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Version 125.1 by Ravi Mendis on 2010/03/04 00:24
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1 Given that todays processors ship with dual or quad cores and server processors ship with between 8 to 32 cores, languages like Java, Ruby, Groovy and Python are struggling to keep up. Scala, as its name suggests is built from the ground-up for concurrent programming - a methodology that can take advantage of these modern multi-core processors.
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3 If you use Scala for a concurrent programming, the chances are that you're using Scala Actor to do that.
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5 {{info title="Scala Actors"}}
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7 Concurrent programming in Scala is based on *Actors* and mailboxes - a common metaphor that is alternatively known as *Message Queues*.
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9 {{/info}}
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11 == Using Scala Actors with EOF ==
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13 EOF being notoriously single-threaded, is incredibly unsuitable for use by Scala Actors.
14 Instead you may still use EOF but only to execute SQL directly.
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16 === Using EOAccess to execute SQL ===
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18 Use Wonder API: [[ERXEOAccessUtilities.evaluateSQLWithEntityNamed()>>http://webobjects.mdimension.com/hudson/job/Wonder53/javadoc/er/extensions/eof/ERXEOAccessUtilities.html#evaluateSQLWithEntity(com.webobjects.eocontrol.EOEditingContext,%20com.webobjects.eoaccess.EOEntity,%20java.lang.String)]]
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20 ==== Caveats ====
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22 If you're updating the state of EOs directly using SQL from Scala Actors, you will subsequently need to refresh/refetch these EOs from the WebObjects application.
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24 == Alternatives ==
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26 You may also manipulate the database from outside of the EOF stack.
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28 === Squeryl ===
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30 [[Squeryl>>http://max-l.github.com/Squeryl/index.html]] is a Scala [[Domain-specific language>>http://en.wikipedia.org/wiki/Domain-specific_language]] for SQL.
31 You may update EOs from Scala Actors using Squeryl instead of using EOF. The advantage here is that you may access the database concurrently avoiding the single-threaded EOF bottleneck in your concurrent application.
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33 However the same caveat applies - you will need to refresh EOs in the EOF stack for the WebObjects application to reflect the changes made by Squeryl.