[infinispan-dev] property tags in configuration files

[Mircea Markus]

Continuing a conversation Vladimir and I had on irc, about how 
<property> tags can be be listed in the documentation.

<property> are a way to configure extension points (e.g. CacheStore 
implementations, ScheduledExecutorFactory implemetations etc), e.g:

<replicationQueueScheduledExecutor 
factory="org.infinispan.executors.DefaultScheduledExecutorFactory">
         <property name="threadNamePrefix" value="ReplicationQueueThread"/>
</replicationQueueScheduledExecutor>

"threadNamePrefix" property is specific to 
DefaultScheduledExecutorFactory, other implementations of 
ScheduledExecutorFactory would not recognize it, and/or use different 
properties.
So there's no way to handle "property" tags as the other 'regular' 
attributes that map to fixed configuration elements: e.g. transportClass 
maps to GlobalConfiguration#transportClass etc.
Even more, in some situations these properties are not being used to 
call setters on the target objects, but are being passed all together 
through a java.util.Properties: which makes them impossible/harder to 
annotate.

On the other hand it would be very nice to have all the properties of 
default extension points (e.g. FileCacheStore, JdbcStringBasedCacheStore 
etc) having all the documentation exposed through annotations.
A possible way I see to make this working is:
1) create a new annotation to denote an extension point, 
@ExtenssionPoint(defaultImplementations={ClassName1, ClassName2, 
ClassName3})
e.g.

CacheLoaderConfig {  
    @ExtenssionPoint(defaultImplementations={FileCacheStore.class, 
JdbcStringBasedCacheStore.class}) //this will break module dependency, 
guess strings should be used
    void setCacheLoaderClassName(String s);
}

2) For all existing extension points the tool will create a different 
table containing all its specific properties, obtained by parsing 
class's @Property tags

3) Make all the current extension points that use java.util.Property are 
replace by setters that can be annotated: this way we would remain 
consistent in all code, and IMHO the code would be more readable

wdyt?
Cheers,
Mircea