rust-nodemap: a method for full invalidation This will be used for exceptional operations, such as a `__delitem__` on the `MixedIndex` with Rust nodemap. In principle, `NodeTree` should also be able to forget an entry in an efficient way, by accepting to insert `Element::None` instead of only `Element::Rev(r)`, but that seems really overkill at this point. We need to support exceptional operations such as `__delitem__`, only for completeness of the revlog index as seen from Python. The Python callers don't seem to even really need it, deciding to drop the nodemap unconditionally at at higher level when calling `hg strip`. Also, `hg strip` is very costly for reasons that are unrelated to nodemap aspects. Differential Revision: https://phab.mercurial-scm.org/D8098

rust-nodemap: accounting for dead blocks By the very append-only nature of the `NodeTree`, inserting new blocks has the effect of making some of the older ones useless as they become unreachable. Therefore some automatic housekeeping will need to be provided. This is standard procedure in the word of databases, under names such as "repack" or "vacuum". The new `masked_readonly_blocks()` will provide callers with useful information to decide if the nodetree is ripe for repacking, but all the `NodeTree` can provide is how many blocks have been masked in the currently mutable part. Analysing the readonly part would be way too long to do it for each transaction and defeat the whole purpose of nodemap persistence. Serializing callers (from the Python layer) will get this figure before each extraction and maintain an aggregate counter of unreachable blocks separately. Note: at this point, the most efficient repacking is just to restart afresh with a full rescan. Differential Revision: https://phab.mercurial-scm.org/D8097

rust-nodemap: core implementation for shortest In this implementation, we just make `lookup()` return also the number of steps that have been needed to come to a conclusion from the nodetree data, and `validate_candidate()` takes care of the special cases related to `NULL_NODE`. This way of doing minimizes code duplication, but it means that the comparatively slower finding of first non zero nybble will run for all calls to `find()` where it is not needed. Still running on the file generated for the mozilla-central repository, it seems indeed that we now get more ofter 320 ns than 310. The odds that this could have a significant impact on real life Mercurial performance are still looking low. Let's wait for actual benchmark runs to see if an optimization is needed here. Differential Revision: https://phab.mercurial-scm.org/D7819

rust-nodemap: special case for prefixes of NULL_NODE We have to behave as though NULL_NODE was stored in the node tree, although we don't store it. Differential Revision: https://phab.mercurial-scm.org/D7798

rust-nodemap: pure Rust example To run, use `cargo run --release --example nodemap` This demonstrates that simple scenarios entirely written in Rust can content themselves with `NodeTree<T>`. The example mmaps both the nodemap file and the changelog index. We had of course to include an implementation of `RevlogIndex` directly, which isn't much at this stage. It felt a bit prematurate to include it in the lib. Here are some first performance measurements, obtained with this example, on a clone of mozilla-central with 440000 changesets: (create) Nodemap constructed in RAM in 153.638305ms (query CAE63161B68962) found in 22.362us: Ok(Some(269489)) (bench) Did 3 queries in 36.418µs (mean 12.139µs) (bench) Did 50 queries in 184.318µs (mean 3.686µs) (bench) Did 100000 queries in 31.053461ms (mean 310ns) To be fair, even between bench runs, results tend to depend whether the file is still in kernel caches, and it's not so easy to get back to a real cold start. The worst we've seen was in the 50us ballpark. In any busy server setting, the pages would always be in RAM. We hope it's good enough not to be significantly slower on any concrete Mercurial operation than the C nodetree when fully in RAM, and of course this implementation has the serious headstart advantage of persistence. Differential Revision: https://phab.mercurial-scm.org/D7797

rust-nodemap: input/output primitives These allow to initiate a `NodeTree` from an immutable opaque sequence of bytes, which could be passed over from Python (extracted from a `PyBuffer`) or directly mmapped from a file. Conversely, we can consume a `NodeTree`, extracting the bytes that express what has been added to the immutable part, together with the original immutable part. This gives callers the choice to start a new Nodetree. After writing to disk, some would prefer to reread for best guarantees (very cheap if mmapping), some others will find it more convenient to grow the memory that was considered immutable in the `NodeTree` and continue from there. This is enough to build examples running on real data and start gathering performance hints. Differential Revision: https://phab.mercurial-scm.org/D7796

