[HDFS-8280] Code Cleanup in DFSInputStream

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Hadoop Flags: Reviewed
• Assignee: Jing Zhao
• Reporter: Jing Zhao
• Created: 28/Apr/15 21:01
• Updated: 30/Aug/16 01:35
• Resolved: 29/Apr/15 01:12

Description

This is some code cleanup separate from HDFS-8272:

1. Avoid duplicated block reader creation code
2. If no new source DN can be found, getBestNodeDNAddrPair returns null instead of throwing Exception. Whether to throw Exception or not should be determined by getBestNodeDNAddrPair's caller.