[HBASE-19473] Miscellaneous changes to ClientScanner

• Type: Improvement
• Status: Resolved
• Priority: Trivial
• Resolution: Fixed
• Affects Version/s: 3.0.0-alpha-1
• Fix Version/s: 2.0.0-beta-2, 2.0.0
• Flags: Patch
• Assignee: David Mollitor
• Reporter: David Mollitor
• Created: 10/Dec/17 02:56
• Updated: 18/Jun/18 15:07
• Resolved: 04/Jan/18 04:30

Description

1. Remove superfluous logging code guard
2. Simplify some of the code
3. Use ArrayDeque instead of LinkedList for queue implementation

https://docs.oracle.com/javase/8/docs/api/index.html?java/util/ArrayDeque.html

Resizable-array implementation of the Deque interface. Array deques have no capacity restrictions; they grow as necessary to support usage. They are not thread-safe; in the absence of external synchronization, they do not support concurrent access by multiple threads. Null elements are prohibited. This class is likely to be faster than Stack when used as a stack, and faster than LinkedList when used as a queue.