pyoxidizer: allow extensions to be loaded from the file system It seems that setting this config is all that's needed to be able to load extensions from the file system (which we clearly want). Thanks for making this work, Gregory Szorc!. Differential Revision: https://phab.mercurial-scm.org/D8122

graft: always allow hg graft --base . (issue6248) `hg graft --base . -r abc` is rejected before this change with a "nothing to merge" error, if `abc` does not descend from `.`. This looks like an artifact of the implementation rather than intended behavior. It makes perfect sense to apply the diff between `.` and `abc` to the working copy (i.e. degenerate into `hg revert`), regardless of what `abc` is. Differential Revision: https://phab.mercurial-scm.org/D8127

revlog-compression: update the config to be a list format.revlog-compression is now a list of engine, the first supported one is to be used. Doing this have several benefits: 1) this is fully backward compatible, config using a single entry will be read as a single item list, not changing any behavior. 2) This open the way to use zstd by default without impacting platform were it is not available. This will be done in a later changesets. Using zstd provide a significant performance boost explained in : bb271ec2fbfb. However zstd is not available in some cases, A notable example is the `--pure` version of Mercurial which doesn't come with zstd support. Differential Revision: https://phab.mercurial-scm.org/D8148

remotefilelog: add 'changelog' arg to shallowcg1packer.generate (issue6269) This cause traceback on widening using narrow extension when remotefilelog is enabled. Differential Revision: https://phab.mercurial-scm.org/D8134

drawdag: abide by new createmarkers() API The `obsolete.createmarkers()` API was changed in 6335c0de80fa (obsolete: allow multiple predecessors in createmarkers, 2018-09-22) to prefer its precursors input to be a tuple instead of a single precursor. Let's fix `drawdag.py` to comply. Differential Revision: https://phab.mercurial-scm.org/D8149

lfutil: provide a hint if the largefiles/lfs cache path cannot be determined A coworker hit this error using an LFS repo in a stripped down environment, and didn't know how to resolve it. The final conditional is a bit fast and loose, but there is currently no 'posix' test in hghave, and it doesn't seem like it's worth adding for this since I think Windows is the only non-POSIX platform we run tests on. Differential Revision: https://phab.mercurial-scm.org/D8145

setup: exclude the __index__ module from itself when generating This module is generated on Windows to hold all of the extension names and the help summaries, so that they are discoverable inside the py2exe zipfile. The problem is this file is generated by dumping the disabled list, and that list comes from walking the filesystem. So once an install from source into a virtualenv created this module, then next build from source from that virtualenv would also see __index__.py in the filesystem, and include it. Clearly that's wrong because this isn't a real extension, so just filter it from the list when generating it. The Mercurial installer was unaffected by this, but the TortoiseHg package was. In the final package, `hg help -v extensions` and the panel of extensions both showed it. Differential Revision: https://phab.mercurial-scm.org/D8142

tests: stabilize test-amend.t on Windows If $TESTTMP isn't quoted in this context, it ends up like `C:Temphgtests.pikkoxchild1test-amend.t-obsstore-off`. Differential Revision: https://phab.mercurial-scm.org/D8144

tests: replace truncate(1) with inline python MSYS doesn't have truncate(1) installed by default, and FreeBSD looked unhappy with the arguments provided. Differential Revision: https://phab.mercurial-scm.org/D8147

tests: stabilize test-rename-merge2.t on Windows I have no idea why, but this shifted in b4057d001760. Differential Revision: https://phab.mercurial-scm.org/D8146

merge with stable

py3: fix EOL detection in commandserver.channeledinput This breaks TortoiseHg's email preview which sends b'\n' while readline request is issued and the loop never ends. Spotted by Matt Harbison.

