Mercurial > hg
view tests/test-encoding.t @ 23785:cb99bacb9b4e
branchcache: introduce revbranchcache for caching of revision branch names
It is expensive to retrieve the branch name of a revision. Very expensive when
creating a changectx and calling .branch() every time - slightly less when
using changelog.branchinfo().
Now, to speed things up, provide a way to cache the results on disk in an
efficient format. Each branchname is assigned a number, and for each revision
we store the number of the corresponding branch name. The branch names are
stored in a dedicated file which is strictly append only.
Branch names are usually reused across several revisions, and the total list of
branch names will thus be so small that it is feasible to read the whole set of
names before using the cache. It will however do that it might be more
efficient to use the changelog for retrieving the branch info for a single
revision.
The revision entries are stored in another file. This file is usually append
only, but if the repository has been modified, the file will be truncated and
the relevant parts rewritten on demand.
The entries for each revision are 8 bytes each, and the whole revision file
will thus be 1/8 of 00changelog.i.
Each revision entry contains the first 4 bytes of the corresponding node hash.
This is used as a check sum that always is verified before the entry is used.
That check is relatively expensive but it makes sure history modification is
detected and handled correctly. It will also detect and handle most revision
file corruptions.
This is just a cache. A new format can always be introduced if other
requirements or ideas make that seem like a good idea. Rebuilding the cache is
not really more expensive than it was to run for example 'hg log -b branchname'
before this cache was introduced.
This new method is still unused but promise to make some operations several
times faster once it actually is used.
Abandoning Python 2.4 would make it possible to implement this more efficiently
by using struct classes and pack_into. The Python code could probably also be
micro optimized or it could be implemented very efficiently in C where it would
be easy to control the data access.
author | Mads Kiilerich <madski@unity3d.com> |
---|---|
date | Thu, 08 Jan 2015 00:01:03 +0100 |
parents | bfc50ff55f3f |
children | 51fa43a3cd58 |
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Test character encoding $ hg init t $ cd t we need a repo with some legacy latin-1 changesets $ hg unbundle "$TESTDIR/bundles/legacy-encoding.hg" adding changesets adding manifests adding file changes added 2 changesets with 2 changes to 1 files (run 'hg update' to get a working copy) $ hg co 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ python << EOF > f = file('latin-1', 'w'); f.write("latin-1 e' encoded: \xe9"); f.close() > f = file('utf-8', 'w'); f.write("utf-8 e' encoded: \xc3\xa9"); f.close() > f = file('latin-1-tag', 'w'); f.write("\xe9"); f.close() > EOF should fail with encoding error $ echo "plain old ascii" > a $ hg st M a ? latin-1 ? latin-1-tag ? utf-8 $ HGENCODING=ascii hg ci -l latin-1 transaction abort! rollback completed abort: decoding near ' encoded: \xe9': 'ascii' codec can't decode byte 0xe9 in position 20: ordinal not in range(128)! (esc) [255] these should work $ echo "latin-1" > a $ HGENCODING=latin-1 hg ci -l latin-1 $ echo "utf-8" > a $ HGENCODING=utf-8 hg ci -l utf-8 $ HGENCODING=latin-1 hg tag `cat latin-1-tag` $ HGENCODING=latin-1 hg branch `cat latin-1-tag` marked working directory as branch \xe9 (esc) (branches are permanent and global, did you want a bookmark?) $ HGENCODING=latin-1 hg ci -m 'latin1 branch' $ hg -q rollback $ HGENCODING=latin-1 hg branch \xe9 (esc) $ HGENCODING=latin-1 hg ci -m 'latin1 branch' $ rm .hg/branch hg log (ascii) $ hg --encoding ascii log changeset: 5:a52c0692f24a branch: ? tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: latin1 branch changeset: 4:94db611b4196 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Added tag ? for changeset ca661e7520de changeset: 3:ca661e7520de tag: ? user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: utf-8 e' encoded: ? changeset: 2:650c6f3d55dd user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: latin-1 e' encoded: ? changeset: 1:0e5b7e3f9c4a user: test date: Mon Jan 12 13:46:40 1970 +0000 summary: koi8-r: ????? = u'\u0440\u0442\u0443\u0442\u044c' changeset: 0:1e78a93102a3 user: test date: Mon Jan 12 13:46:40 1970 +0000 summary: latin-1 e': ? = u'\xe9' hg log (latin-1) $ hg --encoding latin-1 log changeset: 5:a52c0692f24a branch: \xe9 (esc) tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: latin1 branch changeset: 4:94db611b4196 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Added tag \xe9 for changeset ca661e7520de (esc) changeset: 3:ca661e7520de tag: \xe9 (esc) user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: utf-8 e' encoded: \xe9 (esc) changeset: 2:650c6f3d55dd user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: latin-1 e' encoded: \xe9 (esc) changeset: 1:0e5b7e3f9c4a user: test date: Mon Jan 12 13:46:40 1970 +0000 summary: koi8-r: \xd2\xd4\xd5\xd4\xd8 = u'\\u0440\\u0442\\u0443\\u0442\\u044c' (esc) changeset: 0:1e78a93102a3 user: test date: Mon Jan 12 13:46:40 1970 +0000 summary: latin-1 e': \xe9 = u'\\xe9' (esc) hg log (utf-8) $ hg --encoding utf-8 log changeset: 5:a52c0692f24a branch: \xc3\xa9 (esc) tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: latin1 branch changeset: 4:94db611b4196 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Added tag \xc3\xa9 for changeset ca661e7520de (esc) changeset: 3:ca661e7520de tag: \xc3\xa9 (esc) user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: utf-8 e' encoded: \xc3\xa9 (esc) changeset: 2:650c6f3d55dd user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: latin-1 e' encoded: \xc3\xa9 (esc) changeset: 1:0e5b7e3f9c4a user: test date: Mon Jan 12 13:46:40 1970 +0000 summary: koi8-r: \xc3\x92\xc3\x94\xc3\x95\xc3\x94\xc3\x98 = u'\\u0440\\u0442\\u0443\\u0442\\u044c' (esc) changeset: 0:1e78a93102a3 user: test date: Mon Jan 12 13:46:40 1970 +0000 summary: latin-1 e': \xc3\xa9 = u'\\xe9' (esc) hg tags (ascii) $ HGENCODING=ascii hg tags tip 5:a52c0692f24a ? 3:ca661e7520de hg tags (latin-1) $ HGENCODING=latin-1 hg tags tip 5:a52c0692f24a \xe9 3:ca661e7520de (esc) hg tags (utf-8) $ HGENCODING=utf-8 hg tags tip 5:a52c0692f24a \xc3\xa9 3:ca661e7520de (esc) hg tags (JSON) $ hg tags -Tjson [ { "node": "a52c0692f24ad921c0a31e1736e7635a8b23b670", "rev": 5, "tag": "tip", "type": "" }, { "node": "ca661e7520dec3f5438a63590c350bebadb04989", "rev": 3, "tag": "\xc3\xa9", (esc) "type": "" } ] hg branches (ascii) $ HGENCODING=ascii hg branches ? 5:a52c0692f24a default 4:94db611b4196 (inactive) hg branches (latin-1) $ HGENCODING=latin-1 hg branches \xe9 5:a52c0692f24a (esc) default 4:94db611b4196 (inactive) hg branches (utf-8) $ HGENCODING=utf-8 hg branches \xc3\xa9 5:a52c0692f24a (esc) default 4:94db611b4196 (inactive) $ echo '[ui]' >> .hg/hgrc $ echo 'fallbackencoding = koi8-r' >> .hg/hgrc hg log (utf-8) $ HGENCODING=utf-8 hg log changeset: 5:a52c0692f24a branch: \xc3\xa9 (esc) tag: tip user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: latin1 branch changeset: 4:94db611b4196 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Added tag \xc3\xa9 for changeset ca661e7520de (esc) changeset: 3:ca661e7520de tag: \xc3\xa9 (esc) user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: utf-8 e' encoded: \xc3\xa9 (esc) changeset: 2:650c6f3d55dd user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: latin-1 e' encoded: \xc3\xa9 (esc) changeset: 1:0e5b7e3f9c4a user: test date: Mon Jan 12 13:46:40 1970 +0000 summary: koi8-r: \xd1\x80\xd1\x82\xd1\x83\xd1\x82\xd1\x8c = u'\\u0440\\u0442\\u0443\\u0442\\u044c' (esc) changeset: 0:1e78a93102a3 user: test date: Mon Jan 12 13:46:40 1970 +0000 summary: latin-1 e': \xd0\x98 = u'\\xe9' (esc) hg log (dolphin) $ HGENCODING=dolphin hg log abort: unknown encoding: dolphin (please check your locale settings) [255] $ HGENCODING=ascii hg branch `cat latin-1-tag` abort: decoding near '\xe9': 'ascii' codec can't decode byte 0xe9 in position 0: ordinal not in range(128)! (esc) [255] $ cp latin-1-tag .hg/branch $ HGENCODING=latin-1 hg ci -m 'auto-promote legacy name' Test roundtrip encoding of lookup tables when not using UTF-8 (issue2763) $ HGENCODING=latin-1 hg up `cat latin-1-tag` 0 files updated, 0 files merged, 1 files removed, 0 files unresolved $ cd ..