TXMLFile

class TXMLFile : public TFile, public TXMLSetup

    private:

      void operator=(const TXMLFile&)

    protected:

                  void InitXmlFile(Bool_t create)
           static void ProduceFileNames(const char* filename, TString& fname, TString& dtdname)
                Bool_t ReadFromFile()
                  void ReadStreamerElement(xmlNodePointer node, TStreamerInfo* info)
                  void SaveToFile()
                  void StoreStreamerElement(xmlNodePointer node, TStreamerElement* elem)
         virtual Int_t SysClose(Int_t)
         virtual Int_t SysOpen(const char*, Int_t, UInt_t)
         virtual Int_t SysRead(Int_t, void*, Int_t)
      virtual Long64_t SysSeek(Int_t, Long64_t, Int_t)
         virtual Int_t SysStat(Int_t, Long_t*, Long64_t*, Long_t*, Long_t*)
         virtual Int_t SysSync(Int_t)
         virtual Int_t SysWrite(Int_t, const void*, Int_t)

    public:

                       TXMLFile()
                       TXMLFile(const char* filename, Option_t* option = "read", const char* title = "title", Int_t compression = 1)
               virtual ~TXMLFile()
        static TClass* Class()
          virtual void Close(Option_t* option)
          virtual void DrawMap(const char* = "*", Option_t*)
          virtual void FillBuffer(char*&)
          virtual void Flush()
      virtual Long64_t GetEND() const
         virtual Int_t GetErrno() const
         virtual Int_t GetNbytesFree() const
         virtual Int_t GetNbytesInfo() const
         virtual Int_t GetNfree() const
      virtual Long64_t GetSeekFree() const
      virtual Long64_t GetSeekInfo() const
      virtual Long64_t GetSize() const
        virtual TList* GetStreamerInfoList()
       virtual TClass* IsA() const
        virtual Bool_t IsOpen() const
          virtual void MakeFree(Long64_t, Long64_t)
          virtual void MakeProject(const char*, const char* = "*", Option_t* = "new")
          virtual void Map()
          virtual void Paint(Option_t*)
          virtual void Print(Option_t*) const
        virtual Bool_t ReadBuffer(char*, Int_t)
          virtual void ReadFree()
          virtual void ReadStreamerInfo()
         virtual Int_t Recover()
         virtual Int_t ReOpen(Option_t* mode)
          virtual void ResetErrno() const
          virtual void Seek(Long64_t, TFile::ERelativeTo = kBeg)
          virtual void SetEND(Long64_t)
          virtual void SetStoreStreamerInfos(Bool_t iConvert = kTRUE)
          virtual void SetUsedDtd(Bool_t use = kTRUE)
          virtual void SetUseNamespaces(Bool_t iUseNamespaces = kTRUE)
          virtual void SetXmlLayout(TXMLSetup::EXMLLayout layout)
          virtual void ShowMembers(TMemberInspector& insp, char* parent)
         virtual Int_t Sizeof() const
          virtual void Streamer(TBuffer& b)
                  void StreamerNVirtual(TBuffer& b)
          virtual void UseCache(Int_t = 10, Int_t = TCache::kDfltPageSize)
         virtual Int_t Write(const char* = "0", Int_t = 0, Int_t = 0)
         virtual Int_t Write(const char* = "0", Int_t = 0, Int_t = 0) const
        virtual Bool_t WriteBuffer(const char*, Int_t)
          virtual void WriteFree()
          virtual void WriteHeader()
         virtual Int_t WriteObjectAny(const void* obj, const char* classname, const char* name, Option_t* option)
         virtual Int_t WriteObjectAny(const void* obj, const TClass* cl, const char* name, Option_t* option)
          virtual void WriteStreamerInfo()
         virtual Int_t WriteTObject(const TObject* obj, const char* name = "0", Option_t* option)
           TXMLEngine* XML()

Data Members

    protected:

       xmlDocPointer fDoc               !
      xmlNodePointer fStreamerInfoNode  !  pointer of node with streamer info data
         TXMLEngine* fXML               ! object for interface with xml library

Class Description

 The main motivation for the XML  format is to facilitate the
 communication with other non ROOT applications. Currently
 writing and reading XML files is limited to ROOT applications.
 It is our intention to develop a simple reader independent
 of the ROOT libraries that could be used as an example for
 real applications. One of possible approach with code generation
 is implemented in TXMLPlayer class.

