#include <cstring>
#include <set>
#include <sstream>
#include <TFile.h>
#include <TFileMergeInfo.h>
#include <TMemFile.h>
#include <TDirectory.h>
#include <TUUID.h>
#include <TSystem.h>
#include <TString.h>
#include <TList.h>
#include <TMethodCall.h>
#include <TClass.h>
#include <TKey.h>
#include <TTree.h>
#include <TROOT.h>
#include <TFunction.h>
#include <TTreeCloner.h>
#include "xAODRootAccess/tools/TFileMerger.h"
#include "xAODRootAccess/tools/Message.h"
#include "xAODRootAccess/tools/ReturnCheck.h"
#include "xAODRootAccess/tools/Utils.h"
Functions
	ClassImp (xAOD::TFileMerger) namespace xAOD
	Implement the auto-generated functions of the class. More...
Function Documentation

◆ ClassImp()

ClassImp ( xAOD::TFileMerger )
Implement the auto-generated functions of the class.
In order to merge various kinds of metadata from the input files correctly into the output file, it is possible to specify the type names of dual-use metadata handling tools. The object then creates an instance of the specified tool, which should take care of merging its metadata type in the background.
Parameters
typeName The type name of the tool to create
Returns: StatusCode::SUCCESS if the tool was successfully created, StatusCode::FAILURE if the tool could not be created, and StatusCode::RECOVERABLE if a tool of this type is already held by the object
This is the main function of the class. It executes the merging of the input xAOD files in the specified mode, and then closes all the files.
Parameters
mode	The merging mode to be used
entries	Entries to be merged into the output file. Only effective in slow merging mode.
Returns: StatusCode::SUCCESS if the merging was successful, or StatusCode::FAILURE if it wasn't
This function does most of the heavy-lifting in the code. It recursively merges all the objects from an input directory into the output file's corresponding directory.
Parameters
input	Directory in one of the input files
output	The corresponding directory in the output file
mode	The merging mode for the xAOD trees
topLevelDir	Flag whether this is the top directory in the file(s)
Returns: StatusCode::SUCCESS if the merging succeeded, or StatusCode::FAILURE if it didn't
This function is used internally to merge two generic ROOT objects in the file together. It's not the most trivial, since TObject doesn't have a merge function itself.
The function fails with StatusCode::RECOVERABLE when encountering types that don't have a Merge(...) function defined. In this case we need to save both objects, with different versions, into the output.
Parameters
input	The input object
output	The output object
Returns: StatusCode::Success if the merging succeeded, StatusCode::FAILURE if there was a technical issue, and StatusCode::RECOVERABLE if the objects don't define a merging function.
This function finds branches that appear in the first tree, but don't appear in the second one.
Parameters
first	The "first" tree
second	The "second" tree
Returns: The branches that appear in the "first" tree, but don't appear in the "second" one
This function is used during fast merging to create branches that have been encountered first in file N (N >= 2).
Parameters
otree	The output tree to create the branch in
ibranch	Pointer to the branch in the input tree
Returns: The usual StatusCode types
Definition at line 35 of file TFileMerger.cxx.
                {
  
    TFileMerger::TFileMerger()
    : TObject(), m_input(), m_copiedInput(), m_output( 0 ),
      m_treesToSkip( { "##Shapes", "##Links", "##Params",
                       "##Sections",
                       "CollectionTreeInDet::Track_tlp2",
                       "POOLContainerForm", "POOLContainer",
                       "POOLCollectionTree", "MetaData",
                       "MetaDataHdrForm", "MetaDataHdr" } ),
      m_events(), m_helperFiles(),
      m_metaDataToolNames(), m_metaDataTools(),
      m_mode( TEvent::kClassAccess ), m_entriesToMerge( kBigNumber ),
      m_verbosity( 0 ) {
  
    }
  
    TFileMerger::~TFileMerger() {
  
       // Close all the files that may still be open:
       closeFiles().ignore();
    }
  
    StatusCode TFileMerger::setOutputFileName( const std::string& name,
                                                const std::string& mode ) {
  
       // Try to open the file:
       m_output = ::TFile::Open( name.c_str(), mode.c_str() );
       if( ! m_output ) {
          Error( "setOutputFileName",
                 XAOD_MESSAGE( "Couldn't open output file \"%s\" in mode "
                               "\"%s\"" ),
                 name.c_str(), mode.c_str() );
          return StatusCode::FAILURE;
       }
  
       // Tell the user what happened:
       Info( "setOutputFileName", "Opened \"%s\" for writing",
             name.c_str() );
  
       // Return ROOT to its main directory in memory:
       gROOT->cd();
  
       // Return gracefully:
       return StatusCode::SUCCESS;
    }
  
    StatusCode TFileMerger::addFile( const std::string& name,
                                      bool copyLocally ) {
  
       // Decide whether to use the file from its current location, or to make
       // a copy of it first:
       std::string localName = name;
       if( copyLocally ) {
          // Helper object to create a unique name for the local file:
          TUUID uuid;
          // Construct the local name of he file:
          localName =
             TString::Format( "%s/XAODMERGE-%s.root",
                              gSystem->TempDirectory(), uuid.AsString() ).Data();
          // Copy the file:
          if( ! TFile::Cp( name.c_str(), localName.c_str(), kTRUE ) ) {
             Error( "addFile",
                    XAOD_MESSAGE( "Couldn't create local copy of \"%s\" under "
                                  "\"%s\"" ),
                    name.c_str(), localName.c_str() );
             return StatusCode::FAILURE;
          }
          // Tell the user what happened:
          Info( "addFile", "Made a local copy of: %s", name.c_str() );
       }
  
