replicant-frameworks_native/libs/utils/tests/BasicHashtable_test.cpp
Jeff Brown 66fbde3050 Add a basic hashtable data structure, with tests!
The basic hashtable is intended to be used to support a variety
of different datastructures such as map, set, multimap,
multiset, linkedmap, generationcache, etc.

Consequently its interface is fairly primitive.

The basic hashtable supports copy-on-write style functionality
using SharedBuffer.

The change introduces a simple generic function in TypeHelpers for
specifying hash functions.  The idea is to add template
specializations of hash_type<T> next to the relevant data structures
such as String8, String16, sp<T>, etc.

Change-Id: I2c479229e9d4527b4fbfe3b8b04776a2fd32c973
2011-11-22 17:12:22 -08:00

578 lines
17 KiB
C++

/*
* Copyright (C) 2011 The Android Open Source Project
*
* 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.
*/
#define LOG_TAG "BasicHashtable_test"
#include <utils/BasicHashtable.h>
#include <cutils/log.h>
#include <gtest/gtest.h>
#include <unistd.h>
namespace android {
typedef int SimpleKey;
typedef int SimpleValue;
typedef key_value_pair_t<SimpleKey, SimpleValue> SimpleEntry;
typedef BasicHashtable<SimpleKey, SimpleEntry> SimpleHashtable;
struct ComplexKey {
int k;
explicit ComplexKey(int k) : k(k) {
instanceCount += 1;
}
ComplexKey(const ComplexKey& other) : k(other.k) {
instanceCount += 1;
}
~ComplexKey() {
instanceCount -= 1;
}
bool operator ==(const ComplexKey& other) const {
return k == other.k;
}
bool operator !=(const ComplexKey& other) const {
return k != other.k;
}
static ssize_t instanceCount;
};
ssize_t ComplexKey::instanceCount = 0;
template<> inline hash_t hash_type(const ComplexKey& value) {
return hash_type(value.k);
}
struct ComplexValue {
int v;
explicit ComplexValue(int v) : v(v) {
instanceCount += 1;
}
ComplexValue(const ComplexValue& other) : v(other.v) {
instanceCount += 1;
}
~ComplexValue() {
instanceCount -= 1;
}
static ssize_t instanceCount;
};
ssize_t ComplexValue::instanceCount = 0;
typedef key_value_pair_t<ComplexKey, ComplexValue> ComplexEntry;
typedef BasicHashtable<ComplexKey, ComplexEntry> ComplexHashtable;
class BasicHashtableTest : public testing::Test {
protected:
virtual void SetUp() {
ComplexKey::instanceCount = 0;
ComplexValue::instanceCount = 0;
}
virtual void TearDown() {
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(0, 0));
}
void assertInstanceCount(ssize_t keys, ssize_t values) {
if (keys != ComplexKey::instanceCount || values != ComplexValue::instanceCount) {
FAIL() << "Expected " << keys << " keys and " << values << " values "
"but there were actually " << ComplexKey::instanceCount << " keys and "
<< ComplexValue::instanceCount << " values";
}
}
public:
template <typename TKey, typename TEntry>
static void cookieAt(const BasicHashtable<TKey, TEntry>& h, size_t index,
bool* collision, bool* present, hash_t* hash) {
uint32_t cookie = h.cookieAt(index);
*collision = cookie & BasicHashtable<TKey, TEntry>::Bucket::COLLISION;
*present = cookie & BasicHashtable<TKey, TEntry>::Bucket::PRESENT;
*hash = cookie & BasicHashtable<TKey, TEntry>::Bucket::HASH_MASK;
}
template <typename TKey, typename TEntry>
