parse.cpp

#include "event_counter.h"

#include <cassert>
#include <cctype>
#ifndef _MSC_VER
#include <dirent.h>
#endif
#include <unistd.h>
#include <cinttypes>

#include <cstdio>
#include <cstdlib>
#include <cstring>

#include <algorithm>
#include <chrono>
#include <cstring>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <map>
#include <set>
#include <sstream>
#include <string>
#include <vector>

#include "linux-perf-events.h"
#ifdef __linux__
#include <libgen.h>
#endif

#include "simdjson.h"

#include <functional>

#include "benchmarker.h"

using namespace simdjson;
using std::cerr;
using std::cout;
using std::endl;
using std::string;
using std::to_string;
using std::vector;
using std::ostream;
using std::ofstream;
using std::exception;

// Stash the exe_name in main() for functions to use
char* exe_name;

void print_usage(ostream& out) {
  out << "Usage: " << exe_name << " [-vt] [-n #] [-s STAGE] [-a ARCH] <jsonfile> ..." << endl;
  out << endl;
  out << "Runs the parser against the given json files in a loop, measuring speed and other statistics." << endl;
  out << endl;
  out << "Options:" << endl;
  out << endl;
  out << "-n #         - Number of iterations per file. Default: 200" << endl;
  out << "-i #         - Number of times to iterate a single file before moving to the next. Default: 20" << endl;
  out << "-t           - Tabbed data output" << endl;
  out << "-v           - Verbose output." << endl;
  out << "-s stage1    - Stop after find_structural_bits." << endl;
  out << "-s all       - Run all stages." << endl;
  out << "-C           - Leave the buffers cold (includes page allocation and related OS tasks during parsing, speed tied to OS performance)" << endl;
  out << "-H           - Make the buffers hot (reduce page allocation and related OS tasks during parsing) [default]" << endl;
  out << "-a IMPL      - Use the given parser implementation. By default, detects the most advanced" << endl;
  out << "               implementation supported on the host machine." << endl;
  for (auto impl : simdjson::get_available_implementations()) {
    if(impl->supported_by_runtime_system()) {
      out << "-a " << std::left << std::setw(9) << impl->name() << " - Use the " << impl->description() << " parser implementation." << endl;
    }
  }
}

void exit_usage(string message) {
  cerr << message << endl;
  cerr << endl;
  print_usage(cerr);
  exit(EXIT_FAILURE);
}

struct option_struct {
  vector<char*> files{};
  bool stage1_only = false;

  int32_t iterations = 200;
  int32_t iteration_step = -1;

  bool verbose = false;
  bool tabbed_output = false;
  /**
   * Benchmarking on a cold parser instance means that the parsing may include
   * memory allocation at the OS level. This may lead to apparently odd results
   * such that higher speed under the Windows Subsystem for Linux than under the
   * regular Windows, for the same machine. It is arguably misleading to benchmark
   * how the OS allocates memory, when we really want to just benchmark simdjson.
   */
  bool hotbuffers = true;

  option_struct(int argc, char **argv) {
    int c;

    while ((c = getopt(argc, argv, "vtn:i:a:s:HC")) != -1) {
      switch (c) {
      case 'n':
        iterations = atoi(optarg);
        break;
      case 'i':
        iteration_step = atoi(optarg);
        break;
      case 't':
        tabbed_output = true;
        break;
      case 'v':
        verbose = true;
        break;
      case 'a': {
        const implementation *impl = simdjson::get_available_implementations()[optarg];
        if ((!impl) || (!impl->supported_by_runtime_system())) {
          std::string exit_message = string("Unsupported option value -a ") + optarg + ": expected -a  with one of ";
          for (auto imple : simdjson::get_available_implementations()) {
            if(imple->supported_by_runtime_system()) {
              exit_message += imple->name();
              exit_message += " ";
            }
          }
          exit_usage(exit_message);
        }
        simdjson::get_active_implementation() = impl;
        break;
      }
      case 'C':
        hotbuffers = false;
        break;
      case 'H':
        hotbuffers = true;
        break;
      case 's':
        if (!strcmp(optarg, "stage1")) {
          stage1_only = true;
        } else if (!strcmp(optarg, "all")) {
          stage1_only = false;
        } else {
          exit_usage(string("Unsupported option value -s ") + optarg + ": expected -s stage1 or all");
        }
        break;
      default:
        // reaching here means an argument was given to getopt() which did not have a case label
        exit_usage("Unexpected argument - missing case for option "+
                    std::string(1,static_cast<char>(c))+
                    " (programming error)");
      }
    }

    if (iteration_step == -1) {
      iteration_step = iterations / 50;
      if (iteration_step < 200) { iteration_step = 200; }
      if (iteration_step > iterations) { iteration_step = iterations; }
    }

    // All remaining arguments are considered to be files
    for (int i=optind; i<argc; i++) {
      files.push_back(argv[i]);
    }
    if (files.empty()) {
      exit_usage("No files specified");
    }
  }
};

int main(int argc, char *argv[]) {
  // Read options
  exe_name = argv[0];
  option_struct options(argc, argv);
  if (options.verbose) {
    verbose_stream = &cout;
    verbose() << "Implementation: " << simdjson::get_active_implementation()->name() << endl;
  }

  // Start collecting events. We put this early so if it prints an error message, it's the
  // first thing printed.
  event_collector collector;

  // Print preamble
  if (!options.tabbed_output) {
    printf("number of iterations %u \n", options.iterations);
  }

  // Set up benchmarkers by reading all files
  vector<benchmarker*> benchmarkers;
  for (size_t i=0; i<options.files.size(); i++) {
    benchmarkers.push_back(new benchmarker(options.files[i], collector));
  }

  // Run the benchmarks
  progress_bar progress(options.iterations, 50);
  // Put the if (options.stage1_only) *outside* the loop so that run_iterations will be optimized
  if (options.stage1_only) {
    for (int iteration = 0; iteration < options.iterations; iteration += options.iteration_step) {
      if (!options.verbose) { progress.print(iteration); }
      // Benchmark each file once per iteration
      for (size_t f=0; f<options.files.size(); f++) {
        verbose() << "[verbose] " << benchmarkers[f]->filename << " iterations #" << iteration << "-" << (iteration+options.iteration_step-1) << endl;
        benchmarkers[f]->run_iterations(options.iteration_step, true, options.hotbuffers);
      }
    }
  } else {
    for (int iteration = 0; iteration < options.iterations; iteration += options.iteration_step) {
      if (!options.verbose) { progress.print(iteration); }
      // Benchmark each file once per iteration
      for (size_t f=0; f<options.files.size(); f++) {
        verbose() << "[verbose] " << benchmarkers[f]->filename << " iterations #" << iteration << "-" << (iteration+options.iteration_step-1) << endl;
        benchmarkers[f]->run_iterations(options.iteration_step, false, options.hotbuffers);
      }
    }
  }
  if (!options.verbose) { progress.erase(); }

  for (size_t i=0; i<options.files.size(); i++) {
    benchmarkers[i]->print(options.tabbed_output, options.stage1_only);
    delete benchmarkers[i];
  }

  return EXIT_SUCCESS;
}