       // Now try to open the file:
       ::TFile* ifile = ::TFile::Open( localName.c_str(), "READ" );
       if( ! ifile ) {
          Error( "addFile", XAOD_MESSAGE( "Couldn't open file \"%s\"" ),
                 localName.c_str() );
          return StatusCode::FAILURE;
       }
  
       // Add it to our list:
       m_input.push_back( ifile );
       m_copiedInput.push_back( copyLocally );
       Info( "addFile", "Opened \"%s\" for reading", localName.c_str() );
  
       // Return ROOT to its main directory in memory:
       gROOT->cd();
  
       // Return gracefully:
       return StatusCode::SUCCESS;
    }
  
    StatusCode TFileMerger::addMetaDataTool( const std::string& typeName ) {
  
       // Check if we already have a tool of this type:
       if( m_metaDataToolNames.find( typeName ) != m_metaDataToolNames.end() ) {
          Warning( "addMetaDataTool",
                   "Tool of type \"%s\" is already specified",
                   typeName.c_str() );
          return StatusCode::RECOVERABLE;
       }
  
       // Try to create an instance of the tool:
       ::TClass* cl = ::TClass::GetClass( typeName.c_str() );
       if( ! cl ) {
          Error( "addMetaDataTool",
                 XAOD_MESSAGE( "Tool of type \"%s\" not found" ),
                 typeName.c_str() );
          return StatusCode::FAILURE;
       }
  
       // Remember the type:
       m_metaDataToolNames.insert( typeName );
  
       // Tell the user what happened:
       if( m_verbosity > 1 ) {
          Info( "addMetaDataTool", "Added tool of type \"%s\"",
                typeName.c_str() );
       }
  
       // Return gracefully:
       return StatusCode::SUCCESS;
    }
  
    StatusCode TFileMerger::merge( EMergeMode mode, ::Long64_t entries ) {
  
       // Check that we have an output file:
       if( ! m_output ) {
          Error( "merge", XAOD_MESSAGE( "No output file specified" ) );
          return StatusCode::FAILURE;
       }
  
       // Check that we have input files:
       if( ! m_input.size() ) {
          Warning( "merge", "No input files were specified" );
          return StatusCode::RECOVERABLE;
       }
  
       // Check that we received consistent parameters:
       if( ( mode == kFastMerge ) && ( entries != kBigNumber ) ) {
          Warning( "merge", "Number of entries can't be specified in fast "
                   "merging mode" );
          m_entriesToMerge = kBigNumber;
       } else {
          m_entriesToMerge = entries;
       }
  
       // Merge all the input files into the output using the recursive merging
       // function:
       for( ::TFile* file : m_input ) {
          RETURN_CHECK( "xAOD::TFileMerger::merge",
                        mergeDirectory( *file, *m_output, mode, true ) );
       }
  
       // Make sure that everything in the output is written out:
       m_output->SaveSelf();
  
       // Close all the files:
       RETURN_CHECK( "xAOD::TFileMerger::merge", closeFiles() );
  
       // Return gracefully:
       return StatusCode::SUCCESS;
    }
  
    TEvent::EAuxMode TFileMerger::accessMode() const {
  
       return m_mode;
    }
  
    void TFileMerger::setAccessMode( TEvent::EAuxMode mode ) {
  
       m_mode = mode;
       return;
    }
  
    int TFileMerger::verbosity() const {
  
       return m_verbosity;
    }
  
    void TFileMerger::setVerbosity( int value ) {
  
       m_verbosity = value;
       return;
    }
  
    const std::set< std::string >& TFileMerger::treesSkipped() const {
  
       return m_treesToSkip;
    }
  
    void TFileMerger::addTreeToSkip( const std::string& name ) {
  
       m_treesToSkip.insert( name );
       return;
    }
  
    StatusCode TFileMerger::closeFiles() {
  
       if( m_verbosity >= 1 ) {
          Info( "closeFiles", "Closing all open files" );
       }
  
       // A little sanity check:
       if( m_input.size() != m_copiedInput.size() ) {
          Fatal( "closeFiles",
                 XAOD_MESSAGE( "Internal logic error detected" ) );
       }
  
       // Finish writing with the TEvent objects that are still open:
       auto ev_itr = m_events.begin();
       auto ev_end = m_events.end();
       for( ; ev_itr != ev_end; ++ev_itr ) {
          if( ev_itr->second->m_outTree && m_output ) {
             RETURN_CHECK( "xAOD::TFileMerger::closeFiles",
                           ev_itr->second->finishWritingTo( m_output ) );
          }
       }
  