static const void* getBuckets(const BasicHashtable<TKey, TEntry>& h) {
return h.mBuckets;
}
};
template <typename TKey, typename TValue>
static size_t add(BasicHashtable<TKey, key_value_pair_t<TKey, TValue> >& h,
const TKey& key, const TValue& value) {
return h.add(hash_type(key), key_value_pair_t<TKey, TValue>(key, value));
}
template <typename TKey, typename TValue>
static ssize_t find(BasicHashtable<TKey, key_value_pair_t<TKey, TValue> >& h,
ssize_t index, const TKey& key) {
return h.find(index, hash_type(key), key);
}
template <typename TKey, typename TValue>
static bool remove(BasicHashtable<TKey, key_value_pair_t<TKey, TValue> >& h,
const TKey& key) {
ssize_t index = find(h, -1, key);
if (index >= 0) {
h.removeAt(index);
return true;
}
return false;
}
template <typename TEntry>
static void getKeyValue(const TEntry& entry, int* key, int* value);
template <> void getKeyValue(const SimpleEntry& entry, int* key, int* value) {
*key = entry.key;
*value = entry.value;
}
template <> void getKeyValue(const ComplexEntry& entry, int* key, int* value) {
*key = entry.key.k;
*value = entry.value.v;
}
template <typename TKey, typename TValue>
static void dump(BasicHashtable<TKey, key_value_pair_t<TKey, TValue> >& h) {
LOGD("hashtable %p, size=%u, capacity=%u, bucketCount=%u",
&h, h.size(), h.capacity(), h.bucketCount());
for (size_t i = 0; i < h.bucketCount(); i++) {
bool collision, present;
hash_t hash;
BasicHashtableTest::cookieAt(h, i, &collision, &present, &hash);
if (present) {
int key, value;
getKeyValue(h.entryAt(i), &key, &value);
LOGD(" [%3u] = collision=%d, present=%d, hash=0x%08x, key=%3d, value=%3d, "
"hash_type(key)=0x%08x",
i, collision, present, hash, key, value, hash_type(key));
} else {
LOGD(" [%3u] = collision=%d, present=%d",
i, collision, present);
}
}
}
TEST_F(BasicHashtableTest, DefaultConstructor_WithDefaultProperties) {
SimpleHashtable h;
EXPECT_EQ(0U, h.size());
EXPECT_EQ(3U, h.capacity());
EXPECT_EQ(5U, h.bucketCount());
EXPECT_EQ(0.75f, h.loadFactor());
}
TEST_F(BasicHashtableTest, Constructor_WithNonUnityLoadFactor) {
SimpleHashtable h(52, 0.8f);
EXPECT_EQ(0U, h.size());
EXPECT_EQ(77U, h.capacity());
EXPECT_EQ(97U, h.bucketCount());
EXPECT_EQ(0.8f, h.loadFactor());
}
TEST_F(BasicHashtableTest, Constructor_WithUnityLoadFactorAndExactCapacity) {
SimpleHashtable h(46, 1.0f);
EXPECT_EQ(0U, h.size());
EXPECT_EQ(46U, h.capacity()); // must be one less than bucketCount because loadFactor == 1.0f
EXPECT_EQ(47U, h.bucketCount());
EXPECT_EQ(1.0f, h.loadFactor());
}
TEST_F(BasicHashtableTest, Constructor_WithUnityLoadFactorAndInexactCapacity) {
SimpleHashtable h(42, 1.0f);
EXPECT_EQ(0U, h.size());
EXPECT_EQ(46U, h.capacity()); // must be one less than bucketCount because loadFactor == 1.0f
EXPECT_EQ(47U, h.bucketCount());
EXPECT_EQ(1.0f, h.loadFactor());
}
TEST_F(BasicHashtableTest, FindAddFindRemoveFind_OneEntry) {
SimpleHashtable h;
ssize_t index = find(h, -1, 8);
ASSERT_EQ(-1, index);
index = add(h, 8, 1);
ASSERT_EQ(1U, h.size());
ASSERT_EQ(index, find(h, -1, 8));
ASSERT_EQ(8, h.entryAt(index).key);
ASSERT_EQ(1, h.entryAt(index).value);
index = find(h, index, 8);
ASSERT_EQ(-1, index);
ASSERT_TRUE(remove(h, 8));
