1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "suggest/core/dictionary/bloom_filter.h"
18
19#include <gtest/gtest.h>
20
21#include <algorithm>
22#include <cstdlib>
23#include <functional>
24#include <random>
25#include <unordered_set>
26#include <vector>
27
28namespace latinime {
29namespace {
30
31TEST(BloomFilterTest, TestFilter) {
32    static const int TEST_RANDOM_DATA_MAX = 65536;
33    static const int ELEMENT_COUNT = 1000;
34    std::vector<int> elements;
35
36    // Initialize data set with random integers.
37    {
38        // Use the uniform integer distribution [0, TEST_RANDOM_DATA_MAX].
39        std::uniform_int_distribution<int> distribution(0, TEST_RANDOM_DATA_MAX);
40        auto randomNumberGenerator = std::bind(distribution, std::mt19937());
41        for (int i = 0; i < ELEMENT_COUNT; ++i) {
42            elements.push_back(randomNumberGenerator());
43        }
44    }
45
46    // Make sure BloomFilter contains nothing by default.
47    BloomFilter bloomFilter;
48    for (const int elem : elements) {
49        ASSERT_FALSE(bloomFilter.isInFilter(elem));
50    }
51
52    // Copy some of the test vector into bloom filter.
53    std::unordered_set<int> elementsThatHaveBeenSetInFilter;
54    {
55        // Use the uniform integer distribution [0, 1].
56        std::uniform_int_distribution<int> distribution(0, 1);
57        auto randomBitGenerator = std::bind(distribution, std::mt19937());
58        for (const int elem : elements) {
59            if (randomBitGenerator() == 0) {
60                bloomFilter.setInFilter(elem);
61                elementsThatHaveBeenSetInFilter.insert(elem);
62            }
63        }
64    }
65
66    for (const int elem : elements) {
67        const bool existsInFilter = bloomFilter.isInFilter(elem);
68        const bool hasBeenSetInFilter =
69                elementsThatHaveBeenSetInFilter.find(elem) != elementsThatHaveBeenSetInFilter.end();
70        if (hasBeenSetInFilter) {
71            EXPECT_TRUE(existsInFilter) << "elem: " << elem;
72        }
73        if (!existsInFilter) {
74            EXPECT_FALSE(hasBeenSetInFilter) << "elem: " << elem;
75        }
76    }
77}
78
79}  // namespace
80}  // namespace latinime
81