The revbranchcache is read on demand before it will be used for updating the
branch map. It is written back when the branchmap is written and it will thus
use the same locking as branchmap. The revbranchcache instance is short-lived;
it is only stored in the branchmap from .update() is invoked and until .write()
is invoked. Branchmap already assume that the repo is locked in that case.
The use of revbranchcache for branch map updates will make sure that the
revbranchcache "always" is kept up-to-date.
The perfbranchmap benchmark is somewhat bogus, especially when we can see that
the caching makes a significant difference between the realistic case of a
first run and the rare case of rerunning it with a full cache. Here are some
'base' numbers on mozilla-central:
Before:
! wall 6.912745 comb 6.910000 user 6.840000 sys 0.070000 (best of 3)
After - initial, cache is empty:
! wall 7.792569 comb 7.790000 user 7.720000 sys 0.070000 (best of 3)
After - cache is full:
! wall 0.879688 comb 0.880000 user 0.870000 sys 0.010000 (best of 4)
The overhead when running with empty cache comes from checking, missing and
updating it every time.
Most of the performance improvement comes from not having to extract the branch
info from the changelog. The last doubling of performance comes from no longer
having to convert all branch names to local encoding but reuse the few already
converted branch names.
On the hg repo:
Before:
! wall 0.715703 comb 0.710000 user 0.710000 sys 0.000000 (best of 14)
After:
! wall 0.105489 comb 0.110000 user 0.110000 sys 0.000000 (best of 87)
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.
coal style uses every template (except header.tmpl) directly from paper style,
but doesn't use paper/map file. Elements defined in such map files are used in
templates as you would expect. For example, paper/search.tmpl contains
'{searchhint}' and template engine replaces that with the actual hint. But when
coal style reuses paper/search.tmpl, it needs to define searchhint in its map
file as well, or template engine will not find it. So let's copy it from
paper/map to coal/map.
Before this change, if the coal style was selected, the hint for the search
field in page header was present, but it was completely empty. Although the
absence of searchhint in coal/map produced no error.
jsonchangeset._show() was computing the reverse status of the current
changeset. As a result, added files were showing up as removed and
removed files were showing up as adds.
There were existing tests for this code and they were flat out wrong.
It was introduced at deb42ca4dd93, where spanset.__contains__() did not exist.
Nowadays, we have to pay huge penalty for len(subset).
The following example showed that OR operation could be O(n * m^2)
(n: len(repo), m: number of OR operators, m >= 2) probably because of
filteredset.__len__.
revset #0: 0|1|2|3|4|5|6|7|8|9
0) wall 8.092713 comb 8.090000 user 8.090000 sys 0.000000 (best of 3)
1) wall 0.445354 comb 0.450000 user 0.430000 sys 0.020000 (best of 22)
2) wall 0.000389 comb 0.000000 user 0.000000 sys 0.000000 (best of 7347)
(0: 3.2.4, 1: 3.1.2, 2: this patch)
The more aggressive synchronization of lfdirstate that was backed out in
4fe80f20ab06 masked the problem where lfdirstate would hold an 'R' for a
largefile that was added and then removed without a commit between. We could
just conditionally call lfdirstate.drop() or lfdirstate.remove() here, but this
also properly updates lfdirstate if the standin doesn't exist for the file
somehow (i.e. call drop instead of remove).
Without this change, the precommit status in the commit command immediately
after the test change lists the removed (and never committed) largefile as 'R'.
It can also lead to situations where the status command reports the same, long
after the commit [1].
[1] http://www.selenic.com/pipermail/mercurial-devel/2015-January/065153.html
d20af8be6a14 introduced a significant performance regression: All largefiles
were marked 'normallookup' by linear (or noop) updates and had to be rehashed
by the next command.
The previous change introduced a different solution to the problem d20af8be6a14
solved and we can thus back it out again.
This is an alternative solution to the problem addressed by d20af8be6a14. This
implementation has the advantage that it doesn't mark clean largefiles as
normallookup. We can thus avoid repeated rehashing of all largefiles when
d20af8be6a14 is backed out.
This implementation use the existing 'lfmr' actions that 4f7f7352d9d0
introduced for handling another part of the same cases.
d20af8be6a14 introduced a significant performance regression: All largefiles
are marked 'normallookup' in lfdirstate by linear (or noop) updates and has to
be rehashed by the next command.
To avoid such regressions, keep an eye on the dirstate content after a plain
'hg up'.
If resolving a merge conflict result in an empty changesets, we now properly
skip the changeset instead of crashing.
Original patch from Robert Collins <robertc@robertcollins.net>.
This module depends on _winreg, which is windows-only. Recent versions
of setuptools load distutils.msvc9compiler and expect it to
ImportError immediately when on non-Windows platforms, so we need to
let them do that. This breaks in an especially mystifying way, because
setuptools uses vars() on the imported module. We then throw an
exception, which vars doesn't pick up on well. For example:
In [3]: class wat(object):
...: @property
...: def __dict__(self):
...: assert False
...:
In [4]: vars(wat())
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-4-2781ada5ffe6> in <module>()
----> 1 vars(wat())
TypeError: vars() argument must have __dict__ attribute
Which is similar to the problem we run into.
If an uncommitted and deleted file was forgotten, a warning would be emitted,
even though the operation was successful. See the previous patch for
'remove -A' for the exact circumstances, and details about the cause.
The bug report doesn't mention largefiles, but the given recipe doesn't fail
unless the largefiles extension is loaded. The problem only affected normal
files, whether or not any largefiles are committed, and only files that have
not been committed yet. (Files with an 'a' state are dropped from dirstate,
not marked removed.) Further, if the named normal file never existed, the
warning would be printed out twice.
The problem is that the core implementation of remove() calls repo.status(),
which eventually triggers a dirstate.walk(). When the file isn't seen in the
filesystem during the walk, the exception handling finds the file in
dirstate, so it doesn't complain. However, the largefiles implementation
called status() again with all of the original files (including the normal
ones, just dropped). This time, the exception handler doesn't find the file
in dirstate and does complain. This simply excludes the normal files from
the second repo.status() call, which the largefiles extension has no interest
is processing anyway.
This is a copy/paste (with the necessary tweaks) of the composenormalfilematcher
method currently on default, which does the inverse- this trims the normal files
out of the matcher. It will be used in the next patch.
According to Apple Technote 1150 (unavailable from Apple as far as I
can tell, but archived in several places online), HFS+ ignores sixteen
specific unicode runes when doing path normalization. We need to
handle those cases, so this function lets us efficiently strip the
offending characters from a UTF-8 encoded string (which is the only
way it seems to matter on OS X.)
When generating many new files into a set of many possible new directories,
there is the possibility that the same path is chosen as both file and
directory. How likely this is depends on the size of the dictionary used,
the generated directory structure and the number of generated files.
Now that the caching into _status is done in
workingctx._dirstatestatus(), which workingcommitctx._dirstatestatus()
does not call, there is no caching to prevent in _buildstatus(), so
stop overriding it.
Since it's only the dirstate status we cache, it makes more sense to
cache it in the _dirstatestatus() method. Note that this change means
the dirstate status will also be cached when status is requested
between the working copy and some other revision, while we currently
only cache the result if exactly the status between the working copy
and its parent is requested.
manifest.diff() uses None as a special value to denote the absence of
a file, so setting a file node to None means you then can't trust
manifest.diff().
This should also make future manifest work slightly easier.
Instead use a magic value, so that we can identify modified or added
nodes correctly when using manifest.diff().
Thanks to Martin von Zweigbergk for catching that we have to update
_buildstatus as well. That part eluded my debugging for some time.
The log/graphlog revset was not producing stable results since it was
iterating over a dict. Now we sort before iterating to guarantee a fixed order.
This fixes some potential flakiness in the tests.
The revset created when -f was used with a slow path (for patterns and
directories) did not actually contain any logic to enforce follow. Instead it
was depending on the passed in subset to already be limited (which was limited
to :. but not ::.). This fixes it by adding a '& ::.' to any -f log revset.
hg log -f <file> is still broken, in that it can return results that aren't
actually ancestors of the current file, but fixing that has major perf
implications, so we'll deal with it later.
When looking for untracked files that would conflict with a tracked
file in the target revision (or the remote side of a merge), we
explcitly exclude ignored files. The code was added in f1db75422e70
(merge: refactor unknown file conflict checking, 2012-02-09), but it
seems like only unknown, not ignored, files were considered since the
beginning of time.
Although ignored files are mostly build outputs and backup files, we
should still not overwrite them. Fix by simply removing the explicit
check.
We don't seem to have any tests for updating to another revision when
there are untracked files on the local side that conflict with the
those on the remote side, so let's add tests. This shows how we
overwrite untracked ignored files when updating to a revision that
tracks the file.
The state mapping also contains some magic negative values (detached
parent, ignored revision). Blindly reading the state thus lead to
unfortunate usage of the negative value as an update destination. We
now filter them out.
We do a minor alteration of the test to catch this.
Before, merging would in some cases ask "wrong" questions about
"changed/deleted" conflicts ... and even do it before the resolve phase where
they can be postponed, re"resolved" or answered in bulk operations.
Instead, check that the content of the changed file really did change.
Reading and comparing file content is expensive and should be avoided before
the resolve phase. Prompting the user is however even more expensive. Checking
the content here is thus better.
The 'f in ancestors[0]' should not be necessary but is included to be extra
safe.
Use suffix -same for cases where file changed but content is the same - that is
the case where manifestmerge doesn't detect that a file is unchanged.
(The suffix -id is already used for cases where the file didn't change - that
is the trivial case where manifestmerge detects that the file is unchanged.)
These new tests are good but the results are bad. There shouldn't be any merge
conflicts or prompts when one side didn't change.
This allow to gracefully report the failure of the bookmark push and carry on.
Before this change set. Local push would plain quit and wireprotocol would
failed in various ungraceful way.
We need to gracefully handle some aborts for pushkey, especially
because it leads to a user-facing crash over the wireprotocols. So we
need a more specialized exception to catch.
