[HDFS-5781] Use an array to record the mapping between FSEditLogOpCode and the corresponding byte value

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.3.0
• Fix Version/s: 2.4.0
• Component/s: namenode
• Hadoop Flags: Reviewed
• Assignee: Jing Zhao
• Reporter: Jing Zhao
• Created: 15/Jan/14 19:43
• Updated: 10/Apr/14 13:11
• Resolved: 27/Jan/14 19:05

Description

HDFS-5674 uses Enum.values and enum.ordinal to identify an editlog op for a given byte value. While improving the efficiency, it may cause issue. E.g., when several new editlog ops are added to trunk around the same time (for several different new features), it is hard to backport the editlog ops with larger byte values to branch-2 before those with smaller values, since there will be gaps in the byte values of the enum.

This jira plans to still use an array to record the mapping between editlog ops and their byte values, and allow gap between valid ops.

Issue Links

• is related to: HDFS-5674 Editlog code cleanup