bookmarks: prevent pushes of divergent bookmarks (foo@remote) Before this change, such bookmarks are write-only: a client can push them but not pull/read them. And because these bookmark can't be read, even pushes are limited (for instance trying to delete such a bookmark fails with a vanilla client because the client thinks the bookmark is neither on the local nor the remote). This change makes the server refuses such bookmarks, and for earlier errors, makes the client refuse to send them. I think the change of behavior is acceptable because I think this is a bug in push/pull, and I don't think we change the behavior of `hg unbundle`, because it doesn't seem that `hg bundle` ever store bookmarks (and even if it did, it would seem weird anyway to try to send divergent bookmarks). Differential Revision: https://phab.mercurial-scm.org/D8117

bookmarks: refactor in preparation for next commit Differential Revision: https://phab.mercurial-scm.org/D8116

bookmarks: avoid traceback when two pushes race to delete the same bookmark `hg push -f -B remote-only-bookmark` can raise server-side in `bookmarks._del` (specifically in `self._refmap.pop(mark)`), if the remote-only bookmark got deleted concurrently. Fix this by simply not deleting the non-existent bookmark in that case. For avoidance of doubt, refusing to delete a bookmark that doesn't exist when the push starts is taking care of elsewhere; no change of behavior there. Differential Revision: https://phab.mercurial-scm.org/D8124

relnotes: add entry about previous `hg recover` change Differential Revision: https://phab.mercurial-scm.org/D8123

darwin: add another preemptive gui() call when using chg Changeset a89381e04c58 added this gui() call before background forks, and Google's extensions do background forks on essentially every invocation for logging purposes. The crash is reliably (though not 100%) reproducible without this change when running `HGPLAIN=1 chg status` in one of our repos. With this fix, I haven't been able to trigger the crash anymore. Differential Revision: https://phab.mercurial-scm.org/D8141

copy: add experimental support for marking committed copies The simplest way I'm aware of to mark a file as copied/moved after committing is this: hg uncommit --keep <src> <dest> # <src> needed for move, but not copy hg mv --after <src> <dest> hg amend This patch teaches `hg copy` a `--at-rev` argument to simplify that into: hg copy --after --at-rev . <src> <dest> In addition to being simpler, it doesn't touch the working copy, so it can easily be used even if the destination file has been modified in the working copy. Differential Revision: https://phab.mercurial-scm.org/D8035

copy: move argument validation a little earlier Argument validation is usually done early and I will want it done before some code that I'm about to add. Differential Revision: https://phab.mercurial-scm.org/D8033

copy: add experimetal support for unmarking committed copies The simplest way I'm aware of to unmark a file as copied after committing is this: hg uncommit --keep <dest> hg forget <dest> hg add <dest> hg amend This patch teaches `hg copy --forget` a `-r` argument to simplify that into: hg copy --forget --at-rev . <dest> In addition to being simpler, it doesn't touch the working copy, so it can easily be used even if the destination file has been modified in the working copy. I'll teach `hg copy` without `--forget` to work with `--at-rev` next. Differential Revision: https://phab.mercurial-scm.org/D8030

copy: add option to unmark file as copied To unmark a file as copied, the user currently has to do this: hg forget <dest> hg add <dest> The new command simplifies that to: hg copy --forget <dest> That's not a very big improvement, but I'm planning to also teach `hg copy [--forget]` a `--at-rev` argument for marking/unmarking copies after commit (usually with `--at-rev .`). Differential Revision: https://phab.mercurial-scm.org/D8029