       // Close and delete the input files:
       for( size_t i = 0; i < m_input.size(); ++i ) {
          m_input[ i ]->Close();
          if( m_verbosity >= 2 ) {
             Info( "closeFiles", "Closed: %s", m_input[ i ]->GetName() );
          }
          if( m_copiedInput[ i ] ) {
             TString p( m_input[ i ]->GetPath() );
             p = p( 0, p.Index( ':', 0 ) );
             if( gSystem->Unlink( p ) ) {
                Error( "closeFiles",
                       XAOD_MESSAGE( "Couldn't remove local file: %s" ),
                       p.Data() );
                return StatusCode::FAILURE;
             }
             if( m_verbosity >= 2 ) {
                Info( "closeFiles", "Deleted: %s", m_input[ i ]->GetName() );
             }
          }
          delete m_input[ i ];
       }
       m_input.clear();
       m_copiedInput.clear();
  
       // Close the output file:
       if( m_output ) {
          m_output->Close();
          if( m_verbosity >= 2 ) {
             Info( "closeFiles", "Closed: %s", m_output->GetName() );
          }
          delete m_output;
          m_output = 0;
       }
  
       // Delete all the TEvent objects that were created during the merging:
       m_events.clear();
  
       // Delete all the helper in-memory files created during the merging:
       for( ::TFile* file : m_helperFiles ) {
          delete file;
       }
       m_helperFiles.clear();
  
       // Return gracefully:
       return StatusCode::SUCCESS;
    }
  
    StatusCode TFileMerger::mergeDirectory( ::TDirectory& input,
                                             ::TDirectory& output,
                                             EMergeMode mode,
                                             bool topLevelDir ) {
  
       if( m_verbosity >= 1 ) {
          Info( "mergeDirectory", "Merging directories:" );
          Info( "mergeDirectory", "  input : %s", input.GetName() );
          Info( "mergeDirectory", "  output: %s", output.GetName() );
       }
  
       // Get a list of all objects in this directory:
       TList* keyList = input.GetListOfKeys();
       if( ! keyList ) {
          Error( "mergeDirectory",
                 XAOD_MESSAGE( "Couldn't get list of keys from input directory "
                               "\"%s\"" ), input.GetName() );
          return StatusCode::FAILURE;
       }
  
       //
       // Loop over all keys in the directory, and select the ones describing
       // objects that we can deal with. Since one single TTree can appear
       // multiple times in this list (with different "cycles"), keep track of
       // which trees have already been merged into the output.
       //
       std::set< std::string > processedTrees;
       for( Int_t i = 0; i < keyList->GetSize(); ++i ) {
          
          // Convert to a TKey:
          TKey* key = dynamic_cast< TKey* >( keyList->At( i ) );
          if( ! key ) {
             Error( "mergeDirectory",
                    XAOD_MESSAGE( "Couldn't case object to TKey. No idea "
                                  "why..." ) );
             return StatusCode::FAILURE;
          }
          if( m_verbosity >= 3 ) {
             Info( "mergeDirectory", "Evaluating key \"%s;%hi\" with type "
                   "\"%s\"",
                   key->GetName(), key->GetCycle(), key->GetClassName() );
          }
  
          // Get the object:
          TObject* obj = input.Get( TString::Format( "%s;%hi", key->GetName(),
                                                     key->GetCycle() ) );
          if( ! obj ) {
             Error( "mergeDirectory",
                    XAOD_MESSAGE( "Couldn't access object with name "
                                  "\"%s;%hi\"" ),
                    key->GetName(), key->GetCycle() );
             return StatusCode::FAILURE;
          }
  
          //
          // Decide how to handle this object:
          //
          if( obj->IsA()->InheritsFrom( "TDirectory" ) ) {
  
             if( m_verbosity >= 3 ) {
                Info( "mergeDirectory", "Appears to be a TDirectory" );
             }
  
             // Access the input object as a directory:
             TDirectory* indir = dynamic_cast< TDirectory* >( obj );
             if( ! indir ) {
                Error( "mergeDirectory",
                       XAOD_MESSAGE( "Couldn't cast to object to TDirectory" ) );
                return StatusCode::FAILURE;
             }
  
             // Check if such a directory already exists in the output:
             TDirectory* outdir =
                dynamic_cast< TDirectory* >( output.Get( key->GetName() ) );
             // If it doesn't let's create it:
             if( ! outdir ) {
                if( ! ( outdir = output.mkdir( key->GetName(),
                                               "dummy title" ) ) ) {
                   Error( "mergeDirectory",
                          XAOD_MESSAGE( "Failed creating subdirectory with "
                                        "name: %s" ),
                          key->GetName() );
                   return StatusCode::FAILURE;
                }
             }
  
             // Now call this same function recursively. Note that xAOD trees
             // can't be in sub-directories, so the sub-directories are always
             // merged in a fast way.
             RETURN_CHECK( "xAOD::TFileMerger::mergeDirectory",
                           mergeDirectory( *indir, *outdir, kFastMerge,
                                           false ) );
  
          } else if( obj->IsA()->InheritsFrom( "TTree" ) ) {
  
             if( m_verbosity >= 3 ) {
                Info( "mergeDirectory", "Appears to be a TTree" );
             }
  
             // Check if this tree is to be skipped from merging. At least by
             // this code. Because the "MetaData" tree is getting merged. Just
             // not here...
             if( m_treesToSkip.find( key->GetName() ) !=
                 m_treesToSkip.end() ) {
                if( m_verbosity >= 4 ) {
                   Info( "mergeDirectory",
                         "Skipping it because of m_treesToSkip" );
                }
                continue;
             }
  
