/*
* Copyright (C) 2011 The Guava Authors
*
* 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.google.common.hash;
import static com.google.common.base.Charsets.UTF_8;
import static java.util.Arrays.asList;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableTable;
import com.google.common.collect.Lists;
import com.google.common.collect.Table.Cell;
import com.google.common.primitives.Ints;
import com.google.common.testing.EqualsTester;
import com.google.common.testing.NullPointerTester;
import com.google.common.util.concurrent.AtomicLongMap;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.nio.ByteBuffer;
import java.util.Collections;
import java.util.List;
import java.util.Locale;
import java.util.Random;
import junit.framework.TestCase;
/**
* Unit tests for {@link Hashing}.
*
* <p>TODO(b/33919189): Migrate repeated testing methods to {@link #HashTestUtils} and tweak unit
* tests to reference them from there.
*
* @author Dimitris Andreou
* @author Kurt Alfred Kluever
*/
public class HashingTest extends TestCase {
public void testMd5() {
HashTestUtils.checkAvalanche(Hashing.md5(), 100, 0.4);
HashTestUtils.checkNo2BitCharacteristics(Hashing.md5());
HashTestUtils.checkNoFunnels(Hashing.md5());
HashTestUtils.assertInvariants(Hashing.md5());
assertEquals("Hashing.md5()", Hashing.md5().toString());
}
public void testSha1() {
HashTestUtils.checkAvalanche(Hashing.sha1(), 100, 0.4);
HashTestUtils.checkNo2BitCharacteristics(Hashing.sha1());
HashTestUtils.checkNoFunnels(Hashing.sha1());
HashTestUtils.assertInvariants(Hashing.sha1());
assertEquals("Hashing.sha1()", Hashing.sha1().toString());
}
public void testSha256() {
HashTestUtils.checkAvalanche(Hashing.sha256(), 100, 0.4);
HashTestUtils.checkNo2BitCharacteristics(Hashing.sha256());
HashTestUtils.checkNoFunnels(Hashing.sha256());
HashTestUtils.assertInvariants(Hashing.sha256());
assertEquals("Hashing.sha256()", Hashing.sha256().toString());
}
public void testSha384() {
HashTestUtils.checkAvalanche(Hashing.sha384(), 100, 0.4);
HashTestUtils.checkNo2BitCharacteristics(Hashing.sha384());
HashTestUtils.checkNoFunnels(Hashing.sha384());
HashTestUtils.assertInvariants(Hashing.sha384());
assertEquals("Hashing.sha384()", Hashing.sha384().toString());
}
public void testSha512() {
HashTestUtils.checkAvalanche(Hashing.sha512(), 100, 0.4);
HashTestUtils.checkNo2BitCharacteristics(Hashing.sha512());
HashTestUtils.checkNoFunnels(Hashing.sha512());
HashTestUtils.assertInvariants(Hashing.sha512());
assertEquals("Hashing.sha512()", Hashing.sha512().toString());
}
public void testCrc32() {
HashTestUtils.assertInvariants(Hashing.crc32());
assertEquals("Hashing.crc32()", Hashing.crc32().toString());
}
public void testAdler32() {
HashTestUtils.assertInvariants(Hashing.adler32());
assertEquals("Hashing.adler32()", Hashing.adler32().toString());
}
public void testMurmur3_128() {
HashTestUtils.check2BitAvalanche(Hashing.murmur3_128(), 250, 0.20);
HashTestUtils.checkAvalanche(Hashing.murmur3_128(), 250, 0.17);
HashTestUtils.checkNo2BitCharacteristics(Hashing.murmur3_128());
HashTestUtils.checkNoFunnels(Hashing.murmur3_128());
HashTestUtils.assertInvariants(Hashing.murmur3_128());
assertEquals("Hashing.murmur3_128(0)", Hashing.murmur3_128().toString());
}
public void testMurmur3_32() {
HashTestUtils.check2BitAvalanche(Hashing.murmur3_32(), 250, 0.20);
HashTestUtils.checkAvalanche(Hashing.murmur3_32(), 250, 0.17);
HashTestUtils.checkNo2BitCharacteristics(Hashing.murmur3_32());
HashTestUtils.checkNoFunnels(Hashing.murmur3_32());
HashTestUtils.assertInvariants(Hashing.murmur3_32());
assertEquals("Hashing.murmur3_32(0)", Hashing.murmur3_32().toString());
}
public void testSipHash24() {
HashTestUtils.check2BitAvalanche(Hashing.sipHash24(), 250, 0.14);
HashTestUtils.checkAvalanche(Hashing.sipHash24(), 250, 0.10);
HashTestUtils.checkNo2BitCharacteristics(Hashing.sipHash24());
HashTestUtils.checkNoFunnels(Hashing.sipHash24());
HashTestUtils.assertInvariants(Hashing.sipHash24());
assertEquals("Hashing.sipHash24(506097522914230528, 1084818905618843912)",
Hashing.sipHash24().toString());
}
@AndroidIncompatible // slow TODO(cpovirk): Maybe just reduce iterations under Android.
