show: tweak warning message '.' is "working directory parent" not "working directory."

revlog: add an experimental option to mitigated delta issues (issue5480) The general delta heuristic to select a delta do not scale with the number of branch. The delta base is frequently too far away to be able to reuse a chain according to the "distance" criteria. This leads to insertion of larger delta (or even full text) that themselves push the bases for the next delta further away leading to more large deltas and full texts. This full text and frequent recomputation throw Mercurial performance in disarray. For example of a slightly large repository 280 000 files (2 150 000 versions) 430 000 changesets (10 000 topological heads) Number below compares repository with and without the distance criteria: manifest size: with: 21.4 GB without: 0.3 GB store size: with: 28.7 GB without 7.4 GB bundle last 15 00 revisions: with: 800 seconds 971 MB without: 50 seconds 73 MB unbundle time (of the last 15K revisions): with: 1150 seconds (~19 minutes) without: 35 seconds Similar issues has been observed in other repositories. Adding a new option or "feature" on stable is uncommon. However, given that this issues is making Mercurial practically unusable, I'm exceptionally targeting this patch for stable. What is actually needed is a full rework of the delta building and reading logic. However, that will be a longer process and churn not suitable for stable. In the meantime, we introduces a quick and dirty mitigation of this in the 'experimental' config space. The new option introduces a way to set the maximum amount of memory usable to store a diff in memory. This extend the ability for Mercurial to create chains without removing all safe guard regarding memory access. The option should be phased out when core has a more proper solution available. Setting the limit to '0' remove all limits, setting it to '-1' use the default limit (textsize x 4).

tests: use system hg only if changelog or dirstate can't be read The bundled hg should work flawlessly in most cases. Make it depend on the external installation only if necessary since we can't control the whole environment. This patch doesn't implement the "exit 80" idea proposed by Jun. I don't want to keep the capability checking sync with the actual tests.

tests: restore workaround of obsolete warning from 3c9066ed557c It's simple and works well unless you are using third-party extensions that changes the store format.

tests: alias syshg and syshgenv so they can be switched conditionally

tests: actually restore the original environment before running syshg Since os.environ may be overridden in run-tests.py, several important variables such as PATH weren't restored. I don't like the idea of using the system hg *by default* because the executable and the configs are out of our control. But I don't mind as long as the tests pass.

phabricator: add phabread command to read patches This patch adds a `phabread` command generating plain-text patches from Phabricator, suitable for `hg import`. It respects `hg:meta` so user and date information might be preserved. And it removes `Summary:` field name which makes the commit message a bit tidier. To support stacked diffs, a `--stack` flag was added to read dependent patches recursively.

phabricator: add phabsend command to send a stack The `phabsend` command is intended to provide `hg email`-like experience - sending a stack, setup dependency information and do not amend existing changesets. It uses differential.createrawdiff and differential.revision.edit Conduit API to create or update a Differential Revision. Local tags like `D123` are written indicating certain changesets were sent to Phabricator. The `phabsend` command will use obsstore and tags information to decide whether to update or create Differential Revisions.

phabricator: add a contrib script The default Phabricator client arcanist is not friendly to send a stack of changesets. It works better when a feature branch is reviewed as a single review unit. However, we want multiple revisions per feature branch. To be able to have an `hg email`-like UX to send and receive a stack of commits easily, it seems we have to re-invent things. This patch adds `phabricator.py` speaking Conduit API [1] in `contrib` as the first step. This may also be an option for people who don't want to run PHP. Config could be done in `hgrc` (instead of `arcrc` or `arcconfig`): [phabricator] # API token. Get it from https://phab.mercurial-scm.org/conduit/login/ token = cli-xxxxxxxxxxxxxxxxxxxxxxxxxxxx url = https://phab.mercurial-scm.org/ # callsign is used by the next patch callsign = HG This patch only adds a single command: `debugcallconduit` to keep the patch size small. To test it, having the above config, and run: $ hg debugcallconduit diffusion.repository.search <<EOF > {"constraints": {"callsigns": ["HG"]}} > EOF The result will be printed in prettified JSON format. [1]: Conduit APIs are listed at https://phab.mercurial-scm.org/conduit/

