RegionSplitCalculator (Apache HBase 1.4.11 API)

All Classes

Summary:
Nested |
Field |
Constr |
Method

Detail:
Field |
Constr |
Method

java.lang.Object
- org.apache.hadoop.hbase.util.RegionSplitCalculator<R>

Type Parameters:
R -
```
@InterfaceAudience.Private
public class RegionSplitCalculator<R extends KeyRange>
extends Object
```
This is a generic region split calculator. It requires Ranges that provide start, end, and a comparator. It works in two phases -- the first adds ranges and rejects backwards ranges. Then one calls calcRegions to generate the multimap that has a start split key as a key and possibly multiple Ranges as members. To traverse, one normally would get the split set, and iterate through the calcRegions. Normal regions would have only one entry, holes would have zero, and any overlaps would have multiple entries. The interface is a bit cumbersome currently but is exposed this way so that clients can choose how to iterate through the region splits.

Field Summary

Fields
Modifier and Type Field and Description

static Comparator<byte[]> BYTES_COMPARATOR

Constructor Summary

Constructors
Constructor and Description

RegionSplitCalculator(Comparator<R> cmp)

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`add(R range)` Adds an edge to the split calculator
`com.google.common.collect.Multimap<byte[],R>`	`calcCoverage()` Generates a coverage multimap from split key to Regions that start with the split key.
`static <R extends KeyRange> List<R>`	`findBigRanges(Collection<R> bigOverlap, int count)` Find specified number of top ranges in a big overlap group.
`TreeSet<byte[]>`	`getSplits()`
`com.google.common.collect.Multimap<byte[],R>`	`getStarts()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - BYTES_COMPARATOR
```
public static final Comparator<byte[]> BYTES_COMPARATOR
```
- Constructor Detail
  - RegionSplitCalculator
```
public RegionSplitCalculator(Comparator<R> cmp)
```
- Method Detail
  - add
```
public boolean add(R range)
```
    Adds an edge to the split calculator
    
    Returns:
    true if is included, false if backwards/invalid
  - calcCoverage
```
public com.google.common.collect.Multimap<byte[],R> calcCoverage()
```
    Generates a coverage multimap from split key to Regions that start with the split key.
    
    Returns:
    coverage multimap
  - getSplits
```
public TreeSet<byte[]> getSplits()
```
  - getStarts
```
public com.google.common.collect.Multimap<byte[],R> getStarts()
```
  - findBigRanges
```
public static <R extends KeyRange> List<R> findBigRanges(Collection<R> bigOverlap,
                                         int count)
```
    Find specified number of top ranges in a big overlap group. It could return less if there are not that many top ranges. Once these top ranges are excluded, the big overlap group will be broken into ranges with no overlapping, or smaller overlapped groups, and most likely some holes.
    
    Parameters:
    bigOverlap - a list of ranges that overlap with each other
    count - the max number of ranges to find
    
    Returns:
    a list of ranges that overlap with most others

All Classes

Summary:
Nested |
Field |
Constr |
Method

Detail:
Field |
Constr |
Method

Copyright © 2007–2019 The Apache Software Foundation. All rights reserved.