org.evosuite.runtime.Random Maven / Gradle / Ivy
/**
* Copyright (C) 2010-2017 Gordon Fraser, Andrea Arcuri and EvoSuite
* contributors
*
* This file is part of EvoSuite.
*
* EvoSuite is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation, either version 3.0 of the License, or
* (at your option) any later version.
*
* EvoSuite is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with EvoSuite. If not, see
* Random class.
*
*
* @author Gordon Fraser
*/
public class Random {
private static boolean wasAccessed = false;
/**
* We have a unique number that is increased every time a new random number
* is accessed
*/
private static int currentNumber = 0;
/**
* Replacement function for nextInt
*
* @return a int.
*/
public static int nextInt() {
wasAccessed = true;
return currentNumber++;
}
/**
* Replacement function for nextInt
*
* @param max
* a int.
* @return a int.
*/
public static int nextInt(int max) {
wasAccessed = true;
return currentNumber % max;
}
/**
* Replacement function for nextFloat
*
* @return a float.
*/
public static float nextFloat() {
wasAccessed = true;
return (currentNumber++ % 10F) / 10F;
}
/**
* Replacement function for nextBytes
* @param bytes
*/
public static void nextBytes(byte[] bytes) {
wasAccessed = true;
for (int i = 0; i < bytes.length; )
for (int rnd = nextInt(), n = Math.min(bytes.length - i, 4);
n-- > 0; rnd >>= 8)
bytes[i++] = (byte)rnd;
}
/**
* Replacement function for nextDouble
*
* @return a float.
*/
public static double nextDouble() {
wasAccessed = true;
return (currentNumber++ % 10.0) / 10.0;
}
/**
* Replacement function for nextGaussian
*
* @return a double.
*/
public static double nextGaussian() {
wasAccessed = true;
return nextDouble();
}
/**
* Replacement function for nextBoolean
*
* @return a boolean.
*/
public static boolean nextBoolean() {
wasAccessed = true;
return nextInt(1)!=0;
}
/**
* Replacement function for nextLong
*
* @return a long.
*/
public static long nextLong() {
wasAccessed = true;
return currentNumber++;
}
/**
* Set the next random number to a value
*
* @param number
* a int.
*/
public static void setNextRandom(int number) {
currentNumber = Math.abs(number);
}
/**
* Reset runtime to initial state
*/
public static void reset() {
currentNumber = 0;
wasAccessed = false;
}
/**
* Getter to check whether this runtime replacement was accessed during test
* execution
*
* @return a boolean.
*/
public static boolean wasAccessed() {
return wasAccessed;
}
/**
* Replacement for function java.util.UUID.randomUUID()
* @return
*/
public static UUID randomUUID() {
wasAccessed = true;
byte[] randomBytes = new byte[16];
nextBytes(randomBytes);
randomBytes[6] &= 0x0f; /* clear version */
randomBytes[6] |= 0x40; /* set to version 4 */
randomBytes[8] &= 0x3f; /* clear variant */
randomBytes[8] |= 0x80; /* set to IETF variant */
UUID newUUID = buildNewUUID(randomBytes);
return newUUID;
}
/**
* Replacement for creation of new UUID using byte[]
* @param data
* @return
*/
private static UUID buildNewUUID(byte[] data) {
long msb = 0;
long lsb = 0;
assert data.length == 16 : "data must be 16 bytes in length";
for (int i=0; i<8; i++)
msb = (msb << 8) | (data[i] & 0xff);
for (int i=8; i<16; i++)
lsb = (lsb << 8) | (data[i] & 0xff);
UUID newUUID = new UUID(msb,lsb);
return newUUID;
}
public static int getCurrentNumber() {
return currentNumber;
}
}