Class: CacheDictionaryWithFactory

• Inheritance
• Description
• Class protocol
  • instance creation
• Instance protocol
  • accessing
  • initialization
• Examples

Inheritance:

   Object
   |
   +--Collection
      |
      +--Set
         |
         +--Dictionary
            |
            +--CacheDictionary
               |
               +--CacheDictionaryWithFactory

Package:

stx:libbasic2

Category:

Collections-Unordered

Version:

rev: 1.5 date: 2021/12/04 07:30:33

user: cg

file: CacheDictionaryWithFactory.st directory: libbasic2

module: stx stc-classLibrary: libbasic2

Description:

like a Dictionary, but does not grow beyond a given max. size
(i.e. only keeps size items),
It can be used as a cache, for keeping recently used objects alive.
Must be created with an initial (=maximal) size. 
In addition to the normal CacheDictionary behavior, 
this also keeps a factoryBlock to automatically compute missing elements.

copyright
COPYRIGHT (c) 2003 by eXept Software AG
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

Class protocol:

 new: cacheSize factory: aBlock

Instance protocol:

 at: key

(comment from inherited method)
return the element indexed by aKey - report an error if none found

 factory: aBlock

Examples:

  |c|

  c := CacheDictionaryWithFactory
          new:100 factory:[:key | key reversed].

  c at:'hello'.
  c at:'hello'.
  1 to:1000 do:[:i | c at:i printString].
  c at:'hello'.

  |c numHalts|

  numHalts := 0.

  c := CacheDictionaryWithFactory
          new:100 factory:[:key | key = 'hello' ifTrue:[numHalts := numHalts + 1]. key reversed].

  c at:'hello'.
  c at:'hello'.
  1 to:1000 do:[:i | c at:i printString].
  c at:'hello'.
  self assert:( numHalts == 2 ).