[HDFS-7790] Do not create optional fields in DFSInputStream unless they are needed

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.3.0
• Fix Version/s: 2.7.0
• Component/s: hdfs-client
• Target Version/s: 2.7.0
• Assignee: Colin McCabe
• Reporter: Colin McCabe
• Created: 12/Feb/15 19:11
• Updated: 10/Apr/15 20:30
• Resolved: 13/Feb/15 01:49

Description

DFSInputStream#oneByteBuffer and DFSInputStream#extendedReadBuffers are only used some of the time, and they are always used under the positional lock. Let's create them on demand to save memory.