             // Check if this tree was already processed:
             if( processedTrees.find( key->GetName() ) !=
                 processedTrees.end() ) {
                if( m_verbosity >= 4 ) {
                   Info( "mergeDirectory",
                         "Skipping it, because it was processed already" );
                }
                continue;
             }
  
             if( m_verbosity >= 3 ) {
                Info( "mergeDirectory",
                      "Tree not processed yet. Doing so now." );
             }
  
             // Make sure that we have the object with the highest cycle number:
             ::TObject* treeObj = input.Get( key->GetName() );
             if( ! treeObj ) {
                Fatal( "mergeDirectory",
                       XAOD_MESSAGE( "Internal logic error found" ) );
                return StatusCode::FAILURE;
             }
             ::TTree* itree = dynamic_cast< TTree* >( treeObj );
             if( ! itree ) {
                Error( "mergeDirectory",
                       XAOD_MESSAGE( "Couldn't access \"%s\" with a TTree "
                                     "pointer" ),
                       treeObj->GetName() );
                return StatusCode::FAILURE;
             }
  
             // Skip trees that have friends. Those don't play nicely with
             // merging/cloning...
             if( itree->GetListOfFriends() &&
                 itree->GetListOfFriends()->GetSize() ) {
                if( m_verbosity >= 2 ) {
                   Info( "mergeDirectory", "TTree \"%s\" has friends; "
                         "skipping from merge", itree->GetName() );
                }
                continue;
             }
  
             // Trees in the top level directory are all assumed to be xAOD
             // trees. We need to make a TEvent object aware of this output tree
             // regardless of the merge mode. Because it's the TEvent that will
             // take care of merging the metadata from the files.
             if( topLevelDir ) {
                // Instantiate the TEvent object:
                std::unique_ptr< TEvent >& event = m_events[ key->GetName() ];
                if( ( ! event.get() ) || ( event->auxMode() != m_mode ) ) {
                   event.reset( new TEvent( m_mode ) );
                   event->setActive();
                }
                // And now create all the metadata tools:
                RETURN_CHECK( "xAOD::TFileMerger::mergeDirectory",
                              createMetaDataTools() );
                // And now connect it to the input file:
                RETURN_CHECK( "xAOD::TFileMerger::mergeDirectory",
                              event->readFrom( itree ) );
                // Let the user know what's happening:
                Info( "mergeDirectory", "Copying xAOD tree \"%s\"",
                      key->GetName() );
             } else {
                // Let the user know what's happening:
                Info( "mergeDirectory", "Copying non-xAOD tree \"%s\"",
                      key->GetName() );
             }
  
             // Do quite different things in fast and slow merging modes:
             if( mode == kFastMerge ) {
  
                // Connect the TEvent object to the output file in order to
                // handle metadata merging correctly:
                if( topLevelDir ) {
                   std::unique_ptr< TEvent >& event = m_events[ key->GetName() ];
                   if( ! event.get() ) {
                      event.reset( new TEvent() );
                   }
                   if( ! event->m_outTree ) {
                      // Create an in-memory file, that's really only needed
                      // for technical reasons. Tricking the TEvent object into
                      // thinking that it's actually writing event data. While
                      // it really isn't.
                      ::TFile* ofile =
                         new ::TMemFile( TString::Format( "%sHelper.root",
                                                          key->GetName() ),
                                         "CREATE" );
                      m_helperFiles.push_back( ofile );
                      RETURN_CHECK( "xAOD::TFileMerger::mergeDirectory",
                                    event->writeTo( ofile, 200,
                                                    key->GetName() ) );
                   }
                   // Merge the input file's EventFormat object into the one
                   // created for the output file:
                   const EventFormat* ief = event->inputEventFormat();
                   EventFormat* oef = event->m_outputEventFormat;
                   if( ( ! ief ) || ( ! oef ) ) {
                      Error( "mergeDirectory",
                             XAOD_MESSAGE( "Internal logic error detected" ) );
                      Error( "mergeDirectory",
                             XAOD_MESSAGE( "ief = %p, oef = %p" ),
                             static_cast< const void* >( ief ),
                             static_cast< void* >( oef ) );
                      return StatusCode::FAILURE;
                   }
                   auto itr = ief->begin();
                   auto end = ief->end();
                   for( ; itr != end; ++itr ) {
                      if( ! oef->exists( itr->first ) ) {
                         oef->add( itr->second );
                      }
                   }
                }
  
                //
                // See if such a TTree exists in the output already:
                //
                ::TTree* otree =
                   dynamic_cast< ::TTree* >( output.Get( key->GetName() ) );
                if( otree ) {
  
                   if( m_verbosity >= 3 ) {
                      Info( "mergeDirectory",
                            "Merging the tree into an existing one" );
                   }
  
                   // Check if there are any branches in either tree that don't
                   // exist in the other one:
                   const std::vector< ::TBranch* > missingMerged =
                      getMissingBranches( otree, itree );
                   const std::vector< ::TBranch* > missingIncoming =
                      getMissingBranches( itree, otree );
                   if( m_verbosity >= 4 ) {
                      Info( "mergeDirectory", "missingMerged.size() = %i",
                            static_cast< int >( missingMerged.size() ) );
                      Info( "mergeDirectory", "missingIncoming.size() = %i",
                            static_cast< int >( missingIncoming.size() ) );
                   }
  
