1/*
2 * Copyright (C) 2011 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the
10 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
11 * express or implied. See the License for the specific language governing permissions and
12 * limitations under the License.
13 */
14
15package com.google.common.primitives;
16
17import static java.math.BigInteger.ONE;
18
19import java.math.BigInteger;
20import java.util.Random;
21
22import junit.framework.TestCase;
23
24import com.google.common.annotations.GwtCompatible;
25import com.google.common.annotations.GwtIncompatible;
26import com.google.common.testing.NullPointerTester;
27
28/**
29 * Tests for UnsignedLongs
30 *
31 * @author Brian Milch
32 * @author Louis Wasserman
33 */
34@GwtCompatible(emulated = true)
35public class UnsignedLongsTest extends TestCase {
36
37  public void testCompare() {
38    // max value
39    assertTrue((UnsignedLongs.compare(0, 0xffffffffffffffffL) < 0));
40    assertTrue((UnsignedLongs.compare(0xffffffffffffffffL, 0) > 0));
41
42    // both with high bit set
43    assertTrue((UnsignedLongs.compare(0xff1a618b7f65ea12L, 0xffffffffffffffffL) < 0));
44    assertTrue((UnsignedLongs.compare(0xffffffffffffffffL, 0xff1a618b7f65ea12L) > 0));
45
46    // one with high bit set
47    assertTrue((UnsignedLongs.compare(0x5a4316b8c153ac4dL, 0xff1a618b7f65ea12L) < 0));
48    assertTrue((UnsignedLongs.compare(0xff1a618b7f65ea12L, 0x5a4316b8c153ac4dL) > 0));
49
50    // neither with high bit set
51    assertTrue((UnsignedLongs.compare(0x5a4316b8c153ac4dL, 0x6cf78a4b139a4e2aL) < 0));
52    assertTrue((UnsignedLongs.compare(0x6cf78a4b139a4e2aL, 0x5a4316b8c153ac4dL) > 0));
53
54    // same value
55    assertTrue((UnsignedLongs.compare(0xff1a618b7f65ea12L, 0xff1a618b7f65ea12L) == 0));
56  }
57
58  public void testDivide() {
59    assertEquals(2, UnsignedLongs.divide(14, 5));
60    assertEquals(0, UnsignedLongs.divide(0, 50));
61    assertEquals(1, UnsignedLongs.divide(0xfffffffffffffffeL, 0xfffffffffffffffdL));
62    assertEquals(0, UnsignedLongs.divide(0xfffffffffffffffdL, 0xfffffffffffffffeL));
63    assertEquals(281479271743488L, UnsignedLongs.divide(0xfffffffffffffffeL, 65535));
64    assertEquals(0x7fffffffffffffffL, UnsignedLongs.divide(0xfffffffffffffffeL, 2));
65    assertEquals(3689348814741910322L, UnsignedLongs.divide(0xfffffffffffffffeL, 5));
66  }
67
68  public void testRemainder() {
69    assertEquals(4, UnsignedLongs.remainder(14, 5));
70    assertEquals(0, UnsignedLongs.remainder(0, 50));
71    assertEquals(1, UnsignedLongs.remainder(0xfffffffffffffffeL, 0xfffffffffffffffdL));
72    assertEquals(0xfffffffffffffffdL,
73        UnsignedLongs.remainder(0xfffffffffffffffdL, 0xfffffffffffffffeL));
74    assertEquals(65534L, UnsignedLongs.remainder(0xfffffffffffffffeL, 65535));
75    assertEquals(0, UnsignedLongs.remainder(0xfffffffffffffffeL, 2));
76    assertEquals(4, UnsignedLongs.remainder(0xfffffffffffffffeL, 5));
77  }
78
79  @GwtIncompatible("Too slow in GWT (~3min fully optimized)")
80  public void testDivideRemainderEuclideanProperty() {
81    // Use a seed so that the test is deterministic:
82    Random r = new Random(0L);
83    for (int i = 0; i < 1000000; i++) {
84      long dividend = r.nextLong();
85      long divisor = r.nextLong();
86      // Test that the Euclidean property is preserved:
87      assertTrue(dividend - (divisor * UnsignedLongs.divide(dividend, divisor)
88          + UnsignedLongs.remainder(dividend, divisor)) == 0);
89    }
90  }
91
92  public void testParseLong() {
93    try {
