/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package com.github.ggrandes.kvstore.utils;
import java.math.BigInteger;
import java.util.Arrays;
public final class PrimeFinder {
/**
* The prime number list 1-Integer.MAX_VALUE (steps).
*/
private static final int[] primeCapacities = {
1, 2, 7, 17, 37, 79,
149, 271, 479, 827, 1399, 2309, 3739, 5981, 9391, 14557, 22291,
33757, 50627, 75181, 110647, 161507, 233939, 336397, 480409,
681647, 961273, 1347733, 1879151, 2606353, 3596851, 4940051,
6753841, 9193181, 12461041, 16822489, 22622599, 30309211,
40461959, 53828963, 71373193, 94330987, 124285687, 163260059,
213832237, 279280621, 363764831, 472551293, 612293659,
791381131, 1020370069, 1312518343, 1684445207, 2147483647
};
/**
* The prime number list 1-8191 (detailed).
*/
private static final short[] primeCapacities8191 = {
1,2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,
89,97,101,103,107,109,113,127,131,137,139,149,151,157,163,167,173,
179,181,191,193,197,199,211,223,227,229,233,239,241,251,257,263,269,
271,277,281,283,293,307,311,313,317,331,337,347,349,353,359,367,373,
379,383,389,397,401,409,419,421,431,433,439,443,449,457,461,463,467,
479,487,491,499,503,509,521,523,541,547,557,563,569,571,577,587,593,
599,601,607,613,617,619,631,641,643,647,653,659,661,673,677,683,691,
701,709,719,727,733,739,743,751,757,761,769,773,787,797,809,811,821,
823,827,829,839,853,857,859,863,877,881,883,887,907,911,919,929,937,
941,947,953,967,971,977,983,991,997,1009,1013,1019,1021,1031,1033,
1039,1049,1051,1061,1063,1069,1087,1091,1093,1097,1103,1109,1117,
1123,1129,1151,1153,1163,1171,1181,1187,1193,1201,1213,1217,1223,
1229,1231,1237,1249,1259,1277,1279,1283,1289,1291,1297,1301,1303,
1307,1319,1321,1327,1361,1367,1373,1381,1399,1409,1423,1427,1429,
1433,1439,1447,1451,1453,1459,1471,1481,1483,1487,1489,1493,1499,
1511,1523,1531,1543,1549,1553,1559,1567,1571,1579,1583,1597,1601,
1607,1609,1613,1619,1621,1627,1637,1657,1663,1667,1669,1693,1697,
1699,1709,1721,1723,1733,1741,1747,1753,1759,1777,1783,1787,1789,
1801,1811,1823,1831,1847,1861,1867,1871,1873,1877,1879,1889,1901,
1907,1913,1931,1933,1949,1951,1973,1979,1987,1993,1997,1999,2003,
2011,2017,2027,2029,2039,2053,2063,2069,2081,2083,2087,2089,2099,
2111,2113,2129,2131,2137,2141,2143,2153,2161,2179,2203,2207,2213,
2221,2237,2239,2243,2251,2267,2269,2273,2281,2287,2293,2297,2309,
2311,2333,2339,2341,2347,2351,2357,2371,2377,2381,2383,2389,2393,
2399,2411,2417,2423,2437,2441,2447,2459,2467,2473,2477,2503,2521,
2531,2539,2543,2549,2551,2557,2579,2591,2593,2609,2617,2621,2633,
2647,2657,2659,2663,2671,2677,2683,2687,2689,2693,2699,2707,2711,
2713,2719,2729,2731,2741,2749,2753,2767,2777,2789,2791,2797,2801,
2803,2819,2833,2837,2843,2851,2857,2861,2879,2887,2897,2903,2909,
2917,2927,2939,2953,2957,2963,2969,2971,2999,3001,3011,3019,3023,
3037,3041,3049,3061,3067,3079,3083,3089,3109,3119,3121,3137,3163,
3167,3169,3181,3187,3191,3203,3209,3217,3221,3229,3251,3253,3257,
3259,3271,3299,3301,3307,3313,3319,3323,3329,3331,3343,3347,3359,
3361,3371,3373,3389,3391,3407,3413,3433,3449,3457,3461,3463,3467,
3469,3491,3499,3511,3517,3527,3529,3533,3539,3541,3547,3557,3559,
3571,3581,3583,3593,3607,3613,3617,3623,3631,3637,3643,3659,3671,
3673,3677,3691,3697,3701,3709,3719,3727,3733,3739,3761,3767,3769,
3779,3793,3797,3803,3821,3823,3833,3847,3851,3853,3863,3877,3881,
3889,3907,3911,3917,3919,3923,3929,3931,3943,3947,3967,3989,4001,
4003,4007,4013,4019,4021,4027,4049,4051,4057,4073,4079,4091,4093,
4099,4111,4127,4129,4133,4139,4153,4157,4159,4177,4201,4211,4217,
4219,4229,4231,4241,4243,4253,4259,4261,4271,4273,4283,4289,4297,
