data_read.cxx

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// Dear emacs, this is -*- c++ -*-
 
/**
 * @file data_read.cxx
 * @author <a href="mailto:Andre.dos.Anjos@cern.ch">Andre DOS ANJOS</a>
 * $Author: zhangy $
 * $Revision: 1.1.1.1 $
 * $Date: 2009/06/19 07:35:41 $
 *
 * Describes a test that benchmarks ROB reading. Each ROB is read once and all
 * of its ROD fragment data is touched.
 */
 
#include "clocks/Clock.h"
#include "clocks/Time.h"
#include "eformat/eformat.h"
#include <fstream>
#include <iostream>
#include <vector>
 
/**
 * Page size used as reference
 */
const size_t PAGE_SIZE   = 8192;    // 8 kilobytes pages
const size_t BUFFER_SIZE = 4194304; // 4 Megabytes
 
/**
 * Does the exercise itself.
 */
int main( int argc, char** argv ) {
  using namespace eformat;
 
  if ( argc != 2 )
  {
    std::cerr << "usage: " << argv[0] << " <test-file>" << std::endl;
    std::exit( 1 );
  }
 
  // time accounting
  double        cpu_time_used = 0;
  uint32_t      elements_read = 0;
  uint32_t      robs_read     = 0;
  RealTimeClock my_clock;
 
  // open normally a file
  std::fstream in( argv[1], std::ios::in | std::ios::binary );
  if ( !in )
  {
    std::cerr << "File `" << argv[1] << "' does not exist?!" << std::endl;
    std::exit( 1 );
  }
  size_t offset = 0;
 
#ifdef PAGED_MEMORY
  std::cout << "Working with paged storage with page size = " << PAGE_SIZE << " bytes."
            << std::endl;
#else
  std::cout << "Working with contiguous storage." << std::endl;
#endif
 
  while ( in && in.good() && !in.eof() )
  {
    // soft check, so we don't mistake too often
    uint32_t data[2];
    in.read( (char*)data, 8 );
    if ( !in.good() || in.eof() ) break; // end-of-file
    if ( data[0] != eformat::FULL_EVENT )
    {
      // stop!
      std::cout << "Word at offset " << HEX( offset ) << " is not "
                << HEX( eformat::FULL_EVENT ) << std::endl;
      std::exit( 1 );
    }
 
#ifdef PAGED_MEMORY
    // data[1] is the fragment size, in words. Take it and read the fragment
    in.seekg( offset );
    // read the event into my pages
    size_t to_read      = data[1] << 2;
    size_t page_counter = 0;
    // std::cout << "Loading page";
    uint32_t paged_event[BUFFER_SIZE / PAGE_SIZE][PAGE_SIZE / sizeof( uint32_t )];
    while ( to_read > 0 )
    {
      size_t readnow = ( PAGE_SIZE > to_read ) ? to_read : PAGE_SIZE;
      in.read( (char*)paged_event[page_counter], readnow );
      to_read -= readnow;
      ++page_counter;
      // std::cout << " " << page_counter;
    }
    // std::cout << ": ";
    struct iovec myvec[BUFFER_SIZE / PAGE_SIZE];
    for ( size_t i = 0; i < page_counter; ++i )
    {
      myvec[i].iov_base = paged_event[i];
      myvec[i].iov_len  = PAGE_SIZE;
    }
    // correct last page
    myvec[page_counter - 1].iov_len = data[1] << 2 - ( page_counter - 1 ) * PAGE_SIZE;
    eformat::PagedMemory<BUFFER_SIZE / PAGE_SIZE> mem( myvec, page_counter );
#else
    in.seekg( offset );
    uint32_t event[BUFFER_SIZE / 4];
    in.read( (char*)event, data[1] << 2 );
#endif
 
    offset += data[1] << 2;
 
    try
    {
#ifdef PAGED_MEMORY
      FullEventFragment<eformat::PagedMemory<BUFFER_SIZE / PAGE_SIZE>::const_iterator> fe(
          mem.begin() );
      typedef eformat::PagedMemory<BUFFER_SIZE / PAGE_SIZE>::const_iterator pointer_t;
#else
      FullEventFragment<const uint32_t*> fe( event );
      typedef const uint32_t*            pointer_t;
#endif
 
      std::vector<pointer_t> robs;
      // max SD's is well bellow 64
      pointer_t sdp[64];
      uint32_t  nsd = fe.children( sdp, 64 );
      for ( size_t i = 0; i < nsd; ++i )
      {
        SubDetectorFragment<pointer_t> sd( sdp[i] );
        // max ROS's in system is well bellow 256
        pointer_t rosp[256];
        uint32_t  nros = sd.children( rosp, 256 );
        for ( size_t j = 0; j < nros; ++j )
        {
          ROSFragment<pointer_t> ros( rosp[j] );
          // max number of ROB's is well bellow 2048
          pointer_t robp[2048];
          uint32_t  nrob = ros.children( robp, 2048 );
          robs.insert( robs.end(), robp, &robp[nrob] );
        }
      }
 
      uint32_t global_counter = 0;
      Time     start          = my_clock.time();
      for ( std::vector<pointer_t>::const_iterator it = robs.begin(); it != robs.end(); ++it )
      {
        ROBFragment<pointer_t> rob( *it );
        pointer_t              my;
        rob.rod_data( my );
        size_t ndata = rob.rod_ndata();
        for ( size_t m = 0; m < ndata; ++m )
        {
          global_counter += my[m];
          ++elements_read;
        }
        ++robs_read;
      }
      Time end  = my_clock.time();
      Time diff = end - start;
      cpu_time_used += diff.as_milliseconds();
    }
 
    catch ( eformat::Issue& ex )
    {
      std::cerr << std::endl << "Uncaught eformat exception: " << ex.what() << std::endl;
    }
 
    catch ( ers::Issue& ex )
    {
      std::cerr << std::endl << "Uncaught ERS exception: " << ex.what() << std::endl;
    }
 
    catch ( std::exception& ex )
    {
      std::cerr << std::endl << "Uncaught std exception: " << ex.what() << std::endl;
    }
 
    catch ( ... )
    { std::cerr << std::endl << "Uncaught unknown exception" << std::endl; }
  }
 
  std::cout << " Statistics for ROB data access:" << std::endl;
  std::cout << " -------------------------------" << std::endl;
  std::cout << "  - Total reading time: " << cpu_time_used << " millisecs" << std::endl;
  std::cout << "  - Reading time per ROB (" << robs_read
            << "): " << 1e3 * cpu_time_used / robs_read << " microsecs" << std::endl;
  std::cout << "  - Reading time per data word in a ROB (" << elements_read
            << "): " << 1e6 * cpu_time_used / elements_read << " nanosecs" << std::endl;
 
  std::exit( 0 );
}