Simon Farnsworth <simonfar@fb.com> [Fri, 03 Feb 2017 15:10:27 -0800] rev 30876
util: always force line buffered stdout when stdout is a tty (BC)
pager replaced stdout with a line buffered version to work around glibc
deciding on a buffering strategy on the first write to stdout. This is going
to make my next patch hard, as replacing stdout will make tracking time
spent blocked on it more challenging.
Move the line buffering requirement to util.py, and remove it from pager.
This means that the abuse of ui.formatted=True and pager set to cat or equivalent
no longer results in a line-buffered output to a pipe, hence (BC), although
I don't expect anyone to be affected
Stanislau Hlebik <stash@fb.com> [Thu, 02 Feb 2017 02:56:38 -0800] rev 30875
localrepo: avoid unnecessary conversion from node to rev
changelog.heads() first calls headrevs then converts them to nodes.
localrepo.heads() then sorts them using self.changelog.rev function and makes
useless conversion back to revs. Instead let's call changelog.headrevs() from
localrepo.heads(), sort the output and then convert to nodes. Because headrevs
does not support start parameter this optimization only works if start is None.
Anton Shestakov <av6@dwimlabs.net> [Sat, 04 Feb 2017 20:29:34 +0800] rev 30874
debian: update copyright years
Anton Shestakov <av6@dwimlabs.net> [Sat, 04 Feb 2017 20:29:13 +0800] rev 30873
debian: update mailing list address
Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Thu, 02 Feb 2017 14:19:48 +0100] rev 30872
bundle2: implement a basic __repr__ for bundle2 part
We display basic data as the part id and part type. This make debugging bundle2
related code friendlier.
Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Thu, 02 Feb 2017 11:03:41 +0100] rev 30871
bundle2: drop an outdated comment
The function is no longer in "early" stage and have been used in production for
years. We can probably drop that part of the docstring...
Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Thu, 02 Feb 2017 10:53:55 +0100] rev 30870
unbundle: swap conditional branches for clarity
This is a small style update for clarity. The previous situation was:
if foo:
50 lines
else:
2 lines
In such case I tend to invert these to get the simpler branch out of the way
earlier:
if not foo:
2 lines
else:
50 lines
This makes the conditional and various alternatives fit on the same screen,
simpler to read overall.
Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Thu, 02 Feb 2017 10:55:38 +0100] rev 30869
unbundle: add a small comment to tag the bundle1 case as such
This makes the code clearer to understand for someone new to it (or rusted)
Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Thu, 02 Feb 2017 10:51:04 +0100] rev 30868
unbundle: add a small comment to clarify the 'check_heads' call
Bundle2 has its own mechanisms to check for heads (and other) changes, so push
using bundle2 is relying on the "check:heads" bundle part of unbundle and the
'check_heads' call is not checking anything. We add a small comment to make
this clearer.
Simon Farnsworth <simonfar@fb.com> [Thu, 02 Feb 2017 11:17:36 -0800] rev 30867
pager: don't terminate with extreme prejudice on SIGPIPE (BC)
The default SIGPIPE handler causes Mercurial to exit immediately, without
running any Python cleanup code (except and finally blocks, atexit handlers
etc). This creates problems if you want to do something at exit.
If we need a different exit code for broken pipe from pager, then we should
code that ourselves in Python; this appears to have been cargo-culted from
the fork implementation of pager that's no longer used, where it was needed
to stop Broken Pipe errors appearing on the user's terminal.
Martin von Zweigbergk <martinvonz@google.com> [Mon, 23 Jan 2017 10:48:55 -0800] rev 30866
verify: replace _validpath() by matcher
The verifier calls out to _validpath() to check if it should verify
that path and the narrowhg extension overrides _validpath() to tell
the verifier to skip that path. In treemanifest repos, the verifier
calls the same method to check if it should visit a
directory. However, the decision to visit a directory is different
from the condition that it's a matching path, and narrowhg was working
around it by returning True from its _validpath() override if *either*
was true.
Similar to how one can do "hg files -I foo/bar/ -X foo/" (making the
include pointless), narrowhg can be configured to track the same
paths. In that case match("foo/bar/baz") would be false, but
match.visitdir("foo/bar/baz") turns out to be true, causing verify to
fail. This may seem like a bug in visitdir(), but it's explicitly
documented to be undefined for subdirectories of excluded
directories. When using treemanifests, the walk would not descend into
foo/, so verification would pass. However, when using flat manifests,
there is no recursive directory walk and the file path "foo/bar/baz"
would be passed to _validpath() without "foo/" (actually without the
slash) being passed first. As explained above, _validpath() would
return true for the file path and "hg verify" would fail.
Replacing the _validpath() method by a matcher seems like the obvious
fix. Narrowhg can then pass in its own matcher and not have to
conflate the two matching functions (for dirs and files). I think it
also makes the code clearer.
Martin von Zweigbergk <martinvonz@google.com> [Wed, 01 Feb 2017 08:47:27 -0800] rev 30865
rebase: fix code comment to refer to right issue (4504, not 4505)
The comment was introduced in
8a544fb645bb (rebase: ensure rebase
revision remains visible (
issue4504), 2015-01-27), which mentions the
right issue in the description.
Kevin Bullock <kbullock+mercurial@ringworld.org> [Wed, 01 Feb 2017 11:30:26 -0600] rev 30864
merge with stable
Kevin Bullock <kbullock@ringworld.org> [Wed, 01 Feb 2017 10:19:49 -0600] rev 30863
Added signature for changeset
e1526da1e6d8
Kevin Bullock <kbullock@ringworld.org> [Wed, 01 Feb 2017 10:18:59 -0600] rev 30862
Added tag 4.1 for changeset
e1526da1e6d8
Kevin Bullock <kbullock+mercurial@ringworld.org> [Wed, 01 Feb 2017 10:15:10 -0600] rev 30861
merge with i18n
Wagner Bruna <wbruna@softwareexpress.com.br> [Wed, 01 Feb 2017 08:47:11 -0200] rev 30860
i18n-pt_BR: synchronized with
dfc6663f97ca
Mads Kiilerich <mads@kiilerich.com> [Wed, 01 Feb 2017 02:10:30 +0100] rev 30859
merge: more safe detection of criss cross merge conflict between dm and r
41f6af50c0d8 introduced handling of a crash in this case. A review comment
suggested that it was not entirely obvious that a 'dm' always would have a 'r'
for the source file.
To mitigate that risk, make the code more conservative and make less
assumptions.
Augie Fackler <augie@google.com> [Mon, 30 Jan 2017 18:03:17 -0500] rev 30858
tests: correct (I think) command in test-largefiles-update
When this test was introduced, it used the short-form of all the flags
on this update invocation. I suspect, based on the "start with clean
dirstates" comment and the fact that the no-exec branch of the #if
guard leaves dirstate clean, that this should have been 'update -qCr'
instead of 'update -qcr', but that a bug in largefiles --check
handling left this problem unnoticed.
I'll leave a breadcrumb further up about the current failure mode in
the hopes that we can fix this some day.
This was previously discussed in [0] but the trail in that thread goes
cold after a few replies. Given that this is still a flaky test, that
appears to only be passing by bad fortune, I think it's worth
correcting the code of the test to make a correct assertion, and to
keep track of the suspected bug with some other mechanism than an
invalid test (if we had support for "expected failure" blocks this
might be a worthwhile use of them?).
0: https://www.mercurial-scm.org/pipermail/mercurial-devel/2016-October/089501.html
Augie Fackler <augie@google.com> [Mon, 30 Jan 2017 17:57:21 -0500] rev 30857
tests: expand flags to long form in test-largefiles-update.t
I spent some time confused by this test. I'm pretty sure that this
line intends to be cleaning the dirstate, not checking that it's clean
before updating: the preceding #if block leaves the dirstate clean in
the noexec case, and dirty in the exec case, so we can't expect
consistent behavior across that platform variation. A subsequent patch
will modify this command to use --clean instead of --check.
I'll elaborate in that patch about the hypothetical bug here.
Mads Kiilerich <mads@kiilerich.com> [Tue, 31 Jan 2017 03:25:59 +0100] rev 30856
merge: fix crash on criss cross merge with dir move and delete (
issue5020)
Work around that 'dm' in the data model only can have one operation for the
target file, but still can have multiple and conflicting operations on the
source file where the other operation is a 'rm'. The move would thus fail with
'abort: No such file or directory'.
In this case it is "obvious" that the file should be removed, either before or
after moving it. We thus keep the 'rm' of the source file but drop the 'dm'.
This is not a pretty fix but quite "obviously" safe (famous last words...) as
it only touches a rare code path that used to crash. It is possible that it
would be better to swap the files for 'dm' as suggested on
https://bz.mercurial-scm.org/show_bug.cgi?id=5020#c13 but it is not entirely
obvious that it not just would create conflicts on the other file. That can be
revisited later.
Mads Kiilerich <mads@kiilerich.com> [Tue, 31 Jan 2017 03:20:07 +0100] rev 30855
tests: use 'f' in test-merge-criss-cross.t to prepare for recursive dumping
Prepare for adding a test case with files in a directory.
