benchio.cpp

// ibm-clang++64 -std=c++20 -O -o benchio benchio.cpp
#include "argparse.hpp"
#include "file.hpp"

#include <string>

static void read_file(const std::string & filename) {
    std::string mode = "rb";
    if (filename.starts_with("//")) {
        mode += ",type=record,noseek";
    }
    char buf[4096];
    File f(filename, mode);
    while (f.read(buf, sizeof buf));
}

static void write_file(const std::string & filename, size_t numrecs, bool sync) {
   std::string mode = "wb";
    if (filename.starts_with("//")) {
        mode += ",type=record,recfm=fb,lrecl=4096,blksize=0";
    }
    char buf[4096] = {0};
    File f(filename, mode);
    while (numrecs--) {
        f.write(buf, sizeof buf);
        if (sync) f.sync();
    }
}

int main(int argc, char *argv[]) {
    argparse::ArgumentParser program("benchio");

    program.add_argument("--mode")
        .required()
        .help("the mode, 'read' or 'write'");
    program.add_argument("-n", "--numrecs")
        .help("the number of records to write")
        .default_value(1000000)
        .scan<'i', int>();
    program.add_argument("-f", "--sync")
        .help("sync record after write operation")
        .default_value(false)
        .implicit_value(false);
    program.add_argument("filename")
        .help("the name of the file or data set");


    try {
        program.parse_args(argc, argv);
    } catch (const std::runtime_error &err) {
        std::cerr << err.what() << std::endl;
        std::cerr << program;
        return 1;
    }

    auto filename = program.get<std::string>("filename");
    auto mode = program.get<std::string>("mode");

    try {
        if (mode == "read") {
            read_file(filename);
        } else if (mode == "write") {
            auto n = program.get<int>("numrecs");
            write_file(filename, n, program.get<bool>("sync"));
        } else {
            throw std::runtime_error("Invalid mode: " + mode);
        }
    } catch (std::exception & e) {
        std::cerr << e.what() << "\n";
        return 1;
    }
}
/*

########## writes ############

> time ./benchio --mode write -n 200000  "//fb4096"

real	0m9.654s
user	0m0.138s
sys     0m0.055s

> time ./benchio --mode write -n 200000  fb4096.bin

real	0m2.850s
user	0m1.502s
sys     0m0.509s

> time ./benchio --mode write -n 200000 --sync fb4096.bin          

real	0m2.976s
user	0m1.561s
sys     0m0.529s

########## reads ############

> time ./benchio --mode read  "//fb4096"

real	0m3.304s
user	0m0.063s
sys     0m0.031s

> time ./benchio --mode read fb4096.bin

real	0m0.664s
user	0m0.457s
sys     0m0.161s


*/