org.apache.hadoop.hbase.util

类 RegionSplitCalculator<R extends KeyRange>

java.lang.Object

org.apache.hadoop.hbase.util.RegionSplitCalculator<R>

类型参数:

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.

字段概要

字段

限定符和类型	字段和说明
static Comparator<byte[]>	BYTES_COMPARATOR

构造器概要

构造器

构造器和说明
RegionSplitCalculator(Comparator<R> cmp)

方法概要

方法

限定符和类型	方法和说明
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()

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

字段详细资料

BYTES_COMPARATOR

public static final Comparator<byte[]> BYTES_COMPARATOR

构造器详细资料

RegionSplitCalculator

public RegionSplitCalculator(Comparator<R> cmp)

方法详细资料

add

public boolean add(R range)

Adds an edge to the split calculator

返回:

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.

返回:

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.

参数:

bigOverlap - a list of ranges that overlap with each other

count - the max number of ranges to find

返回:

a list of ranges that overlap with most others