BuildTree.cxx

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#include <string>

#include <TString.h>
#include <TSystem.h>

#include "eicsmear/erhic/Forester.h"
#include "eicsmear/erhic/File.h"

Long64_t
BuildTree(const TString& inputFileName,
          const TString& outputDirName,
          const Long64_t maxEvent,
          const std::string& logFileName) {
  // Set the maximum size of the tree on disk.
  // Once this size is reached a new file is opened for continued writing.
  // Set 10 Gb. Us LL to force long integer.
  TTree::SetMaxTreeSize(10LL * 1024LL * 1024LL * 1024LL);

  // Get the input file name, stripping any leading directory path via
  // use of the BaseName() method from TSystem.
  TString outName = gSystem->BaseName(inputFileName);

  // Remove the existing extension, if there is one.
  if (outName.Last('.') > -1) {
    outName.Replace(outName.Last('.'), outName.Length(), "");
  }  // if

  // If we are analysing a subset of events, include the number of events in
  // the file name before the extension.
  if (maxEvent > 0) {
    outName.Append(".");
    outName += maxEvent;
    outName.Append("event");
  }  // if

  outName.Append(".root");

  TString outDir(outputDirName);
  if (!outDir.EndsWith("/")) outDir.Append('/');
  outName.Prepend(outDir);

  // Configure an object of class Forester, which handles processing the text
  // file into a tree.
  erhic::Forester forester;
  forester.SetInputFileName(std::string(inputFileName));
  forester.SetOutputFileName(std::string(outName));
  forester.SetMaxNEvents(maxEvent);
  forester.SetMessageInterval(10000);
  forester.SetBeVerbose(true);
  forester.SetBranchName("event");

  Long64_t result = forester.Plant();  // Plant that tree!
  if (result != 0) {
    std::cerr << "Tree building failed" << std::endl;
    return result;
  }  // if

  // Search the log file for information.
  // Use the provided log file name if there is one, otherwise attempt
  // automated procedure to locate it.
  std::string logFile(logFileName);
  if (logFile.empty()) {
    logFile =
    erhic::LogReaderFactory::GetInstance().Locate(inputFileName.Data());
  }  // if

  // Use the FileType created by Forester when running to generate a
  // LogReader to process the log file, assuming a FileType was created and
  // the log file was located.
  if (forester.GetFileType() && !logFile.empty()) {
    TFile rootFile(outName, "UPDATE");
    erhic::LogReader* reader =
    forester.GetFileType()->CreateLogReader();
    if (reader) {
      bool wasRead = (reader ? reader->Extract(logFile) : false);
      if (wasRead) {
        reader->Save();
      }  // if
      delete reader;
    }  // if
  }  // if

  return result;
}