question: private void writeJournal ( ParcelFileDescriptor newState , Journal journal ) { try { FileOutputStream outStream = new FileOutputStream ( newState . getFileDescriptor ( ) ) ; final byte [ ] journalBytes = writeCheckedBytes ( journal ) ; outStream . write ( journalBytes ) ; if ( VERBOSE ) Log . v ( TAG , "wrote " + journalBytes . length + " bytes of journal" ) ; } catch ( IOException e ) { Log . w ( TAG , "failed to write backup journal" , e ) ; } }
target:  Write the new journal to the output file. In the event of any error, just pretend we didn't have a journal, in that case, do a full backup.