Martin von Zweigbergk <martinvonz@google.com> [Mon, 30 Jan 2017 22:58:56 -0800] rev 30854
util: make sortdict.keys() return a copy
dict.keys() is documented to return a copy, so it's surprising that
sortdict.keys() did not. I noticed this because we have an extension
that calls readlocaltags(). That method tries to remove any tags that
point to non-existent revisions (most likely stripped). However, since
it's unintentionally working on the instance it's modifying, it
sometimes fails to remove tags when there are multiple bad tags in a
row. This was not caught because localrepo.tags() does an additional
layer of filtering.
sortdict is also used in other places, but I have not checked whether
its keys() and/or __delitem__() methods are used there.
Yuya Nishihara <yuya@tcha.org> [Mon, 30 Jan 2017 22:50:20 +0900] rev 30853
test-highlight: add normalization rule for Pygments 2.2
The test failed on Debian sid because of new class="vm".
Danek Duvall <danek.duvall@oracle.com> [Sun, 29 Jan 2017 12:40:56 -0800] rev 30852
tests: account for different newline behavior between Solaris and GNU grep
GNU grep, when emitting a matching line that doesn't have a terminating
newline, will add an extra newline. Solaris grep passes the original line
through without the newline. This causes differences in test output when
looking at the last line of the output of get-with-headers.py, which
doesn't usually emit (and certainly doesn't guarantee) a terminating
newline.
Both grep implementations succeed in matching the requested pattern,
though, so rely on specifying the full pattern on grep's commandline
instead of expecting it in the output, and send the output to /dev/null.
Augie Fackler <augie@google.com> [Fri, 20 Jan 2017 10:17:34 -0500] rev 30851
tests: also allow "Protocol not supported" in test-http-proxy error
I've seen this in a (misconfigured) FreeBSD jail which has ::1 as an
entry for localhost, but IPv6 support is disabled in the jail. It took
me months to figure out what was going on (and I only figured it out
when tinyproxy.py got confused by similar IPv4-level misconfiguration
of the localhost domain in /etc/hosts.)
I don't feel strongly about this patch: on the one hand, it's papering
over a host-level misconfiguration, but on the other it avoids some
weird and hard to diagnose problems that can occur in weirdly
restricted environments.
Yuya Nishihara <yuya@tcha.org> [Fri, 20 Jan 2017 21:33:18 +0900] rev 30850
revset: prevent using outgoing() and remote() in hgweb session (BC)
outgoing() and remote() may stall for long due to network I/O, which seems
unsafe per definition, "whether a predicate is safe for DoS attack." But I'm
not 100% sure about this. If our concern isn't elapsed time but CPU resource,
these predicates are considered safe. Perhaps that would be up to the
web/application server configuration?
Anyway, outgoing() and remote() wouldn't be useful in hgweb, so I think
it's okay to ban them.
Augie Fackler <augie@google.com> [Thu, 19 Jan 2017 16:23:49 -0500] rev 30849
tests: use an absolute path to get around '..' being invalid on a dead CWD
Only FreeBSD seems to be this picky. Note that this explicit
absolute-path `cd` exposes a defect in the test, in that we end up
still inside the cwd-vanish repository, but that's not a regression in
this change. Since we're in a code freeze, I'm doing the smallest
thing possible to try and fix bugs on FreeBSD, rather than cleaning up
the entire problem. I'll follow up with a more complete fix after the
freeze.
Sean Farley <sean@farley.io> [Wed, 18 Jan 2017 18:25:51 -0800] rev 30848
ui: rename tmpdir parameter to more specific repopath
This was requested by Augie and I agree that repopath is more
descriptive.
Yuya Nishihara <yuya@tcha.org> [Thu, 19 Jan 2017 23:01:32 +0900] rev 30847
pager: wrap _runcommand() no matter if stdout is redirected
We've made chg utilize the common code path implemented in pager.py (by
815e1cefd082 and
493935e0327a), but the chg server does not always start
with a tty. Because of this, uisetup() of the pager extension could be
skipped on the chg server.
Kudos given to Sean Farley for dogfooding new chg and spotting this problem.
Kostia Balytskyi <ikostia@fb.com> [Thu, 19 Jan 2017 09:48:40 -0800] rev 30846
shelve: make unshelve not crash when there are missing files (
issue4176)
This patch makes it possible to unshelve while having missing files
in your repo as long as shelved changes don't touch those missing files.
It also makes error message better otherwise.
Gregory Szorc <gregory.szorc@gmail.com> [Wed, 18 Jan 2017 22:45:07 -0800] rev 30845
statprof: require input file
statprof has a __main__ handler that allows viewing of previously
written data files. As Yuya pointed out during review,
f42cd5434cc2
broke this. This patch fixes that.
Augie Fackler <augie@google.com> [Wed, 18 Jan 2017 23:43:41 -0500] rev 30844
tests: work around FreeBSD's unzip having slightly different output
According to man 1 unzip, this unzip appeared in FreeBSD 8.0. It's
what comes as /usr/bin/unzip, so we may as well cater to it since it's
easy.
Augie Fackler <augie@google.com> [Wed, 18 Jan 2017 23:34:35 -0500] rev 30843
contrib: fix check-commit to not reject commits from `hg sign` and `hg tag`
I'm tired of having a spurious red build every time we do a
release. Fix it once and for all.
Augie Fackler <raf@durin42.com> [Wed, 18 Jan 2017 20:03:00 -0500] rev 30842
Added signature for changeset
a1dd2c0c479e
Augie Fackler <raf@durin42.com> [Wed, 18 Jan 2017 20:02:58 -0500] rev 30841
Added tag 4.1-rc for changeset
a1dd2c0c479e
Augie Fackler <augie@google.com> [Wed, 18 Jan 2017 11:54:51 -0500] rev 30840
tests: fix up some http tests for no-zstd case
Augie Fackler <augie@google.com> [Wed, 18 Jan 2017 11:43:36 -0500] rev 30839
freeze: merge default into stable for 4.1 code freeze
Sean Farley <sean@farley.io> [Mon, 16 Jan 2017 21:17:39 -0800] rev 30838
patchbomb: add tmpdir parameter to ui.edit call
Sean Farley <sean@farley.io> [Mon, 16 Jan 2017 21:15:57 -0800] rev 30837
histedit: add tmpdir parameter to ui.edit call
Sean Farley <sean@farley.io> [Mon, 16 Jan 2017 21:15:21 -0800] rev 30836
cmdutil: add tmpdir parament to ui.edit calls
Sean Farley <sean@farley.io> [Mon, 16 Jan 2017 21:05:22 -0800] rev 30835
ui: add a parameter to set the temporary directory for edit
Until callsites are updated, this will have no effect. Once callsites
are updated, specifying experimental.editortmpinhg will create editor
temporary files in a subdirectory of .hg, which will make it easier
for tool integrations to determine what repository is in play when
they're asked to edit an hg-related file.
Pulkit Goyal <7895pulkit@gmail.com> [Wed, 18 Jan 2017 03:44:19 +0530] rev 30834
help: update help for `hg update` which was misleading (
issue5427)
Matt Harbison <matt_harbison@yahoo.com> [Tue, 17 Jan 2017 23:12:54 -0500] rev 30833
templater: add '{envvars}' to access environment variables
Since the option for ui.exportableenviron is experimental, so is this template
until the underlying API is sorted out.
Matt Harbison <matt_harbison@yahoo.com> [Tue, 17 Jan 2017 23:05:12 -0500] rev 30832
ui: introduce an experimental dict of exportable environment variables
Care needs to be taken to prevent leaking potentially sensitive environment
variables through hgweb, if template support for environment variables is to be
introduced. There are a few ideas about the API for preventing accidental
leaking [1]. Option 3 seems best from the POV of not needing to configure
anything in the normal case. I couldn't figure out how to do that, so guard it
with an experimental option for now.
[1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-January/092383.html
Anton Shestakov <av6@dwimlabs.net> [Tue, 17 Jan 2017 13:44:53 +0800] rev 30831
tests: test experimental.spacemovesdown config for commit -i
The feature is still very experimental, but at least its behavior is captured
in the test.
Gregory Szorc <gregory.szorc@gmail.com> [Tue, 17 Jan 2017 10:17:13 -0800] rev 30830
zstd: prevent potential free() of uninitialized memory
This is a cherry pick of an upstream fix. The free() of uninitialed
memory could likely only occur if a malloc() inside zstd fails.
The patched functions aren't currently used by Mercurial. But I don't
like leaving footguns sitting around.
Martin von Zweigbergk <martinvonz@google.com> [Tue, 17 Jan 2017 11:25:02 -0800] rev 30829
revlog: give EXTSTORED flag value to narrowhg
Narrowhg has been using "1 << 14" as its revlog flag value for a long
time. We (Google) have many repos with that value in production
already. When the same value was reserved for EXTSTORED, it made those
repos invalid. Upgrading them will be a little painful. We should
clearly have reserved the value for narrowhg a long time ago. Since
the EXTSTORED flag is not yet in any release and Facebook also says
they have not started using it in production, so it should be okay to
change it. This patch gives the current value (1 << 14) back to
narrowhg and gives a new value (1 << 13) to EXTSTORED.