nodemap: introduce an option to use mmap to read the nodemap mapping The performance and memory benefit is much greater if we don't have to copy all the data in memory for each information. So we introduce an option (on by default) to read the data using mmap. This changeset is the last one definition the API for index support nodemap data. (they have to be able to use the mmaping). Below are some benchmark comparing the best we currently have in 5.3 with the final step of this series (using the persistent nodemap implementation in Rust). The benchmark run `hg perfindex` with various revset and the following variants: Before: * do not use the persistent nodemap * use the CPython implementation of the index for nodemap * use mmapping of the changelog index After: * use the MixedIndex Rust code, with the NodeTree object for nodemap access (still in review) * use the persistent nodemap data from disk * access the persistent nodemap data through mmap * use mmapping of the changelog index The persistent nodemap greatly speed up most operation on very large repositories. Some of the previously very fast lookup end up a bit slower because the persistent nodemap has to be setup. However the absolute slowdown is very small and won't matters in the big picture. Here are some numbers (in seconds) for the reference copy of mozilla-try: Revset Before After abs-change speedup -10000: 0.004622 0.005532 0.000910 × 0.83 -10: 0.000050 0.000132 0.000082 × 0.37 tip 0.000052 0.000085 0.000033 × 0.61 0 + (-10000:) 0.028222 0.005337 -0.022885 × 5.29 0 0.023521 0.000084 -0.023437 × 280.01 (-10000:) + 0 0.235539 0.005308 -0.230231 × 44.37 (-10:) + :9 0.232883 0.000180 -0.232703 ×1293.79 (-10000:) + (:99) 0.238735 0.005358 -0.233377 × 44.55 :99 + (-10000:) 0.317942 0.005593 -0.312349 × 56.84 :9 + (-10:) 0.313372 0.000179 -0.313193 ×1750.68 :9 0.316450 0.000143 -0.316307 ×2212.93 On smaller repositories, the cost of nodemap related operation is not as big, so the win is much more modest. Yet it helps shaving a handful of millisecond here and there. Here are some numbers (in seconds) for the reference copy of mercurial: Revset Before After abs-change speedup -10: 0.000065 0.000097 0.000032 × 0.67 tip 0.000063 0.000078 0.000015 × 0.80 0 0.000561 0.000079 -0.000482 × 7.10 -10000: 0.004609 0.003648 -0.000961 × 1.26 0 + (-10000:) 0.005023 0.003715 -0.001307 × 1.35 (-10:) + :9 0.002187 0.000108 -0.002079 ×20.25 (-10000:) + 0 0.006252 0.003716 -0.002536 × 1.68 (-10000:) + (:99) 0.006367 0.003707 -0.002660 × 1.71 :9 + (-10:) 0.003846 0.000110 -0.003736 ×34.96 :9 0.003854 0.000099 -0.003755 ×38.92 :99 + (-10000:) 0.007644 0.003778 -0.003866 × 2.02 Differential Revision: https://phab.mercurial-scm.org/D7894

rust-dirstatemap: directly return `non_normal` and `other_entries` This cleans up the interface which I previously thought needed to be uglier than in reality. No performance difference, simple refactoring. Differential Revision: https://phab.mercurial-scm.org/D8121

copy: rename `wctx` to `ctx` since it will not necessarily be working copy Differential Revision: https://phab.mercurial-scm.org/D8032

copy: rewrite walkpat() to depend less on dirstate I want to add a `hg cp/mv -r <rev>` option to mark files as copied/moved in an existing commit (amending that commit). The code needs to not depend on the dirstate for that. Differential Revision: https://phab.mercurial-scm.org/D8031

merge with stable

pathutil: resurrect comment about path auditing order It was removed at 51c86c6167c1, but expensive symlink traversal isn't the only reason we should walk path components from the root.

rust-dirstatemap: remove additional lookup in dirstate.matches We use the same trick as the Python implementation Differential Revision: https://phab.mercurial-scm.org/D7119

rust-nodemap: insert method In this implementation, we are in direct competition with the C version: this Rust version will have a clear startup advantage because it will read the data from disk, but the insertion happens all in memory for both. Differential Revision: https://phab.mercurial-scm.org/D7795

recover: don't verify by default The reason is: - it's not that hard to trigger interrupted transactions: just run out of disk space - it takes forever to verify on large repos. Before --no-verify, I told people to C-c hg recover when the progress bar showed up. Now I tell them to pass --no-verify. - I don't remember a single case where the verification step was useful This is technically a change of behavior. Perhaps this would be better suited for tweakdefaults? Differential Revision: https://phab.mercurial-scm.org/D7972

context: use manifest.find() instead of two separate calls I noticed this while debugging an extension that's implementing the manifest interface. Always nice to save a function call. Differential Revision: https://phab.mercurial-scm.org/D8109