 The XML format should be used only for small data volumes,
 typically histogram files, pictures, geometries, calibrations.
 The XML file is built in memory before being dumped to disk.

 Like for normal ROOT files, XML files use the same I/O mechanism
 exploiting the ROOT/CINT dictionary. Any class having a dictionary
 can be saved in XML format.

 This first implementation does not support subdirectories
 or Trees.

 The shared library libRXML.so may be loaded dynamically
 via gSystem->Load("libRXML"). This library is automatically
 loaded by the plugin manager as soon as a XML file is created
 via, eg
   TFile::Open("file.xml","recreate");
 TFile::Open returns a TXMLFile object. When a XML file is open in write mode,
 one can use the normal TObject::Write to write an object in the file.
 Alternatively one can use the new functions TDirectory::WriteObject and
 TDirectory::WriteObjectAny to write a TObject* or any class not deriving
 from TObject.

 example of a session saving a histogram to a XML file
 =====================================================
   TFile *f = TFile::Open("Example.xml","recreate");
   TH1F *h = new TH1F("h","test",1000,-2,2);
   h->FillRandom("gaus");
   h->Write();
   delete f;

 example of a session reading the histogram from the file
 ========================================================
   TFile *f = TFile::Open("Example.xml");
   TH1F *h = (TH1F*)f->Get("h");
   h->Draw();

 A new option in the canvas "File" menu is available to save
 a TCanvas as a XML file. One can also do
   canvas->Print("Example.xml");

 Configuring ROOT with the option "xml"
 ======================================
 The XML package uses the public XML parser and toolkit
 from Gnome. You should download the latest version 2-6.9
 from http://www.xmlsoft.org/downloads.html.

 On Unix systems dowload "libxml2-2.6.9.tar.gz" and create
 $XMLDIR pointing to the directory libxml2-2.6.9. in the $ROOTSYS
 directory, run the normal
   ./configure
   make
 Path to $XMLDIR/.libs should be included in $LD_LIBRARY_PATH variable

 On Windows, from the same web site download
   libxml2-2.6.9.win32.zip
   iconv-1.9.1.win32.zip
 unzip the two files, then copy the file iconv.h from the iconv/include file
 to $XMLDIR/include. Also copy iconv.dll, iconv.lib and iconv_a.lib
 from the iconv/lib directory to $XMLDIR/lib.

 You are now ready to configure ROOT with the XML option. do:
  ./configure -enable-xml -enable-xxxxx, etc

 documentation
 =============
 The "xml" package is currently under development. A more complete
 documentation will be provided shortly in the classes reference guide.
 See classes TXMLFile, TXMLKey, TXMLBuffer, TXMLEngine, TXMLSetup
 and TXMLPlayer.
 An example of XML file corresponding to the small example below
can be found at http://root.cern.ch/root/Example.xml

______________________________________________________________________________

 default TXMLFile constructor

 Open or creates local XML file with name filename.
 It is recommended to specify filename as "<file>.xml". The suffix ".xml"
 will be used by object browsers to automatically identify the file as
 a XML file. If the constructor fails in any way IsZombie() will
 return true. Use IsOpen() to check if the file is (still) open.

 If option = NEW or CREATE   create a new file and open it for writing,
                             if the file already exists the file is
                             not opened.
           = RECREATE        create a new file, if the file already
                             exists it will be overwritten.
           = 2xoo            create a new file with specified xml settings
                             for more details see TXMLSetup class
           = UPDATE          open an existing file for writing.
                             if no file exists, it is created.
           = READ            open an existing file for reading.

 For more details see comments for TFile::TFile() constructor

 For a moment TXMLFile does not support TTree objects and subdirectories

 initialize xml file and correspondent structures
 identical to TFile::Init() function

 Close a XML file
 For more comments see TFile::Close() function

 destructor of TXMLFile object

 return kTRUE if file is opened and can be accessed

 Reopen a file with a different access mode, like from READ to
 See TFile::Open() for details

 write object, derived from TObject class, to file

 Write object of class classname in this directory
 obj may not derive from TObject
 see TDirectory::WriteObject for comments

 write object of any class with disctionary to xml file
 object is tranformed to xml structure, which then kept in TXMLKey
 Data will be stored to file only when Close() or ReOpen() or destructor is called
 For more details see TDirectory::WriteObjectAny() function

 function produces pair of xml and dtd file names

 Saves xml structures to file
 xml elements are kept in list of TXMLKey objects
 When saving, all this elements are linked to root xml node
 In the end StreamerInfo structures are added
 After xml document is saved, all nodes will be unlinked from root node
 and kept in memory.
 Only Close() or destructor relase memory, used by xml structures

 read document from file
 Now full content of docuument reads into the memory
 Then document decomposed to separate keys and streamer info structures
 All inrelevant data will be cleaned

 convert all TStreamerInfo, used in file, to xml format

 Read streamerinfo structures from xml format and provide them in the list
 It is user responsibility to destroy this list