show: implement "stack" view People often want to know what they are working on *now*. As part of this, they also commonly want to know how that work is related to other changesets in the repo so they can perform common actions like rebase, histedit, and merge. `hg show work` made headway into this space. However, it is geared towards a complete repo view as opposed to just the current line of work. If you have a lot of in-flight work or the repo has many heads, the output can be overwhelming. The closest thing Mercurial has to "show me the current thing I'm working on" that doesn't require custom revsets is `hg qseries`. And this requires MQ, which completely changes workflows and repository behavior and has horrible performance on large repos. But as sub-optimal as MQ is, it does some things right, such as expose a model of the repo that is easy for people to reason about. This simplicity is why I think a lot of people prefer to use MQ, despite its shortcomings. One common development workflow is to author a series of linear changesets, using bookmarks, branches, anonymous heads, or even topics (3rd party extension). I'll call this a "stack." You periodically rewrite history in place (using `hg histedit`) and reparent the stack against newer changesets (using `hg rebase`). This workflow can be difficult because there is no obvious way to quickly see the current "stack" nor its relation to other changesets. Figuring out arguments to `hg rebase` can be difficult and may require highlighting and pasting multiple changeset nodes to construct a command. The goal of this commit is to make stack based workflows simpler by exposing a view of the current stack and its relationship to other releant changesets, notably the parent of the base changeset in the stack and newer heads that the stack could be rebased or merged into. Introduced is the `hg show stack` view. Essentially, it finds all mutable changesets from the working directory revision in both directions, stopping at a merge or branch point. This limits the revisions to a DAG linear range. The stack is rendered as a concise list of changesets. Alongside the stack is a visualization of the DAG, similar to `hg log -G`. Newer public heads from the branch point of the stack are rendered above the stack. The presence of these heads helps people understand the DAG model and the relationship between the stack and changes made since the branch point of that stack. If the "rebase" command is available, a `hg rebase` command is printed for each head so a user can perform a simple copy and paste to perform a rebase. This view is alpha quality. There are tons of TODOs documented inline. But I think it is good enough for a first iteration.

tests: demonstrate inconsistencies with dirty state in various commands Not only is the output of these commands inconsistent with respect to each other when a file is deleted, they are internally inconsistent depending upon whether the deleted file is in the top level repo or a subrepo. It seemed easier to show the problems, rather than describe them. The original goal was to fix the summary command with respect to deleted files. I haven't fixed any of the other issues yet, in case anybody believes the current subrepo behavior is correct. I think a natural understanding of clean/dirty is that they are two opposite values of a single binary repo state. If `hg update --clean -r .` changes a file, then naturally that repo was dirty, and `hg update --check` should have blocked it. Deleted files are special, in that they don't block a commit. But they make the filesystem content not the same as a clean checkout.

check-config: syntax to allow inconsistent config values The ignore regular expression has been updated to detect "inconsistent config." If present, we track which configs have that set and we suppress the conflicting defaults error for those options. I also added named groups to the regexp to aid readability. A comment was added to profiling.py to make a desired inconsistent value error go away.

configitems: register the 'badserver.closebeforeaccept' config

configitems: register the 'badserver.closeaftersendbytes' config

configitems: register the 'badserver.closeafterrecvbytes' config

configitems: register the 'badserver.closeafteraccept' config

configitems: register the 'blackbox.logsource' config

configitems: register the 'blackbox.dirty' config

configitems: register the 'automv.similarity' config Default value has been ported.

acl: use configlist to retrieve the source config This is what the previous code was about.

configitems: register the 'acl.sources' config The existing default value is now formally declared. It seems like the whole config should be a list, but this is an adventure for the next changesets.

configitems: register the 'acl.config' config

config: register the 'devel.legacy.exchange' config

configitems: register the 'bundle.reorder' config

configitems: register the 'bundle.mainreporoot' config

configitems: register the 'bookmarks.pushing' config

configitems: register the 'auth.cookiefile' config

configitems: register the 'color.mode' config

zeroconf: blindly forward extra argument to the core config method The new default value handling is simpler if we let the original function handle everything.