                   // Add branches with default values for the variables that
                   // appeared in the input tree now, and were not in the output
                   // tree yet.
                   for( ::TBranch* br : missingIncoming ) {
                      if( m_verbosity >= 4 ) {
                         Info( "mergeDirectory", "Adding auxiliary branch: %s",
                               br->GetName() );
                      }
                      RETURN_CHECK( "xAOD::TFileMerger::mergeDirectory",
                                    addAuxBranch( otree, br ) );
                   }
  
                   // Exclude branches from the incoming tree that have no
                   // dictionary in our environment:
                   const std::vector< ::TBranch* > skippedBranches =
                      getSkippedBranches( itree );
                   for( ::TBranch* br : skippedBranches ) {
                      itree->SetBranchStatus( br->GetName(), 0 );
                      if( m_verbosity >= 4 ) {
                         Info( "mergeDirectory",
                               "Deactivated branch \"%s\" from merging",
                               br->GetName() );
                      }
                   }
  
                   // Get the indices of the aux branches in the merged tree that
                   // need to be excluded from the fast merging:
                   TObjArray* obranches = otree->GetListOfBranches();
                   std::map< ::Int_t, ::TBranch* > auxIndices;
                   for( ::TBranch* br : missingMerged ) {
                      const Int_t index = obranches->IndexOf( br );
                      if( index < 0 ) {
                         Error( "mergeDirectory",
                                XAOD_MESSAGE( "Internal logic error "
                                              "detected" ) );
                         return StatusCode::FAILURE;
                      }
                      auxIndices[ index ] = br;
                      obranches->RemoveAt( index );
                      if( m_verbosity >= 4 ) {
                         Info( "mergeDirectory", "Removed branch \"%s\" from "
                               "fast merge list", br->GetName() );
                      }
                   }
                   if( auxIndices.size() ) {
                      obranches->Compress();
                   }
  
                   // Set up a TTreeCloner object for fast-merging the branches
                   // that appear in both trees:
                   ::TTreeCloner
                      cloner( itree, otree, "fast SortBasketsByBranch",
                              ( ::TTreeCloner::kNoWarnings |
                                ::TTreeCloner::kIgnoreMissingTopLevel ) );
                   // Check if the cloner is valid:
                   if( ! cloner.IsValid()) {
                      // Let's check why
                      static const char* const okerror = "One of the export branch";
                      if( ::strncmp( cloner.GetWarning(), okerror,
                                     ::strlen( okerror ) ) == 0 ) {
                         // That's fine we will handle it
                      } else {
                         Error( "mergeDirectory",
                                XAOD_MESSAGE( "Invalid TTreeCloner (%s)" ),
                                cloner.GetWarning() );
                         return StatusCode::FAILURE;
                      }
                   }
  
                   // Run the fast merging:
                   otree->SetEntries( otree->GetEntries() +
                                      itree->GetEntries() );
                   if( ! cloner.Exec() ) {
                      Error( "mergeDirectory",
                             XAOD_MESSAGE( "Failed to execute TTreeCloner" ) );
                      return StatusCode::FAILURE;
                   }
  
                   // Put back the branches that have no counterpart in the input
                   // tree:
                   for( auto it : auxIndices ) {
                      const Int_t last = obranches->GetLast();
                      if( last >= 0 ) {
                         obranches->AddAtAndExpand( obranches->At( last ),
                                                    last + 1 );
                         for( Int_t ind = last - 1; ind >= it.first; --ind ) {
                            obranches->AddAt( obranches->At( ind ), ind + 1 );
                         }
                         obranches->AddAt( it.second, it.first );
                      } else {
                         obranches->Add( it.second );
                      }
                   }
                   // And fill them with default values:
                   const ::Long64_t ientries = itree->GetEntries();
                   for( ::TBranch* br : missingMerged ) {
                      br->SetAddress( 0 );
                      for( ::Long64_t i = 0; i < ientries; ++i ) {
                         if( br->Fill() < 0 ) {
                            Error( "mergeDirectory",
                                   XAOD_MESSAGE( "Failed to fill branch \"%s\" "
                                                 "with default content" ),
                                   br->GetName() );
                            return StatusCode::FAILURE;
                         }
                      }
                   }
  
                   // Make sure that the tree is flushed:
                   otree->AutoSave( "FlushBaskets" );
  
                } else {
  
                   if( m_verbosity >= 3 ) {
                      Info( "mergeDirectory", "Cloning the tree as is" );
                   }
  
                   //
                   // If it doesn't exist, then use the TTree::CloneTree function
                   // to create a copy of the TTree in the input file. Then save
                   // this copy into the output file.
                   //
                   // But first, let's turn off all the branches that don't have
                   // a dictionary in our environment. As those will have to be
                   // skipped.
                   //
                   const std::vector< ::TBranch* > skippedBranches =
                      getSkippedBranches( itree );
                   for( ::TBranch* br : skippedBranches ) {
                      itree->SetBranchStatus( br->GetName(), 0 );
                      if( m_verbosity >= 4 ) {
                         Info( "mergeDirectory",
                               "Deactivated branch \"%s\" from cloning",
                               br->GetName() );
                      }
                   }
  
                   // Now do the clone:
                   output.cd();
                   if( ! ( otree =
                           itree->CloneTree( -1,
                                             "fast SortBasketsByBranch" ) ) ) {
                      Error( "mergeDirectory",
                             XAOD_MESSAGE( "TTree \"%s\" couldn't be cloned "
                                           "into the output" ),
                             itree->GetName() );
                      return StatusCode::FAILURE;
                   }
                   otree->SetDirectory( &output );
                   otree->AutoSave();
                }
  
                // Later on the metadata merging will come here.
  
