Mercurial > hg
view tests/test-hgk.t @ 36672:9e7b14caf67f
xdiff: remove patience and histogram diff algorithms
Patience diff is the normal diff algorithm, plus some greediness that
unconditionally matches common common unique lines. That means it is easy to
construct cases to let it generate suboptimal result, like:
```
open('a', 'w').write('\n'.join(list('a' + 'x' * 300 + 'u' + 'x' * 700 + 'a\n')))
open('b', 'w').write('\n'.join(list('b' + 'x' * 700 + 'u' + 'x' * 300 + 'b\n')))
```
Patience diff has been advertised as being able to generate better results for
some C code changes. However, the more scientific way to do that is the
indention heuristic [1].
Since patience diff could generate suboptimal result more easily and its
"better" diff feature could be replaced by the new indention heuristic, let's
just remove it and its variant histogram diff to simplify the code.
[1]: https://github.com/git/git/commit/433860f3d0beb0c6f205290bd16cda413148f098
Test Plan:
`gcc -fPIC *.c --shared -o xdiff.so` still builds.
Differential Revision: https://phab.mercurial-scm.org/D2573
author | Jun Wu <quark@fb.com> |
---|---|
date | Sat, 03 Mar 2018 10:39:55 -0800 |
parents | 5fb1fc2e1281 |
children |
line wrap: on
line source
Minimal hgk check $ echo "[extensions]" >> $HGRCPATH $ echo "hgk=" >> $HGRCPATH $ hg init repo $ cd repo $ echo a > a $ hg ci -Am adda adding a $ hg debug-cat-file commit 0 tree a0c8bcbbb45c parent 000000000000 author test 0 0 revision 0 branch default phase draft adda $ echo b > b $ hg ci -Am addb adding b $ hg log -T '{node}\n' 102a90ea7b4a3361e4082ed620918c261189a36a 07f4944404050f47db2e5c5071e0e84e7a27bba9 $ hg debug-diff-tree 07f494440405 102a90ea7b4a :000000 100664 000000000000 1e88685f5dde N b b $ hg debug-diff-tree 07f494440405 102a90ea7b4a --patch diff --git a/b b/b new file mode 100644 --- /dev/null +++ b/b @@ -0,0 +1,1 @@ +b Ensure that diff-tree output isn't affected by diffopts $ hg --config diff.noprefix=True debug-diff-tree 07f494440405 102a90ea7b4a :000000 100664 000000000000 1e88685f5dde N b b $ hg --config diff.noprefix=True debug-diff-tree --patch 07f494440405 102a90ea7b4a diff --git a/b b/b new file mode 100644 --- /dev/null +++ b/b @@ -0,0 +1,1 @@ +b $ cd ..