HardenedBSD/contrib/libdiff
Dag-Erling Smørgrav 974ea6b297 libdiff: Detect and recover from file truncation.
If a memory-mapped file is truncated before we get to the end, the
atomizer may catch SIGBUS.  Detect that, reduce the input length to
what we were actually able to read, and set a flag so the caller can
take further action (e.g. warn the user and / or start over).

Sponsored by:	Klara, Inc.
Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D45217
2024-05-20 15:26:33 +02:00
..
compat
diff
include libdiff: Detect and recover from file truncation. 2024-05-20 15:26:33 +02:00
lib libdiff: Detect and recover from file truncation. 2024-05-20 15:26:33 +02:00
man
test
.gitignore
diff-version.mk
LICENCE
README

This is a collection of diff algorithms, to test various combinations.

The initial aim was to provide a faster diff implementation for got
(gameoftrees.org) with a BSD license, at the u2k20 OpenBSD hackathon.
A side effect could be improving OpenBSD's /usr/bin/diff utility.

At the time of writing, this is little more than a playground / benchmark basis
/ diff algorithm analysis platform. What could be done:
- add profiling and test series to rate diff algorithm combinations.
- interface with / merge into got.

The Myers and Patience Diff algorithm implementations found here are based on
the explanations found in these blog post series:
  https://blog.jcoglan.com/2017/02/12/the-myers-diff-algorithm-part-1/ ff.
and
  https://blog.jcoglan.com/2017/09/19/the-patience-diff-algorithm/ ff.
-- possibly the single most comprehensive explanations of these algorithms.
Many thanks for this valuable door opener!
The source code itself is not based on the code found in those blogs, but
written from scratch with the knowledge gained.

Compile:
  make -C diff

Test:
  make -C test/