[LOG4J2-1715] (GC) Avoid allocating temporary objects in NdcPatternConverter

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.7
• Fix Version/s: 2.8
• Component/s: Pattern Converters
• Epic Link: GC-free
• Assignee: Remko Popma
• Reporter: Remko Popma
• Created: 19/Nov/16 13:09
• Updated: 19/Nov/16 13:25
• Resolved: 19/Nov/16 13:25

Description

Make NdcPatternConverter garbage-free by letting ThreadContext.ContextStack implementations implement StringBuilderFormattable.

Note that use of the ThreadContext stack is not garbage-free: the stack is cloned for each log message. This only avoids creating objects during formatting in the layout.