[HDFS-11939] Ozone : add read/write random access to Chunks of a key

• Type: Sub-task
• Status: In Progress
• Priority: Major
• Resolution: Unresolved
• Component/s: ozone
• Labels: OzonePostMerge
• Assignee: Chen Liang
• Reporter: Chen Liang
• Created: 06/Jun/17 22:56
• Updated: 27/Sep/17 16:46

Description

In Ozone, the value of a key is a sequence of container chunks. Currently, the only way to read/write the chunks is by using ChunkInputStream and ChunkOutputStream. However, by the nature of streams, these classes are currently implemented to only allow sequential read/write.

Ideally we would like to support random access of the chunks. For example, we want to be able to seek to a specific offset and read/write some data. This will be critical for key range read/write feature, and potentially important for supporting parallel read/write.

This JIRA tracks adding support by implementing FileChannel class on top Chunks.