Kevin Bullock <kbullock+mercurial@ringworld.org> [Sat, 03 Mar 2018 19:02:50 -0500] rev 36682
dispatch: don't clamp the range of the exit code twice
We already limit the range to (0, 255) in the call to sys.exit(). The
duplicated operation can't possibly be hurting us, but let's clean it up
to avoid confusion.
Matt Harbison <matt_harbison@yahoo.com> [Sat, 03 Mar 2018 23:29:40 -0500] rev 36681
bdiff: avoid pointer arithmetic on void*
MSVC 2008 complains:
mercurial/cext/bdiff.c(106) : error C2036: 'void *' : unknown size
mercurial/cext/bdiff.c(107) : error C2036: 'void *' : unknown size
Maybe it's a gcc extension?
https://stackoverflow.com/questions/
37460579/error-c2036-void-unknown-size
Augie Fackler <augie@google.com> [Sat, 03 Mar 2018 19:26:30 -0500] rev 36680
fuzz: add a quick README to try and document how to test new fuzzers
Differential Revision: https://phab.mercurial-scm.org/D2633
Augie Fackler <augie@google.com> [Sat, 03 Mar 2018 18:58:13 -0500] rev 36679
fuzz: add a fuzzer for xdiff
Based entirely on the fuzzer for bdiff.
Differential Revision: https://phab.mercurial-scm.org/D2632
Jun Wu <quark@fb.com> [Sat, 03 Mar 2018 12:39:15 -0800] rev 36678
tests: add tests about diff quality
These show the differences between bdiff and xdiff.
Differential Revision: https://phab.mercurial-scm.org/D2604
Jun Wu <quark@fb.com> [Sat, 03 Mar 2018 12:39:14 -0800] rev 36677
run-tests: allow #require inside #if
Used by the next patch.
Differential Revision: https://phab.mercurial-scm.org/D2605
Jun Wu <quark@fb.com> [Sat, 03 Mar 2018 12:39:14 -0800] rev 36676
mdiff: add a config option to use xdiff algorithm
The `experimental.xdiff` will affect the default diffopts and make mdiff use
the xdiff algorithm for better diff quality.
Differential Revision: https://phab.mercurial-scm.org/D2603
Jun Wu <quark@fb.com> [Sat, 03 Mar 2018 12:39:14 -0800] rev 36675
bdiff: add a xdiffblocks method
This is similar to `bdiff.blocks`, but uses xdiff as the backend.
The indent heuristic is turned on by default since it has little overhead
and improves diff quality significantly.
Differential Revision: https://phab.mercurial-scm.org/D2602
Jun Wu <quark@fb.com> [Sat, 03 Mar 2018 12:39:11 -0800] rev 36674
xdiff: reduce indent heuristic overhead
Adds some threshold to avoid expensive cases, like:
```
#!python
open('a', 'w').write(" \n" * 1000000)
open('b', 'w').write(" \n" * 1000001)
```
The indent heuristic is O(N * 20) (N = 1000000) for the above case, and
makes diff much slower.
Before this patch (system git 2.14.2):
```
git diff --no-indent-heuristic a b 0.21s user 0.03s system 100% cpu 0.239 total
git diff --indent-heuristic a b 0.77s user 0.02s system 99% cpu 0.785 total
```
After this patch (git
2fc74f41, with xdiffi.c patched):
```
# with the changed xdiffi.c
git diff --indent-heuristic a b 0.16s user 0.01s system 90% cpu 0.188 total
git diff --no-indent-heuristic a b 0.18s user 0.01s system 99% cpu 0.192 total
```
Now turning on indent-heuristic has no visible impact on performance.
Differential Revision: https://phab.mercurial-scm.org/D2601
Jun Wu <quark@fb.com> [Sat, 03 Mar 2018 12:38:41 -0800] rev 36673
xdiff: add a bdiff hunk mode
xdiff generated hunks for the differences (ex. questionmarks in the
`@@ -?,? +?,? @@` part from `diff --git` output). However, bdiff generates
matched hunks instead.
This patch adds a `XDL_EMIT_BDIFFHUNK` flag used by the output function
`xdl_call_hunk_func`. Once set, xdiff will generate bdiff-like hunks
instead. That makes it easier to use xdiff as a drop-in replacement of bdiff.
Note that since `bdiff('', '')` returns `[(0, 0, 0, 0)]`, the shortcut path
`if (xscr)` is removed. I have checked functions called with `xscr` argument
(`xdl_mark_ignorable`, `xdl_call_hunk_func`, `xdl_emit_diff`,
`xdl_free_script`) work just fine with `xscr = NULL`.
Test Plan:
Will be tested in a later patch.
Differential Revision: https://phab.mercurial-scm.org/D2575