question: private synchronized int readRecordLength ( ) throws IOException { if ( in . getPos ( ) >= end ) { return - 1 ; } int length = in . readInt ( ) ; if ( sync != null && length == SYNC_ESCAPE ) { in . readFully ( syncCheck ) ; if ( ! Arrays . equals ( sync , syncCheck ) ) { throw new IOException ( "File is corrupt!" ) ; } syncSeen = true ; if ( in . getPos ( ) >= end ) { return - 1 ; } length = in . readInt ( ) ; } else { syncSeen = false ; } return length ; }
target:  Read and return the next record length, potentially skipping over a sync block.