rust-matchers: implement `visit_children_set` for `FileMatcher` As per the removed inline comment, this will become useful in a future patch in this series as the `IncludeMatcher` is introduced. Differential Revision: https://phab.mercurial-scm.org/D7914

manifest: move matches method to be outside the interface In order to adequately smoke out any legacy consumers of the method, we rename it to _matches so it's clear that it's class-private. To my amazement, all consumers of this method really only wanted matching filenames, not a full filtered manifest. Differential Revision: https://phab.mercurial-scm.org/D8085

tags: use modern // operator for division Fixes a test on Python 3. # skip-blame only correcting a division operator, not a substantive change Differential Revision: https://phab.mercurial-scm.org/D8108

tags: fix some type confusion exposed in python 3 # skip-blame just b-prefix and %-format cleanup, no meaningful change Differential Revision: https://phab.mercurial-scm.org/D8107

rebase: remove some now-unused parent arguments Differential Revision: https://phab.mercurial-scm.org/D7829

rebase: remove some redundant setting of dirstate parents Since we're now setting the dirstate parents to its correct values from the beginning (right after `merge.update()`), we usually don't need to set them again before committing. The only case we need to care about is when committing collapsed commits. So we can remove the `setparents()` calls just before committing and add one only for the collapse case. Differential Revision: https://phab.mercurial-scm.org/D7828

rebase: don't use rebased node as dirstate p2 (BC) When rebasing a node, we currently use the rebased node as p2 in the dirstate until just before we commit it (we then change to the desired parents). This p2 is visible to the user when the rebase gets interrupted because of merge conflicts. That can be useful to the user as a reminder of which commit is currently being rebased, but I believe it's incorrect for a few reasons: * I think the dirstate parents should be the ones that will be set when the commit is created. * I think having two parents means that you're merging those two commits, but when rebasing, you're generally grafting, not merging. * When rebasing a merge commit, we should use the two desired parents as dirstate parents (and we clearly can't have the rebased node as a third dirstate parent). * `hg graft` (and `hg update --merge`) sets only one parent and `hg rebase` should be consistent with that. I realize that this is a somewhat large user-visible change, but I think it's worth it because it will simplify things quite a bit. Differential Revision: https://phab.mercurial-scm.org/D7827

rebase: stop relying on having two parents to resume rebase I'm about to make it so we don't have two parents when a rebase is interrupted (unless we're just rebasing on a merge commit). The code for detecting if we're resuming a rebase relied on having two parents, so this patch rewrites that to instead set a boolean when we resume. Note that `self.resume` in the new condition implies `not self.inmemory` (rebase cannot be resumed in memory), so that's why that part can be omitted. Differential Revision: https://phab.mercurial-scm.org/D7826

graphlog: use '%' for other context in merge conflict This lets the user more easily find the commit that is involved in the conflict, such as the source of `hg update -m` or the commit being grafted by `hg graft`. Differential Revision: https://phab.mercurial-scm.org/D8043

tests: add `hg log -G` output when there are merge conflicts The next commit will change the behavior for these. I've used slightly different commands in the different tests to match the surrounding style. Differential Revision: https://phab.mercurial-scm.org/D8042

revset: add a revset for parents in merge state This may be particularly useful soon, when I'm going to change how `hg rebase` sets its parents during conflict resolution. Differential Revision: https://phab.mercurial-scm.org/D8041

tests: add test of rebase with conflict in merge commit It doesn't seem like we had any tests of this. I think it's pretty weird that the two parents we're merging are not the working copy parents during the conflict resolution. Differential Revision: https://phab.mercurial-scm.org/D7824

rebase: always be graft-like, not merge-like, also for merges Rebase works by updating to a commit and then grafting changes on top. However, before this patch, it would actually merge in changes instead of grafting them in in some cases. That is, it would use the common ancestor as base instead of using one of the parents. That seems wrong to me, so I'm changing it so `defineparents()` always returns a value for `base`. This fixes the bad behavior in test-rebase-newancestor.t, which was introduced in 65f215ea3e8e (tests: add test for rebasing merges with ancestors of the rebase destination, 2014-11-30). The difference in test-rebase-dest.t is because the files in the tip revision were A, D, E, F before this patch and A, D, F, G after it. I think both files should ideally be there. Differential Revision: https://phab.mercurial-scm.org/D7907

