Mercurial > hg
view tests/test-requires.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 | 68bc85f46fe3 |
children | ecac0006b90e |
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$ hg init t $ cd t $ echo a > a $ hg add a $ hg commit -m test $ rm .hg/requires $ hg tip abort: unknown version (2) in revlog 00changelog.i! [255] $ echo indoor-pool > .hg/requires $ hg tip abort: repository requires features unknown to this Mercurial: indoor-pool! (see https://mercurial-scm.org/wiki/MissingRequirement for more information) [255] $ echo outdoor-pool >> .hg/requires $ hg tip abort: repository requires features unknown to this Mercurial: indoor-pool outdoor-pool! (see https://mercurial-scm.org/wiki/MissingRequirement for more information) [255] $ cd .. Test checking between features supported locally and ones required in another repository of push/pull/clone on localhost: $ mkdir supported-locally $ cd supported-locally $ hg init supported $ echo a > supported/a $ hg -R supported commit -Am '#0 at supported' adding a $ echo 'featuresetup-test' >> supported/.hg/requires $ cat > $TESTTMP/supported-locally/supportlocally.py <<EOF > from __future__ import absolute_import > from mercurial import extensions, localrepo > def featuresetup(ui, supported): > for name, module in extensions.extensions(ui): > if __name__ == module.__name__: > # support specific feature locally > supported |= {'featuresetup-test'} > return > def uisetup(ui): > localrepo.localrepository.featuresetupfuncs.add(featuresetup) > EOF $ cat > supported/.hg/hgrc <<EOF > [extensions] > # enable extension locally > supportlocally = $TESTTMP/supported-locally/supportlocally.py > EOF $ hg -R supported status $ hg init push-dst $ hg -R supported push push-dst pushing to push-dst abort: required features are not supported in the destination: featuresetup-test [255] $ hg init pull-src $ hg -R pull-src pull supported pulling from supported abort: required features are not supported in the destination: featuresetup-test [255] $ hg clone supported clone-dst abort: repository requires features unknown to this Mercurial: featuresetup-test! (see https://mercurial-scm.org/wiki/MissingRequirement for more information) [255] $ hg clone --pull supported clone-dst abort: required features are not supported in the destination: featuresetup-test [255] $ cd ..