configitem: fix default value for 'serverrequirecert'

localrepo: factor out base of filecache annotation class It isn't needed that storecache is derived from repofilecache. Changes in this patch allow repofilecache and storecache to do in own __init__() differently from each other.

manifest: apply checkambig=True only for root 00manifest.i This is a fix for my 14ad8e2a4abe, which used 'bool(dir)' as checkambig value for revlog.__init__(). I can't remember why I did so in 14ad8e2a4abe, but this is obviously wrong, because only root indexfile is cached via filecache-ed property of localrepository.

revlog: address review feedback for deltachain C implementation * Scope of "value" is reduced * index_baserev() is documented * Error is no longer redundantly set for -2 return values * Error values are compared <= -2 instead of == -2 to protect against odd failure scenarios

test-rebase-interruptions: stabilize for Windows External hooks end up launching cmd.exe, which knows nothing about $VAR syntax. For some reason, I thought that Mercurial would substitute in the value, in order to paper over the platform difference. But I can't find that in the documentation, and there's at least one other use of this pattern [1]. [1] https://www.mercurial-scm.org/repo/hg/file/tip/tests/test-histedit-fold.t#l477

drawdag: inline transaction() function I suspect Jun wrote the method before he learnt that Python 2.7 allows multiple context managers in a single with-clause.

revlog: C implementation of delta chain resolution I've seen revlog._deltachain() appear in a number of performance profiles. I suspect there are 2 reasons for this: 1. Delta chain resolution performs many index lookups, thus triggering population of index tuples. Creating possibly tens of thousands of PyObject will have overhead. 2. Delta chain resolution is a tight loop. By moving delta chain resolution to C, we can defer instantiation of full index entry tuples and make the loop faster courtesy of not running in Python. We can measure the impact to delta chain resolution via `hg perflogrevision` using the mozilla-central repo with a recent manifest having delta chain length of 33726: $ hg perfrevlogrevision -m 364895 ! full ! wall 0.367585 comb 0.370000 user 0.340000 sys 0.030000 (best of 27) ! wall 0.357581 comb 0.360000 user 0.350000 sys 0.010000 (best of 28) ! deltachain ! wall 0.010644 comb 0.010000 user 0.010000 sys 0.000000 (best of 270) ! wall 0.000292 comb 0.000000 user 0.000000 sys 0.000000 (best of 8729) $ hg perfrevlogrevision --cache -m 364895 ! deltachain ! wall 0.003904 comb 0.000000 user 0.000000 sys 0.000000 (best of 712) ! wall 0.000284 comb 0.000000 user 0.000000 sys 0.000000 (best of 9926) The first test measures savings from both not instantiating index entries and moving to C. The second test (which doesn't clear the index caches) essentially isolates the benefits of moving from Python to C. It still shows a 13.7x speedup (versus 36.4x). And there are multiple milliseconds of savings within the critical path for resolving revision data. I think that justifies the existence of C code. A more striking example of the benefits of this change can be demonstrated by timing `hg debugdeltachain -m` for the mozilla-central repo: $ time hg debugdeltachain -m > /dev/null before: 1057.4s after: 503.3s PyPy2.7 5.8.0: 220.0s It's worth noting that the C code isn't as optimal as it could be. We're still instantiating a new PyObject for every revision. A future optimization would be to reuse the PyObject on the cached index tuple. We could potentially also get wins by using a memory array of raw integers. There is also room for a delta chain cache on revlog instances. Of course, the best optimization is to implement revlog reading outside of Python so Python doesn't need to be concerned about the relatively expensive index entries and operations on them.

config: register the 'devel.strip-obsmarkers' config The single explicit default that existed so far is converted to registered config value.

config: register the 'devel.serverrequirecert' config

config: register the 'devel.serverexactprotocol' config

config: register the 'devel.servercafile' config

config: register the 'devel.disableloaddefaultcerts' config

config: register the 'devel.check-relroot' config

config: register the devel.check-locks config

config: register the 'devel.bundle2.debug' config Existing explicit default are dropped now that the default is centralised.

