bench_main.cpp

#include <cstdlib>
#include <iostream>
#include <string>
#include <string_view>

#include "benchmark.h"

// Single-config benchmark runner. Emits ONE CSV row so the sweep script can run
// each thread count in its own process (giving an accurate per-config peak RSS).
//
//   log_bench --input <file> --threads N [--chunk-mb 16] [--header]
//
// CSV columns: threads,runtime_ms,throughput_mb_s,peak_rss_mb,total_requests
int main(int argc, char** argv) {
  std::string input;
  unsigned threads = 1;
  std::size_t chunk_mb = 16;
  bool header = false;

  for (int i = 1; i < argc; ++i) {
    std::string_view a = argv[i];
    auto next = [&]() -> std::string { return (i + 1 < argc) ? argv[++i] : ""; };
    if (a == "--input") {
      input = next();
    } else if (a == "--threads") {
      threads = static_cast<unsigned>(std::stoul(next()));
    } else if (a == "--chunk-mb") {
      chunk_mb = static_cast<std::size_t>(std::stoul(next()));
    } else if (a == "--header") {
      header = true;
    } else {
      std::cerr << "Unknown argument: " << a << "\n";
      return 2;
    }
  }
  if (input.empty()) {
    std::cerr << "Usage: log_bench --input <file> --threads N "
                 "[--chunk-mb 16] [--header]\n";
    return 2;
  }

  try {
    BenchmarkResult r = run_benchmark(input, threads, chunk_mb * 1024 * 1024);
    if (header) {
      std::cout << "threads,runtime_ms,throughput_mb_s,peak_rss_mb,total_requests\n";
    }
    std::cout << r.threads << "," << r.runtime_ms << "," << r.throughput_mb_s << ","
              << r.peak_rss_mb << "," << r.total_requests << "\n";
    return 0;
  } catch (const std::exception& ex) {
    std::cerr << "Error: " << ex.what() << "\n";
    return 1;
  }
}