# datarecord

## datarecord.txt

```
//  Release 3.02.06
//  A ROOT file is mostly a suite of consecutive data records with the following format
// <Name>;<Cycle> uniquely identifies the record in a directory
// ----------TKey-(never compressed)--------------
//  byte 0->3  Nbytes    = Number of bytes in compressed record (Tkey+data)   TKey::fNbytes
//       4->5  Version   = TKey class version identifier                      TKey::fVersion
//       6->9  ObjLen    = Number of bytes of uncompressed data               TKey::fObjLen
//      10->13 Datime    = Date and time when record was written to file      TKey::fDatime
//                       | (year-1995)<<26|month<<22|day<<17|hour<<12|minute<<6|second
//      14->15 KeyLen    = Number of bytes in key structure (TKey)            TKey::fKeyLen
//      16->17 Cycle     = Cycle of key (e.g. 1)                              TKey::fCycle
//      18->21 SeekKey   = Byte offset of record itself (consistency check)   TKey::fSeekKey
//      22->25 SeekPdir  = Byte offset of parent directory record             TKey::fSeekPdir
//      26->26 lname     = Number of bytes in the class name                  TKey::fClassName
//      27->.. ClassName = Object Class Name                                  TKey::fClassName
//       0->0  lname     = Number of bytes in the object name                 TNamed::fName
//       1->.. Name      = lName bytes with the name of the object            TNamed::fName
//       0->0  lTitle    = Number of bytes in the object title                TNamed::fTitle
//       1->.. Title     = lTitle bytes with the title of the object          TNamed::fTitle
// ----------DATA---(may be compressed)-----------
//       0->..             The data object itself.  For an example, see dobject.txt
```