Class: CacheDictionaryWithFactory

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

Inheritance:

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

Package:

stx:libbasic2

Category:

Collections-Unordered

Version:

rev: 1.3 date: 2016/10/13 22:09:33

user: cg

file: CacheDictionaryWithFactory.st directory: libbasic2

module: stx stc-classLibrary: libbasic2

Author:

Claus Gittinger (cg@alan)

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, 
this also keeps a factoryBlock to automatically compute missing elements.

Related information:

    CacheDictionary
    Dictionary

Class protocol:

 new: cacheSize factory: aBlock

Instance protocol:

 at: key

 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 ).