ASSERT_EQ(0U, h.size());
index = find(h, -1, 8);
ASSERT_EQ(-1, index);
}
TEST_F(BasicHashtableTest, FindAddFindRemoveFind_MultipleEntryWithUniqueKey) {
const size_t N = 11;
SimpleHashtable h;
for (size_t i = 0; i < N; i++) {
ssize_t index = find(h, -1, int(i));
ASSERT_EQ(-1, index);
index = add(h, int(i), int(i * 10));
ASSERT_EQ(i + 1, h.size());
ASSERT_EQ(index, find(h, -1, int(i)));
ASSERT_EQ(int(i), h.entryAt(index).key);
ASSERT_EQ(int(i * 10), h.entryAt(index).value);
index = find(h, index, int(i));
ASSERT_EQ(-1, index);
}
for (size_t i = N; --i > 0; ) {
ASSERT_TRUE(remove(h, int(i))) << "i = " << i;
ASSERT_EQ(i, h.size());
ssize_t index = find(h, -1, int(i));
ASSERT_EQ(-1, index);
}
}
TEST_F(BasicHashtableTest, FindAddFindRemoveFind_MultipleEntryWithDuplicateKey) {
const size_t N = 11;
const int K = 1;
SimpleHashtable h;
for (size_t i = 0; i < N; i++) {
ssize_t index = find(h, -1, K);
if (i == 0) {
ASSERT_EQ(-1, index);
} else {
ASSERT_NE(-1, index);
}
add(h, K, int(i));
ASSERT_EQ(i + 1, h.size());
index = -1;
int values = 0;
for (size_t j = 0; j <= i; j++) {
index = find(h, index, K);
ASSERT_GE(index, 0);
ASSERT_EQ(K, h.entryAt(index).key);
values |= 1 << h.entryAt(index).value;
}
ASSERT_EQ(values, (1 << (i + 1)) - 1);
index = find(h, index, K);
ASSERT_EQ(-1, index);
}
for (size_t i = N; --i > 0; ) {
ASSERT_TRUE(remove(h, K)) << "i = " << i;
ASSERT_EQ(i, h.size());
ssize_t index = -1;
for (size_t j = 0; j < i; j++) {
index = find(h, index, K);
ASSERT_GE(index, 0);
ASSERT_EQ(K, h.entryAt(index).key);
}
index = find(h, index, K);
ASSERT_EQ(-1, index);
}
}
TEST_F(BasicHashtableTest, Clear_WhenAlreadyEmpty_DoesNothing) {
SimpleHashtable h;
h.clear();
EXPECT_EQ(0U, h.size());
EXPECT_EQ(3U, h.capacity());
EXPECT_EQ(5U, h.bucketCount());
EXPECT_EQ(0.75f, h.loadFactor());
}
TEST_F(BasicHashtableTest, Clear_AfterElementsAdded_RemovesThem) {
SimpleHashtable h;
add(h, 0, 0);
add(h, 1, 0);
h.clear();
EXPECT_EQ(0U, h.size());
EXPECT_EQ(3U, h.capacity());
EXPECT_EQ(5U, h.bucketCount());
EXPECT_EQ(0.75f, h.loadFactor());
}
TEST_F(BasicHashtableTest, Clear_AfterElementsAdded_DestroysThem) {
ComplexHashtable h;
add(h, ComplexKey(0), ComplexValue(0));
add(h, ComplexKey(1), ComplexValue(0));
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(2, 2));
h.clear();
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(0, 0));
EXPECT_EQ(0U, h.size());
EXPECT_EQ(3U, h.capacity());
EXPECT_EQ(5U, h.bucketCount());
EXPECT_EQ(0.75f, h.loadFactor());
}
TEST_F(BasicHashtableTest, Remove_AfterElementsAdded_DestroysThem) {
ComplexHashtable h;
add(h, ComplexKey(0), ComplexValue(0));
add(h, ComplexKey(1), ComplexValue(0));
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(2, 2));
ASSERT_TRUE(remove(h, ComplexKey(0)));
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(1, 1));
ASSERT_TRUE(remove(h, ComplexKey(1)));
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(0, 0));
EXPECT_EQ(0U, h.size());
EXPECT_EQ(3U, h.capacity());
EXPECT_EQ(5U, h.bucketCount());
EXPECT_EQ(0.75f, h.loadFactor());
}
TEST_F(BasicHashtableTest, Destructor_AfterElementsAdded_DestroysThem) {
{
ComplexHashtable h;
add(h, ComplexKey(0), ComplexValue(0));