nodemap: update the index with the newly written data (when appropriate) If we are to use mmap to read the nodemap data, and if the python code is responsible for the IO, we need to refresh the mmap after each write and provide it back to the index. We start this dance without the mmap first. Differential Revision: https://phab.mercurial-scm.org/D7893

nodemap: never read more than the expected data amount Since we are tracking this number we can use it to detect corrupted rawdata file and to only read the correct amount of data when possible. Differential Revision: https://phab.mercurial-scm.org/D7892

nodemap: write new data from the expected current data length If the amount of data in the file exceed the expect amount, we will overwrite the extra data. This is a simple way to be safer. Differential Revision: https://phab.mercurial-scm.org/D7891

nodemap: double check the source docket when doing incremental update In theory, the index will have the information we expect it to have. However by security, it seems safer to double check that the incremental data are generated from the data currently on disk. Differential Revision: https://phab.mercurial-scm.org/D7890

nodemap: track the total and unused amount of data in the rawdata file We need to keep that information around: * total data will allow transaction to start appending new information without confusing other reader. * unused data will allow to detect when we should regenerate new rawdata file. Differential Revision: https://phab.mercurial-scm.org/D7889

nodemap: track the maximum revision tracked in the nodemap We need a simple way to detect when the on disk data contains less revision than the index we read from disk. The docket file is meant for this, we just had to start tracking that data. We should also try to detect strip operation, but we will deal with this in later changesets. Right now we are focusing on defining the API for index supporting persistent nodemap. Differential Revision: https://phab.mercurial-scm.org/D7888

nodemap: add a flag to dump the details of the docket We are about to add more information to the docket. We first introduce a way to debug its content. Differential Revision: https://phab.mercurial-scm.org/D7887

nodemap: introduce append-only incremental update of the persistent data Rewriting the full nodemap for each transaction has a cost we would like to avoid. We introduce a new way to write persistent nodemap data by adding new information at the end for file. Any new and updated block as added at the end of the file. The last block is the new root node. With this method, some of the block already on disk get "dereferenced" and become dead data. In later changesets, We'll start tracking the amount of dead data to eventually re-generate a full nodemap. Differential Revision: https://phab.mercurial-scm.org/D7886

shelve: fix ordering of merge labels Differential Revision: https://phab.mercurial-scm.org/D8140

shelve: add test clearly demonstrating that the conflict labels are backwards Differential Revision: https://phab.mercurial-scm.org/D8139

import: don't ignore `--secret` when `--bypass` is specified Differential Revision: https://phab.mercurial-scm.org/D8126

phabricator: fix a phabsend crash when processing a renamed binary This was a trivial fix, and some more tests are added to cover binary files. Since the old filecontext is passed in, the old name is still available. But I noticed some weirdness around what it marked as binary and not, and what is viewable in Phabricator. Those things have been flagged, and will probably take some digging. Differential Revision: https://phab.mercurial-scm.org/D8133

test: pin the number of CPU for issue4074 tests On machine with an hundreds of CPUs, the "user" CPU time reported can be inflated by the status steps. Since the test especially focus on the diff computation, we restrict the number of CPU to avoid potential issues. Differential Revision: https://phab.mercurial-scm.org/D8112

rust-dirstatemap: add `NonNormalEntries` class This fix introduces the same encapsulation as the `copymap`. There is no easy way of doing this any better for now. `hg up -r null && time HGRCPATH= HGMODULEPOLICY=rust+c hg up tip` on Mozilla Central, (not super recent, but it doesn't matter): Before: 7:44,08 total After: 1:03,23 total Pretty brutal regression! This is a graft on stable of cf1f8660e568 Differential Revision: https://phab.mercurial-scm.org/D8111