Martin von Zweigbergk <martinvonz@google.com> [Tue, 17 Jan 2017 11:45:10 -0800] rev 30828
help: don't let tools reflow revlog flags list
Before this change, the text about revlog flags was reflowed into a
single paragraph, which made it a bit hard to read. I don't even know
the rules around this, but adding a blank line before each flag seems
to prevent the reflowing.
Martin von Zweigbergk <martinvonz@google.com> [Tue, 17 Jan 2017 11:29:06 -0800] rev 30827
help: format revlog.txt more closely to result
The rendered text has spaces before each item in the list
Denis Laxalde <denis.laxalde@logilab.fr> [Tue, 17 Jan 2017 09:19:24 +0100] rev 30826
hgweb: simplify calculation of first revision in filelog command
Denis Laxalde <denis.laxalde@logilab.fr> [Tue, 17 Jan 2017 09:17:29 +0100] rev 30825
hgweb: restore ascending iteration on revs in filelog web command
Follow-up on
96f811bceb85. Adjust back the "parity" generator's offset to keep
rendering the same.
Denis Laxalde <denis.laxalde@logilab.fr> [Mon, 16 Jan 2017 09:22:32 +0100] rev 30824
context: extract _changesinrange() out of blockancestors()
We'll need it to write a blockdescendants function in next changeset.
Pulkit Goyal <7895pulkit@gmail.com> [Sat, 14 Jan 2017 01:23:07 +0530] rev 30823
shelve: allow multiple shelves with --patch and --stat
Before this patch, there was a single way to see multiple shelves using
`--patch --list` which show all the shelves. Doing `--patch s1 s2` returns an
error. This patch allows to show multiple shelves using `--patch` and `--stat`.
Gregory Szorc <gregory.szorc@gmail.com> [Sat, 14 Jan 2017 19:41:43 -0800] rev 30822
zstd: vendor python-zstandard 0.6.0
Commit
63c68d6f5fc8de4afd9bde81b13b537beb4e47e8 from
https://github.com/indygreg/python-zstandard is imported without
modifications (other than removing unwanted files).
This includes minor performance and feature improvements. It also
changes the vendored zstd library from 1.1.1 to 1.1.2.
# no-check-commit
Pulkit Goyal <7895pulkit@gmail.com> [Sat, 14 Jan 2017 20:05:15 +0530] rev 30821
util: add length argument to util.buffer()
util.buffer() either returns inbuilt buffer function or defines a new one which
slices. The inbuilt buffer() also has a length argument which is missing from
the ones we defined. This patch adds that length argument.
Pulkit Goyal <7895pulkit@gmail.com> [Sun, 15 Jan 2017 13:17:05 +0530] rev 30820
py3: replace pycompat.getenv with encoding.environ.get
pycompat.getenv returns os.getenvb on py3 which is not available on Windows.
This patch replaces them with encoding.environ.get and checks to ensure no
new instances of os.getenv or os.setenv are introduced.
Yuya Nishihara <yuya@tcha.org> [Sun, 15 Jan 2017 16:33:15 +0900] rev 30819
patch: check length of git index header only if integer is specified
Otherwise TypeError would be raised. Follows up
d1901c4c8ec0.
Gregory Szorc <gregory.szorc@gmail.com> [Fri, 13 Jan 2017 20:16:56 -0800] rev 30818
localrepo: experimental support for non-zlib revlog compression
The final part of integrating the compression manager APIs into
revlog storage is the plumbing for repositories to advertise they
are using non-zlib storage and for revlogs to instantiate a non-zlib
compression engine.
The main intent of the compression manager work was to zstd all
of the things. Adding zstd to revlogs has proved to be more involved
than other places because revlogs are... special. Very small inputs
and the use of delta chains (which are themselves a form of
compression) are a completely different use case from streaming
compression, which bundles and the wire protocol employ. I've
conducted numerous experiments with zstd in revlogs and have yet
to formalize compression settings and a storage architecture that
I'm confident I won't regret later. In other words, I'm not yet
ready to commit to a new mechanism for using zstd - or any other
compression format - in revlogs.
That being said, having some support for zstd (and other compression
formats) in revlogs in core is beneficial. It can allow others to
conduct experiments.
This patch introduces *highly experimental* support for non-zlib
compression formats in revlogs. Introduced is a config option to
control which compression engine to use. Also introduced is a namespace
of "exp-compression-*" requirements to denote support for non-zlib
compression in revlogs. I've prefixed the namespace with "exp-"
(short for "experimental") because I'm not confident of the
requirements "schema" and in no way want to give the illusion of
supporting these requirements in the future. I fully intend to drop
support for these requirements once we figure out what we're doing
with zstd in revlogs.
A good portion of the patch is teaching the requirements system
about registered compression engines and passing the requested
compression engine as an opener option so revlogs can instantiate
the proper compression engine for new operations.
That's a verbose way of saying "we can now use zstd in revlogs!"
On an `hg pull` conversion of the mozilla-unified repo with no extra
redelta settings (like aggressivemergedeltas), we can see the impact
of zstd vs zlib in revlogs:
$ hg perfrevlogchunks -c
! chunk
! wall 2.032052 comb 2.040000 user 1.990000 sys 0.050000 (best of 5)
! wall 1.866360 comb 1.860000 user 1.820000 sys 0.040000 (best of 6)
! chunk batch
! wall 1.877261 comb 1.870000 user 1.860000 sys 0.010000 (best of 6)
! wall 1.705410 comb 1.710000 user 1.690000 sys 0.020000 (best of 6)
$ hg perfrevlogchunks -m
! chunk
! wall 2.721427 comb 2.720000 user 2.640000 sys 0.080000 (best of 4)
! wall 2.035076 comb 2.030000 user 1.950000 sys 0.080000 (best of 5)
! chunk batch
! wall 2.614561 comb 2.620000 user 2.580000 sys 0.040000 (best of 4)
! wall 1.910252 comb 1.910000 user 1.880000 sys 0.030000 (best of 6)
$ hg perfrevlog -c -d 1
! wall 4.812885 comb 4.820000 user 4.800000 sys 0.020000 (best of 3)
! wall 4.699621 comb 4.710000 user 4.700000 sys 0.010000 (best of 3)
$ hg perfrevlog -m -d 1000
! wall 34.252800 comb 34.250000 user 33.730000 sys 0.520000 (best of 3)
! wall 24.094999 comb 24.090000 user 23.320000 sys 0.770000 (best of 3)
Only modest wins for the changelog. But manifest reading is
significantly faster. What's going on?
One reason might be data volume. zstd decompresses faster. So given
more bytes, it will put more distance between it and zlib.
Another reason is size. In the current design, zstd revlogs are
*larger*:
debugcreatestreamclonebundle (size in bytes)
zlib: 1,638,852,492
zstd: 1,680,601,332
I haven't investigated this fully, but I reckon a significant cause of
larger revlogs is that the zstd frame/header has more bytes than
zlib's. For very small inputs or data that doesn't compress well, we'll
tend to store more uncompressed chunks than with zlib (because the
compressed size isn't smaller than original). This will make revlog
reading faster because it is doing less decompression.
Moving on to bundle performance:
$ hg bundle -a -t none-v2 (total CPU time)
zlib: 102.79s
zstd: 97.75s
So, marginal CPU decrease for reading all chunks in all revlogs
(this is somewhat disappointing).
$ hg bundle -a -t <engine>-v2 (total CPU time)
zlib: 191.59s
zstd: 115.36s
This last test effectively measures the difference between zlib->zlib
and zstd->zstd for revlogs to bundle. This is a rough approximation of
what a server does during `hg clone`.
There are some promising results for zstd. But not enough for me to
feel comfortable advertising it to users. We'll get there...
Gregory Szorc <gregory.szorc@gmail.com> [Fri, 13 Jan 2017 19:58:00 -0800] rev 30817
revlog: use compression engine APIs for decompression
Now that compression engines declare their header in revlog chunks
and can decompress revlog chunks, we refactor revlog.decompress()
to use them.
Making full use of the property that revlog compressor objects are
reusable, revlog instances now maintain a dict mapping an engine's
revlog header to a compressor object. This is not only a performance
optimization for engines where compressor object reuse can result in
better performance, but it also serves as a cache of header values
so we don't need to perform redundant lookups against the compression
engine manager. (Yes, I measured and the overhead of a function call
versus a dict lookup was observed.)
Replacing the previous inline lookup table with a dict lookup was
measured to make chunk reading ~2.5% slower on changelogs and ~4.5%
slower on manifests. So, the inline lookup table has been mostly
preserved so we don't lose performance. This is unfortunate. But
many decompression operations complete in microseconds, so Python
attribute lookup, dict lookup, and function calls do matter.
The impact of this change on mozilla-unified is as follows:
$ hg perfrevlogchunks -c
! chunk
! wall 1.953663 comb 1.950000 user 1.920000 sys 0.030000 (best of 6)
! wall 1.946000 comb 1.940000 user 1.910000 sys 0.030000 (best of 6)
! chunk batch
! wall 1.791075 comb 1.800000 user 1.760000 sys 0.040000 (best of 6)
! wall 1.785690 comb 1.770000 user 1.750000 sys 0.020000 (best of 6)
$ hg perfrevlogchunks -m
! chunk
! wall 2.587262 comb 2.580000 user 2.550000 sys 0.030000 (best of 4)
! wall 2.616330 comb 2.610000 user 2.560000 sys 0.050000 (best of 4)
! chunk batch
! wall 2.427092 comb 2.420000 user 2.400000 sys 0.020000 (best of 5)
! wall 2.462061 comb 2.460000 user 2.400000 sys 0.060000 (best of 4)
Changelog chunk reading is slightly faster but manifest reading is
slower. What gives?
On this repo, 99.85% of changelog entries are zlib compressed (the 'x'
header). On the manifest, 67.5% are zlib and 32.4% are '\0'. This patch
swapped the test order of 'x' and '\0' so now 'x' is tested first. This
makes changelogs faster since they almost always hit the first branch.
This makes a significant percentage of manifest '\0' chunks slower
because that code path now performs an extra test. Yes, I too can't
believe we're able to measure the impact of an if..elif with simple
string compares. I reckon this code would benefit from being written
in C...
Denis Laxalde <denis.laxalde@logilab.fr> [Fri, 13 Jan 2017 10:22:25 +0100] rev 30816
hgweb: build the "entries" list directly in filelog command
There's no apparent reason to have this "entries" generator function that
builds a list and then yields its elements in reverse order and which is only
called to build the "entries" list. So just build the list directly, in
reverse order.
Adjust "parity" generator's offset to keep rendering the same.
Gregory Szorc <gregory.szorc@gmail.com> [Sat, 14 Jan 2017 10:11:19 -0800] rev 30815
convert: remove "replacecommitter" action
As pointed out by Yuya, this action doesn't add much (any?) value.
Yuya Nishihara <yuya@tcha.org> [Sat, 14 Jan 2017 20:31:35 +0900] rev 30814
ui: check EOF of getpass() response read from command-server channel
readline() returns '' only when EOF is encountered, in which case, Python's
getpass() raises EOFError. We should do the same to abort the session as
"response expected."
This bug was reported to
https://bitbucket.org/tortoisehg/thg/issues/4659/
Gregory Szorc <gregory.szorc@gmail.com> [Fri, 13 Jan 2017 23:21:10 -0800] rev 30813
convert: config option to control Git committer actions
When converting a Git repository to Mercurial at Mozilla, I encountered
a scenario where I didn't want `hg convert` to automatically add the
"committer: <committer>" line to commit messages. While I can hack around
this by rewriting the Git commit before it is fed into `hg convert`,
I figured it would be a useful knob to control.
This patch introduces a config option that allows lots of control
over the committer value. I initially implemented this as a single
boolean flag to control whether to save the committer message. But
then there was feedback that it would be useful to save the committer
in extra data. While this patch doesn't implement support for saving
in extra data, it does add a mechanism for extending which actions
to take on the committer field. We should be able to easily add
actions to save in extra data.
Some of the implemented features weren't asked for. But I figured they
could be useful. If nothing else they demonstrate the extensibility
of this mechanism.
Gregory Szorc <gregory.szorc@gmail.com> [Fri, 13 Jan 2017 21:21:02 -0800] rev 30812
help: make "mergetool" an alias for "merge-tools"
I've probably typed `hg help mergetool` dozens of times. I'm tired
of it not working.
Matthieu Laneuville <mlaneuville@protonmail.com> [Thu, 12 Jan 2017 21:06:55 +0900] rev 30811
templatekw: force noprefix=False to insure diffstat consistency (
issue4755)
The result of diffstatdata should not depend on having noprefix set or not, as
was reported in issue 4755. Forcing noprefix to false on call makes sure the
parser receives the diff in the correct format and returns the proper result.
Another way to fix this would have been to change the regular expressions in
path.diffstatdata(), but that would have introduced many unecessary special
cases.
Martin von Zweigbergk <martinvonz@google.com> [Fri, 13 Jan 2017 10:11:37 -0800] rev 30810
check-code: reject module-level @cachefunc
Module-level @cachefunc usage is risky because it can easily create a
memory "leak". Let's reject it completely for now. If a valid usage
comes up in the future, we can always improve the check or reconsider.
Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Fri, 13 Jan 2017 11:42:36 -0800] rev 30809
similar: remove caching from the module level
To prevent Bad Thingsâ„¢ from happening, let's rework the logic to not use
util.cachefunc.
Sean Farley <sean@farley.io> [Mon, 09 Jan 2017 11:01:45 -0800] rev 30808
patch: add label for coloring the similarity extended header
Just like the summary says, this will colorize the:
similarity index 88%
line in the diff output.
Sean Farley <sean@farley.io> [Mon, 09 Jan 2017 11:24:18 -0800] rev 30807
patch: use opt.showsimilarity to calculate and show the similarity
Tests have been added.
Sean Farley <sean@farley.io> [Mon, 09 Jan 2017 10:51:44 -0800] rev 30806
patch: add similarity config knob in experimental section
This config knob will control whether or not to show the similarity
calculation in the diff output:
diff --git a/README.md b/foo.md
similarity index 88%
rename from README.md
rename to foo.md
--- a/README.md
+++ b/foo.md
Sean Farley <sean@farley.io> [Sat, 07 Jan 2017 20:47:57 -0800] rev 30805
similar: move score function to module level
Future patches will use this to report the similarity of a rename / copy
in the patch output.
Yuya Nishihara <yuya@tcha.org> [Mon, 09 Jan 2017 17:58:19 +0900] rev 30804
revset: abuse x:y syntax to specify line range of followlines()
This slightly complicates the parsing (see the previous patch), but the
overall result seems not bad.
I keep x:, :y and : for future extension.
Yuya Nishihara <yuya@tcha.org> [Mon, 09 Jan 2017 16:55:56 +0900] rev 30803
revset: do not transform range* operators in parsed tree
This allows us to handle x:y range as a general range object. A primary user
of it is followlines().
Yuya Nishihara <yuya@tcha.org> [Mon, 09 Jan 2017 17:45:11 +0900] rev 30802
revset: add default value to getinteger() helper
This seems handy.
Yuya Nishihara <yuya@tcha.org> [Mon, 09 Jan 2017 17:39:44 +0900] rev 30801
revset: factor out getinteger() helper
We have 4 revset functions that take integer arguments, and they handle
their arguments in slightly different ways. This patch unifies them:
- getstring() in place of getsymbol(), which is more consistent with the
handling of integer revisions (both 1 and '1' are valid)
- say "expects" instead of "requires" for type errors
We don't need to catch TypeError since getstring() must return a string.
Yuya Nishihara <yuya@tcha.org> [Mon, 09 Jan 2017 16:16:26 +0900] rev 30800
revset: rename rev argument of followlines() to startrev
The rev argument has the same meaning as startrev of follow(), and I think
startrev is more informative.
followlines() is new function, we can make BC now.
Yuya Nishihara <yuya@tcha.org> [Fri, 13 Jan 2017 23:48:21 +0900] rev 30799
help: use :hg: role and canonical name to point to revset string patterns
Follows up
5dd67f0993ce. Now revisions.txt and revsets.txt has been merged,
so use revisions.* as a pointer.
Gregory Szorc <gregory.szorc@gmail.com> [Mon, 02 Jan 2017 13:27:20 -0800] rev 30798
util: compression APIs to support revlog decompression
Previously, compression engines had APIs for performing revlog
compression but no mechanism to perform revlog decompression. This
patch changes that.
Revlog decompression is slightly more complicated than compression
because in the compression case there is (currently) only a single
engine that can be used at a time. However for decompression, a
revlog could contain chunks from multiple compression engines. This
means decompression needs to map to multiple engines and
decompressors. This functionality is outside the scope of this patch.
But it drives the decision for engines to declare a byte header
sequence that identifies revlog data as belonging to an engine and
an API for obtaining an engine from a revlog header.
Anton Shestakov <av6@dwimlabs.net> [Sun, 08 Jan 2017 10:08:29 +0800] rev 30797
crecord: add an experimental option for space key to move cursor down
I really want to have an option of toggling a selection on a line and also
moving cursor down as a single keystroke. It also kinda makes sense for space
key to do this, because some other curses UIs in the wild do this (e.g. various
file managers, htop). So I got an idea to make a config option that defaults to
False for compatibility, but allows making crecord UI a lot more useful for
people with big hunks.
We add this an experimental option to experiment with this behavior.
Gregory Szorc <gregory.szorc@gmail.com> [Mon, 02 Jan 2017 12:02:08 -0800] rev 30796
perf: support multiple compression engines in perfrevlogchunks
Now that the revlog has a reference to a compressor, it is
possible to swap in other compression engines. So, teach
`hg perfrevlogchunks` to do that.
The default behavior of `hg perfrevlogchunks` is now to measure the
compression performance of all compression engines implementing the
revlog compressor API. This effectively adds the no-op "none"
compressor and zstd (when available) into the default set.
While we can't yet plug alternate compressors into revlogs, this
command gives us a preview of the performance. On the mozilla-unified
repository:
$ hg perfrevlogchunks -c
! compress w/ none
! wall 0.115159 comb 0.110000 user 0.110000 sys 0.000000 (best of 86)
! compress w/ zlib
! wall 5.681406 comb 5.680000 user 5.680000 sys 0.000000 (best of 3)
! compress w/ zstd
! wall 2.624781 comb 2.620000 user 2.620000 sys 0.000000 (best of 4)
$ hg perfrevlogchunks -m
! compress w/ none
! wall 0.124486 comb 0.120000 user 0.120000 sys 0.000000 (best of 79)
! compress w/ zlib
! wall 10.144701 comb 10.150000 user 10.150000 sys 0.000000 (best of 3)
! compress w/ zstd
! wall 4.383118 comb 4.390000 user 4.390000 sys 0.000000 (best of 3)
Those numbers for zstd look promising. But they aren't the full story.
For that, we'll need to look at decompression times and storage sizes.
Stay tuned...
Gregory Szorc <gregory.szorc@gmail.com> [Mon, 02 Jan 2017 11:22:52 -0800] rev 30795
revlog: use compression engine API for compression
This commit swaps in the just-added revlog compressor API into
the revlog class.
Instead of implementing zlib compression inline in compress(), we
now store a cached-on-first-use revlog compressor on each revlog
instance and invoke its "compress()" method.
As part of this, revlog.compress() has been refactored a bit to use
a cleaner code flow and modern formatting (e.g. avoiding
parenthesis around returned tuples).
On a mozilla-unified repo, here are the "compress" times for a few
commands:
$ hg perfrevlogchunks -c
! wall 5.772450 comb 5.780000 user 5.780000 sys 0.000000 (best of 3)
! wall 5.795158 comb 5.790000 user 5.790000 sys 0.000000 (best of 3)
$ hg perfrevlogchunks -m
! wall 9.975789 comb 9.970000 user 9.970000 sys 0.000000 (best of 3)
! wall 10.019505 comb 10.010000 user 10.010000 sys 0.000000 (best of 3)
Compression times did seem to slow down just a little. There are
360,210 changelog revisions and 359,342 manifest revisions. For the
changelog, mean time to compress a revision increased from ~16.025us to
~16.088us. That's basically a function call or an attribute lookup. I
suppose this is the price you pay for abstraction. It's so low that
I'm not concerned.
Gregory Szorc <gregory.szorc@gmail.com> [Mon, 02 Jan 2017 12:39:03 -0800] rev 30794
util: compression APIs to support revlog compression
As part of "zstd all of the things," we need to teach revlogs to
use non-zlib compression formats. Because we're routing all compression
via the "compression manager" and "compression engine" APIs, we need to
introduction functionality there for performing revlog operations.
Ideally, revlog compression and decompression operations would be
implemented in terms of simple "compress" and "decompress" primitives.
However, there are a few considerations that make us want to have a
specialized primitive for handling revlogs:
1) Performance. Revlogs tend to do compression and especially
decompression operations in batches. Any overhead for e.g.
instantiating a "context" for performing an operation can be
noticed. For this reason, our "revlog compressor" primitive is
reusable. For zstd, we reuse the same compression "context" for
multiple operations. I've measured this to have a performance
impact versus constructing new contexts for each operation.
2) Specialization. By having a primitive dedicated to revlog use,
we can make revlog-specific choices and leave the door open for
more functionality in the future. For example, the zstd revlog
compressor may one day make use of dictionary compression.
A future patch will introduce a decompress() on the compressor
object.
The code for the zlib compressor is basically copied from
revlog.compress(). Although it doesn't handle the empty input
case, the null first byte case, and the 'u' prefix case. These
cases will continue to be handled in revlog.py once that code is
ported to use this API.
Gregory Szorc <gregory.szorc@gmail.com> [Mon, 02 Jan 2017 13:00:16 -0800] rev 30793
revlog: move decompress() from module to revlog class (API)
Upcoming patches will convert revlogs to use the compression engine
APIs to perform all things compression. The yet-to-be-introduced
APIs support a persistent "compressor" object so the same object
can be reused for multiple compression operations, leading to
better performance. In addition, compression engines like zstd
may wish to tweak compression engine state based on the revlog
(e.g. per-revlog compression dictionaries).
A global and shared decompress() function will shortly no longer
make much sense. So, we move decompress() to be a method of the
revlog class. It joins compress() there.
On the mozilla-unified repo, we can measure the impact of this change
on reading performance:
$ hg perfrevlogchunks -c
! chunk
! wall 1.932573 comb 1.930000 user 1.900000 sys 0.030000 (best of 6)
! wall 1.955183 comb 1.960000 user 1.930000 sys 0.030000 (best of 6)
! chunk batch
! wall 1.787879 comb 1.780000 user 1.770000 sys 0.010000 (best of 6
! wall 1.774444 comb 1.770000 user 1.750000 sys 0.020000 (best of 6)
"chunk" appeared to become slower but "chunk batch" got faster. Upon
further examination by running both sets multiple times, the numbers
appear to converge across all runs. This tells me that there is no
perceived performance impact to this refactor.
Gregory Szorc <gregory.szorc@gmail.com> [Mon, 02 Jan 2017 11:50:17 -0800] rev 30792
revlog: make compressed size comparisons consistent
revlog.compress() compares the compressed size to the input size
and throws away the compressed data if it is larger than the input.
This is the correct thing to do, as storing compressed data that
is larger than the input takes up more storage space and makes reading
slower.
However, the comparison was implemented inconsistently. For the
streaming compression mode, we threw away the result if it was
greater than or equal to the input size. But for the one-shot
compression, we threw away the compression only if it was greater
than the input size!
This patch changes the comparison for the simple case so it is
consistent with the streaming case.
As a few tests demonstrate, this adds 1 byte to some revlog entries.
This is because of an added 'u' header on the chunk. It seems
somewhat wrong to increase the revlog size here. However, IMO the cost
of 1 byte in storage is insignificant compared to the performance gains
of avoiding decompression. This patch should invite questions around
the heuristic for throwing away compressed data. For example, I'd argue
we should be more liberal about rejecting compressed data, additionally
doing so where the number of bytes saved fails to reach a threshold.
But we can have this discussion another time.
Sean Farley <sean@farley.io> [Sat, 07 Jan 2017 20:43:49 -0800] rev 30791
similar: rename local variable to not collide with previous
Future patches will move the score function to the module level, so
let's not shadow that.
Sean Farley <sean@farley.io> [Mon, 09 Jan 2017 10:59:45 -0800] rev 30790
patch: add label for coloring the index extended header
Just like the summary says, this will colorize the:
index
3d3ba4b65e11..
57274a0f46b2 100644
line in the diff output.
Sean Farley <sean@farley.io> [Sat, 31 Dec 2016 15:41:57 -0600] rev 30789
patch: add index line for diff output
This helps highlighting in third-party diff coloring (which assumes git
output) and maintains pedantic correctness with diff --git.
Tests will be added at the end of the series.
Sean Farley <sean@farley.io> [Mon, 09 Jan 2017 11:13:47 -0800] rev 30788
patch: add config knob for displaying the index header
This config knob can take an integer between 0 and 40 or a
keyword ('none', 'short', 'full') to control the length of hash to
output. It will display diffs with the git index header as such,
diff --git a/mercurial/mdiff.py b/mercurial/mdiff.py
index 112edf7..d6b52c5 100644
We'll put this in the experimental section for now.
Martin von Zweigbergk <martinvonz@google.com> [Thu, 12 Jan 2017 12:05:23 -0800] rev 30787
bisect: refer directly to bisect() revset predicate in help
We have specific syntax for displaying the help text for a particular
revset predicate, so let's refer directly to the bisect() revset in
the verbose bisect help. It seems likely that the user doesn't care
about other revsets at that point, so they will probably not miss the
text about the other revset predicates.
Martin von Zweigbergk <martinvonz@google.com> [Thu, 12 Jan 2017 11:43:26 -0800] rev 30786
tests: use "hg help revisions.<predicate>" instead of grepping
We have specific syntax for displaying the help text for a particular
revset predicate, so use that instead of grepping through the full
output.
Martin von Zweigbergk <martinvonz@google.com> [Thu, 12 Jan 2017 11:52:05 -0800] rev 30785
help: remove now-redundant pointer to revsets help
"hg help revisions" and "hg help revsets" now point to the same text,
so drop the revsets reference.
Matt Harbison <matt_harbison@yahoo.com> [Sat, 07 Jan 2017 23:35:35 -0500] rev 30784
help: eliminate duplicate text for revset string patterns
There's no reason to duplicate this so many times, and it's likely an instance
will be missed if support for a new pattern is added and documented. The
stringmatcher is mostly used by revsets, though it is also used for the 'tag'
related templates, and namespace filtering in the journal extension. So maybe
there's a better place to document it. `hg help patterns` seems inappropriate,
because that is all file pattern matching.
While here, indicate how to perform case insensitive regex searches.
Matt Harbison <matt_harbison@yahoo.com> [Sat, 07 Jan 2017 21:26:32 -0500] rev 30783
revset: add regular expression support to 'desc'
This is a case insensitive predicate like 'author', so it conforms to the
existing behavior of performing a case insensitive regex.
Matt Harbison <matt_harbison@yahoo.com> [Wed, 11 Jan 2017 22:42:10 -0500] rev 30782
revset: stop lowercasing the regex pattern for 'author'
It was probably unintentional for regex, as the meaning of some sequences like
\S and \s is actually inverted by changing the case. For backward compatibility
however, the matching is forced to case insensitive.
Gregory Szorc <gregory.szorc@gmail.com> [Thu, 24 Nov 2016 18:45:29 -0800] rev 30781
repair: clean up stale lock file from store backup
Since we did a directory rename on the stores, the source
repository's lock path now references the dest repository's
lock path and the dest repository's lock path now references
a non-existent filename.
So releasing the lock on the source will unlock the dest and
releasing the lock on the dest will no-op because it fails due
to file not found. So we clean up the dest's lock manually.
Gregory Szorc <gregory.szorc@gmail.com> [Thu, 24 Nov 2016 18:34:50 -0800] rev 30780
repair: copy non-revlog store files during upgrade
The store contains more than just revlogs. This patch teaches the
upgrade code to copy regular files as well.
As the test changes demonstrate, the phaseroots file is now copied.
Gregory Szorc <gregory.szorc@gmail.com> [Sun, 18 Dec 2016 17:00:15 -0800] rev 30779
repair: migrate revlogs during upgrade
Our next step for in-place upgrade is to migrate store data. Revlogs
are the biggest source of data within the store and a store is useless
without them, so we implement their migration first.
Our strategy for migrating revlogs is to walk the store and call
`revlog.clone()` on each revlog. There are some minor complications.
Because revlogs have different storage options (e.g. changelog has
generaldelta and delta chains disabled), we need to obtain the
correct class of revlog so inserted data is encoded properly for its
type.
Various attempts at implementing progress indicators that didn't lead
to frustration from false "it's almost done" indicators were made.
I initially used a single progress bar based on number of revlogs.
However, this quickly churned through all filelogs, got to 99% then
effectively froze at 99.99% when it got to the manifest.
So I converted the progress bar to total revision count. This was a
little bit better. But the manifest was still significantly slower
than filelogs and it took forever to process the last few percent.
I then tried both revision/chunk bytes and raw bytes as the
denominator. This had the opposite effect: because so much data is in
manifests, it would churn through filelogs without showing much
progress. When it got to manifests, it would fill in 90+% of the
progress bar.
I finally gave up having a unified progress bar and instead implemented
3 progress bars: 1 for filelog revisions, 1 for manifest revisions, and
1 for changelog revisions. I added extra messages indicating the total
number of revisions of each so users know there are more progress bars
coming.
I also added extra messages before and after each stage to give extra
details about what is happening. Strictly speaking, this isn't
necessary. But the numbers are impressive. For example, when converting
a non-generaldelta mozilla-central repository, the messages you see are:
migrating 2475593 total revisions (1833043 in filelogs, 321156 in manifests, 321394 in changelog)
migrating 1.67 GB in store; 2508 GB tracked data
migrating 267868 filelogs containing 1833043 revisions (1.09 GB in store; 57.3 GB tracked data)
finished migrating 1833043 filelog revisions across 267868 filelogs; change in size: -415776 bytes
migrating 1 manifests containing 321156 revisions (518 MB in store; 2451 GB tracked data)
That "2508 GB" figure really blew me away. I had no clue that the raw
tracked data in mozilla-central was that large. Granted, 2451 GB is in
the manifest and "only" 57.3 GB is in filelogs. But still.
It's worth noting that gratuitous loading of source revlogs in order
to display numbers and progress bars does serve a purpose: it ensures
we can open all source revlogs. We don't want to spend several minutes
copying revlogs only to encounter a permissions error or similar later.
As part of this commit, we also add swapping of the store directory
to the upgrade function. After revlogs are converted, we move the
old store into the backup directory then move the temporary repo's
store into the old store's location. On well-behaved systems, this
should be 2 atomic operations and the window of inconsistency show be
very narrow.
There are still a few improvements to be made to store copying and
upgrading. But this commit gets the bulk of the work out of the way.
Gregory Szorc <gregory.szorc@gmail.com> [Sun, 18 Dec 2016 17:02:57 -0800] rev 30778
revlog: add clone method
Upcoming patches will introduce functionality for in-place
repository/store "upgrades." Copying the contents of a revlog
feels sufficiently low-level to warrant being in the revlog
class. So this commit implements that functionality.
Because full delta recomputation can be *very* expensive (we're
talking several hours on the Firefox repository), we support
multiple modes of execution with regards to delta (re)use. This
will allow repository upgrades to choose the "level" of
processing/optimization they wish to perform when converting
revlogs.
It's not obvious from this commit, but "addrevisioncb" will be
used for progress reporting.
Gregory Szorc <gregory.szorc@gmail.com> [Sun, 18 Dec 2016 16:59:04 -0800] rev 30777
repair: begin implementation of in-place upgrading
Now that all the upgrade planning work is in place, we can start
doing the real work: actually upgrading a repository.
The main goal of this commit is to get the "framework" for running
in-place upgrade actions in place.
Rather than get too clever and low-level with regards to in-place
upgrades, our strategy is to create a new, temporary repository,
copy data to it, then replace the old data with the new. This allows
us to reuse a lot of code in localrepo.py around store interaction,
which will eventually consume the bulk of the upgrade code.
But we have to start small. This patch implements adding new
repository requirements. But it still sets up a temporary
repository and locks it and the source repo before performing the
requirements file swap. This means all the plumbing is in place
to implement store copying in subsequent commits.
Gregory Szorc <gregory.szorc@gmail.com> [Sun, 18 Dec 2016 16:51:09 -0800] rev 30776
repair: determine what upgrade will do
This commit introduces code for determining what actions/improvements
an upgrade should perform.
The "upgradefindimprovements" function introduces a mechanism to
return a list of improvements that can be made to a repository.
Each improvement is effectively an action that an upgrade will
perform. Associated with each of these improvements is metadata
that will be used to inform users what's wrong and what an
upgrade will do.
Each "improvement" is categorized as a "deficiency" or an
"optimization." TBH, I'm not thrilled about the terminology and
am receptive to constructive bikeshedding. The main difference
between a "deficiency" and an "optimization" is a deficiency
is always corrected (if it deviates from the current config) and
an "optimization" is an optional action that goes above and beyond
to improve the state of the repository (usually by requiring more
CPU during upgrade).
Our initial set of improvements identifies missing repository
requirements, a single, easily correctable problem with
changelog storage, and a set of "optimizations" related to delta
recalculation.
The main "upgraderepo" function has been expanded to handle
improvements. It queries for the list of improvements and determines
which of them will run based on the current repository state and user
I went through numerous iterations of the output format before
settling on a ReST-inspired definition list format. (I used
bulleted lists in the first submission of this commit and could
not get it to format just right.) Even with the various iterations,
I'm still not super thrilled with the format. But, this is a debug*
command, so that should mean we can refine the output without BC
concerns.
Gregory Szorc <gregory.szorc@gmail.com> [Sun, 18 Dec 2016 16:16:54 -0800] rev 30775
repair: implement requirements checking for upgrades
This commit introduces functionality for upgrading a repository in
place. The first part that's implemented is testing for upgrade
"compatibility." This is done by examining repository requirements.
There are 5 functions returning sets of requirements that control
upgrading. Why so many functions? Mainly to support extensions.
Functions are easier to monkeypatch than module variables.
Astute readers will see that we don't support "manifestv2" and
"treemanifest" requirements in the upgrade mechanism. I don't have
a great answer for why other than this is a complex set of patches
and I don't want to deal with the complexity of these experimental
features just yet. We can teach the upgrade mechanism about them
later, once the basic upgrade mechanism is in place.
This commit also introduces the "upgraderepo" function. This will be
our main routine for performing an in-place upgrade. Currently, it
just implements requirements checking. The structure of some code in
this function may look a bit weird (e.g. the inline function that is
only called once). But this will make sense after future commits.
Gregory Szorc <gregory.szorc@gmail.com> [Thu, 24 Nov 2016 16:24:09 -0800] rev 30774
debugcommands: stub for debugupgraderepo command
Currently, if Mercurial introduces a new repository/store feature or
changes behavior of an existing feature, users must perform an
`hg clone` to create a new repository with hopefully the
correct/optimal settings. Unfortunately, even `hg clone` may not
give the correct results. For example, if you do a local `hg clone`,
you may get hardlinks to revlog files that inherit the old state.
If you `hg clone` from a remote or `hg clone --pull`, changegroup
application may bypass some optimization, such as converting to
generaldelta.
Optimizing a repository is harder than it seems and requires more
than a simple `hg` command invocation.
This commit starts the process of changing that. We introduce
`hg debugupgraderepo`, a command that performs an in-place upgrade
of a repository to use new, optimal features. The command is just
a stub right now. Features will be added in subsequent commits.
This commit does foreshadow some of the behavior of the new command,
notably that it doesn't do anything by default and that it takes
arguments that influence what actions it performs. These will be
explained more in subsequent commits.
Matt Harbison <matt_harbison@yahoo.com> [Wed, 11 Jan 2017 21:47:19 -0500] rev 30773
util: teach stringmatcher to handle forced case insensitive matches
The 'author' and 'desc' revsets are documented to be case insensitive.
Unfortunately, this was implemented in 'author' by forcing the input to
lowercase, including for regex like '\B'. (This actually inverts the meaning of
the sequence.) For backward compatibility, we will keep that a case insensitive
regex, but by using matcher options instead of brute force.
This doesn't preclude future hypothetical 'icase-literal:' style prefixes that
can be provided by the user. Such user specified cases can probably be handled
up front by stripping 'icase-', setting the variable, and letting it drop
through the existing code.
Matt Harbison <matt_harbison@yahoo.com> [Wed, 11 Jan 2017 23:13:51 -0500] rev 30772
revset: point to 'grep' in the 'keyword' help for regex searches
The help for 'grep' already points to 'keyword'.
Martin von Zweigbergk <martinvonz@google.com> [Wed, 11 Jan 2017 23:13:00 -0800] rev 30771
help: explain that revsets can be used where 1 or 2 revs are wanted
We did not seem to document that one can do things like "hg up :@"
where the last revision of the revset ":@".
Martin von Zweigbergk <martinvonz@google.com> [Wed, 11 Jan 2017 22:46:07 -0800] rev 30770
help: explain what the term "revset" means
We refer to revsets in a few places (e.g. in "hg help config"), but we
never explained what they are. Until now.
Martin von Zweigbergk <martinvonz@google.com> [Wed, 11 Jan 2017 11:37:38 -0800] rev 30769
help: merge revsets.txt into revisions.txt
Selecting single and multiple revisions is closely related, so let's
put it in one place, so users can easily find it. We actually did not
even point to "hg help revsets" from "hg help revisions", but now that
they're on a single page, that won't be necessary.
Martin von Zweigbergk <martinvonz@google.com> [Wed, 11 Jan 2017 11:40:40 -0800] rev 30768
tests: use `hg help dates` instead of `hg help revs` in test
The revisions help is already long and will get longer, so switch to
another short and stable topic.
Martin von Zweigbergk <martinvonz@google.com> [Wed, 11 Jan 2017 11:28:54 -0800] rev 30767
help: use a single paragraph to describe full and abbreviated nodeids
The texts describing 40-digit strings and the abbreviated form are
closely related, so make it a single paragraph.
Gregory Szorc <gregory.szorc@gmail.com> [Tue, 10 Jan 2017 23:37:08 -0800] rev 30766
hgweb: support Content Security Policy
Content-Security-Policy (CSP) is a web security feature that allows
servers to declare what loaded content is allowed to do. For example,
a policy can prevent loading of images, JavaScript, CSS, etc unless
the source of that content is whitelisted (by hostname, URI scheme,
hashes of content, etc). It's a nifty security feature that provides
extra mitigation against some attacks, notably XSS.
Mitigation against these attacks is important for Mercurial because
hgweb renders repository data, which is commonly untrusted. While we
make attempts to escape things, etc, there's the possibility that
malicious data could be injected into the site content. If this happens
today, the full power of the web browser is available to that
malicious content. A restrictive CSP policy (defined by the server
operator and sent in an HTTP header which is outside the control of
malicious content), could restrict browser capabilities and mitigate
security problems posed by malicious data.
CSP works by emitting an HTTP header declaring the policy that browsers
should apply. Ideally, this header would be emitted by a layer above
Mercurial (likely the HTTP server doing the WSGI "proxying"). This
works for some CSP policies, but not all.
For example, policies to allow inline JavaScript may require setting
a "nonce" attribute on <script>. This attribute value must be unique
and non-guessable. And, the value must be present in the HTTP header
and the HTML body. This means that coordinating the value between
Mercurial and another HTTP server could be difficult: it is much
easier to generate and emit the nonce in a central location.
This commit introduces support for emitting a
Content-Security-Policy header from hgweb. A config option defines
the header value. If present, the header is emitted. A special
"%nonce%" syntax in the value triggers generation of a nonce and
inclusion in <script> elements in templates. The inclusion of a
nonce does not occur unless "%nonce%" is present. This makes this
commit completely backwards compatible and the feature opt-in.
The nonce is a type 4 UUID, which is the flavor that is randomly
generated. It has 122 random bits, which should be plenty to satisfy
the guarantees of a nonce.
Gregory Szorc <gregory.szorc@gmail.com> [Tue, 10 Jan 2017 20:47:48 -0800] rev 30765
hgweb: call process_dates() via DOM event listener
All the hgweb templates include mercurial.js in their header. All
the hgweb templates have the same <script> boilerplate to run
process_dates(). This patch factors that function call into
mercurial.js as part of a DOMContentLoaded event listener.
Gregory Szorc <gregory.szorc@gmail.com> [Sat, 24 Dec 2016 15:29:32 -0700] rev 30764
protocol: send application/mercurial-0.2 responses to capable clients
With this commit, the HTTP transport now parses the X-HgProto-<N>
header to determine what media type and compression engine to use for
responses. So far, we only compress responses that are already being
compressed with zlib today (stream response types to specific
commands). We can expand things to cover additional response types
later.
The practical side-effect of this commit is that non-zlib compression
engines will be used if both ends support them. This means if both
ends have zstd support, zstd - not zlib - will be used to compress
data!
When cloning the mozilla-unified repository between a local HTTP
server and client, the benefits of non-zlib compression are quite
noticeable:
engine server CPU (s) client CPU (s) bundle size
zlib (l=6) 174.1 283.2 1,148,547,026
zstd (l=1) 99.2 267.3 1,127,513,841
zstd (l=3) 103.1 266.9 1,018,861,363
zstd (l=7) 128.3 269.7 919,190,278
zstd (l=10) 162.0 - 894,547,179
none 95.3 277.2 4,097,566,064
The default zstd compression level is 3. So if you deploy zstd
capable Mercurial to your clients and servers and CPU time on
your server is dominated by "getbundle" requests (clients cloning
and pulling) - and my experience at Mozilla tells me this is often
the case - this commit could drastically reduce your server-side
CPU usage *and* save on bandwidth costs!
Another benefit of this change is that server operators can install
*any* compression engine. While it isn't enabled by default, the
"none" compression engine can now be used to disable wire protocol
compression completely. Previously, commands like "getbundle" always
zlib compressed output, adding considerable overhead to generating
responses. If you are on a high speed network and your server is under
high load, it might be advantageous to trade bandwidth for CPU.
Although, zstd at level 1 doesn't use that much CPU, so I'm not
convinced that disabling compression wholesale is worthwhile. And, my
data seems to indicate a slow down on the client without compression.
I suspect this is due to a lack of buffering resulting in an increase
in socket read() calls and/or the fact we're transferring an extra 3 GB
of data (parsing HTTP chunked transfer and processing extra TCP packets
can add up). This is definitely worth investigating and optimizing. But
since the "none" compressor isn't enabled by default, I'm inclined to
punt on this issue.
This commit introduces tons of tests. Some of these should arguably
have been implemented on previous commits. But it was difficult to
test without the server functionality in place.
Gregory Szorc <gregory.szorc@gmail.com> [Sat, 24 Dec 2016 15:22:18 -0700] rev 30763
httppeer: advertise and support application/mercurial-0.2
Now that servers expose a capability indicating they support
application/mercurial-0.2 and compression, clients can key off
this to say they support responses that are compressed with
various compression formats.
After this commit, the HTTP wire protocol client now sends an
"X-HgProto-<N>" request header indicating its support for
"application/mercurial-0.2" media type and various compression
formats.
This commit also implements support for handling
"application/mercurial-0.2" responses. It simply reads the header
compression engine identifier then routes the remainder of the
response to the appropriate decompressor.
There were some test changes, but only to logging. That points to
an obvious gap in our test coverage. This will be addressed in a
subsequent commit once server support is in place (it is hard to
test without server support).
Gregory Szorc <gregory.szorc@gmail.com> [Sat, 24 Dec 2016 15:21:46 -0700] rev 30762
wireproto: advertise supported media types and compression formats
This commit introduces support for advertising a server's support for
media types and compression formats in accordance with the spec defined
in internals.wireproto.
The bulk of the new code is a helper function in wireproto.py to
obtain a prioritized list of compression engines available to the
wire protocol. While not utilized yet, we implement support
for obtaining the list of compression engines advertised by the
client.
The upcoming HTTP protocol enhancements are a bit lower-level than
existing tests (most existing tests are command centric). So,
this commit establishes a new test file that will be appropriate
for holding tests around the functionality of the HTTP protocol
itself.
Rounding out this change, `hg debuginstall` now prints compression
engines available to the server.
Gregory Szorc <gregory.szorc@gmail.com> [Sat, 24 Dec 2016 13:51:12 -0700] rev 30761
util: declare wire protocol support of compression engines
This patch implements a new compression engine API allowing
compression engines to declare support for the wire protocol.
Support is declared by returning a compression format string
identifier that will be added to payloads to signal the compression
type of data that follows and default integer priorities of the
engine.
Accessor methods have been added to the compression engine manager
class to facilitate use.
Note that the "none" and "bz2" engines declare wire protocol support
but aren't enabled by default due to their priorities being 0. It
is essentially free from a coding perspective to support these
compression formats, so we do it in case anyone may derive use from
it.
Gregory Szorc <gregory.szorc@gmail.com> [Sat, 24 Dec 2016 13:56:36 -0700] rev 30760
internals: document compression negotiation
As part of adding zstd support to all of the things, we'll need
to teach the wire protocol to support non-zlib compression formats.
This commit documents how we'll implement that.
To understand how we arrived at this proposal, let's look at how
things are done today.
The wire protocol today doesn't have a unified format. Instead,
there is a limited facility for differentiating replies as successful
or not. And, each command essentially defines its own response format.
A significant deficiency in the current protocol is the lack of
payload framing over the SSH transport. In the HTTP transport,
chunked transfer is used and the end of an HTTP response body (and
the end of a Mercurial command response) can be identified by a 0
length chunk. This is how HTTP chunked transfer works. But in the
SSH transport, there is no such framing, at least for certain
responses (notably the response to "getbundle" requests). Clients
can't simply read until end of stream because the socket is
persistent and reused for multiple requests. Clients need to know
when they've encountered the end of a request but there is nothing
simple for them to key off of to detect this. So what happens is
the client must decode the payload (as opposed to being dumb and
forwarding frames/packets). This means the payload itself needs
to support identifying end of stream. In some cases (bundle2), it
also means the payload can encode "error" or "interrupt" events
telling the client to e.g. abort processing. The lack of framing
on the SSH transport and the transfer of its responsibilities to
e.g. bundle2 is a massive layering violation and a wart on the
protocol architecture. It needs to be fixed someday by inventing a
proper framing protocol.
So about compression.
The client transport abstractions have a "_callcompressable()"
API. This API is called to invoke a remote command that will
send a compressible response. The response is essentially a
"streaming" response (no framing data at the Mercurial layer)
that is fed into a decompressor.
On the HTTP transport, the decompressor is zlib and only zlib.
There is currently no mechanism for the client to specify an
alternate compression format. And, clients don't advertise what
compression formats they support or ask the server to send a
specific compression format. Instead, it is assumed that non-error
responses to "compressible" commands are zlib compressed.
On the SSH transport, there is no compression at the Mercurial
protocol layer. Instead, compression must be handled by SSH
itself (e.g. `ssh -C`) or within the payload data (e.g. bundle
compression).
For the HTTP transport, adding new compression formats is pretty
straightforward. Once you know what decompressor to use, you can
stream data into the decompressor until you reach a 0 size HTTP
chunk, at which point you are at end of stream.
So our wire protocol changes for the HTTP transport are pretty
straightforward: the client and server advertise what compression
formats they support and an appropriate compression format is
chosen. We introduce a new HTTP media type to hold compressed
payloads. The header of the payload defines the compression format
being used. Whoever is on the receiving end can sniff the first few
bytes route to an appropriate decompressor.
Support for multiple compression formats is advertised on both
server and client. The server advertises a "compression" capability
saying which compression formats it supports and in what order they
are preferred. Clients advertise their support for multiple
compression formats and media types via the introduced "X-HgProto"
request header.
Strictly speaking, servers don't need to advertise which compression
formats they support. But doing so allows clients to fail fast if
they don't support any of the formats the server does. This is useful
in situations like sending bundles, where the client may have to
perform expensive computation before sending data to the server.
Rather than simply advertise a list of supported compression formats,
we introduce an additional "httpmediatype" server capability
advertising which media types the server supports. This means servers
are explicit about what formats they exchange. IMO, this is superior
to inferring support from other capabilities (like "compression").
By advertising compression support on each request in the "X-HgProto"
header and media type and direction at the server level, we are able
to gradually transition existing commands/responses to the new media
type and possibly compression. Contrast with the old world, where we
only supported a single media type and the use of compression was
built-in to the semantics of the command on both client and server.
In the new world, if "application/mercurial-0.2" is supported,
compression is supported. It's that simple.
It's worth noting that we explicitly don't use "Accept,"
"Accept-Encoding," "Content-Encoding," or "Transfer-Encoding" for
content negotiation and compression. People knowledgeable of the HTTP
specifications will say that we should use these because that's
what they are designed to be used for. They have a point and I
sympathize with the argument. Earlier versions of this commit even
defined supported media types in the "Accept" header. However, my
years of experience rolling out services leveraging HTTP has taught
me to not trust the HTTP layer, especially if you are going outside
the normal spec (such as using a custom "Content-Encoding" value to
represent zstd streams). I've seen load balancers, proxies, and other
network devices do very bad and unexpected things to HTTP messages
(like insisting zlib compressed content is decoded and then re-encoded
at a different compression level or even stripping compression
completely). I've found that the best way to avoid surprises when
writing protocols on top of HTTP is to use HTTP as a dumb transport as
much as possible to minimize the chances that an "intelligent" agent
between endpoints will muck with your data. While the widespread use of
TLS is mitigating many intermediate network agents interfering with
HTTP, there are still problems at the edges, with e.g. the origin HTTP
server needing to convert HTTP to and from WSGI and buggy or
feature-lacking HTTP client implementations. I've found the best way to
avoid these problems is to avoid using headers like "Content-Encoding"
and to bake as much logic as possible into media types and HTTP message
bodies. The protocol changes in this commit do rely on a custom HTTP
request header and the "Content-Type" headers. But we used them before,
so we shouldn't be increasing our exposure to "bad" HTTP agents.
For the SSH transport, we can't easily implement content negotiation
to determine compression formats because the SSH transport has no
content negotiation capabilities today. And without a framing protocol,
we don't know how much data to feed into a decompressor. So in order
to implement compression support on the SSH transport, we'd need to
invent a mechanism to represent content types and an outer framing
protocol to stream data robustly. While I'm fully capable of doing
that, it is a lot of work and not something that should be undertaken
lightly. My opinion is that if we're going to change the SSH transport
protocol, we should take a long hard look at implementing a grand
unified protocol that attempts to address all the deficiencies with
the existing protocol. While I want this to happen, that would be
massive scope bloat standing in the way of zstd support. So, I've
decided to take the easy solution: the SSH transport will not gain
support for multiple compression formats. Keep in mind it doesn't
support *any* compression today. So essentially nothing is changing
on the SSH front.
Gregory Szorc <gregory.szorc@gmail.com> [Sat, 24 Dec 2016 14:46:02 -0700] rev 30759
httppeer: extract code for HTTP header spanning
A second consumer of HTTP header spanning will soon be introduced.
Factor out the code to do this so it can be reused.
Gregory Szorc <gregory.szorc@gmail.com> [Tue, 10 Jan 2017 11:20:32 -0800] rev 30758
commands: config option to control bundle compression level
Currently, bundle compression uses the default compression level
for the active compression engine. The default compression level
is tuned as a compromise between speed and size.
Some scenarios may call for a different compression level. For
example, with clone bundles, bundles are generated once and used
several times. Since the cost to generate is paid infrequently,
server operators may wish to trade extra CPU time for better
compression ratios.
This patch introduces an experimental and undocumented config
option to control the bundle compression level. As the inline
comment says, this approach is a bit hacky. I'd prefer for
the compression level to be encoded in the bundle spec. e.g.
"zstd-v2;complevel=15." However, given that the 4.1 freeze is
imminent, I'm not comfortable implementing this user-facing
change without much time to test and consider the implications.
So, we're going with the quick and dirty solution for now.
Having this option in the 4.1 release will enable Mozilla to
easily produce and test zlib and zstd bundles with non-default
compression levels in production. This will help drive future
development of the feature and zstd integration with Mercurial.
Gregory Szorc <gregory.szorc@gmail.com> [Tue, 10 Jan 2017 11:19:37 -0800] rev 30757
bundle2: allow compression options to be passed to compressor
Compression engines allow options to be passed to them to control
behavior. This patch exposes an argument to bundle2.writebundle()
that passes options to the compression engine when writing compressed
bundles. The argument is honored for both bundle1 and bundle2, the
latter requiring a bit of plumbing to pass the value around.