add(h, ComplexKey(1), ComplexValue(0));
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(2, 2));
} // h is destroyed here
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(0, 0));
}
TEST_F(BasicHashtableTest, Next_WhenEmpty_ReturnsMinusOne) {
SimpleHashtable h;
ASSERT_EQ(-1, h.next(-1));
}
TEST_F(BasicHashtableTest, Next_WhenNonEmpty_IteratesOverAllEntries) {
const int N = 88;
SimpleHashtable h;
for (int i = 0; i < N; i++) {
add(h, i, i * 10);
}
bool set[N];
memset(set, 0, sizeof(bool) * N);
int count = 0;
for (ssize_t index = -1; (index = h.next(index)) != -1; ) {
ASSERT_GE(index, 0);
ASSERT_LT(size_t(index), h.bucketCount());
const SimpleEntry& entry = h.entryAt(index);
ASSERT_GE(entry.key, 0);
ASSERT_LT(entry.key, N);
ASSERT_EQ(false, set[entry.key]);
ASSERT_EQ(entry.key * 10, entry.value);
set[entry.key] = true;
count += 1;
}
ASSERT_EQ(N, count);
}
TEST_F(BasicHashtableTest, Add_RehashesOnDemand) {
SimpleHashtable h;
size_t initialCapacity = h.capacity();
size_t initialBucketCount = h.bucketCount();
for (size_t i = 0; i < initialCapacity; i++) {
add(h, int(i), 0);
}
EXPECT_EQ(initialCapacity, h.size());
EXPECT_EQ(initialCapacity, h.capacity());
EXPECT_EQ(initialBucketCount, h.bucketCount());
add(h, -1, -1);
EXPECT_EQ(initialCapacity + 1, h.size());
EXPECT_GT(h.capacity(), initialCapacity);
EXPECT_GT(h.bucketCount(), initialBucketCount);
EXPECT_GT(h.bucketCount(), h.capacity());
}
TEST_F(BasicHashtableTest, Rehash_WhenCapacityAndBucketCountUnchanged_DoesNothing) {
ComplexHashtable h;
add(h, ComplexKey(0), ComplexValue(0));
const void* oldBuckets = getBuckets(h);
ASSERT_NE((void*)NULL, oldBuckets);
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(1, 1));
h.rehash(h.capacity(), h.loadFactor());
ASSERT_EQ(oldBuckets, getBuckets(h));
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(1, 1));
}
TEST_F(BasicHashtableTest, Rehash_WhenEmptyAndHasNoBuckets_ButDoesNotAllocateBuckets) {
ComplexHashtable h;
ASSERT_EQ((void*)NULL, getBuckets(h));
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(0, 0));
h.rehash(9, 1.0f);
EXPECT_EQ(0U, h.size());
EXPECT_EQ(10U, h.capacity());
EXPECT_EQ(11U, h.bucketCount());
EXPECT_EQ(1.0f, h.loadFactor());
EXPECT_EQ((void*)NULL, getBuckets(h));
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(0, 0));
}
TEST_F(BasicHashtableTest, Rehash_WhenEmptyAndHasBuckets_ReleasesBucketsAndSetsCapacity) {
ComplexHashtable h(10);
add(h, ComplexKey(0), ComplexValue(0));
ASSERT_TRUE(remove(h, ComplexKey(0)));
ASSERT_NE((void*)NULL, getBuckets(h));
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(0, 0));
h.rehash(0, 0.75f);
EXPECT_EQ(0U, h.size());
EXPECT_EQ(3U, h.capacity());
EXPECT_EQ(5U, h.bucketCount());
EXPECT_EQ(0.75f, h.loadFactor());
EXPECT_EQ((void*)NULL, getBuckets(h));
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(0, 0));
}
TEST_F(BasicHashtableTest, Rehash_WhenLessThanCurrentCapacity_ShrinksBuckets) {
ComplexHashtable h(10);
add(h, ComplexKey(0), ComplexValue(0));
add(h, ComplexKey(1), ComplexValue(1));
const void* oldBuckets = getBuckets(h);
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(2, 2));
h.rehash(0, 0.75f);
EXPECT_EQ(2U, h.size());
