org.apache.hadoop.hive.ql.exec.vector.expressions

Class CuckooSetLong

java.lang.Object

org.apache.hadoop.hive.ql.exec.vector.expressions.CuckooSetLong

public class CuckooSetLong
extends Object

A high-performance set implementation used to support fast set membership testing, using Cuckoo hashing. This is used to support fast tests of the form column IN ( list-of-values ) For details on the algorithm, see R. Pagh and F. F. Rodler, "Cuckoo Hashing," Elsevier Science preprint, Dec. 2003. http://www.itu.dk/people/pagh/papers/cuckoo-jour.pdf.

Field Summary

Fields

Modifier and Type	Field and Description
static int[]	primes

Constructor Summary

Constructors

Constructor and Description
CuckooSetLong(int expectedSize) Allocate a new set to hold expectedSize values.

Method Summary

Modifier and Type	Method and Description
void	insert(long x)
void	load(long[] a) Insert all values in the input array into the set.
boolean	lookup(long x) Return true if and only if the value x is present in the set.

Methods inherited from class java.lang.Object

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

Field Detail

primes

public static int[] primes

Constructor Detail

CuckooSetLong

public CuckooSetLong(int expectedSize)

Allocate a new set to hold expectedSize values. Re-allocation to expand the set is not implemented, so the expected size must be at least the size of the set to be inserteed.

Parameters:

expectedSize - At least the size of the set of values that will be inserted.

Method Detail

lookup

public boolean lookup(long x)

Return true if and only if the value x is present in the set.

insert

public void insert(long x)

load

public void load(long[] a)

Insert all values in the input array into the set.