public void testGoodFastHash() {
for (int i = 1; i < 200; i += 17) {
HashFunction hasher = Hashing.goodFastHash(i);
assertTrue(hasher.bits() >= i);
HashTestUtils.assertInvariants(hasher);
}
}
// goodFastHash(32) uses Murmur3_32. Use the same epsilon bounds.
public void testGoodFastHash32() {
HashTestUtils.check2BitAvalanche(Hashing.goodFastHash(32), 250, 0.20);
HashTestUtils.checkAvalanche(Hashing.goodFastHash(32), 250, 0.17);
HashTestUtils.checkNo2BitCharacteristics(Hashing.goodFastHash(32));
HashTestUtils.checkNoFunnels(Hashing.goodFastHash(32));
HashTestUtils.assertInvariants(Hashing.goodFastHash(32));
}
// goodFastHash(128) uses Murmur3_128. Use the same epsilon bounds.
public void testGoodFastHash128() {
HashTestUtils.check2BitAvalanche(Hashing.goodFastHash(128), 250, 0.20);
HashTestUtils.checkAvalanche(Hashing.goodFastHash(128), 250, 0.17);
HashTestUtils.checkNo2BitCharacteristics(Hashing.goodFastHash(128));
HashTestUtils.checkNoFunnels(Hashing.goodFastHash(128));
HashTestUtils.assertInvariants(Hashing.goodFastHash(128));
}
// goodFastHash(256) uses Murmur3_128. Use the same epsilon bounds.
public void testGoodFastHash256() {
HashTestUtils.check2BitAvalanche(Hashing.goodFastHash(256), 250, 0.20);
HashTestUtils.checkAvalanche(Hashing.goodFastHash(256), 250, 0.17);
HashTestUtils.checkNo2BitCharacteristics(Hashing.goodFastHash(256));
HashTestUtils.checkNoFunnels(Hashing.goodFastHash(256));
HashTestUtils.assertInvariants(Hashing.goodFastHash(256));
}
public void testConsistentHash_correctness() {
long[] interestingValues = { -1, 0, 1, 2, Long.MAX_VALUE, Long.MIN_VALUE };
for (long h : interestingValues) {
checkConsistentHashCorrectness(h);
}
Random r = new Random(7);
for (int i = 0; i < 20; i++) {
checkConsistentHashCorrectness(r.nextLong());
}
}
private void checkConsistentHashCorrectness(long hashCode) {
int last = 0;
for (int shards = 1; shards <= 100000; shards++) {
int b = Hashing.consistentHash(hashCode, shards);
if (b != last) {
assertEquals(shards - 1, b);
last = b;
}
}
}
public void testConsistentHash_probabilities() {
AtomicLongMap<Integer> map = AtomicLongMap.create();
Random r = new Random(9);
for (int i = 0; i < ITERS; i++) {
countRemaps(r.nextLong(), map);
}
for (int shard = 2; shard <= MAX_SHARDS; shard++) {
// Rough: don't exceed 1.2x the expected number of remaps by more than 20
assertTrue(map.get(shard) <= 1.2 * ITERS / shard + 20);
}
}
private void countRemaps(long h, AtomicLongMap<Integer> map) {
int last = 0;
for (int shards = 2; shards <= MAX_SHARDS; shards++) {
int chosen = Hashing.consistentHash(h, shards);
if (chosen != last) {
map.incrementAndGet(shards);
last = chosen;
}
}
}
private static final int ITERS = 10000;
private static final int MAX_SHARDS = 500;
public void testConsistentHash_outOfRange() {
try {
Hashing.consistentHash(5L, 0);
fail();
} catch (IllegalArgumentException expected) {
}
}
public void testConsistentHash_ofHashCode() {
checkSameResult(HashCode.fromLong(1), 1);
