libkiwix/test/lrucache.cpp

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#include "../src/tools/lrucache.h"
#include "../src/tools/concurrent_cache.h"
#include "gtest/gtest.h"

const unsigned int NUM_OF_TEST2_RECORDS = 100;
const unsigned int TEST2_CACHE_CAPACITY = 50;

TEST(CacheTest, SimplePut) {
    kiwix::lru_cache<int, int> cache_lru(1);
    cache_lru.put(7, 777);
    EXPECT_TRUE(cache_lru.exists(7));
    EXPECT_EQ(777, cache_lru.get(7));
    EXPECT_EQ(1U, cache_lru.size());
}

TEST(CacheTest, OverwritingPut) {
    kiwix::lru_cache<int, int> cache_lru(1);
    cache_lru.put(7, 777);
    cache_lru.put(7, 222);
    EXPECT_TRUE(cache_lru.exists(7));
    EXPECT_EQ(222, cache_lru.get(7));
    EXPECT_EQ(1U, cache_lru.size());
}

TEST(CacheTest, MissingValue) {
    kiwix::lru_cache<int, int> cache_lru(1);
    EXPECT_TRUE(cache_lru.get(7).miss());
    EXPECT_FALSE(cache_lru.get(7).hit());
    EXPECT_THROW(cache_lru.get(7).value(), std::range_error);
}

TEST(CacheTest, DropValue) {
    kiwix::lru_cache<int, int> cache_lru(3);
    cache_lru.put(7, 777);
    cache_lru.put(8, 888);
    cache_lru.put(9, 999);
    EXPECT_EQ(3U, cache_lru.size());
    EXPECT_TRUE(cache_lru.exists(7));
    EXPECT_EQ(777, cache_lru.get(7));

    EXPECT_TRUE(cache_lru.drop(7));

    EXPECT_EQ(2U, cache_lru.size());
    EXPECT_FALSE(cache_lru.exists(7));
    EXPECT_THROW(cache_lru.get(7).value(), std::range_error);

    EXPECT_FALSE(cache_lru.drop(7));
}

TEST(CacheTest1, KeepsAllValuesWithinCapacity) {
    kiwix::lru_cache<int, int> cache_lru(TEST2_CACHE_CAPACITY);

    for (unsigned int i = 0; i < NUM_OF_TEST2_RECORDS; ++i) {
        cache_lru.put(i, i);
    }

    for (unsigned int i = 0; i < NUM_OF_TEST2_RECORDS - TEST2_CACHE_CAPACITY; ++i) {
        EXPECT_FALSE(cache_lru.exists(i));
    }

    for (unsigned int i = NUM_OF_TEST2_RECORDS - TEST2_CACHE_CAPACITY; i < NUM_OF_TEST2_RECORDS; ++i) {
        EXPECT_TRUE(cache_lru.exists(i));
        EXPECT_EQ((int)i, cache_lru.get(i));
    }

    size_t size = cache_lru.size();
    EXPECT_EQ(TEST2_CACHE_CAPACITY, size);
}

TEST(ConcurrentCacheTest, handleException) {
    kiwix::ConcurrentCache<int, int> cache(1);
    auto val = cache.getOrPut(7, []() { return 777; });
    EXPECT_EQ(val, 777);
    EXPECT_THROW(cache.getOrPut(8, []() { throw std::runtime_error("oups"); return 0; }), std::runtime_error);
    val = cache.getOrPut(8, []() { return 888; });
    EXPECT_EQ(val, 888);
}

TEST(ConcurrentCacheTest, weakPtr) {
    kiwix::ConcurrentCache<int, std::shared_ptr<int>> cache(1);
    auto refValue = cache.getOrPut(7, []() { return std::make_shared<int>(777); });
    EXPECT_EQ(*refValue, 777);
    EXPECT_EQ(refValue.use_count(), 2);

    // This will drop shared(777) from the cache
    cache.getOrPut(8, []() { return std::make_shared<int>(888); });
    EXPECT_EQ(refValue.use_count(), 1);

    // We must get the shared value from the weakPtr we have
    EXPECT_NO_THROW(cache.getOrPut(7, []() { throw std::runtime_error("oups"); return nullptr; }));
    EXPECT_EQ(refValue.use_count(), 2);

    // Drop all ref
    cache.getOrPut(8, []() { return std::make_shared<int>(888); });
    refValue.reset();

    // Be sure we call the construction function
    EXPECT_THROW(cache.getOrPut(7, []() { throw std::runtime_error("oups"); return nullptr; }), std::runtime_error);
}