             } else if( mode == kSlowMerge ) {
  
                // Access the TEvent object made for this tree. Such a thing
                // needs to access, because we can only slow-merge top level
                // trees. Which are always assumed to be xAOD trees.
                std::unique_ptr< TEvent >& event = m_events[ key->GetName() ];
                if( ! event.get() ) {
                   event.reset( new TEvent() );
                }
  
                // Check whether it's already writing to the output:
                if( ! event->m_outTree ) {
                   // Make a TFile pointer out of the TDirectory:
                   ::TFile* ofile = dynamic_cast< ::TFile* >( &output );
                   if( ! ofile ) {
                      Error( "mergeDirectory",
                             XAOD_MESSAGE( "Internal logic error found" ) );
                      return StatusCode::FAILURE;
                   }
                   RETURN_CHECK( "xAOD::TFileMerger::mergeDirectory",
                                 event->writeTo( ofile, 200, key->GetName() ) );
                }
  
                // Let the user know what's happening:
                if( m_verbosity >= 3 ) {
                   Info( "mergeDirectory", "Slow copying xAOD tree \"%s\"",
                         key->GetName() );
                }
  
                // Loop over the events using the TEvent object:
                const ::Long64_t entries = event->getEntries();
                for( ::Long64_t entry = 0; entry < entries; ++entry ) {
  
                   // Check whether we're done already:
                   if( event->m_outTree->GetEntries() >= m_entriesToMerge ) {
                      break;
                   }
  
                   // Load the entry:
                   if( event->getEntry( entry ) < 0 ) {
                      Error( "mergeDirectory",
                             XAOD_MESSAGE( "Couldn't get entry %i from tree "
                                           "%s" ),
                            static_cast< int >( entry ), key->GetName() );
                      return StatusCode::FAILURE;
                   }
  
                   // Give the user feedback about the processing status:
                   if( ! ( entry % 500 ) ) {
                      Info( "mergeDirectory", "Copied %i / %i entries",
                            static_cast< int >( entry ),
                            ( m_entriesToMerge == kBigNumber ?
                              static_cast< int >( entries ) :
                              static_cast< int >( m_entriesToMerge ) ) );
                   }
  
                   // Copy the full event to the output:
                   RETURN_CHECK( "xAOD::TFileMerger::mergeDirectory",
                                 event->copy() );
  
                   // Write the event:
                   const ::Int_t bytes = event->fill();
                   if( bytes < 0 ) {
                      Error( "mergeDirectory",
                             XAOD_MESSAGE( "There was an error in writing entry "
                                           "%i from tree %s" ),
                             static_cast< int >( entry ), key->GetName() );
                      return StatusCode::FAILURE;
                   } else if( bytes == 0 ) {
                      Warning( "mergeDirectory",
                               "No payload was written for entry %i",
                               static_cast< int >( entry ) );
                   }
                }
  
             } else {
                Fatal( "mergeDirectory",
                       XAOD_MESSAGE( "Unknown mode (%i) received" ),
                       static_cast< int >( mode ) );
             }
  
             // Remember that this TTree has already been processed:
             processedTrees.insert( key->GetName() );
  
          } else if( obj->IsA()->InheritsFrom( "TObject" ) ) {
  
             if( m_verbosity >= 3 ) {
                Info( "mergeDirectory", "Appears to be a TObject of type %s",
                      obj->IsA()->GetName() );
             }
  
             // Skip objects that we don't have a dictionary for:
             ::TClass* cl = ::TClass::GetClass( key->GetClassName() );
             if( ( ! cl ) || ( ! cl->IsLoaded() ) ) {
                continue;
             }
  
             if( m_verbosity >= 3 ) {
                Info( "mergeDirectory", "We seem to have a dictionary for it" );
             }
  
             // Check if the object is already in the output:
             TObject* oobj = output.Get( key->GetName() );
  
             // If the output object already exists, and we can merge this input
             // object into it, then that's all that we need to do:
             if( oobj ) {
                const StatusCode ret = mergeObject( *obj, *oobj );
                if( ret.isSuccess() ) {
                   // Make sure that the output object is updated in the output
                   // file:
                   oobj->Write( 0, TObject::kOverwrite );
                   continue;
                } else if( ret.isFailure() ) {
                   // This is not good:
                   Error( "mergeDirectory",
                          XAOD_MESSAGE( "Error detected while merging object "
                                        "\"%s\"" ), obj->GetName() );
                   return StatusCode::FAILURE;
                }
             }
  
             if( m_verbosity >= 3 ) {
                Info( "mergeDirectory", "Simply writing it to the output" );
             }
  
             // If the object doesn't exist yet, or there's no merge operation
             // defined for it, just write this object to the output as is:
             output.cd();
             obj->Write();
          }
       }
  
