Custom fifo feature + automatic removal + jetscape usage example

Author: jackal1-66

Generators/include/Generators/GeneratorFileOrCmd.h

@@ -141,13 +141,19 @@ struct GeneratorFileOrCmd {
    * @return true if the temporary file name was generated
    * successfully.
    */
-  virtual bool makeTemp();
+  virtual bool makeTemp(const bool&);
   /**
    * Remove the temporary file if it was set and it exists.
    *
    * @return true if the temporary file was removed.
    */
   virtual bool removeTemp() const;
+  /**
+   * Remove the FIFO if it was set and it exists.
+   *
+   * @return true if the FIFO file was removed.
+   */
+  virtual bool removeFifo() const;
   /**
    * Make a fifo at the location of the first element of the list of
    * file names (presumably a temporary file as created by

Generators/src/GeneratorFileOrCmd.cxx

@@ -126,19 +126,40 @@ bool GeneratorFileOrCmd::executeCmdLine(const std::string& cmd) const
   return true;
 }
 // -----------------------------------------------------------------
-bool GeneratorFileOrCmd::makeTemp()
+bool GeneratorFileOrCmd::makeTemp(const bool& fromName)
 {
-  mFileNames.clear();
-  char buf[] = "generatorFifoXXXXXX";
-  auto fp = mkstemp(buf);
-  if (fp < 0) {
-    LOG(fatal) << "Failed to make temporary file: "
-               << std::strerror(errno);
-    return false;
-  }
-  mTemporary = std::string(buf);
-  mFileNames.push_back(mTemporary);
-  close(fp);
+  if (fromName) {
+    if (mFileNames.empty()) {
+      LOG(fatal) << "No file names to make temporary file from";
+      return false;
+    } else if (mFileNames.size() > 1) {
+      LOG(warning) << "More than one file name to make temporary file from";
+      LOG(warning) << "Using the first one: " << mFileNames.front();
+      LOG(warning) << "Removing all the others";
+      mFileNames.erase(++mFileNames.begin(), mFileNames.end());
+    } else {
+      LOG(debug) << "Making temporary file from: " << mFileNames.front();
+    }
+    std::ofstream ofs(mFileNames.front().c_str());
+    if (!ofs) {
+      LOG(fatal) << "Failed to create temporary file: " << mFileNames.front();
+      return false;
+    }
+    mTemporary = std::string(mFileNames.front());
+    ofs.close();
+  } else {
+    mFileNames.clear();
+    char buf[] = "generatorFifoXXXXXX";
+    auto fp = mkstemp(buf);
+    if (fp < 0) {
+      LOG(fatal) << "Failed to make temporary file: "
+                 << std::strerror(errno);
+      return false;
+    }
+    mTemporary = std::string(buf);
+    mFileNames.push_back(mTemporary);
+    close(fp);
+  }  
   return true;
 }
 // -----------------------------------------------------------------
@@ -169,6 +190,29 @@ bool GeneratorFileOrCmd::removeTemp() const
   return true;
 }
 // -----------------------------------------------------------------
+bool GeneratorFileOrCmd::removeFifo() const
+{
+  if (mFileNames.empty()) {
+    LOG(warn) << "No FIFO filename available";
+  } else {
+    // Check if FIFO exist and remove it from filesystem
+    std::filesystem::path p(mFileNames.front());
+    if (not std::filesystem::exists(p)) {
+      LOG(warn) << "FIFO " << p << " did not exist";
+    } else {
+      std::error_code ec;
+      std::filesystem::remove(p, ec);
+      if (ec) {
+        LOG(error) << "Error while removing" << p << ": " << ec.message();
+        return false;
+      } else {
+        LOG(info) << "Removed FIFO " << p;
+      }
+    }
+  }  
+  return true;
+}
+// -----------------------------------------------------------------
 bool GeneratorFileOrCmd::makeFifo() const
 {
   // First remove the temporary file if it exists,

Generators/src/GeneratorHepMC.cxx

@@ -66,6 +66,9 @@ GeneratorHepMC::~GeneratorHepMC()
     delete mEvent;
   }
   removeTemp();
+  if (not mCmd.empty()) {
+    removeFifo();
+  }
 }
 
 /*****************************************************************/
@@ -574,9 +577,16 @@ Bool_t GeneratorHepMC::Init()
   // All of this can conviniently be achieved via a wrapper script
   // around the actual EG program.
   if (not mCmd.empty()) {
-    // Set filename to be a temporary name
-    if (not makeTemp()) {
-      return false;
+    if (mFileNames.empty()) {
+      // Set filename to be a temporary name
+      if (not makeTemp(false)) {
+        return false;
+      }
+    } else {
+      // Use the first filename as output for cmd line
+      if (not makeTemp(true)) {
+        return false;
+      }
     }
 