checkSameResult(HashCode.fromLong(0x9999999999999999L), 0x9999999999999999L);
checkSameResult(HashCode.fromInt(0x99999999), 0x0000000099999999L);
}
public void checkSameResult(HashCode hashCode, long equivLong) {
assertEquals(Hashing.consistentHash(equivLong, 5555), Hashing.consistentHash(hashCode, 5555));
}
/**
* Check a few "golden" values to see that implementations across languages
* are equivalent.
*/
public void testConsistentHash_linearCongruentialGeneratorCompatibility() {
int[] golden100 =
{ 0, 55, 62, 8, 45, 59, 86, 97, 82, 59,
73, 37, 17, 56, 86, 21, 90, 37, 38, 83 };
for (int i = 0; i < golden100.length; i++) {
assertEquals(golden100[i], Hashing.consistentHash(i, 100));
}
assertEquals(6, Hashing.consistentHash(10863919174838991L, 11));
assertEquals(3, Hashing.consistentHash(2016238256797177309L, 11));
assertEquals(5, Hashing.consistentHash(1673758223894951030L, 11));
assertEquals(80343, Hashing.consistentHash(2, 100001));
assertEquals(22152, Hashing.consistentHash(2201, 100001));
assertEquals(15018, Hashing.consistentHash(2202, 100001));
}
private static final double MAX_PERCENT_SPREAD = 0.5;
private static final long RANDOM_SEED = 177L;
public void testCombineOrdered_empty() {
try {
Hashing.combineOrdered(Collections.<HashCode>emptySet());
fail();
} catch (IllegalArgumentException expected) {
}
}
public void testCombineOrdered_differentBitLengths() {
try {
HashCode unused =
Hashing.combineOrdered(ImmutableList.of(HashCode.fromInt(32), HashCode.fromLong(32L)));
fail();
} catch (IllegalArgumentException expected) {
}
}
public void testCombineOrdered() {
HashCode hash31 = HashCode.fromInt(31);
HashCode hash32 = HashCode.fromInt(32);
assertEquals(hash32, Hashing.combineOrdered(ImmutableList.of(hash32)));
assertEquals(HashCode.fromBytes(new byte[] { (byte) 0x80, 0, 0, 0 }),
Hashing.combineOrdered(ImmutableList.of(hash32, hash32)));
assertEquals(HashCode.fromBytes(new byte[] { (byte) 0xa0, 0, 0, 0 }),
Hashing.combineOrdered(ImmutableList.of(hash32, hash32, hash32)));
assertFalse(
Hashing.combineOrdered(ImmutableList.of(hash31, hash32)).equals(
Hashing.combineOrdered(ImmutableList.of(hash32, hash31))));
}
public void testCombineOrdered_randomHashCodes() {
Random random = new Random(7);
List<HashCode> hashCodes = Lists.newArrayList();
for (int i = 0; i < 10; i++) {
hashCodes.add(HashCode.fromLong(random.nextLong()));
}
HashCode hashCode1 = Hashing.combineOrdered(hashCodes);
Collections.shuffle(hashCodes, random);
HashCode hashCode2 = Hashing.combineOrdered(hashCodes);
assertFalse(hashCode1.equals(hashCode2));
}
public void testCombineUnordered_empty() {
try {
Hashing.combineUnordered(Collections.<HashCode>emptySet());
fail();
} catch (IllegalArgumentException expected) {
}
}
public void testCombineUnordered_differentBitLengths() {
try {
HashCode unused =
Hashing.combineUnordered(ImmutableList.of(HashCode.fromInt(32), HashCode.fromLong(32L)));
fail();
} catch (IllegalArgumentException expected) {
}
}
public void testCombineUnordered() {
HashCode hash31 = HashCode.fromInt(31);