       // Return gracefully:
       return StatusCode::SUCCESS;
    }
  
    StatusCode TFileMerger::mergeObject( ::TObject& input, ::TObject& output ) {
  
       if( m_verbosity >= 3 ) {
          Info( "mergeObject", "Called mergeObject( %s, %s )",
                input.GetName(), output.GetName() );
       }
  
       // A little sanity check:
       if( strcmp( input.IsA()->GetName(), output.IsA()->GetName() ) ) {
          Error( "mergeObject",
                 XAOD_MESSAGE( "Received objects of different types" ) );
          Error( "mergeObject",
                 XAOD_MESSAGE( "input = %s" ), input.IsA()->GetName() );
          Error( "mergeObject",
                 XAOD_MESSAGE( "output = %s" ), output.IsA()->GetName() );
          return StatusCode::FAILURE;
       }
  
       // Check if there is a merge function defined for these objects:
       ::TMethodCall mergeMethod;
       mergeMethod.InitWithPrototype( output.IsA(), "Merge", "TCollection*" );
       if( ! mergeMethod.IsValid() ) {
          // No, there isn't:
          if( m_verbosity >= 3 ) {
             Info( "mergeObject", "Type doesn't have a Merge function" );
          }
          return StatusCode::RECOVERABLE;
       }
  
       // Put the input object into a list, since that's what we need to give
       // to the merge function.
       ::TList list;
       list.Add( &input );
  
       // Execute the merging:
       mergeMethod.SetParam( ( Long_t ) &list );
       mergeMethod.Execute( &output );
  
       if( m_verbosity >= 3 ) {
          Info( "mergeObject", "Merging executed successfully" );
       }
  
       // Return gracefully:
       return StatusCode::SUCCESS;
    }
  
    StatusCode TFileMerger::createMetaDataTools() {
  
       // Create all the specified tool types:
       for( const std::string& typeName : m_metaDataToolNames ) {
  
          // If the tool was already created, don't do it again:
          if( m_metaDataTools.find( typeName ) != m_metaDataTools.end() ) {
             continue;
          }
  
          // Try to create an instance of the tool:
          ::TClass* cl = ::TClass::GetClass( typeName.c_str() );
          if( ! cl ) {
             Error( "createMetaDataTools",
                    XAOD_MESSAGE( "Tool of type \"%s\" not found" ),
                    typeName.c_str() );
             return StatusCode::FAILURE;
          }
          void* ptr = cl->New();
          if( ! ptr ) {
             Error( "createMetaDataTools",
                    XAOD_MESSAGE( "Failed to create an instance of tool "
                                  "\"%s\"" ), typeName.c_str() );
             return StatusCode::FAILURE;
          }
  
          // Try to call the tool's initialize() function:
          ::TMethodCall initMethod;
          initMethod.InitWithPrototype( cl, "initialize", "" );
          if( initMethod.IsValid() ) {
             // Check the return type of the initialize() function. If it's a
             // class that has an ignore() function, then let's call that.
             const std::string returnTypeName =
                initMethod.GetMethod()->GetReturnTypeNormalizedName();
             ::TClass* returnCl = ::TClass::GetClass( returnTypeName.c_str(),
                                                      kTRUE, kTRUE );
             if( returnCl &&
                 returnCl->GetListOfMethods()->FindObject( "ignore" ) ) {
                char* statusCode = 0;
                initMethod.Execute( ptr, "", &statusCode );
                if( ! statusCode ) {
                   Warning( "createMetaDataTools", "No StatusCode was returned" );
                }
                ::TMethodCall ignoreMethod;
                ignoreMethod.InitWithPrototype( returnCl, "ignore", "" );
                if( ignoreMethod.IsValid() && statusCode ) {
                   ignoreMethod.Execute( static_cast< void* >( statusCode ) );
                } else {
                   Error( "createMetaDataTools",
                          XAOD_MESSAGE( "Failed to access the ignore() function "
                                        "of the initialize() function's return "
                                        "type" ) );
                }
             } else {
                // If not, then let's just ignore the return value of the
                // function:
  
             initMethod.Execute( ptr );
             }
          } else {
             Warning( "createMetaDataTools",
                      "No initialize() function found for tool \"%s\"",
                      typeName.c_str() );
          }
  
          // Store the pointer of this object:
          m_metaDataTools[ typeName ] = THolder( ptr, cl );
          if( m_verbosity > 0 ) {
             Info( "createMetaDataTools", "Created tool of type \"%s\"",
                   typeName.c_str() );
          }
       }
  
       // Return gracefully:
       return StatusCode::SUCCESS;
    }
  
    std::vector< ::TBranch* >
    TFileMerger::getMissingBranches( ::TTree* first,
                                     ::TTree* second ) const {
  
       // The result object:
       std::vector< ::TBranch* > result;
  
       // List of branches from the two trees:
       ::TObjArray* brFirst  = first->GetListOfBranches();
       ::TObjArray* brSecond = second->GetListOfBranches();
  
