Add info about boost archive versions + version checker binary

README.md

@@ -214,6 +214,11 @@ FairRoot: `v18.6.7`
 
 Clang-format: `v11.0`
 
+Boost archives being only ensured to be `backward compatible` (and therefore not necessarily 
+`forward compatible`), care must be taken when writing data and/or parameter files with it 
+that the versions used when writing and when using/reading are compatible. \
+More information in the [following document](docs/boost_serialization_version.md).
+
 # 5. Further remarks
 
 Compiling CbmRoot with multicore support using "make -j", without

docs/boost_serialization_version.md

+# Boost serialization archive version
+
+```
+Boost version | BOOST_ARCHIVE_VERSION | Used in
+
+1.54          | 10                    |  [Ubuntu Trusty 14.04 LTS default, EOL: 2024-04]
+[...]
+1.67          | 16                    |  [Debian 10 Buster 19.07, EOL: 2022-08]
+1.68          | 17                    |  [Fairsoft jun19 and its patch versions]
+1.69          | 17                    |
+1.70          | 17                    |
+1.71          | 17                    |  [Ubuntu Focal 20.04 LTS, EOL: 2030-04]
+1.72          | 17                    |  [Fairsoft nov20]
+1.73          | 18                    |
+1.74          | 18                    |  [Debian 11 Bullseye 21.08, EOL: 2024-07] 
+                                         [Debian 12 Bookworm 23.07] 
+                                         [Ubuntu Jammy 22.04 LTS, EOL: 2032-04]
+1.75          | 18                    |  [Fairsoft apr21 and its patch versions]
+1.76          | 19                    |
+1.77          | 19                    |
+1.78          | 19                    |  [Fairsoft apr22 and its patch versions]
+1.79          | 19                    |
+1.80          | 19                    |  [Fairsoft nov22 and its patch versions]
+1.81          | 19                    |
+1.82          | 19                    |
+1.83          | 19                    |  [Fairsoft jan24 and its patch versions]
+1.84          | 20                    |
+dev           | 20                    |
+```
+
+-------------------
+- Based on [the corresponding list in the Flesnet repository](https://github.com/cbm-fles/flesnet/blob/master/doc/boost_serialization.txt)
+- List of BOOST_ARCHIVE_VERSION changes:
+https://github.com/boostorg/serialization/blob/develop/src/basic_archive.cpp
+
+# Version checker binary
+
+See the [README of services/boost_bin_arch_version_checker](../services/boost_bin_arch_version_checker/README.md)

services/boost_bin_arch_version_checker/README.md

+Standalone binary printing out the BOOST_ARCHIVE_VERSION of a boost binary archive and the minimal version of Fairsoft needed to read it.
+
+# Caveats
+
+1. The binary has to fully load/open the file to access the version number
+1. `boost` throws an `unsupported version` exception of type `boost::archive::archive_exception` when encountering an archive created with a more recent and non-backward compatible version
+
+=> !!! Use the newest version of `Fairsoft` or a most up to date version of `boost` to have largest compatibility !!!
+=> User will probably want to use another version of `boost` than the one making troubles, therefore the independent compilation
+
+# Compilation
+
+With `Fairsoft nov22p1`
+```
+g++ check_archive_version.cpp -I/cvmfs/fairsoft.gsi.de/debian10/fairsoft/nov22p1/include/boost/archive/ -L/cvmfs/fairsoft.gsi.de/debian10/fairsoft/nov22p1/lib -Wl,-rpath,/cvmfs/fairsoft.gsi.de/debian10/fairsoft/nov22p1/lib -lboost_serialization -o check_archive_version
+```
+
+# Usage 
+
+```
+./check_archive_version <PATH TO BOOST BINARY ARCHIVE>
+```
+
+# Example
+```
+> ./check_archive_version /lustre/cbm/online/output/mCBM_24/2914_00_00.rra 
+trying to check BOOST_ARCHIVE_VERSION of /lustre/cbm/online/output/mCBM_24/2914_00_00.rra
+get_library_version() for /lustre/cbm/online/output/mCBM_24/2914_00_00.rra
+ => 19
+Minimal Fairsoft version: apr22 and its patch versions
+```
+
+# Pre-compiled version on lustre 
+
+- !!! Subject to changes without warning !!!
+- Should work as long as operating under `Debian10` with `cvmfs` available (e.g. `vae23`or `GSI Linux on lxg/lxi`)
+- Tested on `vae23` and one lxg machine
+
+```
+/lustre/cbm/users/ploizeau/tools/boost/check_archive_version
+```

services/boost_bin_arch_version_checker/check_archive_version.cpp

+/* Copyright (C) 2024 GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt
+   SPDX-License-Identifier: GPL-3.0-only
+   Authors: Pierre-Alain Loizeau [committer] */
+
+#include <boost/archive/binary_iarchive.hpp>
+
+#include <fstream>
+#include <iostream>
+#include <sstream>
+
+int main(int argc, char* argv[])
+{
+
+  if (2 != argc) {
+    std::cout << "This small programm needs a path to a boost archive as input argument!" << std::endl;
+    return -1;
+  }
+
+  std::cout << "trying to check BOOST_ARCHIVE_VERSION of " << argv[1] << std::endl;
+
+  std::ifstream ifs(argv[1], std::ios::binary);
+  if (!ifs) {
+    std::stringstream msg;
+    msg << "file \"" << argv[1] << "\" was not found";
+    throw std::runtime_error(msg.str());
+  }
+
+  boost::archive::binary_iarchive ia(ifs);
+  unsigned v = ia.get_library_version();
+
+  std::cout << "get_library_version() for " << argv[1] << "\n => " << v << std::endl;
+  if (v < 17) {
+    std::cout << "Any version of Fairsoft supported by Cbmroot should work" << std::endl;
+  }
+  else {
+    switch (v) {
+      case 17: {
+        std::cout << "Minimal Fairsoft version: jun19 and its patch versions" << std::endl;
+        break;
+      }
+      case 18: {
+        std::cout << "Minimal Fairsoft version: apr21 and its patch versions" << std::endl;
+        break;
+      }
+      case 19: {
+        std::cout << "Minimal Fairsoft version: apr22 and its patch versions" << std::endl;
+        break;
+      }
+      case 20:
+      default: {
+        std::cout << "No Fairsoft version supporting this file to date (10/04/2024)" << std::endl;
+        break;
+      }
+    }
+  }
+
+  return v;
+}