config: register the 'devel.all-warnings' config Let us start registering the existing option. I'm starting with the 'devel' section because it is full of useful things that are poorly documented. So registering these will more than other section.

rebase: always pass destination as revnum to _handleskippingobsolete() We were passing it as a revision number in one place and as a context in another. It worked because the only use was in "repo[dest].rev()", but it was confusing. By always passing a revision number, we can also remove that unnecessary lookup.

patch: remove unused fsbackend._join() The function lost its last caller in 2a095d3442e0 (patch: replace functions in fsbackend to use vfs, 2014-06-05) when the callers started relying on the opener to do the join.

patch: add close() to abstractbackend patchbackend() seems to call it on an arbitrary backend, so it seems to be part of the API. Since all subclasses do something in their close() methods, I decided to let this one raise an exception rather than just pass.

log: add an extension hook-point in changeset_printer Extensions sometimes wants to add other information in the default log output format (when no templating is used). Add an empty function named '_exthook' for easing the extension life. Extensions will be able to wrap this function and collaborate to display additional information. Exthook is called after displaying troubles and just before displaying the files, extra and description. Add a new test file to test it and not pollute other test files.

drawdag: support obsmarker creation in comments This patch adds special comment handling so one can create obsmarkers in drawdag comments like "# replace: A -> B -> C", "# prune: X, Y, Z", "split: P -> M, N" and they are just self-explained.

test-drawdag: add a test for drawdag.py The drawdag script is useful but does not have a formal test. This patch adds it.

filemerge: convert a couple of wvfs calls in internal mergetools to contexts One hitch is that sometimes fcd is actually an absentfilectx which does not expose any mutator functions. In order to still use the context functions, we look up the underlying workingfilectx to perform the write there. One alternate way would be to put the write functions on the absentfilectx and have them pass-through. While this makes the callsites cleaner, we would need to decide what its getter functions would return after this point, since returning None for `data` (and True for `isabsent()`) might no longer be correct after a write. I discussed with Sidd about just having the getters raise RuntimeErrors after a mutator has been called, but we actually call isabsent() in merge.py after running the internal merge tools.

configitems: support callable as a default value Yuya pointed out that using mutable value as the default could be problematic. To work around this we now support callable object as default value. This allows for creating new mutable objects on demand when needed.

obsutil: move 'getmarkers' to the new modules We have a new 'obsutil' module now. We move the high level utility there to bring 'obsolete.py' back to a more reasonable size.

obsutil: move the 'marker' class to the new modules We have a new 'obsutil' module now. We move high level utility there to bring 'obsolete.py' back to a more reasonable size.

obsolete: delete three unused utility functions None of this function has been used in the past 5 years, so I think it is safe to just kill them. All code accessing rich markers is using 'getmarkers(...)' instead (or raw markers).

obsutil: move 'foreground' to the new modules We have a new 'obsutil' module now. We move the high level utility there to bring 'obsolete.py' back to a more reasonable size.

obsutil: move 'allsuccessors' to the new modules We have a new 'obsutil' module now. We move the high level utility there to bring 'obsolete.py' back to a more reasonable size.

obsutil: move 'allprecursors' to the new modules We have a new 'obsutil' module now. We move the high level utility there to bring 'obsolete.py' back to a more reasonable size.

obsutil: move 'exclusivemarkers' to the new modules We have a new 'obsutil' module now. We move the high level utility there to bring 'obsolete.py' back to a more reasonable size.

obsutil: move 'successorssets' to the new modules We have a new 'obsutil' module now. We move this high level utility there to bring 'obsolete.py' back to a more reasonable size.

tests: fix variable name regular expression in _genrestoreenv() Update the code to correctly anchor the expression on the end of the name, to require that the entire name match this expression. It was already anchored at the start by using re.match(), but this does not anchor it at the end.

merge with stable

pushrace: avoid crash on bare push when using concurrent push mode If the remote is empty, we do now bother computing head changes and the 'pushbranchmap' attribute stays at None. We now handle and tests this case.