4327,4337,4339,4349,4357,4363,4373,4391,4397,4409,4421,4423,4441,
4447,4451,4457,4463,4481,4483,4493,4507,4513,4517,4519,4523,4547,
4549,4561,4567,4583,4591,4597,4603,4621,4637,4639,4643,4649,4651,
4657,4663,4673,4679,4691,4703,4721,4723,4729,4733,4751,4759,4783,
4787,4789,4793,4799,4801,4813,4817,4831,4861,4871,4877,4889,4903,
4909,4919,4931,4933,4937,4943,4951,4957,4967,4969,4973,4987,4993,
4999,5003,5009,5011,5021,5023,5039,5051,5059,5077,5081,5087,5099,
5101,5107,5113,5119,5147,5153,5167,5171,5179,5189,5197,5209,5227,
5231,5233,5237,5261,5273,5279,5281,5297,5303,5309,5323,5333,5347,
5351,5381,5387,5393,5399,5407,5413,5417,5419,5431,5437,5441,5443,
5449,5471,5477,5479,5483,5501,5503,5507,5519,5521,5527,5531,5557,
5563,5569,5573,5581,5591,5623,5639,5641,5647,5651,5653,5657,5659,
5669,5683,5689,5693,5701,5711,5717,5737,5741,5743,5749,5779,5783,
5791,5801,5807,5813,5821,5827,5839,5843,5849,5851,5857,5861,5867,
5869,5879,5881,5897,5903,5923,5927,5939,5953,5981,5987,6007,6011,
6029,6037,6043,6047,6053,6067,6073,6079,6089,6091,6101,6113,6121,
6131,6133,6143,6151,6163,6173,6197,6199,6203,6211,6217,6221,6229,
6247,6257,6263,6269,6271,6277,6287,6299,6301,6311,6317,6323,6329,
6337,6343,6353,6359,6361,6367,6373,6379,6389,6397,6421,6427,6449,
6451,6469,6473,6481,6491,6521,6529,6547,6551,6553,6563,6569,6571,
6577,6581,6599,6607,6619,6637,6653,6659,6661,6673,6679,6689,6691,
6701,6703,6709,6719,6733,6737,6761,6763,6779,6781,6791,6793,6803,
6823,6827,6829,6833,6841,6857,6863,6869,6871,6883,6899,6907,6911,
6917,6947,6949,6959,6961,6967,6971,6977,6983,6991,6997,7001,7013,
7019,7027,7039,7043,7057,7069,7079,7103,7109,7121,7127,7129,7151,
7159,7177,7187,7193,7207,7211,7213,7219,7229,7237,7243,7247,7253,
7283,7297,7307,7309,7321,7331,7333,7349,7351,7369,7393,7411,7417,
7433,7451,7457,7459,7477,7481,7487,7489,7499,7507,7517,7523,7529,
7537,7541,7547,7549,7559,7561,7573,7577,7583,7589,7591,7603,7607,
7621,7639,7643,7649,7669,7673,7681,7687,7691,7699,7703,7717,7723,
7727,7741,7753,7757,7759,7789,7793,7817,7823,7829,7841,7853,7867,
7873,7877,7879,7883,7901,7907,7919,7927,7933,7937,7949,7951,7963,
7993,8009,8011,8017,8039,8053,8059,8069,8081,8087,8089,8093,8101,
8111,8117,8123,8147,8161,8167,8171,8179,8191
};
/**
* Returns a prime number which is very close to
* <code>desiredCapacity</code>
*
* @param desiredCapacity the capacity desired by the user.
* @return the capacity which should be used for a hash.
*/
public static final int nextPrime(final int desiredCapacity) {
final int i = Arrays.binarySearch(primeCapacities, desiredCapacity);
return primeCapacities[((i < 0) ? ((-i) - 1) : i)];
}
/**
* Returns a prime number which is very close to
* <code>desiredCapacity</code>
* with detailed steps between {1-8191}
*
* @param desiredCapacity the capacity desired by the user.
* @return the capacity which should be used for a hash.
*/
public static final int nextPrime8191(final int desiredCapacity) {
if (desiredCapacity < 0)
return 1;
if (desiredCapacity <= 8191) {
final int i = Arrays.binarySearch(primeCapacities8191, (short)desiredCapacity);
return primeCapacities8191[((i < 0) ? ((-i) - 1) : i)];
}
return nextPrime(desiredCapacity);
}
/**
* Prime Generator
*/
public static void main(final String[] args) {
int min, max;
min = 0;
max = Integer.MAX_VALUE;
//
BigInteger x = BigInteger.valueOf(min);
int i = min;
final StringBuilder sb = new StringBuilder(64);
while (i < max) {
x = x.nextProbablePrime();
i = x.intValue();
sb.append(i).append(',');
if (sb.length() > 64) {
System.out.println(sb.toString());
sb.setLength(0);
}
}
if (sb.length() > 0) {
System.out.println(sb.toString());
sb.setLength(0);
}
}
}