One comment on eliminating the read-behind in map_ptr(): The sender's read pattern can jump back a blocksize or so when it is scanning the file using the rolling checksum and it needs to send out the just-passed data that it didn't find a match for. We don't want this data to be re-read from disk, so we should make sure that this unmatched data is retained in the buffer.
I think a good way to do this (when combined with the removal of the window_start-kluge in map_ptr() that your patch removed) would be to have the sender code call map_ptr() with a read range that includes the start of the unmatched data that it needs up through the rolling- checksum area that it is processing. This way it would always tell map_ptr() what memory must be preserved to prevent a re-read. ..wayne.. -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html
