For Pegasus issue #1089

bench.cpp

// Based on https://gist.github.com/Motherboard/9bce170327140a709dd40ac23bd863fa


#include <QDirIterator>
#include <chrono>
#include <filesystem>
#include <iostream>
#include <functional>
#include <dirent.h>

#define TEST_PATH "/tmp/Arcade"


unsigned long long get_time_for_qiter() {
    using namespace std::chrono;
    QDirIterator qiter(TEST_PATH);
    int num_files = 0;
    auto start_time = high_resolution_clock::now();
    while (qiter.hasNext()) {
        num_files++;
        qiter.next();
    }
    return (high_resolution_clock::now() - start_time).count();
}

unsigned long long get_time_for_ts() {
    using namespace std::chrono;
    using namespace std;
    int num_files = 0;
    auto start_time = high_resolution_clock::now();
    for (auto &_: filesystem::directory_iterator(TEST_PATH)) {
        num_files++;
    }
    return (high_resolution_clock::now() - start_time).count();
}

unsigned long long get_time_for_dirent() {
    using namespace std::chrono;
    int num_files = 0;

    auto start_time = high_resolution_clock::now();
    DIR* dir = opendir(TEST_PATH);
    for (struct dirent* entry = readdir(dir); entry != NULL; entry = readdir(dir)) {
        const QString name(entry->d_name);
        num_files++;
    }
    closedir(dir);
    return (high_resolution_clock::now() - start_time).count();
}


unsigned long long loop_test(std::function<double()> func) {
    unsigned long long time_sum = 0;
    for (int i=0; i < 10; ++i)
        time_sum += func();
    return time_sum;
}


int main(int argc, char *argv[])
{
    std::cout << "QDirIterator:             " << loop_test(get_time_for_qiter) << std::endl;
    std::cout << "c++17 directory_iterator: " << loop_test(get_time_for_ts) << std::endl;
    std::cout << "classic dirent:           " << loop_test(get_time_for_dirent) << std::endl;
}