     // Make a fifo

Generators/src/GeneratorTParticle.cxx

@@ -54,9 +54,16 @@ Bool_t GeneratorTParticle::Init()
   mChain->SetBranchAddress(mBranchName.c_str(), &mTParticles);
 
   if (not mCmd.empty()) {
-    // Set filename to be a temporary name
-    if (not makeTemp()) {
-      return false;
+    if(mFileNames.empty()) {
+      // Set filename to be a temporary name
+      if (not makeTemp(false)) {
+        return false;
+      }
+    } else {
+      // Use the first filename as output for cmd line
+      if (not makeTemp(true)) {
+        return false;
+      }
     }
 
     // Build command line, Assumes command line parameter

run/SimExamples/HepMC_JETSCAPE/README.md

@@ -0,0 +1,67 @@
+<!-- doxy
+\page refrunSimExamplesHepMC_EPOS4 Example HepMC_EPOS4
+/doxy -->
+
+The usage of EPOS4 with the O2 machinery is presented in this short manual.
+An in-depth explanation of the mechanisms behind the HepMC(3) data handling can be found in the
+HepMC_fifo folder of the MC examples. The scripts use the `cmd` parameter of `GeneratorHepMC`
+to spawn the EPOS4 generation via the `epos.sh` script.
+
+EPOS4 uses the outdated HepMC2 libraries, so this had to be specified in the steering scripts
+of the generators configuration. If `HepMC.version=2` is removed then the scripts will not work
+anymore. This is to say that the balance achieved with the configurations provided is easily
+destroyed if the user base edits parts that are not understood completely.
+
+# Scripts description
+
+Four scripts are available to run the simulations
+- **epos.sh** &rarr; starts the actual EPOS4 generation
+- **runo2sim.sh** &rarr; allows the generation of events using o2-sim
+- **rundpg.sh** &rarr; starts the DPG machinery for event generation
+- **rundpl.sh** &rarr; starts the event generation with DPL
+
+In addition an example.optns file is provided to start EPOS4, but more can be found in the generator example folder
+or in the website [epos4learn.web.cern.ch](https://epos4learn.docs.cern.ch/) where an extensive tutorial on the generator is provided.
+
+## epos.sh
+
+It can be run without the help of the other scripts to simply generate an .hepmc file or print
+to the stdout the HepMC results. It it worth nothing though that EPOS4 must be loaded (via cvmfs through AliGenerators or O2sim for example) or installed. In this case the user should simply redirect the stdout to a file:
+```
+./epos.sh -i test -s 234345 > test.hepmc
+```
+This example shows all the functionalities of the script (which are implemented in a similar way inside
+the generation steering scripts). In particular the `-i` flag allows to provide .optns parameters to EPOS4,
+`-s` feeds the generator with a user seed, and the HepMC output is given by test.hepmc by redirecting the
+stdout which will contain only the HepMC data thanks to the `-hepstd` flag set automatically in epos.sh and
+the `set ihepmc 2` option which **MUST** be set in the option file (otherwise either an hepmc file will be created - ihepmc 1 - or nothing will be generated - missing ihepmc or != 1|2 ).
+
+It is important to note that setting an empty/null seed in the generator out of the box makes EPOS4 crash, so a protection was added in our steering epos.sh script which now generates a random number if 0 is provided.
+
+## runo2sim.sh, rundpg.sh and rundpl.sh
+
+The three scripts have little differences (especially in the first part), so they will be described together. They work after loading any O2sim version after the 20/09/2024 (included), since multiple modifications had to be performed on both EPOS4 and the introduction of AliGenO2 in order to be able to load both O2sim and EPOS4 simultaneously.
+
+If no parameters are provided to the scripts, they will run with default values (energy and nevents provided in the example.optns file), but few flags are available to change the settings of the generation:
+- **-m , --more** &rarr; feeds the simulation with advanced parameters provided to the configuration key flags
+- **-n , --nevents** &rarr; changes the number of events in the .optns file or gets the one in the file if no events are provided
+- **-i , --input** &rarr; .optns filename to feed EPOS4, no extension must be set in the filename
+- **-j , --jobs** &rarr; sets the number of workers (jobs)
+- **-h , --help** &rarr; prints usage instructions
+- **-e , --ecm** &rarr; sets the center-of-mass energy in the options file
+
+In the `rundpg.sh` script an additional flag is available
+- **-t , --tf** &rarr; number of timeframes to be generated
+
+In this case the options file will be copied in each tf$n folder, otherwise the epos script won't be able to run with multiple timeframes.
+In o2sim and DPG scripts the randomly generated seed is set directly, instead this is not feasible with the DPL one, given that the --seed option is not able to redirect this number to GeneratorHepMC. So a seed 0 is automatically given to epos.sh which generates a random number in return.
+
+Now the three scripts start to differ:
+
+- **runo2sim.sh** &rarr; o2-sim is launched
+- **rundpg.sh** &rarr; first the o2dpg_sim_workflow.py script will be launched generating the json configuration, then the o2_dpg_workflow_runner.py script will start the workflow
+- **rundpl.sh** &rarr; o2-sim-dpl-eventgen is executed piping its results to o2-sim-mctracks-to-aod and afterwards to o2-analysis-mctracks-to-aod-simple-task
+
+The last few lines of the scripts contain the execution of o2-sim, DPG worflow creator/runner and DPL software respectively, so this part can be modified by the users following their requirements. It's important not to delete from the configuration keys `GeneratorFileOrCmd.cmd=$cmd -i $optns;GeneratorFileOrCmd.bMaxSwitch=none;HepMC.version=2;` and it would be better to provide additional configurations via the -m flag. EPOS4 cannot set a maximum impact parameter value, so it's better to leave the bMaxSwitch to none, while the others serve the sole purpose of running successfully the generator using auto generated FIFOs.
+
+

