The Trunk: Collections-fbs.544.mcz

Frank Shearar uploaded a new version of Collections to project The Trunk:
http://source.squeak.org/trunk/Collections-fbs.544.mcz

==================== Summary ====================

Name: Collections-fbs.544
Author: fbs
Time: 24 November 2013, 12:47:44.329 pm
UUID: 15771139-bae8-3347-8d63-a02d324e1e48
Ancestors: Collections-nice.543

Move LRUCache from System to Collections, because that's a more sensible home.

This also has the nice property that it breaks the Balloon->System dependency.

=============== Diff against Collections-nice.543 ===============

Item was changed:
  SystemOrganization addCategory: #'Collections-Abstract'!
  SystemOrganization addCategory: #'Collections-Arrayed'!
+ SystemOrganization addCategory: #'Collections-Cache'!
  SystemOrganization addCategory: #'Collections-Exceptions'!
  SystemOrganization addCategory: #'Collections-Sequenceable'!
  SystemOrganization addCategory: #'Collections-Stack'!
  SystemOrganization addCategory: #'Collections-Streams'!
  SystemOrganization addCategory: #'Collections-Strings'!
  SystemOrganization addCategory: #'Collections-Support'!
  SystemOrganization addCategory: #'Collections-Text'!
  SystemOrganization addCategory: #'Collections-Unordered'!
  SystemOrganization addCategory: #'Collections-Weak'!

Item was added:
+ Object subclass: #LRUCache
+ instanceVariableNames: 'size factory calls hits values'
+ classVariableNames: ''
+ poolDictionaries: ''
+ category: 'Collections-Cache'!
+
+ !LRUCache commentStamp: '<historical>' prior: 0!
+ I'm a cache of values, given a key I return a Value from the cache or from the factory!

Item was added:
+ ----- Method: LRUCache class>>size:factory: (in category 'instance creation') -----
+ size: aNumber factory: aBlock
+ "answer an instance of the receiver"
+ ^ self new initializeSize: aNumber factory: aBlock!

Item was added:
+ ----- Method: LRUCache class>>test (in category 'testing') -----
+ test
+ "
+ LRUCache test
+ "
+ | c |
+ c := LRUCache
+ size: 5
+ factory: [:key | key * 2].
+ c at: 1.
+ c at: 2.
+ c at: 3.
+ c at: 4.
+ c at: 1.
+ c at: 5.
+ c at: 6.
+ c at: 7.
+ c at: 8.
+ c at: 1.
+ ^ c!

Item was added:
+ ----- Method: LRUCache class>>test2 (in category 'testing') -----
+ test2
+ "
+ LRUCache test2.  
+ Time millisecondsToRun:[LRUCache test2].
+ MessageTally spyOn:[LRUCache test2].  
+ "
+ | c |
+ c := LRUCache
+ size: 600
+ factory: [:key | key * 2].
+ 1
+ to: 6000
+ do: [:each | c at: each].
+ ^ c!

Item was added:
+ ----- Method: LRUCache>>at: (in category 'accessing') -----
+ at: aKey
+ "answer the object for aKey, if not present in the cache creates it"
+ | element keyHash |
+ calls := calls + 1.
+ keyHash := aKey hash.
+ 1
+ to: size
+ do: [:index |
+ element := values at: index.
+ (keyHash
+ = (element at: 2)
+ and: [aKey
+ = (element at: 1)])
+ ifTrue: ["Found!!"
+ hits := hits + 1.
+ values
+ replaceFrom: 2
+ to: index
+ with: (values first: index - 1).
+ values at: 1 put: element.
+ ^ element at: 3]].
+ "Not found!!"
+ element := {aKey. keyHash. factory value: aKey}.
+ values
+ replaceFrom: 2
+ to: size
+ with: values allButLast.
+ values at: 1 put: element.
+ ^ element at: 3!

Item was added:
+ ----- Method: LRUCache>>initializeSize:factory: (in category 'initialization') -----
+ initializeSize: aNumber factory: aBlock
+ "initialize the receiver's size and factory"
+ size := aNumber.
+ values := Array new: aNumber withAll: {nil. nil. nil}.
+ factory := aBlock.
+ calls := 0.
+ hits := 0!

Item was added:
+ ----- Method: LRUCache>>printOn: (in category 'printing') -----
+ printOn: aStream
+ "Append to the argument, aStream, a sequence of characters
+ that identifies the receiver."
+ aStream nextPutAll: self class name;
+ nextPutAll: ' size:';
+ nextPutAll: size asString;
+ nextPutAll: ', calls:';
+ nextPutAll: calls asString;
+ nextPutAll: ', hits:';
+ nextPutAll: hits asString;
+ nextPutAll: ', ratio:';
+ nextPutAll: ((hits isNumber and: [calls isNumber and: [calls ~= 0]])
+ ifTrue: [hits / calls]
+ ifFalse: [0]) asFloat asString!