Mercurial > hg
view tests/cgienv @ 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 | aa3f726a2bdb |
children |
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DOCUMENT_ROOT="/var/www/hg"; export DOCUMENT_ROOT GATEWAY_INTERFACE="CGI/1.1"; export GATEWAY_INTERFACE HTTP_ACCEPT="text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5"; export HTTP_ACCEPT HTTP_ACCEPT_CHARSET="ISO-8859-1,utf-8;q=0.7,*;q=0.7"; export HTTP_ACCEPT_CHARSET HTTP_ACCEPT_ENCODING="gzip,deflate"; export HTTP_ACCEPT_ENCODING HTTP_ACCEPT_LANGUAGE="en-us,en;q=0.5"; export HTTP_ACCEPT_LANGUAGE HTTP_CACHE_CONTROL="max-age=0"; export HTTP_CACHE_CONTROL HTTP_CONNECTION="keep-alive"; export HTTP_CONNECTION HTTP_HOST="hg.omnifarious.org"; export HTTP_HOST HTTP_KEEP_ALIVE="300"; export HTTP_KEEP_ALIVE HTTP_USER_AGENT="Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.0.4) Gecko/20060608 Ubuntu/dapper-security Firefox/1.5.0.4"; export HTTP_USER_AGENT PATH_INFO="/"; export PATH_INFO PATH_TRANSLATED="/var/www/hg/index.html"; export PATH_TRANSLATED QUERY_STRING=""; export QUERY_STRING REMOTE_ADDR="127.0.0.2"; export REMOTE_ADDR REMOTE_PORT="44703"; export REMOTE_PORT REQUEST_METHOD="GET"; export REQUEST_METHOD REQUEST_URI="/test/"; export REQUEST_URI SCRIPT_FILENAME="/home/hopper/hg_public/test.cgi"; export SCRIPT_FILENAME SCRIPT_NAME="/test"; export SCRIPT_NAME SCRIPT_URI="http://hg.omnifarious.org/test/"; export SCRIPT_URI SCRIPT_URL="/test/"; export SCRIPT_URL SERVER_ADDR="127.0.0.1"; export SERVER_ADDR SERVER_ADMIN="eric@localhost"; export SERVER_ADMIN SERVER_NAME="hg.omnifarious.org"; export SERVER_NAME SERVER_PORT="80"; export SERVER_PORT SERVER_PROTOCOL="HTTP/1.1"; export SERVER_PROTOCOL SERVER_SIGNATURE="<address>Apache/2.0.53 (Fedora) Server at hg.omnifarious.org Port 80</address>"; export SERVER_SIGNATURE SERVER_SOFTWARE="Apache/2.0.53 (Fedora)"; export SERVER_SOFTWARE