//
// File   : EyeEventFile.hh
//
// Purpose: Header file for TEyeEventFile.cc, 
//          containing TEyeEventFile class declaration
//
// $Id: EyeEventFile.hh 11637 2010-10-29 10:07:29Z mathes $
//


/* Generated by Together */

/** @file EyeEventFile.hh
  * Declaration for the class TEyeEventFile.
  * @author H.-J. Mathes, FzK
  */
  
#ifndef EYEEVENTFILE_HH
#define EYEEVENTFILE_HH

#include <iostream>
#include <list>

#include <TObject.h>
#include <TFile.h>

// ----- forward declaration(s)

class TBranch;
class TTree;

class TEyeEvent;
class TEyeEventHeader;
class TEyeRunHeader;
class TEyeRunTrailer;

class TEyeEventFileSignalHandler;

/** Class to handle saving/loading of the Eyes event data.
  *
  * This class inherits from ROOTs TFile class, thus all operations defined
  * for a TFile object are also valid here.
  *
  * This class is able to create/read from a ROOT file containing TEyeEvent
  * related objects. These objects are:
  * @li a TEyeRunheader named "RunHeader"
  * @li a TEyeRunTrailer named "RunTrailer"
  * @li a TTree named "EventTree", containing TEyeEvent objects
  */
class TEyeEventFile : public TFile {
friend class TEyeEventFileSignalHandler;

public:
    
    /** Create a new TEyeEventFile object using the defaults
      * given by the TFile default constructor.
      */
    TEyeEventFile();
	
    /** Create a new TEyeEventFile object with given name 'fname'. */
    TEyeEventFile(const char *fname, Option_t *option="", 
	          const char *ftitle="", Int_t compress=1);

    /** Destructor for a TEyeEventFile object.
      *
      * Close an eventually open TEyeEventFile object, release all
      * resources occupied by it and delete it.
      */
    virtual ~TEyeEventFile();

    /** Close input/output file. See documentation of ROOT class TFile. */
    void Close(Option_t *option="");

    /** Get the current Id of the entry just read to access it later again. 
      *
      * Note: Method might fail when writing to the file...
      */
    unsigned int GetCurrentEntryId() const;

    /** Get the number of events present in the current file. 
      *
      * If no file is open, 0 is be returned. In case of a file opened for 
      * writing, the number of events written to the file/tree so far is 
      * returned.
      */
    unsigned int GetNEvents();
    
    /** Read a TEyeEvent object into an already allocated event buffer
      */
    Bool_t ReadEvent(TEyeEvent**);

    /** Read a TEyeEvent object at the specified position into an already 
      * allocated event buffer.
      */
    Bool_t ReadEvent(TEyeEvent** event,unsigned int pos)
     { TEyeEventFile::Seek( pos ); return ReadEvent( event ); }
    
    /** Read a TEyeEventHeader object into an already allocated buffer
      */
    Bool_t ReadEventHeader(TEyeEventHeader**);
	
    /** Read the run header (TEyeRunHeader) of the current file.
      *
      * Either a pointer to an allocated TEyeRunHeader or to a NULL-object 
      * must be passed.
      * @return kTRUE, if the read was successful.
      */
    Bool_t ReadRunHeader(TEyeRunHeader**);
	
    /** Read the run trailer (TEyeRunTrailer) of the current file.
      *
      * Either a pointer to an allocated TEyeRunTrailer or to a NULL-object 
      * must be passed.
      * @return kTRUE, if the read was successful.
      */
    Bool_t ReadRunTrailer(TEyeRunTrailer**);

    /** Rewind the internal pointer to the first entry of the TTree. */
    void Rewind() { TEyeEventFile::Seek( (unsigned int)0 ); }

#if (defined __GNUC__) && !(__GNUC__ < 3)
    // don't override method of base class, avoid warning -Woverloaded-virtual
    using TFile::Seek;
#endif // __GNUC__

    /** Seek (position) the read 'pointer' before the specified event (tree
      * entry in the file. 
      *
      * The next read will then return the specified event or no event (and 
      * kFALSE) if the number of tree entries is less than
      * the specified number.
      *
      * Note: Second argument is currently ignored!
      */
    //void TFile::Seek(Seek_t pos,TFile::ERelativeTo rel = TFile::kBeg)
    void Seek(unsigned int pos) 
     { fCurrentEntry = pos; }
    
    /** Set the print (verbosity) level for this class. */
    static void SetPrintLevel(int level=1)
     { fgPrintLevel = level; }

    /** Show some information about the TEyeEventFile verbosely to the
      * specified ostream, with default cout.
      */
    void Show(std::ostream& str=std::cout);
    
    /** Write TEyeEvent to file, assume that address of TEyeEvent
      * is never changed (for TBranch reasons)
      */
    Bool_t WriteEvent(TEyeEvent**);
	
    /** Write the TEyeRunHeader object to the file.
      * Return kTRUE, if the write was successful.
      */
    Bool_t WriteRunHeader(TEyeRunHeader*);
	
    /** Write TEyeRunTrailer object to the file.
      *
      * Return kTRUE, if the write was successful.
      */
    Bool_t WriteRunTrailer(TEyeRunTrailer*);

protected:

    /** Exit handler (atexit()) for the class TEyeEventFile.
      *
      * Needed to close open files properly.
      */
    static void ExitHandler();
    
    /** Internal method: Get access handles to all branches of the tree.
      *
      * @return kFALSE if any expected branch could not be resolved.
      */
    Bool_t GetBranches(TEyeEvent**);
    
    /** Internal method: Get access to the TTree object in the files and
      * determine the number of events in file.
      *
      * @return kFALSE if the expected TTree could not be found.
      */
    Bool_t GetTree();
    
    /** Setup a few internal things:
      *
      * @li install program exit handler
      */
    void Setup();

    /** A list of all files opened for writing.
      *
      * These files will be closed when the program is terminated abnormally.
      * The following signals when caught, are considered as 'abnormal':
      * @li SIGABRT
      * @li SIGINT
      * @li SIGTERM
      * @li SIGSEGV (via SIGABRT)
      */
    static std::list<TEyeEventFile*> fgFileList;
    
    /** */
    static int        fgPrintLevel;

private:
    TBranch          *fBranch;          // event branch in split level=1
    Int_t             fCurrentEntry;    // current entry id on file (read mode)
    TEyeEvent        *fPartialEvent;    // buffer for partial readout
    TEyeEvent        *fEventBuffer;     // backup pointer for branch
    Int_t             fNEntries;        // number of entries/events in tree
    TTree            *fTree;            // event data tree

    TBranch          *fEventHeaderBranch;
    //TBranch          *fFADCDataBranch;
    //TBranch          *fPixelDataBranch;
    //TBranch          *fPixelListBranch;

    static std::list<TEyeEventFileSignalHandler*> fgSignalHandlerList;
    
#ifndef DPA
    static void SigSegvHandler(int);
#ifndef __DARWIN__
    static struct sigaction fgOldSigSegvAction;
#endif // __DARWIN__
#endif // DPA

    ClassDef(TEyeEventFile,0)
};

#endif //EYEEVENTFILE_HH