EXPECT_EQ(3U, h.capacity());
EXPECT_EQ(5U, h.bucketCount());
EXPECT_EQ(0.75f, h.loadFactor());
EXPECT_NE(oldBuckets, getBuckets(h));
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(2, 2));
}
TEST_F(BasicHashtableTest, CopyOnWrite) {
ComplexHashtable h1;
add(h1, ComplexKey(0), ComplexValue(0));
add(h1, ComplexKey(1), ComplexValue(1));
const void* originalBuckets = getBuckets(h1);
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(2, 2));
ssize_t index0 = find(h1, -1, ComplexKey(0));
EXPECT_GE(index0, 0);
// copy constructor acquires shared reference
ComplexHashtable h2(h1);
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(2, 2));
ASSERT_EQ(originalBuckets, getBuckets(h2));
EXPECT_EQ(h1.size(), h2.size());
EXPECT_EQ(h1.capacity(), h2.capacity());
EXPECT_EQ(h1.bucketCount(), h2.bucketCount());
EXPECT_EQ(h1.loadFactor(), h2.loadFactor());
EXPECT_EQ(index0, find(h2, -1, ComplexKey(0)));
// operator= acquires shared reference
ComplexHashtable h3;
h3 = h2;
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(2, 2));
ASSERT_EQ(originalBuckets, getBuckets(h3));
EXPECT_EQ(h1.size(), h3.size());
EXPECT_EQ(h1.capacity(), h3.capacity());
EXPECT_EQ(h1.bucketCount(), h3.bucketCount());
EXPECT_EQ(h1.loadFactor(), h3.loadFactor());
EXPECT_EQ(index0, find(h3, -1, ComplexKey(0)));
// editEntryAt copies shared contents
h1.editEntryAt(index0).value.v = 42;
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(4, 4));
ASSERT_NE(originalBuckets, getBuckets(h1));
EXPECT_EQ(42, h1.entryAt(index0).value.v);
EXPECT_EQ(0, h2.entryAt(index0).value.v);
EXPECT_EQ(0, h3.entryAt(index0).value.v);
// clear releases reference to shared contents
h2.clear();
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(4, 4));
EXPECT_EQ(0U, h2.size());
ASSERT_NE(originalBuckets, getBuckets(h2));
// operator= acquires shared reference, destroys unshared contents
h1 = h3;
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(2, 2));
ASSERT_EQ(originalBuckets, getBuckets(h1));
EXPECT_EQ(h3.size(), h1.size());
EXPECT_EQ(h3.capacity(), h1.capacity());
EXPECT_EQ(h3.bucketCount(), h1.bucketCount());
EXPECT_EQ(h3.loadFactor(), h1.loadFactor());
EXPECT_EQ(index0, find(h1, -1, ComplexKey(0)));
// add copies shared contents
add(h1, ComplexKey(2), ComplexValue(2));
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(5, 5));
ASSERT_NE(originalBuckets, getBuckets(h1));
EXPECT_EQ(3U, h1.size());
EXPECT_EQ(0U, h2.size());
EXPECT_EQ(2U, h3.size());
// remove copies shared contents
h1 = h3;
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(2, 2));
ASSERT_EQ(originalBuckets, getBuckets(h1));
h1.removeAt(index0);
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(3, 3));
ASSERT_NE(originalBuckets, getBuckets(h1));
EXPECT_EQ(1U, h1.size());
EXPECT_EQ(0U, h2.size());
EXPECT_EQ(2U, h3.size());
// rehash copies shared contents
h1 = h3;
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(2, 2));
ASSERT_EQ(originalBuckets, getBuckets(h1));
h1.rehash(10, 1.0f);
ASSERT_NO_FATAL_FAILURE(assertInstanceCount(4, 4));
ASSERT_NE(originalBuckets, getBuckets(h1));
EXPECT_EQ(2U, h1.size());
EXPECT_EQ(0U, h2.size());
EXPECT_EQ(2U, h3.size());
}
} // namespace android