question: private void basicRemove ( DiskRegion dr , DiskEntry entry ) throws IOException , InterruptedException { DiskId id = entry . getDiskId ( ) ; if ( EntryBits . isNeedsValue ( id . getUserBits ( ) ) ) { long oldOffset = id . getOffsetInOplog ( ) ; if ( oldOffset != - 1 ) { id . setOffsetInOplog ( - 1 ) ; if ( rmLive ( entry ) ) { if ( ! isCompacting ( ) || calledByCompactorThread ( ) ) { handleNoLiveValues ( ) ; } } } } }
target:  Asif: A helper function which identifies whether to record a removal of entry in the current oplog or to make the switch to the next oplog. This function enables us to reuse the byte buffer which got created for an oplog which no longer permits us to use itself.