[LOG4J2-1874] Add ByteBufferDestionation.write(ByteBuffer) and write(byte[], int, int) methods and call them from TextEncoderHelper whenever possible

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.6
• Fix Version/s: 2.9.0
• Assignee: Remko Popma
• Reporter: Roman Leventov
• Created: 11/Apr/17 07:12
• Updated: 25/Jun/17 04:34
• Resolved: 18/Jun/17 07:10

Description

Existing ByteBufferDestination API: getByteBuffer() and drain() is designed so that synchronization couldn't be avoided. This doesn't allow to implement LOG4J2-928.

Github PR: https://github.com/apache/logging-log4j2/pull/71

Added methods: write(ByteBuffer data) and write(byte[] data, int offset, int length) are designed so that they should care about synchronization themselves, internally, if needed. They should also synchronize with possible concurrent users of the synchronized getByteBuffer() + drain() API. Nevertheless, it allows for ByteBufferDestination implementations to implement write() methods without lock-free.

TextEncoderHelper (hence StringBuilderEncoder, which delegates it's logic to TextEncoderHelper) is changed so that it calls ByteBufferDestination.write() whenever possible. There is an expectation that most of encoded events fit the thread-local buffers, and write() could be called instead of writing to destination.getByteBuffer() with synchronization.

The PR also includes a sanity improvement: uses ByteBuffer.arrayOffset() at some places.

Issue Links

• blocks: LOG4J2-928 Lock-free synchronous sub-microsecond appender
• links to: GitHub Pull Request #70
• links to: GitHub Pull Request #71