@GwtIncompatible // TODO
public void testLog10Ceiling() {
for (BigInteger x : POSITIVE_BIGINTEGER_CANDIDATES) {
for (RoundingMode mode : asList(CEILING, UP)) {
int result = BigIntegerMath.log10(x, mode);
assertTrue(TEN.pow(result).compareTo(x) >= 0);
assertTrue(result == 0 || TEN.pow(result - 1).compareTo(x) < 0);
}
}
}
@GwtIncompatible // TODO
public void testLog10Floor() {
for (BigInteger x : POSITIVE_BIGINTEGER_CANDIDATES) {
for (RoundingMode mode : asList(FLOOR, DOWN)) {
int result = BigIntegerMath.log10(x, mode);
assertTrue(TEN.pow(result).compareTo(x) <= 0);
assertTrue(TEN.pow(result + 1).compareTo(x) > 0);
}
}
}
@GwtIncompatible // TODO
public void testLog10HalfDown() {
for (BigInteger x : POSITIVE_BIGINTEGER_CANDIDATES) {
int result = BigIntegerMath.log10(x, HALF_DOWN);
BigInteger x2 = x.pow(2);
// x^2 <= 10^(2 * result + 1), or else we would have rounded up
assertTrue(TEN.pow(2 * result + 1).compareTo(x2) >= 0);
// x^2 > 10^(2 * result - 1), or else we would have rounded down
assertTrue(result == 0 || TEN.pow(2 * result - 1).compareTo(x2) < 0);
}
}
@Override
public BigInteger generate(SourceOfRandomness random, GenerationStatus status) {
int numberOfBits = status.size() + 1;
if (min == null && max == null) return random.nextBigInteger(numberOfBits);
BigInteger minToUse = min;
BigInteger maxToUse = max;
if (minToUse == null) minToUse = maxToUse.subtract(TEN.pow(numberOfBits));
else if (maxToUse == null) maxToUse = minToUse.add(TEN.pow(numberOfBits));
return Ranges.randomBigIntegerInRange(random, minToUse, maxToUse);
}
@Override
protected void primeSourceOfRandomness() {
first = TEN.subtract(TEN.negate());
second = TEN.pow(2).subtract(TEN.pow(2).negate());
third = TEN.pow(3).subtract(TEN.pow(3).negate());
when(randomForParameterGenerator.nextBigInteger(first.toBigInteger().bitLength()))
.thenReturn(new BigInteger("999999999999"))
.thenReturn(BigInteger.ONE);
when(randomForParameterGenerator.nextBigInteger(second.toBigInteger().bitLength()))
.thenReturn(new BigInteger("136"));
when(randomForParameterGenerator.nextBigInteger(third.toBigInteger().bitLength()))
.thenReturn(new BigInteger("768"));
when(distro.sampleWithMean(1, randomForParameterGenerator)).thenReturn(0);
when(distro.sampleWithMean(2, randomForParameterGenerator)).thenReturn(1);
when(distro.sampleWithMean(3, randomForParameterGenerator)).thenReturn(2);
}
// Relies on the correctness of log10(BigInteger, FLOOR).
@GwtIncompatible // TODO
public void testLog10Exact() {
for (BigInteger x : POSITIVE_BIGINTEGER_CANDIDATES) {
int logFloor = BigIntegerMath.log10(x, FLOOR);
boolean expectSuccess = TEN.pow(logFloor).equals(x);
try {
assertEquals(logFloor, BigIntegerMath.log10(x, UNNECESSARY));
assertTrue(expectSuccess);
} catch (ArithmeticException e) {
assertFalse(expectSuccess);
}
}
}