[
https://issues.apache.org/jira/browse/SLING-913?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14061740#comment-14061740
]
Chetan Mehrotra commented on SLING-913:
---------------------------------------
bq. I'm not 100% sure if the last modified approach is the best.
Agreed. However compared to current where we read whole script content for
compilation the overhead would be small. Further we can have different cache
policies depending on need and deployment scenario
* cache disabled - No caching at all
* cache untill modified - Check for last modified to invalidate the cache
* cache forever - For production deployments where we do not expect the script
content to change we can switch to cache for ever. If script content changes
say via some content package deployment then either we expect system restart or
expose a JMX operation to invalidate the cache
> Add a cache for pre-compiled scripts
> ------------------------------------
>
> Key: SLING-913
> URL: https://issues.apache.org/jira/browse/SLING-913
> Project: Sling
> Issue Type: New Feature
> Components: Scripting
> Affects Versions: Scripting Core 2.0.2
> Reporter: Felix Meschberger
> Attachments: SLING-913.patch
>
>
> The Java Scripting API provides support for scripting langugages which may
> precompile script source and reuse the precompiled scripts:
> javax.script.Compilable: May be implemented by a ScriptEngine if
> precompilation is
> supported
> javax.script.CompiledScript: Result of calling the Compilable.compile
> method.
> The CompiledScript can be called to repeatedly execute the script without the
> need for recompilation and thus for improved performance.
> The Sling Core Scripting support should make use of this functionality by
> maintaining a cache compiled scripts with the following properties
> * indexed by script path
> * size limited (using LinkedHashMap overwriting the removeEldestEntry
> method)
> * entries are weak or soft references ot cache entries
> A cache entry consists of the following information:
> * The CompiledScript instance
> * The time of last compilation. this is compared to the last modification
> time of the script to decide on whether to recompile
> We might probaly also try to add a reference to the script engine
> implementation bundle to only use the cache entry if the bundle has not been
> stopped since adding the cache entry
> Executing the script would then consist of the following steps:
> 1 Check the cache of precompiled scripts. if an entry exists and can be
> used, use it
> 2. if the ScriptEngine is Compilable:
> 2a. Compile the script and add it to the cache and use it
> 2b. Otherwise have the script engine execute the script
--
This message was sent by Atlassian JIRA
(v6.2#6252)
