question: private void ensureFileOpen ( ) { if ( savingDisabled ) { Log . e ( TAG , "Saving disabled but tried to ensureFileOpen" ) ; return ; } if ( saveFileStream != null ) return ; File saveFile = new File ( ctx . getFilesDir ( ) , SAVEFILE ) ; try { FileOutputStream fileOutput = null ; DataOutputStream out = null ; if ( saveFile . exists ( ) ) { fileOutput = ctx . openFileOutput ( SAVEFILE , Context . MODE_APPEND ) ; out = new DataOutputStream ( new BufferedOutputStream ( fileOutput ) ) ; } else { fileOutput = ctx . openFileOutput ( SAVEFILE , Context . MODE_PRIVATE ) ; out = new DataOutputStream ( new BufferedOutputStream ( fileOutput ) ) ; out . writeInt ( TrackPoint . FORMAT_VERSION ) ; savedTrackPoints = 0 ; } saveFileStream = out ; } catch ( Exception e ) { markSavingBroken ( "Failed to open track save file" , e ) ; } }
target:  Opens the saveFileStream if necessary