ClickHouse/dbms/src/Common/tests/array_cache.cpp

#include <iostream>
#include <cstring>
#include <thread>
#include <Common/ArrayCache.h>
#include <IO/ReadHelpers.h>


int main(int argc, char ** argv)
{
    size_t cache_size = DB::parse<size_t>(argv[1]);
    size_t num_threads = DB::parse<size_t>(argv[2]);
    size_t num_iterations = DB::parse<size_t>(argv[3]);
    size_t region_max_size = DB::parse<size_t>(argv[4]);
    size_t max_key = DB::parse<size_t>(argv[5]);

    using Cache = ArrayCache<int, int>;
    Cache cache(cache_size);

    std::vector<std::thread> threads;
    for (size_t i = 0; i < num_threads; ++i)
    {
        threads.emplace_back([&]
        {
            std::mt19937 generator(randomSeed());

            for (size_t i = 0; i < num_iterations; ++i)
            {
                size_t size = std::uniform_int_distribution<size_t>(1, region_max_size)(generator);
                int key = std::uniform_int_distribution<int>(1, max_key)(generator);

                cache.getOrSet(
                    key,
                    [=]{ return size; },
                    [=](void * ptr, int & payload)
                    {
                        payload = i;
                        memset(ptr, i, size);
                    },
                    nullptr);
            }
        });
    }

    std::atomic_bool stop{};

    std::thread stats_thread([&]
    {
        while (!stop)
        {
            sleep(1);
            Cache::Statistics statistics = cache.getStatistics();
            std::cerr
                << "total_chunks_size: " << statistics.total_chunks_size << "\n"
                << "total_allocated_size: " << statistics.total_allocated_size << "\n"
                << "total_size_currently_initialized: " << statistics.total_size_currently_initialized << "\n"
                << "total_size_in_use: " << statistics.total_size_in_use << "\n"
                << "num_chunks: " << statistics.num_chunks << "\n"
                << "num_regions: " << statistics.num_regions << "\n"
                << "num_free_regions: " << statistics.num_free_regions << "\n"
                << "num_regions_in_use: " << statistics.num_regions_in_use << "\n"
                << "num_keyed_regions: " << statistics.num_keyed_regions << "\n"
                << "hits: " << statistics.hits << "\n"
                << "concurrent_hits: " << statistics.concurrent_hits << "\n"
                << "misses: " << statistics.misses << "\n\n";
        }
    });

    for (auto & thread : threads)
        thread.join();

    stop = true;
    stats_thread.join();

    return 0;
}