gearman/examples/reverse_worker.cc

/*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
 * 
 *  Gearmand client and server library.
 *
 *  Copyright (C) 2011 Data Differential, http://datadifferential.com/
 *  Copyright (C) 2008 Brian Aker, Eric Day
 *  All rights reserved.
 *
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 *  modification, are permitted provided that the following conditions are
 *  met:
 *
 *      * Redistributions of source code must retain the above copyright
 *  notice, this list of conditions and the following disclaimer.
 *
 *      * Redistributions in binary form must reproduce the above
 *  copyright notice, this list of conditions and the following disclaimer
 *  in the documentation and/or other materials provided with the
 *  distribution.
 *
 *      * The names of its contributors may not be used to endorse or
 *  promote products derived from this software without specific prior
 *  written permission.
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 *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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 */



#include "gear_config.h"

#include <cerrno>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <signal.h>

#include <libgearman/gearman.h>
#include <boost/program_options.hpp>

struct reverse_worker_options_t
{
  bool chunk;
  bool status;
  bool unique;
  bool verbose;

  reverse_worker_options_t():
    chunk(false),
    status(false),
    unique(false),
    verbose(true)
  { }
};

#ifndef __INTEL_COMPILER
#pragma GCC diagnostic ignored "-Wold-style-cast"
#endif

static gearman_return_t reverse_worker(gearman_job_st *job, void *context)
{
  reverse_worker_options_t options= *((reverse_worker_options_t *)context);

  const char *workload= (const char *)gearman_job_workload(job);
  const size_t workload_size= gearman_job_workload_size(job);

  if (options.verbose)
  {
    std::cout << "Received " << workload_size << " bytes" << std::endl;
  }

  std::vector<char> result;
  result.resize(workload_size);

  // Copy workload
  for (size_t y= 0, x= workload_size; x; x--, y++)
  {
    result[y]= ((uint8_t *)workload)[x - 1];
  }

  if (options.chunk) // Chunk the result set
  {
    for (size_t y= 0, x= workload_size; x; x--, y++)
    {
      if (gearman_failed(gearman_job_send_data(job, &result[y], 1)))
      {
        return GEARMAN_ERROR;
      }

      if (options.status)
      {
        // Notice that we send based on y divided by zero.
        if (gearman_failed(gearman_job_send_status(job, (uint32_t)y, (uint32_t)workload_size)))
        {
          return GEARMAN_ERROR;
        }
      }
    }
  }
  else
  {
    if (options.status)
    {
      // Notice that we send based on y divided by zero.
      if (gearman_failed(gearman_job_send_status(job, (uint32_t)0, (uint32_t)workload_size)))
      {
        return GEARMAN_ERROR;
      }
    }

    if (gearman_failed(gearman_job_send_data(job, &result[0], workload_size)))
    {
      return GEARMAN_ERROR;
    }

    if (options.status)
    {
      // Notice that we send based on y divided by zero.
      if (gearman_failed(gearman_job_send_status(job, (uint32_t)workload_size, (uint32_t)workload_size)))
      {
        return GEARMAN_ERROR;
      }
    }
  }

  if (options.verbose)
  {
    std::cout << "Job=" << gearman_job_handle(job);
  }

  if (options.unique and options.verbose)
  {
    std::cout << "Unique=" << gearman_job_unique(job);
  }


  if (options.verbose)
  {
    std::cout << "  Reversed=";
    std::cout.write(workload, workload_size);
    std::cout << std::endl;
  }

  return GEARMAN_SUCCESS;
}

int main(int args, char *argv[])
{
  uint64_t limit;
  reverse_worker_options_t options;
  int timeout;

  in_port_t port;
  std::string host;
  std::string identifier;
  boost::program_options::options_description desc("Options");
  desc.add_options()
    ("help", "Options related to the program.")
    ("host,h", boost::program_options::value<std::string>(&host)->default_value("localhost"),"Connect to the host")
    ("identifier", boost::program_options::value<std::string>(&identifier),"Assign identifier")
    ("port,p", boost::program_options::value<in_port_t>(&port)->default_value(GEARMAN_DEFAULT_TCP_PORT), "Port number use for connection")
    ("count,c", boost::program_options::value<uint64_t>(&limit)->default_value(0), "Number of jobs to run before exiting")
    ("timeout,u", boost::program_options::value<int>(&timeout)->default_value(-1), "Timeout in milliseconds")
    ("chunk,d", boost::program_options::bool_switch(&options.chunk)->default_value(false), "Send result back in data chunks")
    ("status,s", boost::program_options::bool_switch(&options.status)->default_value(false), "Send status updates and sleep while running job")
    ("unique,u", boost::program_options::bool_switch(&options.unique)->default_value(false), "When grabbing jobs, grab the uniqie id")
    ("verbose", boost::program_options::bool_switch(&options.verbose)->default_value(true), "Print to stdout information as job is processed.")
            ;

  boost::program_options::variables_map vm;
  try
  {
    boost::program_options::store(boost::program_options::parse_command_line(args, argv, desc), vm);
    boost::program_options::notify(vm);
  }
  catch(std::exception &e)
  { 
    std::cout << e.what() << std::endl;
    return EXIT_FAILURE;
  }

  if (vm.count("help"))
  {
    std::cout << desc << std::endl;
    return EXIT_SUCCESS;
  }

  if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
  {
    std::cerr << "signal:" << strerror(errno) << std::endl;
    return EXIT_FAILURE;
  }

  gearman_worker_st *worker;
  if ((worker= gearman_worker_create(NULL)) == NULL)
  {
    std::cerr << "Memory allocation failure on worker creation." << std::endl;
    return EXIT_FAILURE;
  }

  if (options.unique)
  {
    gearman_worker_add_options(worker, GEARMAN_WORKER_GRAB_UNIQ);
  }

  if (timeout >= 0)
  {
    gearman_worker_set_timeout(worker, timeout);
  }

  if (gearman_failed(gearman_worker_add_server(worker, host.c_str(), port)))
  {
    std::cerr << gearman_worker_error(worker) << std::endl;
    return EXIT_FAILURE;
  }

  if (identifier.empty() == false)
  {
    if (gearman_failed(gearman_worker_set_identifier(worker, identifier.c_str(), identifier.size())))
    {
      std::cerr << gearman_worker_error(worker) << std::endl;
      return EXIT_FAILURE;
    }
  }

  gearman_function_t worker_fn= gearman_function_create(reverse_worker);
  if (gearman_failed(gearman_worker_define_function(worker,
                                                    gearman_literal_param("reverse"),
                                                    worker_fn,
                                                    0, 
                                                    &options)))
  {
    std::cerr << gearman_worker_error(worker) << std::endl;
    return EXIT_FAILURE;
  }

  // Add one if count is not zero
  if (limit != 0)
  {
    limit++;
  }

  while (--limit)
  {
    if (gearman_failed(gearman_worker_work(worker)))
    {
      std::cerr << gearman_worker_error(worker) << std::endl;
      break;
    }
  }

  gearman_worker_free(worker);

  return EXIT_SUCCESS;
}