L1MuCSCPtLut.cc

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#include "CondFormats/L1TObjects/interface/L1MuCSCPtLut.h"
#include <FWCore/MessageLogger/interface/MessageLogger.h>
#include <sstream>
#include <iostream>
#include <cerrno>

void L1MuCSCPtLut::readFromDBS(std::string& ptLUT) {
  //edm::LogInfo( "L1-O2O: L1MuCSCPtLut" ) <<" Reading from DBS";

  // the ptLUT returned by the OMDS query will have a structure like number"\n"number"\n"
  // e.g., 32896\n32896\n32896\n32896\n and so on
  // remove the \n separator to write the pt_lut[1<<21] line-by-line
  for (size_t pos = ptLUT.find("\\n"); pos != std::string::npos; pos = ptLUT.find("\\n", pos)) {
    ptLUT[pos] = ' ';
    ptLUT[pos + 1] = '\n';
  }

  unsigned long length = 1 << 21;  //length of the ptLUT file

  std::stringstream file(ptLUT);
  if (file.fail())
    throw cms::Exception("Cannot open the ptLUT") << "L1MuCSCPtLut cannot open "
                                                  << "ptLUT from DBS (errno=" << errno << ")" << std::endl;

  // filling the ptLUT
  unsigned int address = 0;
  for (address = 0; !file.eof() && address < length; address++) {
    char buff[1024];
    file.getline(buff, 1024);
    int ptOutput = atoi(buff);

    // uncomment if you want to see line-by-line
    //edm::LogInfo( "L1-O2O: L1MuCSCPtLut" ) << "writing line "
    //                     << ptOutput;

    // Warning: this may throw non-cms like exception
    pt_lut[address] = ptOutput;
  }

  if (address != length)
    throw cms::Exception("Incorrect LUT size")
        << "L1MuCSCPtLut read " << address << " words from DBS instead of expected " << length << std::endl;
}