show: config option to register aliases for views As part of using `hg show` in my daily workflow, I've found it slightly annoying to have to type full view names, complete with a space. I've locally registered an alias for "swork = show work." I think others will have this same complaint and could benefit from some automation to streamline the creation of aliases. So, this commit introduces a config option that allows `hg show` views to be automatically aliased using a given prefix. e.g. a value of "s" will automatically register "swork" and "sbookmarks." Multiple values can be given for ultimate flexibility. This arguably isn't needed now. But since we don't register aliases if there will be a collision and we're bound to have a collision, it makes sense to allow multiple prefixes so specific views can avoid collisions by using different prefixes.

blackbox: use a human readable version of the default Now that the default value is also converted we can use a human readable version for it. This will be useful if we start to automatically display the default config value in various place.

configitems: register 'blackbox.maxsize' as an example of 'configbytes' This exercise the default value handling in 'configbytes'.

blackbox: minor code reordering The version declaration should come first in my opinion. This will help gather the command table with the config table.

configitems: add a devel warning for extensions items overiding core one We do not want such case to pass silently. In the future we'll likely have useful tool for an extension to alter the existing definition in core.

configitems: add an official API for extensions to register config item Extensions can have a 'configtable' mapping and use 'registrar.configitem(table)' to retrieve the registration function. This behave in the same way as the other way for extensions to register new items (commands, colors, etc).

configitems: extract the logic to build a registrar on any configtable Having the logic available independently from the mapping used is a necessary step toward extensions support.

obsolete: skip 'changectx' usage in unstable computation We simplify the unstable computation code, skipping the expensive creation of changectx object. We focus on efficient set operation and revnumber centric functions. In my mercurial development repository, this provides a 3x speedup to the function: before: 5.319 ms after: 1.844 ms repo details: total changesets: 40886 obsolete changesets: 7756 mutable (not obsolete): 293 unstable: 30

obsolete: provide a small function to retrieve all mutable revisions More obsolescence related algorithm focus on the mutable revision. We provide a tiny utility function to make it easy to access this set.

bundle2: add debug info about the number of stream params Seems like the %i was never substituted.

bundle2: add some debugging information to the not-a-bundle error I found this useful while trying to debug wireproto-related issues.

tests: more completely restore the environment in syshgenv Update the syshgenv function to attempt to completely restore the original environment, rather than only updating a few specific variables. run_tests.py now generates a shell script that can be used to restore the original environment, and syshgenv sources it. This is a bit more complicated than the previous code, but should do a better job of running the system hg in the correct environment. I've tested it on Linux using python 2.x, but let me know if it causes issues in other environments. I'm not terribly familiar with how the tests get run on Windows, for instance, and how the environment needs to be updated there.

tests: do not use system hg if it does not have "files" command Ancient hg does not have "hg files" so test-check-*.t will fail with "unknown command 'files'": $ hg files hg: unknown command 'files' $ hg --version Mercurial Distributed SCM (version 2.6.2) Test "hg files" and give up using syshg if it does not have "files" command.

setup: fix runcmd() usage on darwin Fix one invocation of runcmd() that was missed in the recent change to make runcmd() also return the process exit status.

py3: update the python3-whitelist with new tests which pass on Python 3 We have now 34 tests passing on Python 3.

setup: fix localhgenv It should return env as a dict instead of None.

tests: use the system hg for examining the local repository Most test scripts use "hg" to interact with a temporary test repository. However a few tests also want to run hg commands to interact with the local repository containing the mercurial source code. Notably, many of the test-check-* tests want to check local files and commit messages. These tests were previously using the version of hg being tested to query the source repository. However, this will fail if the source repository requires extensions or other settings not supported by the version of mercurial being tested. The source repository was typically initially cloned using the system hg installation, so we should use the system hg installation to query it. There was already a helpers-testrepo.sh script designed to help cope with different requirements for the source repository versus the test repositories. However, it only handled the evolve extension. This new behavior works with any extensions that are different between the system installation and the test installation.

