[dna-dev] Fwd: Updated: (DNA-270) Simplify the ExecutionContext framework

[Randall Hauch]

Something about the ExecutionContext framework has been bugging me  
over the past few weeks, so today I took a whack at addressing what I  
perceived to be the problems.  Some of these are outlined in the issue  
below, but perhaps the biggest problem was in what users/clients saw:  
the current design seemed to emphasize design/dependency perspective  
and sacrificed simplicity for the user/client.

The patch outlined below (and attached to the issue) has the changes  
I'm proposing.  I'm pretty positive about these changes, because I  
really think it simplifies what users/clients see (including how DNA  
repositories will be configured).  Basically, the existing  
ExecutionContext interface is changed to a concrete implementation  
(with default constructor, and methods to create other instances  
relative to the context), and ExecutionContext now implements the  
ExecutionContextFactory interface.  Also, several implementations were  
removed, and now there really is just one component (ExecutionContext)  
that users/clients have to worry about.

If you have a chance, please review the patch and provide feedback.   
Note that the patch was created using revision 701 (the current  
revision as of tonight) as a baseline, so it should be easy to grab  
the latest and apply the patch.

Best regards,

Randall


Begin forwarded message:

> From: "Randall Hauch (JIRA)" <jira-events at lists.jboss.org>
> Date: January 12, 2009 5:40:03 PM CST
> To: dna-issues at lists.jboss.org
> Subject: [dna-issues] [JBoss JIRA] Updated: (DNA-270) Simplify the  
> ExecutionContext framework
>
>
>     [ https://jira.jboss.org/jira/browse/DNA-270?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel 
>  ]
>
> Randall Hauch updated DNA-270:
> ------------------------------
>
>    Attachment: dna-270-executioncontext.patch
>
>
> Attached a patch file that has the proposed changes (relative to  
> revision 701), and which results in all tests passing.
>
>> Simplify the ExecutionContext framework
>> ---------------------------------------
>>
>>                Key: DNA-270
>>                URL: https://jira.jboss.org/jira/browse/DNA-270
>>            Project: DNA
>>         Issue Type: Task
>>         Components: API, Connectors, Documentation, Examples,  
>> Graph, Sequencers
>>   Affects Versions: 0.3
>>           Reporter: Randall Hauch
>>           Assignee: Randall Hauch
>>            Fix For: 0.4
>>
>>        Attachments: dna-270-executioncontext.patch
>>
>>
>> The ExecutionContext interface is used throughout the system.  It's  
>> defined in 'dna-graph', and used to represent the context or  
>> environment for executing various activities.  There is also  
>> ExecutionContextFactory, which is an interface for creating other  
>> contexts with different JAAS security contexts (login context or  
>> access control contexts).  There are also the Basic*  
>> implementations of these interfaces, as well as several subclasses  
>> (with various implementations).
>> The idea of using an interface for this was to simplify the design  
>> of the components that uses/took an ExecutionContext, to prevent  
>> propagating dependencies, and to allow customization.  However,  
>> since ExecutionContext is largely just an aggregation of  
>> references, there's little need to customize the behavior, and this  
>> doesn't really add any other dependencies to the classpath (all  
>> implementations of the aggregated components are already in 'dna- 
>> graph') and it doesn't expose any implementations through the  
>> method signatures.  Using interfaces also complicates the usage,  
>> since clients have to know about the concrete implementations.   
>> This is even more true when they're setting up the DNA services and  
>> repositories in 'dna-repository' and 'dna-jcr'.
>> So, consider changing this interface to a concrete class, with  
>> methods that make it easy to create instances as well as instances  
>> with custom components (e.g., a new context that is the same as  
>> 'this' but with a supplied NamespaceRegistry implementation).
>> This will change the public API, but this should be acceptable  
>> given that we're not yet at 1.0 (and this really improves both the  
>> client code, and doesn't really change extension implementations).
>
> -- 
> This message is automatically generated by JIRA.
> -
> If you think it was sent incorrectly contact one of the  
> administrators: https://jira.jboss.org/jira/secure/Administrators.jspa
> -
> For more information on JIRA, see: http://www.atlassian.com/software/jira
>
>
> _______________________________________________
> dna-issues mailing list
> dna-issues at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/dna-issues

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.jboss.org/pipermail/dna-dev/attachments/20090112/80b790e8/attachment.html