org.iq80.leveldb

Interface DBComparator

All Superinterfaces:

Comparator<byte[]>

public interface DBComparator
extends Comparator<byte[]>

Author:

Hiram Chirino

Method Summary

Modifier and Type	Method and Description
byte[]	findShortestSeparator(byte[] start, byte[] limit) If start < limit, returns a short key in [start,limit).
byte[]	findShortSuccessor(byte[] key) returns a 'short key' where the 'short key' is greater than or equal to key.
String	name() The name of the comparator.

Methods inherited from interface java.util.Comparator

compare, comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Method Detail

name

String name()

The name of the comparator. Used to check for comparator mismatches (i.e., a DB created with one comparator is accessed using a different comparator.

The client of this package should switch to a new name whenever the comparator implementation changes in a way that will cause the relative ordering of any two keys to change.

Returns:

comparator name

findShortestSeparator

byte[] findShortestSeparator(byte[] start,
                             byte[] limit)

If start < limit, returns a short key in [start,limit). Simple comparator implementations should return start unchanged, i.e., an implementation of this method that does nothing is correct.

findShortSuccessor

byte[] findShortSuccessor(byte[] key)

returns a 'short key' where the 'short key' is greater than or equal to key. Simple comparator implementations should return key unchanged, i.e., an implementation of this method that does nothing is correct.