CVS commit: othersrc/external/bsd/delta

["Alistair G. Crooks" <agc%netbsd.org@localhost>]

Module Name:    othersrc
Committed By:   agc
Date:           Thu Apr 28 05:21:31 UTC 2016

Added Files:
        othersrc/external/bsd/delta: Makefile README
        othersrc/external/bsd/delta/bin: 1 2 3 4 Makefile
        othersrc/external/bsd/delta/dist: Makefile delta.1 delta.c delta.h
            libdelta.3 libdelta.c main.c
        othersrc/external/bsd/delta/lib: Makefile shlib_version

Log Message:
Add the delta library and utility program, providing
space-efficient binary diff/patch functionality.

delta is a library (and an associated utility) which allow
us to perform binary diff and patching in an efficient way. It
is similar in function to xdelta and vcdiff (RFC 3284), but more
(space-)efficient.

        -rw-r--r--  1 agc  users  10107 Apr 14 10:41 1
        -rw-r--r--  1 agc  users    206 Apr 19 16:50 1.bsd
        -rw-r--r--  1 agc  users    109 Apr 27 22:11 1.diff
        -rw-r--r--  1 agc  users    222 Apr 19 16:48 1.xd
        -rw-r--r--  1 agc  users    158 Apr 19 17:48 1.xd3
        -rw-r--r--  1 agc  users  10113 Apr 14 10:41 2
        -rw-r--r--  1 agc  users  10113 Apr 27 22:11 2.new

The delta(1) utility takes 3 arguments - oldfile, newfile and
patchfile - and creates the patchfile from the binary difference of
the old and new files. There's an optional -d or -p to diff and
to patch, respectively. The default is to patch.

        % delta -d 2 1 2.diff
        % delta -p 2 1.new 2.diff
        % diff 1 1.new
        %

The patchfile uses bzip2, and is more efficient than both xdelta (v1
and v3) by Josh MacDonald, and bsdiff from Colin Percival, dated 2005.
It also uses zigzag encoding for the numbers stored internally, in
order to be space-efficient.

I also tried using xz/lzma compression, but the results were not good
- around 160 bytes for a delta file where bzip2 ended up with 109
bytes.


To generate a diff of this commit:
cvs rdiff -u -r0 -r1.1 othersrc/external/bsd/delta/Makefile \
    othersrc/external/bsd/delta/README
cvs rdiff -u -r0 -r1.1 othersrc/external/bsd/delta/bin/1 \
    othersrc/external/bsd/delta/bin/2 othersrc/external/bsd/delta/bin/3 \
    othersrc/external/bsd/delta/bin/4 \
    othersrc/external/bsd/delta/bin/Makefile
cvs rdiff -u -r0 -r1.1 othersrc/external/bsd/delta/dist/Makefile \
    othersrc/external/bsd/delta/dist/delta.1 \
    othersrc/external/bsd/delta/dist/delta.c \
    othersrc/external/bsd/delta/dist/delta.h \
    othersrc/external/bsd/delta/dist/libdelta.3 \
    othersrc/external/bsd/delta/dist/libdelta.c \
    othersrc/external/bsd/delta/dist/main.c
cvs rdiff -u -r0 -r1.1 othersrc/external/bsd/delta/lib/Makefile \
    othersrc/external/bsd/delta/lib/shlib_version

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.