tests: save the original PATH and PYTHONPATH variables When running the tests, define ORIG_PATH and ORIG_PYTHONPATH environment variables that contain the original contents of PATH and PYTHONPATH, before they were modified by run-tests.py This will make it possible for tests to refer to the original contents of these variables if necessary. In particular, this is necessary for invoking the correct version of hg for examining the local repository (the mercurial repository itself, not the temporary test repositories). Various tests examine the local repository to check the file lists and contents of commit messages.

setup: prefer using the system hg to interact with the local repository Add a findhg() function that tries to be smarter about figuring out how to run hg for examining the local repository. It first tries running "hg" from the user's PATH, with the default HGRCPATH settings intact, but with HGPLAIN enabled. This will generally use the same version of mercurial and the same settings used to originally clone the repository, and should have a higher chance of working successfully than trying to run the hg script from the local repository. If that fails findhg() falls back to the existing behavior of running the local hg script.

setup: replace runhg() with an hgcommand helper class Replace the runhg() function with an hgcommand helper class. hgcommand has as run() function similar to runhg(), but no longer requires the caller to pass in the exact path to python and the hg script, and the environment settings for invoking hg. For now this diff contains no behavior changes, but in the future this will make it easier for the hgcommand helper class to more intelligently figure out the proper way to invoke hg.

setup: move environment computation into a helper function Add a helper function to compute the environment used for invoking mercurial, rather than doing this computation entirely at global scope. This will make it easier to do some subsequent refactoring.

setup: update runcmd() to also return the exit status Update the runcmd() helper function so it also returns the process exit status. This allows callers to more definitively determine if a command failed, rather than testing only for the presence of data on stderr. I don't expect this to have any behavioral changes for now: the commands invoked by setup generally should print data on stderr if and only if they failed.

setup: fail if we cannot determine the version number If running hg fails, exit the setup script unsuccessfully, rather than proceeding to use a bogus version of "+0-". Using an invalid version number causes various tests to fail later. Failing early makes it easier to identify the source of the problem. It is currently easy for setup.py to fail this way since it sets HGRCPTH to the empty string before running "hg", which may often disable extensions necessary to interact with the local repository.

smartset: fix generatorset.last() to not return the first element (issue5609)

strip: respect the backup option in stripcallback The backup option was mistakenly ignored. It should be respected. Thanks Martin von Zweigbergk for finding this out!

py3: use pycompat.bytestr() to convert str to bytes

py3: pass the memoryview object into bytes() to get the value

py3: use pycompat.bytestr instead of str

py3: use '%d' to convert integers to bytes

py3: slice over bytes to prevent getting it's ascii value

py3: use pycompat.strkwargs() to convert kwargs keys to str

py3: use r'' to prevent the addition of b'' by transformer There are cases in opts handling in debugcommands.py where we don't need to convert opts keys back to bytes as there are some handful cases and no other function using opts value. Using r'', we prevent the transformer to add a b'' which will keep the value str.

py3: use pycompat.byteskwargs() to convert kwargs' keys to bytes This is used where ever required like where kwargs are passed into ui.formatter(), scmutil.match() or cmdutil.openrevlog() which expects bytes.

tests: use cgienv to minimize environment setup at hgweb tests This patch follows other hgweb tests.

tests: avoid test failure for mangling path-like string by MSYS

py3: make sure commands name are bytes in tests

py3: add b'' to make the regex pattern bytes

py3: use hex() to convert the hash to bytes

py3: add b'' to make a triple quoted string bytes on Python 3 Transformer does not adds b'' in front of triple quoted strings to prevent converting docs to bytes.

py3: add tests to show `hg bookmarks` and `hg branches` work on Python 3

py3: fix kwargs handling for `hg bookmarks`

identify: provide changectx to templater

formatter: proxy fm.context() through converter Otherwise nested template formatter would not see the context objects. It's just a boolean flag now. We might want to change it to 'ctxs -> items' function so changectx attributes are populated automatically in JSON, but I'm not sure.

identify: change p1/p2 to a list of parents It makes sense because the nested data structure is a list of items.