HashCode hash32 = HashCode.fromInt(32);
assertEquals(hash32, Hashing.combineUnordered(ImmutableList.of(hash32)));
assertEquals(HashCode.fromInt(64), Hashing.combineUnordered(ImmutableList.of(hash32, hash32)));
assertEquals(HashCode.fromInt(96),
Hashing.combineUnordered(ImmutableList.of(hash32, hash32, hash32)));
assertEquals(
Hashing.combineUnordered(ImmutableList.of(hash31, hash32)),
Hashing.combineUnordered(ImmutableList.of(hash32, hash31)));
}
public void testCombineUnordered_randomHashCodes() {
Random random = new Random(RANDOM_SEED);
List<HashCode> hashCodes = Lists.newArrayList();
for (int i = 0; i < 10; i++) {
hashCodes.add(HashCode.fromLong(random.nextLong()));
}
HashCode hashCode1 = Hashing.combineUnordered(hashCodes);
Collections.shuffle(hashCodes);
HashCode hashCode2 = Hashing.combineUnordered(hashCodes);
assertEquals(hashCode1, hashCode2);
}
// This isn't specified by contract, but it'll still be nice to know if this behavior changes.
public void testConcatenating_equals() {
new EqualsTester()
.addEqualityGroup(Hashing.concatenating(asList(Hashing.md5())))
.addEqualityGroup(Hashing.concatenating(asList(Hashing.murmur3_32())))
.addEqualityGroup(
Hashing.concatenating(Hashing.md5(), Hashing.md5()),
Hashing.concatenating(asList(Hashing.md5(), Hashing.md5())))
.addEqualityGroup(
Hashing.concatenating(Hashing.murmur3_32(), Hashing.md5()),
Hashing.concatenating(asList(Hashing.murmur3_32(), Hashing.md5())))
.addEqualityGroup(
Hashing.concatenating(Hashing.md5(), Hashing.murmur3_32()),
Hashing.concatenating(asList(Hashing.md5(), Hashing.murmur3_32())))
.testEquals();
}
public void testConcatenatingIterable_bits() {
assertEquals(
Hashing.md5().bits() + Hashing.md5().bits(),
Hashing.concatenating(asList(Hashing.md5(), Hashing.md5())).bits());
assertEquals(
Hashing.md5().bits() + Hashing.murmur3_32().bits(),
Hashing.concatenating(asList(Hashing.md5(), Hashing.murmur3_32())).bits());
assertEquals(
Hashing.md5().bits() + Hashing.murmur3_32().bits() + Hashing.murmur3_128().bits(),
Hashing.concatenating(
asList(Hashing.md5(), Hashing.murmur3_32(), Hashing.murmur3_128())).bits());
}
public void testConcatenatingVarArgs_bits() {
assertEquals(
Hashing.md5().bits() + Hashing.md5().bits(),
Hashing.concatenating(Hashing.md5(), Hashing.md5()).bits());
assertEquals(
Hashing.md5().bits() + Hashing.murmur3_32().bits(),
Hashing.concatenating(Hashing.md5(), Hashing.murmur3_32()).bits());
assertEquals(
Hashing.md5().bits() + Hashing.murmur3_32().bits() + Hashing.murmur3_128().bits(),
Hashing.concatenating(Hashing.md5(), Hashing.murmur3_32(), Hashing.murmur3_128()).bits());
}
public void testConcatenatingHashFunction_makeHash() {
byte[] md5Hash = Hashing.md5().hashLong(42L).asBytes();
byte[] murmur3Hash = Hashing.murmur3_32().hashLong(42L).asBytes();
byte[] combined = new byte[md5Hash.length + murmur3Hash.length];
ByteBuffer buffer = ByteBuffer.wrap(combined);
buffer.put(md5Hash);
buffer.put(murmur3Hash);
HashCode expected = HashCode.fromBytes(combined);
