[HBASE-20932] Effective MemStoreSize::hashCode()

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.2
• Fix Version/s: 2.2.0
• Hadoop Flags: Reviewed
• Assignee: Mingliang Liu
• Reporter: Mingliang Liu
• Created: 24/Jul/18 23:41
• Updated: 01/Aug/18 06:20
• Resolved: 25/Jul/18 21:43

Description

After HBASE-20411 we have

MemStoreSize::hashCode()

  @Override
  public int hashCode() {
    long h = 31 * this.dataSize;
    h = h + 31 * this.heapSize;
    h = h + 31 * this.offHeapSize;
    return (int) h;
  }
 

This is not effective hashCode() implementation. Instead we can use:

MemStoreSize::hashCode()

  @Override
  public int hashCode() {
    long h = this.dataSize;
    h = h * 31 + this.heapSize;
    h = h * 31 + this.offHeapSize;
    return (int) h;
  }
 

Issue Links

• relates to: HBASE-20411 Ameliorate MutableSegment synchronize