 Read the list of StreamerInfo from this file
 The corresponding TClass objects are updated.

 store data of single TStreamerElement in streamer node

 read and reconstruct single TStreamerElement from xml node

 Change layout of objects in xml file
 Can be changed only for newly created file.

 Currently there are two supported layouts:

 TXMLSetup::kSpecialized = 2
    This is default layout of the file, when xml nodes names class names and data member
    names are used. For instance:
          <TAttLine version="1">
            <fLineColor v="1"/>
            <fLineStyle v="1"/>
            <fLineWidth v="1"/>
          </TAttLine>

 TXMLSetup::kGeneralized = 3
    For this layout all nodes name does not depend from class definitions.
    The same class looks like
          <Class name="TAttLine" version="1">
            <Member name="fLineColor" v="1"/>
            <Member name="fLineStyle" v="1"/>
            <Member name="fLineWidth" v="1"/>
          </Member>

 If true, all correspondent to file TStreamerInfo objects will be stored in file
 this allows to apply schema avolution later for this file
 may be usefull, when file used outside ROOT and TStreamerInfo objects does not required
 Can be changed only for newly created file.

 Specify usage of DTD for this file.
 Currently this option not avaliable (always false).
 Can be changed only for newly created file.

 Specifiy usage of namespaces in xml file
 In current implementation every instrumented class in file gets its unique namespace,
 which is equal to name of class and refer to root documentation page like
 <TAttPad xmlns:TAttPad="http://root.cern.ch/root/htmldoc/TAttPad.html" version="3">
 And xml node for class member gets its name as combination of class name and member name
            <TAttPad:fLeftMargin v="0.100000"/>
            <TAttPad:fRightMargin v="0.100000"/>
            <TAttPad:fBottomMargin v="0.100000"/>
            and so on
 Usage of namespace increase size of xml file, but makes file more readable
 and allows to produce DTD in the case, when in several classes data member has same name
 Can be changed only for newly created file.

Inline Functions

              Int_t SysOpen(const char*, Int_t, UInt_t)
              Int_t SysClose(Int_t)
              Int_t SysRead(Int_t, void*, Int_t)
              Int_t SysWrite(Int_t, const void*, Int_t)
           Long64_t SysSeek(Int_t, Long64_t, Int_t)
              Int_t SysStat(Int_t, Long_t*, Long64_t*, Long_t*, Long_t*)
              Int_t SysSync(Int_t)
               void operator=(const TXMLFile&)
               void DrawMap(const char* = "*", Option_t*)
               void FillBuffer(char*&)
               void Flush()
           Long64_t GetEND() const
              Int_t GetErrno() const
               void ResetErrno() const
              Int_t GetNfree() const
              Int_t GetNbytesInfo() const
              Int_t GetNbytesFree() const
           Long64_t GetSeekFree() const
           Long64_t GetSeekInfo() const
           Long64_t GetSize() const
               void MakeFree(Long64_t, Long64_t)
               void MakeProject(const char*, const char* = "*", Option_t* = "new")
               void Map()
               void Paint(Option_t*)
               void Print(Option_t*) const
             Bool_t ReadBuffer(char*, Int_t)
               void ReadFree()
              Int_t Recover()
               void Seek(Long64_t, TFile::ERelativeTo = kBeg)
               void SetEND(Long64_t)
              Int_t Sizeof() const
               void UseCache(Int_t = 10, Int_t = TCache::kDfltPageSize)
             Bool_t WriteBuffer(const char*, Int_t)
              Int_t Write(const char* = "0", Int_t = 0, Int_t = 0)
              Int_t Write(const char* = "0", Int_t = 0, Int_t = 0) const
               void WriteFree()
               void WriteHeader()
        TXMLEngine* XML()
            TClass* Class()
            TClass* IsA() const
               void ShowMembers(TMemberInspector& insp, char* parent)
               void Streamer(TBuffer& b)
               void StreamerNVirtual(TBuffer& b)