assertEquals(expected,
Hashing.concatenating(Hashing.md5(), Hashing.murmur3_32()).hashLong(42L));
assertEquals(expected,
Hashing.concatenating(asList(Hashing.md5(), Hashing.murmur3_32())).hashLong(42L));
}
public void testHashIntReverseBytesVsHashBytesIntsToByteArray() {
int input = 42;
assertEquals(
Hashing.md5().hashBytes(Ints.toByteArray(input)),
Hashing.md5().hashInt(Integer.reverseBytes(input)));
}
public void testHashIntVsForLoop() {
int input = 42;
HashCode expected = Hashing.md5().hashInt(input);
Hasher hasher = Hashing.md5().newHasher();
for (int i = 0; i < 32; i += 8) {
hasher.putByte((byte) (input >> i));
}
HashCode actual = hasher.hash();
assertEquals(expected, actual);
}
private static final String EMPTY_STRING = "";
private static final String TQBFJOTLD = "The quick brown fox jumps over the lazy dog";
private static final String TQBFJOTLDP = "The quick brown fox jumps over the lazy dog.";
private static final ImmutableTable<HashFunction, String, String> KNOWN_HASHES =
ImmutableTable.<HashFunction, String, String>builder()
.put(Hashing.adler32(), EMPTY_STRING, "01000000")
.put(Hashing.adler32(), TQBFJOTLD, "da0fdc5b")
.put(Hashing.adler32(), TQBFJOTLDP, "0810e46b")
.put(Hashing.md5(), EMPTY_STRING, "d41d8cd98f00b204e9800998ecf8427e")
.put(Hashing.md5(), TQBFJOTLD, "9e107d9d372bb6826bd81d3542a419d6")
.put(Hashing.md5(), TQBFJOTLDP, "e4d909c290d0fb1ca068ffaddf22cbd0")
.put(Hashing.murmur3_128(), EMPTY_STRING, "00000000000000000000000000000000")
.put(Hashing.murmur3_128(), TQBFJOTLD, "6c1b07bc7bbc4be347939ac4a93c437a")
.put(Hashing.murmur3_128(), TQBFJOTLDP, "c902e99e1f4899cde7b68789a3a15d69")
.put(Hashing.murmur3_32(), EMPTY_STRING, "00000000")
.put(Hashing.murmur3_32(), TQBFJOTLD, "23f74f2e")
.put(Hashing.murmur3_32(), TQBFJOTLDP, "fc8bc4d5")
.put(Hashing.sha1(), EMPTY_STRING, "da39a3ee5e6b4b0d3255bfef95601890afd80709")
.put(Hashing.sha1(), TQBFJOTLD, "2fd4e1c67a2d28fced849ee1bb76e7391b93eb12")
.put(Hashing.sha1(), TQBFJOTLDP, "408d94384216f890ff7a0c3528e8bed1e0b01621")
.put(
Hashing.sha256(),
EMPTY_STRING,
"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")
.put(
Hashing.sha256(),
TQBFJOTLD,
"d7a8fbb307d7809469ca9abcb0082e4f8d5651e46d3cdb762d02d0bf37c9e592")
.put(
Hashing.sha256(),
TQBFJOTLDP,
"ef537f25c895bfa782526529a9b63d97aa631564d5d789c2b765448c8635fb6c")
.put(
Hashing.sha384(),
EMPTY_STRING,
"38b060a751ac96384cd9327eb1b1e36a21fdb71114be07434c0cc7bf63f6e1da2"
+ "74edebfe76f65fbd51ad2f14898b95b")
.put(
Hashing.sha384(),
TQBFJOTLD,
"ca737f1014a48f4c0b6dd43cb177b0afd9e5169367544c494011e3317dbf9a509"
+ "cb1e5dc1e85a941bbee3d7f2afbc9b1")
.put(
Hashing.sha384(),
TQBFJOTLDP,
"ed892481d8272ca6df370bf706e4d7bc1b5739fa2177aae6c50e946678718fc67"
+ "a7af2819a021c2fc34e91bdb63409d7")
.put(
Hashing.sha512(),
EMPTY_STRING,
"cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce"
+ "47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e")
.put(
Hashing.sha512(),
TQBFJOTLD,
"07e547d9586f6a73f73fbac0435ed76951218fb7d0c8d788a309d785436bbb64"
