[HBASE-14826] Small improvement in KVHeap seek() API

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Hadoop Flags: Reviewed
• Assignee: ramkrishna.s.vasudevan
• Reporter: ramkrishna.s.vasudevan
• Created: 17/Nov/15 11:36
• Updated: 25/Nov/15 05:58
• Resolved: 25/Nov/15 05:58

Description

Currently in seek/reseek() APIs we tend to do lot of priorityqueue related operations. We initially add the current scanner to the heap, then poll and again add the scanner back if the seekKey is greater than the topkey in that scanner. Since the KVs are always going to be in increasing order and in ideal scan flow every seek/reseek is followed by a next() call it should be ok if we start with checking the current scanner and then do a poll to get the next scanner. Just avoid the initial PQ.add(current) call. This could save some comparisons.