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MATH-1012 

Removed duplicate code.


git-svn-id: https://svn.apache.org/repos/asf/commons/proper/math/trunk@1509237 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Gilles Sadowski 2013-08-01 13:57:57 +00:00
parent a846ced6e3
commit fc1d4f9e91
1 changed files with 11 additions and 59 deletions
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70
src/main/java/org/apache/commons/math3/random/RandomDataGenerator.java
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@ -118,7 +118,7 @@ public class RandomDataGenerator implements RandomData, Serializable {
private RandomGenerator rand = null;
/** underlying secure random number generator */
private SecureRandom secRand = null;
private RandomGenerator secRand = null;
/**
* Construct a RandomDataGenerator, using a default random generator as the source
@ -278,7 +278,7 @@ public class RandomDataGenerator implements RandomData, Serializable {
}
// Get SecureRandom and setup Digest provider
SecureRandom secRan = getSecRan();
final RandomGenerator secRan = getSecRan();
MessageDigest alg = null;
try {
alg = MessageDigest.getInstance("SHA-1");
@ -323,25 +323,7 @@ public class RandomDataGenerator implements RandomData, Serializable {
/** {@inheritDoc} */
public int nextSecureInt(final int lower, final int upper) throws NumberIsTooLargeException {
if (lower >= upper) {
throw new NumberIsTooLargeException(LocalizedFormats.LOWER_BOUND_NOT_BELOW_UPPER_BOUND,
lower, upper, false);
}
final int max = (upper - lower) + 1;
if (max <= 0) {
// the range is too wide to fit in a positive int (larger than 2^31); as it covers
// more than half the integer range, we use directly a simple rejection method
final SecureRandom rng = getSecRan();
while (true) {
final int r = rng.nextInt();
if (r >= lower && r <= upper) {
return r;
}
}
} else {
// we can shift the range and generate directly a positive int
return lower + getSecRan().nextInt(max);
}
return new UniformIntegerDistribution(getSecRan(), lower, upper).sample();
}
/** {@inheritDoc} */
@ -350,11 +332,11 @@ public class RandomDataGenerator implements RandomData, Serializable {
throw new NumberIsTooLargeException(LocalizedFormats.LOWER_BOUND_NOT_BELOW_UPPER_BOUND,
lower, upper, false);
}
final RandomGenerator rng = getSecRan();
final long max = (upper - lower) + 1;
if (max <= 0) {
// the range is too wide to fit in a positive long (larger than 2^63); as it covers
// more than half the long range, we use directly a simple rejection method
final SecureRandom rng = getSecRan();
while (true) {
final long r = rng.nextLong();
if (r >= lower && r <= upper) {
@ -363,44 +345,13 @@ public class RandomDataGenerator implements RandomData, Serializable {
}
} else if (max < Integer.MAX_VALUE){
// we can shift the range and generate directly a positive int
return lower + getSecRan().nextInt((int) max);
return lower + rng.nextInt((int) max);
} else {
// we can shift the range and generate directly a positive long
return lower + nextLong(getSecRan(), max);
return lower + nextLong(rng, max);
}
}
/**
* Returns a pseudorandom, uniformly distributed <tt>long</tt> value
* between 0 (inclusive) and the specified value (exclusive), drawn from
* this random number generator's sequence.
*
* @param rng random generator to use
* @param n the bound on the random number to be returned. Must be
* positive.
* @return a pseudorandom, uniformly distributed <tt>long</tt>
* value between 0 (inclusive) and n (exclusive).
* @throws IllegalArgumentException if n is not positive.
*/
private static long nextLong(final SecureRandom rng, final long n) throws IllegalArgumentException {
if (n > 0) {
final byte[] byteArray = new byte[8];
long bits;
long val;
do {
rng.nextBytes(byteArray);
bits = 0;
for (final byte b : byteArray) {
bits = (bits << 8) | (((long) b) & 0xffL);
}
bits = bits & 0x7fffffffffffffffL;
val = bits % n;
} while (bits - val + (n - 1) < 0);
return val;
}
throw new NotStrictlyPositiveException(n);
}
/**
* {@inheritDoc}
* <p>
@ -793,7 +744,7 @@ public class RandomDataGenerator implements RandomData, Serializable {
*/
public void setSecureAlgorithm(String algorithm, String provider)
throws NoSuchAlgorithmException, NoSuchProviderException {
secRand = SecureRandom.getInstance(algorithm, provider);
secRand = RandomGeneratorFactory.createRandomGenerator(SecureRandom.getInstance(algorithm, provider));
}
/**
@ -829,11 +780,12 @@ public class RandomDataGenerator implements RandomData, Serializable {
* {@code System.currentTimeMillis() + System.identityHashCode(this)} as the default seed.
* </p>
*
* @return the SecureRandom used to generate secure random data
* @return the SecureRandom used to generate secure random data, wrapped in a
* {@link RandomGenerator}.
*/
private SecureRandom getSecRan() {
private RandomGenerator getSecRan() {
if (secRand == null) {
secRand = new SecureRandom();
secRand = RandomGeneratorFactory.createRandomGenerator(new SecureRandom());
secRand.setSeed(System.currentTimeMillis() + System.identityHashCode(this));
}
return secRand;