+ "2e93a252a954f23912547d1e8a3b5ed6e1bfd7097821233fa0538f3db854fee6")
.put(
Hashing.sha512(),
TQBFJOTLDP,
"91ea1245f20d46ae9a037a989f54f1f790f0a47607eeb8a14d12890cea77a1bb"
+ "c6c7ed9cf205e67b7f2b8fd4c7dfd3a7a8617e45f3c463d481c7e586c39ac1ed")
.put(Hashing.crc32(), EMPTY_STRING, "00000000")
.put(Hashing.crc32(), TQBFJOTLD, "39a34f41")
.put(Hashing.crc32(), TQBFJOTLDP, "e9259051")
.put(Hashing.sipHash24(), EMPTY_STRING, "310e0edd47db6f72")
.put(Hashing.sipHash24(), TQBFJOTLD, "e46f1fdc05612752")
.put(Hashing.sipHash24(), TQBFJOTLDP, "9b602581fce4d4f8")
.put(Hashing.crc32c(), EMPTY_STRING, "00000000")
.put(Hashing.crc32c(), TQBFJOTLD, "04046222")
.put(Hashing.crc32c(), TQBFJOTLDP, "b3970019")
.put(Hashing.farmHashFingerprint64(), EMPTY_STRING, "4f40902f3b6ae19a")
.put(Hashing.farmHashFingerprint64(), TQBFJOTLD, "34511b3bf383beab")
.put(Hashing.farmHashFingerprint64(), TQBFJOTLDP, "737d7e5f8660653e")
.build();
public void testAllHashFunctionsHaveKnownHashes() throws Exception {
// The following legacy hashing function methods have been covered by unit testing already.
List<String> legacyHashingMethodNames = ImmutableList.of("murmur2_64", "fprint96");
for (Method method : Hashing.class.getDeclaredMethods()) {
if (method.getReturnType().equals(HashFunction.class) // must return HashFunction
&& Modifier.isPublic(method.getModifiers()) // only the public methods
&& method.getParameterTypes().length == 0 // only the seed-less grapes^W hash functions
&& !legacyHashingMethodNames.contains(method.getName())) {
HashFunction hashFunction = (HashFunction) method.invoke(Hashing.class);
assertTrue("There should be at least 3 entries in KNOWN_HASHES for " + hashFunction,
KNOWN_HASHES.row(hashFunction).size() >= 3);
}
}
}
public void testKnownUtf8Hashing() {
for (Cell<HashFunction, String, String> cell : KNOWN_HASHES.cellSet()) {
HashFunction func = cell.getRowKey();
String input = cell.getColumnKey();
String expected = cell.getValue();
assertEquals(
String.format(Locale.ROOT, "Known hash for hash(%s, UTF_8) failed", input),
expected,
func.hashString(input, UTF_8).toString());
}
}
public void testNullPointers() {
NullPointerTester tester = new NullPointerTester()
.setDefault(byte[].class, "secret key".getBytes(UTF_8))
.setDefault(HashCode.class, HashCode.fromLong(0));
tester.testAllPublicStaticMethods(Hashing.class);
}
public void testSeedlessHashFunctionEquals() throws Exception {
assertSeedlessHashFunctionEquals(Hashing.class);
}
public void testSeededHashFunctionEquals() throws Exception {
assertSeededHashFunctionEquals(Hashing.class);
}
/**
* Tests equality of {@link Hashing#goodFastHash} instances. This test must be separate from
* {@link #testSeededHashFunctionEquals} because the parameter to {@code goodFastHash} is a size,
* not a seed, and because that size is rounded up. Thus, {@code goodFastHash} instances with
* different parameters can be equal. That fact is a problem for {@code
* testSeededHashFunctionEquals}.