run/SimExamples/HepMC_JETSCAPE/jetscape.sh

@@ -0,0 +1,72 @@
+#!/bin/sh
+# Script based on EPOS4 example
+# EPOS4 option files must contain ihepmc set to 2 to print HepMC
+# data on stdout. -hepmc flag is not needed anymore, but -hepstd is fundamental
+# in order not to print useless information on stdout (a z-*optns*.mtr file will be created)
+
+xml="example"
+seed=$RANDOM
+hepmc="jetout.hepmc"
+
+usage()
+{
+    cat <<EOF
+Usage: $0 [OPTIONS]
+
+Options:
+
+  -i,--input   INPUT       XML user file fed to JETSCAPE ($xml)
+  -o,--output  OUTPUT      HepMC output file ($hepmc)
+  -s,--seed    SEED        RNG seed ($seed)
+  -h,--help                Print these instructions
+  --                       Rest of command line sent to o2-sim
+
+EOF
+}
+
+while test $# -gt 0 ; do
+    case $1 in
+        -i|--input)   xml=$2 ; shift ;;
+        -o|--output)  hepmc=$2 ; shift ;;
+        -s|--seed)    seed=$2 ; shift ;;
+        -h|--help) usage; exit 0 ;;
+    esac
+    shift
+done
+
+if [ ! -f $xml.xml ]; then
+    echo "Error: Options file $xml.xml not found"
+    exit 1
+fi
+
+if [ $seed -eq 0 ]; then
+    echo "Seed can't be 0, random number will be used"
+    seed=$RANDOM
+else
+    if grep -Fq "<seed>" $xml.xml; then
+        sed -i "/<seed>/c\  <seed>$seed</seed>" $xml.xml
+    else
+        sed -i "/<\/jetscape>/i\  <Random>\n    <seed>$seed</seed>\n  </Random>" $xml.xml
+    fi
+    echo "Seed set to $seed"
+fi
+
+# Workaround to use the automatically generated FIFO as output file in JETSCAPE 
+# since no support for stdout is available and a better solution needs to be found
+# Check if hepmc is not empty and it's a fifo
+if [ ! -z "$hepmc" ]; then
+    # if $hepmc contains .hepmc remove it
+    newhep=$(echo $hepmc | sed 's/.hepmc//')
+    if grep -Fq "<outputFilename>" $xml.xml; then
+        sed -i "/<outputFilename>/c\  <outputFilename>$newhep</outputFilename>" $xml.xml
+    else
+        sed -i "/<jetscape>/a\  <outputFilename>$newhep</outputFilename>" $xml.xml
+    fi
+    echo "HepMC output file set to $hepmc"
+else
+    echo "Error: HepMC output file not set"
+    exit 2
+fi
+
+# Master XML file pulled directly from the JETSCAPE directory
+runJetscape $xml.xml $JETSCAPE_ROOT/config/jetscape_master.xml

run/SimExamples/HepMC_JETSCAPE/jetscape_user_example.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0"?>
+
+<jetscape>
+  
+  <nEvents>1000</nEvents>
+  
+  <Random>
+    <seed>1</seed>
+  </Random>
+
+  <outputFilename>jetscape</outputFilename>
+  
+  <!--Do not delete HepMC setting-->
+  <JetScapeWriterHepMC> on </JetScapeWriterHepMC>
+  
+  <!-- Hard Process -->
+  <Hard>
+    <PythiaGun>
+      <pTHatMin>235</pTHatMin>
+      <pTHatMax>1000</pTHatMax>
+      <eCM>5020</eCM>
+    </PythiaGun>
+  </Hard>
+  
+  <!--Eloss Modules -->
+  <Eloss>
+    <Matter> 
+      <Q0> 1.0 </Q0>
+      <in_vac> 1 </in_vac>
+      <vir_factor> 0.25 </vir_factor>
+      <recoil_on> 0 </recoil_on>
+      <broadening_on> 0 </broadening_on>
+      <brick_med> 0 </brick_med>
+    </Matter>
+  </Eloss>
+  
+  <!-- Jet Hadronization Module -->
+  <JetHadronization>
+    <name>colorless</name>
+  </JetHadronization>
+  
+</jetscape>