com.netflix.astyanax.util.TokenGenerator Maven / Gradle / Ivy
/*******************************************************************************
* Copyright 2011 Netflix
*
* 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.netflix.astyanax.util;
import java.math.BigInteger;
public class TokenGenerator {
public static final BigInteger MINIMUM = new BigInteger("" + 0);
public static final BigInteger MAXIMUM = new BigInteger("" + 2).pow(127);
public static String initialToken(int size, int position) {
return TokenGenerator.initialToken(size,position,MINIMUM,MAXIMUM);
}
public static String initialToken(int size, int position, BigInteger minInitialToken, BigInteger maxInitialToken ) {
BigInteger decValue = minInitialToken;
if (position != 0)
decValue = maxInitialToken.multiply(new BigInteger("" + position)).divide(new BigInteger("" + size));
return decValue.toString();
}
public static String tokenMinusOne(String payload) {
BigInteger bigInt = new BigInteger(payload);
// if zero rotate to the Maximum else minus one.
if (bigInt.equals(MINIMUM))
bigInt = MAXIMUM;
bigInt = bigInt.subtract(new BigInteger("1"));
return bigInt.toString();
}
public static BigInteger tokenDifference(BigInteger startToken, BigInteger endToken) {
if (startToken.compareTo(endToken) < 0) {
return endToken.subtract(startToken);
}
else {
return endToken.add(MAXIMUM).subtract(startToken);
}
}
public static BigInteger tokenDifference(String startToken, String endToken) {
return tokenDifference(new BigInteger(startToken), new BigInteger(endToken));
}
public static String getMaximumToken() {
return MAXIMUM.toString();
}
public static String getMinimumToken() {
return MINIMUM.toString();
}
}