*/
public void testGoodFastHashEquals() throws Exception {
HashFunction hashFunction1a = Hashing.goodFastHash(1);
HashFunction hashFunction1b = Hashing.goodFastHash(32);
HashFunction hashFunction2a = Hashing.goodFastHash(33);
HashFunction hashFunction2b = Hashing.goodFastHash(128);
HashFunction hashFunction3a = Hashing.goodFastHash(129);
HashFunction hashFunction3b = Hashing.goodFastHash(256);
HashFunction hashFunction4a = Hashing.goodFastHash(257);
HashFunction hashFunction4b = Hashing.goodFastHash(384);
new EqualsTester()
.addEqualityGroup(hashFunction1a, hashFunction1b)
.addEqualityGroup(hashFunction2a, hashFunction2b)
.addEqualityGroup(hashFunction3a, hashFunction3b)
.addEqualityGroup(hashFunction4a, hashFunction4b)
.testEquals();
assertEquals(hashFunction1a.toString(), hashFunction1b.toString());
assertEquals(hashFunction2a.toString(), hashFunction2b.toString());
assertEquals(hashFunction3a.toString(), hashFunction3b.toString());
assertEquals(hashFunction4a.toString(), hashFunction4b.toString());
}
static void assertSeedlessHashFunctionEquals(Class<?> clazz) throws Exception {
for (Method method : clazz.getDeclaredMethods()) {
if (method.getReturnType().equals(HashFunction.class) // must return HashFunction
&& Modifier.isPublic(method.getModifiers()) // only the public methods
&& method.getParameterTypes().length == 0) { // only the seed-less hash functions
HashFunction hashFunction1a = (HashFunction) method.invoke(clazz);
HashFunction hashFunction1b = (HashFunction) method.invoke(clazz);
new EqualsTester()
.addEqualityGroup(hashFunction1a, hashFunction1b)
.testEquals();
// Make sure we're returning not only equal instances, but constants.
assertSame(hashFunction1a, hashFunction1b);
assertEquals(hashFunction1a.toString(), hashFunction1b.toString());
}
}
}
static void assertSeededHashFunctionEquals(Class<?> clazz) throws Exception {
Random random = new Random(RANDOM_SEED);
for (Method method : clazz.getDeclaredMethods()) {
if (method.getReturnType().equals(HashFunction.class) // must return HashFunction
&& Modifier.isPublic(method.getModifiers()) // only the public methods
&& method.getParameterTypes().length != 0 // only the seeded hash functions
&& !method.getName().equals("concatenating") // don't test Hashing.concatenating()
&& !method.getName().equals("goodFastHash") // tested in testGoodFastHashEquals
&& !method.getName().startsWith("hmac")) { // skip hmac functions
Object[] params1 = new Object[method.getParameterTypes().length];
Object[] params2 = new Object[method.getParameterTypes().length];
for (int i = 0; i < params1.length; i++) {
if (method.getParameterTypes()[i] == int.class) {
params1[i] = random.nextInt();
params2[i] = random.nextInt();
} else if (method.getParameterTypes()[i] == long.class) {
params1[i] = random.nextLong();
params2[i] = random.nextLong();
} else {
fail("Unable to create a random parameter for " + method.getParameterTypes()[i]);
}
}
HashFunction hashFunction1a = (HashFunction) method.invoke(clazz, params1);
HashFunction hashFunction1b = (HashFunction) method.invoke(clazz, params1);
HashFunction hashFunction2 = (HashFunction) method.invoke(clazz, params2);
new EqualsTester()
.addEqualityGroup(hashFunction1a, hashFunction1b)
.addEqualityGroup(hashFunction2)
.testEquals();
assertEquals(hashFunction1a.toString(), hashFunction1b.toString());
}
}
}
// Parity tests taken from //util/hash/hash_unittest.cc
}