94      assertEquals(0xffffffffffffffffL, UnsignedLongs.parseUnsignedLong("18446744073709551615"));
95      assertEquals(0x7fffffffffffffffL, UnsignedLongs.parseUnsignedLong("9223372036854775807"));
96      assertEquals(0xff1a618b7f65ea12L, UnsignedLongs.parseUnsignedLong("18382112080831834642"));
97      assertEquals(0x5a4316b8c153ac4dL, UnsignedLongs.parseUnsignedLong("6504067269626408013"));
98      assertEquals(0x6cf78a4b139a4e2aL, UnsignedLongs.parseUnsignedLong("7851896530399809066"));
99    } catch (NumberFormatException e) {
100      fail(e.getMessage());
101    }
102
103    boolean overflowCaught = false;
104    try {
105      // One more than maximum value
106      UnsignedLongs.parseUnsignedLong("18446744073709551616");
107    } catch (NumberFormatException e) {
108      overflowCaught = true;
109    }
110    assertTrue(overflowCaught);
111  }
112
113  public void testParseLongWithRadix() throws NumberFormatException {
114    assertEquals(0xffffffffffffffffL, UnsignedLongs.parseUnsignedLong("ffffffffffffffff", 16));
115    assertEquals(0x1234567890abcdefL, UnsignedLongs.parseUnsignedLong("1234567890abcdef", 16));
116
117    BigInteger max = BigInteger.ZERO.setBit(64).subtract(ONE);
118    // loops through all legal radix values.
119    for (int radix = Character.MIN_RADIX; radix <= Character.MAX_RADIX; radix++) {
120      // tests can successfully parse a number string with this radix.
121      String maxAsString = max.toString(radix);
122      assertEquals(max.longValue(), UnsignedLongs.parseUnsignedLong(maxAsString, radix));
123
124      try {
125        // tests that we get exception whre an overflow would occur.
126        BigInteger overflow = max.add(ONE);
127        String overflowAsString = overflow.toString(radix);
128        UnsignedLongs.parseUnsignedLong(overflowAsString, radix);
129        fail();
130      } catch (NumberFormatException nfe) {
131        // expected
132      }
133    }
134  }
135
136  public void testParseLongThrowsExceptionForInvalidRadix() {
137    // Valid radix values are Character.MIN_RADIX to Character.MAX_RADIX,
138    // inclusive.
139    try {
140      UnsignedLongs.parseUnsignedLong("0", Character.MIN_RADIX - 1);
141      fail();
142    } catch (NumberFormatException nfe) {
143      // expected
144    }
145
146    try {
147      UnsignedLongs.parseUnsignedLong("0", Character.MAX_RADIX + 1);
148      fail();
149    } catch (NumberFormatException nfe) {
150      // expected
151    }
152
153    // The radix is used as an array index, so try a negative value.
154    try {
155      UnsignedLongs.parseUnsignedLong("0", -1);
156      fail();
157    } catch (NumberFormatException nfe) {
158      // expected
159    }
160  }
161
162  public void testToString() {
163    String[] tests = {
164        "ffffffffffffffff",
165        "7fffffffffffffff",
166        "ff1a618b7f65ea12",
167        "5a4316b8c153ac4d",
168        "6cf78a4b139a4e2a"};
169    int[] bases = {2, 5, 7, 8, 10, 16};
170    for (int base : bases) {
171      for (String x : tests) {
172        BigInteger xValue = new BigInteger(x, 16);
173        long xLong = xValue.longValue(); // signed
174        assertEquals(xValue.toString(base), UnsignedLongs.toString(xLong, base));
175      }
176    }
177  }
178
179  @GwtIncompatible("NullPointerTester")
180  public void testNulls() throws Exception {
181    NullPointerTester tester = new NullPointerTester();
182    tester.setDefault(long[].class, new long[0]);
183    tester.setDefault(BigInteger.class, BigInteger.ZERO);
184    tester.testAllPublicStaticMethods(UnsignedLongs.class);
185  }
186}
187