public final class PrimeFinder extends Object
Choosing prime numbers as hash table capacities is a good idea to keep them working fast, particularly under hash table expansions.
However, JDK 1.2, JGL 3.1 and many other toolkits do nothing to keep capacities prime. This class provides efficient means to choose prime capacities.
Choosing a prime is O(log 300) (binary search in a list of 300 int's). Memory requirements: 1 KB static memory.
|Modifier and Type||Field and Description|
The largest prime this class can generate; currently equal to Integer.MAX_VALUE.
|Modifier and Type||Method and Description|
Returns a prime number which is
public static final int LARGEST_PRIME
public static int nextPrime(int desiredCapacity)
<= desiredCapacityand very close to
desiredCapacity(within 11% if
desiredCapacity <= 1000).
desiredCapacity- the capacity desired by the user.
Copyright © 2008–2015 The Apache Software Foundation. All rights reserved.