Issue 3232 in pharo: SharedQueue code simplication

Status: FixedWaitingToBePharoed
Owner: stephane.ducasse
Labels: Type-Squeak

New issue 3232 by stephane.ducasse: SharedQueue code simplication
http://code.google.com/p/pharo/issues/detail?id=3232

We should really review carefully this changes


A new version of Collections was added to project The Inbox:
http://source.squeak.org/inbox/Collections-ul.404.mcz

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

Name: Collections-ul.404
Author: ul
Time: 7 November 2010, 4:52:11.401 am
UUID: 2e0defd1-6e46-7243-be6f-b571c6805ae4
Ancestors: Collections-ul.403

- simplified SharedQueue >> #makeRoomAtEnd
- enhanced SharedQueue >> #peek

=============== Diff against Collections-ul.403 ===============

Item was changed:
  ----- Method: SharedQueue>>makeRoomAtEnd (in category 'private') -----
  makeRoomAtEnd

+       | contentsSize newContentsArray |
-       | contentsSize |
        contentsSize := writePosition - readPosition.
+       newContentsArray := contentsSize * 2 > contentsArray size
+               ifTrue: [ contentsArray class new: contentsArray size * 2 ]
-       contentsSize * 2 > contentsArray size
-               ifTrue: [
-                       "grow"
-                       contentsArray := (contentsArray class new:  
contentsArray size * 2)
-                               replaceFrom: 1
-                               to: contentsSize
-                               with: contentsArray
-                               startingAt: readPosition;
-                               yourself ]
                ifFalse: [
                        (contentsArray size > 10 and: [ contentsSize * 4 <=  
contentsArray size ])
+                               ifTrue: [ contentsArray class new:  
(contentsSize * 2 max: 10) ]
+                               ifFalse: [ contentsArray ] ].
+       newContentsArray
+               replaceFrom: 1
+               to: contentsSize
+               with: contentsArray
+               startingAt: readPosition.
+       contentsArray == newContentsArray
+               ifFalse: [ contentsArray := newContentsArray ]
+               ifTrue: [ contentsArray from: contentsSize + 1 to:  
contentsArray size put: nil ].
-                               ifTrue: [
-                                       "shrink"
-                                       contentsArray := (contentsArray  
class new: (contentsSize * 2 max: 10))
-                                               replaceFrom: 1
-                                               to: contentsSize
-                                               with: contentsArray
-                                               startingAt: readPosition;
-                                               yourself ]
-                               ifFalse: [
-                                       "just move the elements to the  
front"
-                                       contentsArray
-                                               replaceFrom: 1
-                                               to: contentsSize
-                                               with: contentsArray
-                                               startingAt: readPosition.
-                                       contentsArray
-                                               from: contentsSize + 1
-                                               to: contentsArray size
-                                               put: nil ] ].
        readPosition := 1.
        writePosition := contentsSize + 1!

Item was changed:
  ----- Method: SharedQueue>>peek (in category 'accessing') -----
  peek
        "Answer the object that was sent through the receiver first and has  
not
        yet been received by anyone but do not remove it from the receiver.  
If
        no object has been sent, return nil"

+       readSynch isSignaled ifFalse: [ ^nil ].
+       ^accessProtect critical: [
+               readPosition >= writePosition ifFalse: [
+                       contentsArray at: readPosition ] ]!
-       ^accessProtect
-               critical: [
-                       | value |
-                       readPosition >= writePosition
-                                       ifTrue: [readPosition := 1.
-                                                       writePosition := 1.
-                                                       value := nil]
-                                       ifFalse: [value := contentsArray  
at: readPosition].
-                       value].!