       // Loop over the branches of the first tree:
       for( ::Int_t i = 0; i < brFirst->GetEntries(); ++i ) {
          // Check if such a branch exists in the second tree:
          if( brSecond->FindObject( brFirst->At( i )->GetName() ) ) {
             continue;
          }
          // Access the branch:
          ::TBranch* br = dynamic_cast< ::TBranch* >( brFirst->At( i ) );
          if( ! br ) {
             Fatal( "getMissingBranches",
                    XAOD_MESSAGE( "Couldn't cast branch to TBranch?!?" ) );
             return result;
          }
          // Skip it if we don't have a dictionary for it:
          ::TClass* cl = 0;
          ::EDataType dt = kOther_t;
          if( br->GetExpectedType( cl, dt ) ) {
             Error( "getMissingBranches",
                    XAOD_MESSAGE( "Type could not be extracted for branch "
                                  "\"%s\"" ), br->GetName() );
             continue;
          }
          if( cl && ( ! cl->IsLoaded() ) ) {
             continue;
          }
          // Okay, this is apparently a branch that we'll be able to handle
          // correctly.
          result.push_back( br );
       }
  
       // Return the collected branches:
       return result;
    }
  
    std::vector< ::TBranch* >
    TFileMerger::getSkippedBranches( ::TTree* tree ) const {
  
       // The result object:
       std::vector< ::TBranch* > result;
  
       // The list of all branches from the tree:
       ::TObjArray* branches = tree->GetListOfBranches();
  
       // Select the ones that we don't have a dictionary for. These will not
       // be cloned.
       for( ::Int_t i = 0; i < branches->GetEntries(); ++i ) {
          // The branch:
          ::TBranch* br = dynamic_cast< ::TBranch* >( branches->At( i ) );
          if( ! br ) {
             Fatal( "getSkippedBranches",
                    XAOD_MESSAGE( "Couldn't cast branch to TBranch?!?" ) );
             return result;
          }
          // Check the type of it:
          ::TClass* cl = 0;
          ::EDataType dt = kOther_t;
          if( br->GetExpectedType( cl, dt ) ) {
             Error( "getSkippedBranches",
                    XAOD_MESSAGE( "Type could not be extracted for branch "
                                  "\"%s\"" ), br->GetName() );
             continue;
          }
          // Skip the branches that come from a class that doesn't have a
          // compiled dictionary:
          if( cl && ( ! cl->IsLoaded() ) ) {
             result.push_back( br );
          }
       }
  
       return result;
    }
  
    StatusCode TFileMerger::addAuxBranch( ::TTree* otree,
                                           ::TBranch* ibranch ) const {
  
       // Get the type of the branch:
       ::TClass* cl = 0;
       ::EDataType dt = kOther_t;
       if( ibranch->GetExpectedType( cl, dt ) ) {
          Error( "addAuxBranch",
                 XAOD_MESSAGE( "Type could not be extracted for branch \"%s\"" ),
                 ibranch->GetName() );
          return StatusCode::FAILURE;
       }
  
       // Pointer to the output branch:
       ::TBranch* obranch = 0;
  
       // Decide what sort of branch it is:
       if( cl ) {
          // It's an object type:
          void* ptr = 0;
          obranch = otree->Branch( ibranch->GetName(), cl->GetName(),
                                   &ptr, ibranch->GetBasketSize(),
                                   ibranch->GetSplitLevel() );
          if( ! obranch ) {
             Error( "addAuxBranch",
                    XAOD_MESSAGE( "Couldn't create auxiliary branch \"%s\" with "
                                  "type: %s" ),
                    ibranch->GetName(), cl->GetName() );
             return StatusCode::FAILURE;
          }
       } else if( dt != kOther_t ) {
          // It's a primitive type:
          const char rootType =
             Utils::rootType( Utils::getTypeInfo( dt ).name()[ 0 ] );
          if( rootType == '\0' ) {
             Error( "addAuxBranch",
                     XAOD_MESSAGE( "Type can't be extracted for EDataType = %i"),
                     static_cast< int >( dt ) );
             return StatusCode::FAILURE;
          }
          std::ostringstream leaflist;
          leaflist << ibranch->GetName() << "/" << rootType;
          void* ptr = 0;
          obranch = otree->Branch( ibranch->GetName(), ptr,
                                   leaflist.str().c_str(),
                                   ibranch->GetBasketSize() );
          if( ! obranch ) {
             Error( "addAuxBranch",
                    XAOD_MESSAGE( "Couldn't create auxiliary branch \"%s\" with "
                                  "data type: %i" ),
                    ibranch->GetName(), static_cast< int >( dt ) );
             return StatusCode::FAILURE;
          }
       } else {
          Error( "addAuxBranch",
                 XAOD_MESSAGE( "Couldn't figure out the type of branch \"%s\"" ),
                 ibranch->GetName() );
          return StatusCode::FAILURE;
       }
  
       // Fill up the branch with dummy entries:
       obranch->SetAddress( 0 );
       for( ::Long64_t i = 0; i < otree->GetEntries(); ++i ) {
          if( obranch->Fill() < 0 ) {
             Error( "addAuxBranch",
                   XAOD_MESSAGE( "Failed to fill branch \"%s\" with dummy "
                                "data" ), obranch->GetName() );
             return StatusCode::FAILURE;
          }
       }
  
       // Return gracefully:
       return StatusCode::SUCCESS;
    }
  
 } // namespace xAOD
Functions

Function Documentation

◆ ClassImp()