scmutil: add a cleanupnodes method for developers It's now common that an old node gets replaced by zero or more new nodes, that could happen with amend, rebase, histedit, etc. And it's a common requirement to do bookmark movements, strip or obsolete nodes and even moving working copy parent. Previously, amend, rebase, history have their own logic doing the above. This patch is an attempt to unify them and future code. This enables new developers to be able to do "replace X with Y" thing correctly, without any knowledge about bookmarks, strip or obsstore. The next step will be migrating rebase to the new API, so it works inside a transaction, and its code could be simplified.

strip: add a delayedstrip method that works in a transaction For long, the fact that strip does not work inside a transaction and some code has to work with both obsstore and fallback to strip lead to duplicated code like: with repo.transaction(): .... if obsstore: obsstore.createmarkers(...) if not obsstore: repair.strip(...) Things get more complex when you want to call something which may call strip under the hood. Like you cannot simply write: with repo.transaction(): .... rebasemod.rebase(...) # may call "strip", so this doesn't work But you do want rebase to run inside a same transaction if possible, so the code may look like: with repo.transaction(): .... if obsstore: rebasemod.rebase(...) obsstore.createmarkers(...) if not obsstore: rebasemod.rebase(...) repair.strip(...) That's ugly and error-prone. Ideally it's possible to just write: with repo.transaction(): rebasemod.rebase(...) saferemovenodes(...) This patch is the first step towards that. It adds a "delayedstrip" method to repair.py which maintains a postclose callback in the transaction object.

workingfilectx: add audit() as a wrapper for wvfs.audit()

workingfilectx: add backgroundclose as a kwarg to write() This is necessary because some callers in merge.py pass backgroundclose=True when writing. As with previous changes in this series, this should be a no-op.

merge: change repo.wvfs.setflags calls to a new wctx[f].setflags function As with previous changes in this series, this should be a no-op.

merge: convert repo.wwrite() calls to wctx[f].write() As with the previous patch in this series, workingfilectx.write() is a direct call to repo.wwrite(), so this change should be a no-op.

merge: replace repo.wvfs.unlinkpath() with calls to wctx[f].remove() The code inside workingfilectx.remove() is a straight call to repo.wvfs.unlinkpath, so this should be a no-op.

merge: pass wctx to batchremove and batchget We would like to migrate direct calls of repo.wvfs/wwrite/wread/etc to a call on the relevant workingfilectx, both as a cleanup (to reduce the number of working copy functions on `repo`), and also to facilitate an in-memory merge that doesn't write to the working copy. In order to do that, the first step is to ensure we pass the target wctx around and perform our writes and reads on it. Later, this object might become a memctx.

revset: add depth limit to descendants() (issue5374) This is naive implementation using two-pass scanning. Tracking descendants isn't an easy problem if both start and stop depths are specified. It's impractical to remember all possible depths of each node while scanning from roots to descendants because the number of depths explodes. Instead, we could cache (min, max) depths as a good approximation and track ancestors back when needed, but that's likely to have off-by-one bug. Since this implementation appears not significantly slower, and is quite straightforward, I think it's good enough for practical use cases. The time and space complexity is O(n) ish. revisions: 0) 1-pass scanning with (min, max)-depth cache (worst-case quadratic) 1) 2-pass scanning (this version) repository: mozilla-central # descendants(0) (for reference) *) 0.430353 # descendants(0, depth=1000) 0) 0.264889 1) 0.398289 # descendants(limit(tip:0, 1, offset=10000), depth=1000) 0) 0.025478 1) 0.029099 # descendants(0, depth=2000, startdepth=1000) 0) painfully slow (due to quadratic backtracking of ancestors) 1) 1.531138

dagop: make walk direction switchable so it can track descendants # ancestors(tip) using hg repo 2) 0.068527 3) 0.069097

dagop: factor out generator of ancestor nodes # ancestors(tip) using hg repo 1) 0.068976 2) 0.068527

dagop: factor out pfunc from revancestors() generator This generator will be reused for tracking descendants with depth limit. # ancestors(tip) using hg repo 0) 0.065868 1) 0.068976