From: Richard Dawe (rich@phekda.freeserve.co.uk)

Subject: ANNOUNCE: Release 2 of DJGPP port of XDelta 1.1.1

Newsgroups: comp.os.msdos.djgpp

Date: 2001-04-05 13:42:13 PST

Hello.

I've updated the port of XDelta 1.1.1 to DJGPP. If you used the previous

release, PLEASE UPGRADE. This release fixes a bug that could cause data

loss. Several other minor bugfixes should make the port much more usable.

See below for a list of bugfixes. The DJGPP readme has also been updated

to include a little more information on XDelta, since the XDelta

documentation is not very helpful.

Here is a description of XDelta, from its 'readme' file:

"XDelta is a library interface and application program designed to compute

changes between files. These changes (deltas) are similar to the output

of the "diff" program in that they may be used to store and transmit only

the changes between files. However, unlike diff, the output of XDelta is

not expressed in a human-readable format--XDelta can also also apply these

deltas to a copy of the original file(s). XDelta uses a fast, linear

algorithm and performs well on both binary and text files. XDelta

typically outperforms GNU diff in both time and generated-delta-size, even

for plain text files. XDelta also includes a simple implementation of the

Rsync algorithm and several advanced features for implementing RCS-like

file-archival with."

XDelta is distributed under the GNU General Public License.

The port is available from the DJGPP archive on SimTel.NET:

ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2apps/xdlt111b.zip

ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2apps/xdlt111s.zip

These are binary and source distributions respectively. If you only want

to use XDelta, please download the binary distribution. If you would like

to rebuild XDelta, please download the source distribution. Minor changes

were required to port XDelta to DJGPP - the diffs are included in the

source distribution.

Bugs fixed since Release 1

--------------------------

* Temporary filenames are now generated to fit into the MS-DOS 8+3

filename convention.

* Temporary files should now be removed, when XDelta has finised.

Previously, XDelta tried to remove them before they had been closed. On

MS-DOS this can cause filesystem corruption; on Windows this just leaves

the temporary files lying around.

* XDelta's buffers are now sized by default according to the amount of

free physical memory. It defaults to using 87.5% (7/8) of

the available memory.

Previously, XDelta would try to entire files into memory, to patch them.

This included decompressing gzip files. Hence, it was quite easy for

XDelta to exhaust available memory, resulting in XDelta crashing.

* The '-m' or '--maxmem' switches, which set the maximum memory usage

by XDelta, are now honoured. XDelta will use up to the specified size.

NB: XDelta will not check the amount specified - be careful. If you

give it too little memory, it will take a long time. If you give it

more memory than is actually available, it will crash.

Previously, XDelta would take the maximum of the specified size or 8MB.

Since XDelta may be running on computers with 8MB or less, this was

unsatisfactory.

To see XDelta's maximum memory usage, run in verbose mode, e.g.:

xdelta patch -V <patch> <fromfile> <tofile>

It will display a message like:

xdelta: using 4096 kilobytes of buffer space

* A couple of error messages were modified to include the file name, to

make it clearer what the error is.

* The info manual is now omitted from the distribution, since it does not

contain any useful information about XDelta.

* A formatted man page is now included.

Thanks to Eli Zaretskii for his detailed bug reports, suggestions and

testing!

If you have any problems, suggestions, etc. about the port, please mail

me.

Bye,

--

Richard Dawe <richdawe@bigfoot.com> http://www.bigfoot.com/~richdawe/