[logback-dev] [JIRA] Commented: (LBCLASSIC-281) Don't evaluate formattedMessage in LoggingEvent constructor

[Andrew Brett (JIRA)]

    [ http://jira.qos.ch/browse/LBCLASSIC-281?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12059#action_12059 ] 

Andrew Brett commented on LBCLASSIC-281:
----------------------------------------

Sorry for the inexact terminology above, when I say "custom formatter", I mean a class which implements ch.qos.logback.core.pattern.Converter, and is used as an alternative to ch.qos.logback.classic.pattern.MessageConverter - it doesn't simply return the formattedMessage, but instead looks at the types of objects in the argArray, and is able to call things other than toString() on those objects in certain cases.

> Don't evaluate formattedMessage in LoggingEvent constructor
> -----------------------------------------------------------
>
>                 Key: LBCLASSIC-281
>                 URL: http://jira.qos.ch/browse/LBCLASSIC-281
>             Project: logback-classic
>          Issue Type: Improvement
>    Affects Versions: 0.9.29
>            Reporter: Andrew Brett
>            Assignee: Logback dev list
>
> Whenever a ch.qos.logback.classic.spi.LoggingEvent is constructed, MessageFormatter.arrayFormat(...) is called, and the formattedMessage member variable assigned. This involves calling toString() on all arguments in argArray, which can be slow, and occurs even if the formattedMessage is not part of any appender layouts.
> For my project's purposes, I have a custom formatter which only outputs an abbreviated string form of certain objects with expensive toString() methods; however, I am still paying the overhead in the toString() calls, since they're made even when getFormattedMessage() is never called. Note that I don't control the source of the objects with expensive toString() methods, nor do I control the source everywhere they're logged, so I can't simply change them directly.
> formattedMessage is already evaluated lazily in getFormattedMessage(), so the only side effect of this change is the introspection of argsArray to look for a Throwable at the end, which is a trivial operation to perform separately.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: http://jira.qos.ch/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira