We have a nice API now. Use it.
This does mean we introduce an extra index lookup for each revision.
Considering this is a debug command, the overhead should be acceptable.
We could add the chain size to revlog._deltachain(). However, that
feels like avoidable overhead.
Now that we have multiple directories where help topics can live,
we need a mechanism to access them. We already use "." to
separate topic from section. So it seems logical to also use "." to
denote the sub-directory of a topic.
This patch teaches the help command to parse out the possible
sub-topic and pass it to the help system.
We generally make modules importable from the front-end layer, dispatch ->
commands -> x. So the import cycle to dispatch should be resolved by the
commandserver module.
Since 3be994f0f015, #fragment was missing in "hg paths" output because
path.loc was changed to a parsed URL. "hg paths" should use path.rawloc to
show complete URLs.
Previously, we'd restore the .orig file after the premerge is complete but
before the merge was complete. This would lead to the .orig file potentially
containing merge conflict markers in it, as a leftover from the last merge
attempt.
Power users often want to apply per-path configuration options. For
example, they may want to declare an alternate URL for push operations
or declare a revset of revisions to push when `hg push` is used
(as opposed to attempting to push all revisions by default).
This patch establishes the use of sub-options (config options with
":" in the name) to declare additional behavior for paths.
New sub-options are declared by using the new ``@ui.pathsuboption``
decorator. This decorator serves multiple purposes:
* Declaring which sub-options are registered
* Declaring how a sub-option maps to an attribute on ``path``
instances (this is needed to `hg paths` can render sub-options
and values properly)
* Validation and normalization of config options to attribute
values
* Allows extensions to declare new sub-options without monkeypatching
* Allows extensions to overwrite built-in behavior for sub-option
handling
As convenient as the new option registration decorator is, extensions
(and even core functionality) may still need an additional hook point
to perform finalization of path instances. For example, they may wish
to validate that multiple options/attributes aren't conflicting with
each other. This hook point could be added later, if needed.
To prove this new functionality works, we implement the "pushurl"
path sub-option. This option declares the URL that `hg push` should
use by default.
We require that "pushurl" is an actual URL. This requirement might be
controversial and could be dropped if there is opposition. However,
objectors should read the complicated code in ui.path.__init__ and
commands.push for resolving non-URL values before making a judgement.
We also don't allow #fragment in the URLs. I intend to introduce a
":pushrev" (or similar) option to define a revset to control which
revisions are pushed when "-r <rev>" isn't passed into `hg push`.
This is much more powerful than #fragment and I don't think #fragment
is useful enough to continue supporting.
The [paths] section of the "config" help page has been updated
significantly. `hg paths` has been taught to display path sub-options.
The docs mention that "default-push" is now deprecated. However, there
are several references to it that need to be cleaned up. A large part
of this is converting more consumers to the new paths API. This will
happen naturally as more path sub-options are added and more and more
components need to access them.
The magic @property is going to interfere with the ability to print
path sub-options. We only access it in one location and it is trivial
to in-line, so do that.
We have debug commands for displaying overall revlog statistics
(debugrevlog) and for dumping a revlog index (debugindex). As part
of investigating various aspects of revlog behavior and performance,
I found it important to have an understanding of how revlog
delta chains behave in practice.
This patch implements a "debugdeltachain" command. For each revision
in a revlog, it dumps information about the delta chain. Which delta
chain it is part of, length of the delta chain, distance since base
revision, info about base revision, size of the delta chain, etc. The
generic formatting facility is used, which means we can templatize
output and get machine readable output like JSON.
This command has already uncovered some weird history in
mozilla-central I didn't know about. So I think it's valuable.
We should probably avoid strong quotes around command line args in the examples,
since cmd.exe doesn't recognize them, and it will surprise a user who cargo
cults them. I don't see a way to make a rule for this, since strong quoting is
OK inside command line args, like within revsets.
Future patches will make a node symbol templatable. Because arguments of a
templatekw function are repo and ctx, "showparents" list will have to be
built from a repo object by that function.
Before this patch, "hg import" executes below before acquisition of
wlock:
- cmdutil.checkunfinished()
- cmdutil.bailifchanged()
It may cause unintentional result, if another command runs parallelly
(see also issue4368).
To avoid this issue, this patch executes 'cmdutil.checkunfinished()'
and 'cmdutil.bailifchanged()' inside wlock scope of "hg import".
Before this patch, "hg graft" executes below before acquisition of
wlock.
- cmdutil.checkunfinished()
- cmdutil.bailifchanged()
- repo.dirstate.parents() via 'repo["."]'
- unlinking '.hg/graftstate'
It may cause unintentional result, if another command runs parallelly
(see also issue4368).
This patch widens wlock scope of "hg graft" for consitency while
processing.
Before this patch, "hg backout" executes below before acquisition of
wlock.
- cmdutil.checkunfinished()
- cmdutil.bailifchanged()
- repo.dirstate.parents()
It may cause unintentional result, if another command runs parallelly
(see also issue4368).
In addition to it, "hg backout" refers changelog for purposes below
without acquisition of store lock (slock), and it may cause
unintentional result, if store is updated parallelly.
- show and update to the revision by 'repo.changelog.tip()'
- examine for "created new head" by 'repo.branchheads()' and
'cmdutil.commitstatus()'
To avoid this issue, this patch makes "hg backout" acquire wlock and
slock before processing.
Before this patch, "hg commit" (process A) executes steps below:
1. get current branch heads via 'repo.branchheads()'
- cache 'repo.changelog'
2. invoke 'repo.commit()'
3. acquire wlock
- invalidate 'repo.dirstate'
4. access 'repo.dirstate'
- re-read '.hg/dirstate'
- check validity of parent revisions with 'repo.changelog'
5. invoke 'repo.commitctx()'
6. acquire store lock (slock)
- invalidate 'repo.changelog'
7. do committing
8. release slock
9. release wlock
10. check new branch head (via 'cmdutil.commitstatus()')
If acquisition of wlock at (3) above waits for another "hg commit"
(process B) or so running parallelly to release wlock, process A
causes creating orphan revision, because:
- '.hg/dirstate' refers the revision, which is newly added by
process B, as its parent
- but already cached 'repo.changelog' doesn't contain such revision
- therefore, validating parents of '.hg/dirstate' at (4) above
replaces such revision with 'nullid'
Then, process A creates "orphan" revision, of which parent is "null"
revision.
In addition to it, "created new head" may be shown at the end of
process A unintentionally, if store is updated parallelly, because
both getting branch heads (1) and checking new branch head (10) are
executed outside slock scope.
To avoid this issue, this patch makes "hg commit" acquire wlock and
slock before processing.
This patch resolves the issue between "hg commit" processes, but not
one between "hg commit" and other commands. Subsequent patches resolve
the latter.
Even after this patch, there are still corner case problems below:
- filecache may overlook changes of '.hg/dirstate', and it causes
similar issue (see below for detail)
https://bz.mercurial-scm.org/show_bug.cgi?id=4368#c10
- 3rd party extension may cause similar issue, if it directly uses
'repo.commit()' without acquisition of wlock and slock
This can be fixed by acquisition of slock at the beginning of
'repo.commit()', but it seems suitable for "default" branch
In fact, acquisition of slock itself is already introduced at
"default" branch by ec227b188932, but acquisition is not at the
beginning of 'repo.commit()'.
This patch also changes some tests:
- test-fncache.t needs this tricky wrapping, to release (= forced
failure of) wlock certainly
- order of "hg commit" output is changed by widening scope of locks,
because some hooks are fired after releasing wlock
When debugrebuilddirstate --minimal is called, rebuilding the dirstate was done
outside of the appropriate rebuild function. This patch makes
debugrebuilddirstate use dirstate.rebuild.
This was done to allow our extension to become aware debugrebuilddirstate
--minimal
before, if you ran hg graft --user ... --date ... --log ... revs,
and if it failed, it would suggest "hg graft --continue",
but if you did that, your --user / --date / --log options
were lost, because they were not persisted anywhere...
localrepo.parents() has relatively few users, and most of those were
actually implicitly looking at the wctx, which is now made explicit
via repo[None].
