?st=E9phane_ducasse?= <ducasse@iam.unibe.ch>: "with 3.8 6273 I get \| allClasses allClassesSet block \| allClasses := Smalltalk allClasses. block _ [allClassesSet _ allClasses asSet. [allClasses do: [:class \| allClassesSet remove: class]] timeToRun]. {block value. block value. block value} #(51 48 53) and nearly the same in 6208 Stef could you check because something certainly changed."

(0002210 - 3944 - 5797 - 5831 - 5831 - 5831 - 5831) KenCausey 08-08-05 22:00	Stephan Rudlof <sr@evolgo.de>: "now I've tested with Squeak3.8alpha #6285: and the results remain the same for me as for Squeak3.7! With fileIn of the cs or doIt of the postscript in the cs directly: always the same. I don't understand your results. Please give me your results exactly as I've done them below (two doIts before and two other ones after fileIn of the cs, the first and second doIt (of the two) are different!). I have tried to be very explicit in my explanations, sine I just have the idea that we are testing different things. Any other takers? My results: first doIt \| allClasses allClassesSet block \| allClasses := Smalltalk allClasses. block _ [allClassesSet _ allClasses asSet. [allClasses do: [:class \| allClassesSet remove: class]] timeToRun]. {block value. block value. block value} #(6840 6863 6823) #(6988 6907 6862) "before" #(199 204 200) #(203 219 206) "after fileIn" second doIt \| allClasses allClassesSet block \| allClasses := Smalltalk allClasses. block _ [allClassesSet _ allClasses asIdentitySet. [allClasses do: [:class \| allClassesSet remove: class]] timeToRun]. {block value. block value. block value}. #(3112 3166 3108) #(3152 3160 3129) "before" #(3196 3225 3186) #(3193 3181 3163) "after fileIn" My cs has been (you can also doIt the postscript manually): 'From Squeak3.7beta of ''1 April 2004'' [latest update: #5963] on 22 June 2004 at 8:51:57 pm'! "Change Set: BehaviorHashEnh v1.1 Date: 22 June 2004 Author: Stephan Rudlof Improves the default Object>>hash for Behaviors by installing Behavior>>hash. String>>hash has been changed a little to avoid infinite recursion (without changing its semantics). All is done in the postscript. Important ----------- This is a special changeset: Do not export and import this changeset again after importing it the first time!! Then the methods are not installed alone in the postscript anymore, leading to serious problems!! ----------- Rationale: Object>>hash calling ProtoObject>>identityHash gives poor results for Behaviors. Therefore a new Behavior>>hash using Symbol>>hash or String>>hash (the latter slightly changed to avoide infinite recursion) will be installed. Consequences: - It speeds up Set/Dictionary operations with Behaviors a lot (see below). - The main consequence for other objects as Behaviors seems to be a changed hash if they use self species hash as a start value for computing their hash. But AFAICS this doesn't hurt, since in most cases (non meta classes as species) it maps to Symbol>>hash, which is fast. Test: doIt \| allClasses allClassesSet block \| allClasses := Smalltalk allClasses. block _ [allClassesSet _ allClasses asSet. [allClasses do: [:class \| allClassesSet remove: class]] timeToRun]. {block value. block value. block value} before and after filing in this cs. To see the problem again just doIt \| allClasses allClassesSet block \| allClasses := Smalltalk allClasses. block _ [allClassesSet _ allClasses asIdentitySet. [allClasses do: [:class \| allClassesSet remove: class]] timeToRun]. {block value. block value. block value}. Future: Best would probably be a better identityHash with more bits (possibly in V4?). PS: I've been stumbled over BrowserEnvironmentTest>>testAllClassesDo, which is dog slow without this cs. History -------- - v1.1: changed cs comment - without v no: original version --------"! "Postscript: Compile String and Behavior >>hash here, since compilation has to be tight together with rehashing Sets possibly containing objects with changed >>hash." String compile: 'hash "#hash is implemented, because #= is implemented" ^ByteArray hashBytes: self startingWith: self species identityHash'. Set quickRehashAllSets. Behavior compile: 'hash ^ self name hash'. Set quickRehashAllSets. !"

(0002211 - 82 - 82 - 82 - 82 - 82 - 82) KenCausey 08-08-05 22:02	I loaded this changeset in 3.8-6665-basic without errors but did not test further.

(0003883 - 13 - 13 - 13 - 13 - 13 - 13) MarcusDenker 02-16-06 17:40	added to 3.9a

Issue History
Date Modified	Username	Field	Change
08-08-05 21:53	KenCausey	New Issue
08-08-05 21:53	KenCausey	File Added: BehaviorHashEnh.cs.gz
08-08-05 21:54	KenCausey	Note Added: 0002207
08-08-05 21:56	KenCausey	Note Added: 0002208
08-08-05 21:57	KenCausey	Note Added: 0002209
08-08-05 22:00	KenCausey	Note Added: 0002210
08-08-05 22:02	KenCausey	Note Added: 0002211
01-22-06 12:35	pmm	Issue Monitored: pmm
02-16-06 17:40	MarcusDenker	Status	new => closed
02-16-06 17:40	MarcusDenker	Note Added: 0003883
02-16-06 17:40	MarcusDenker	Resolution	open => fixed
02-16-06 17:40	MarcusDenker	Fixed in Version	=> 3.9

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