tests: don't be as verbose in wireprotov2 tests I don't think that printing low-level I/O and frames is beneficial to testing command-level functionality. Protocol-level testing, yes. But command-level functionality shouldn't care about low-level details in most cases. This output makes tests more verbose and harder to read. It also makes them harder to maintain, as you need to glob over various dynamic width fields. Let's remove these low-level details from many of the wireprotov2 tests. Differential Revision: https://phab.mercurial-scm.org/D4861

repository: define and use revision flag constants Revlogs have a per-revision 2 byte field holding integer flags that define how revision data should be interpreted. For historical reasons, these integer values are sent verbatim on the wire protocol as part of changegroup data. From a semantic standpoint, the flags that go out over the wire are different from the flags stored internally by revlogs. Failure to establish this semantic distinction creates unwanted strong coupling between revlog's internals and the wire protocol. This commit establishes new constants on the repository module that define the revision flags used by the wire protocol (and by some internal storage APIs, sadly). The changegroups internals documentation has been updated to document them explicitly. Various references throughout the repo now use the repository constants instead of the revlog constants. This is done to make it clear that we're operating on generic revision data and this isn't tied to revlogs. Differential Revision: https://phab.mercurial-scm.org/D4860

context: reverse conditional branch order in introrev Positive logic will be simpler to follow. It will help to clarify coming refactoring.

context: drop a redundant fast path in introrev Now that _adjustlinkrev fast path this case itself, we no longer need an extra conditional. A nice side effect is that we are no longer calling `self.rev()`. In case where `_descendantrev` is set, calling `self.rev` will trigger a potentially expensive `_adjustlinkrev` call. So blindly calling `self.rev()` to avoid another `_adjustlinkrev` call can be counterproductive. Note that `_descendantrev` is currently never taken into account in `introrev` so far which is wrong. We'll fix that in changeset later in this series.

context: fast path linkrev adjustement in trivial case If the search starts from the linkrev, there is nothing to adjust.

url: allow to configure timeout on http connection By default, httplib.HTTPConnection opens connection with no timeout. If the server is hanging, Mercurial will wait indefinitely. This may be an issue for automated scripts. Differential Revision: https://phab.mercurial-scm.org/D4878

obsolete: explicitly track folds inside the markers We now record information to be able to recognize "fold" event from obsolescence markers. To do so, we track the following pieces of information: a) a fold ID. Unique to that fold (per successor), b) the number of predecessors, c) the index of the predecessor in that fold. We will now be able to create an algorithm able to find "predecessorssets". We now store this data in the generic "metadata" field of the markers. Updating the format to have a more compact storage for this would be useful. This way of tracking a fold through multiple markers could be applied to split too. This would have two advantages: 1) We get a simpler format, since number of successors is limited to [0-1]. 2) We can better deal with situations where only some of the split successors are pushed to a remote repository. We should look into the relevance of such a change before updating the on-disk format. note: unlike splits, folds do not have to deal with cases where only some of the markers have been synchronized. As they all share the same successor changesets, they are all relevant to the same nodes.

cleanupnodes: update comment to drop mention of filtering Since changeset 1857f50a9643 drop the filtering, we should not longer mention it in code comment.

treemanifests: remove _loadalllazy when doing copies 'before' here is https://phab.mercurial-scm.org/D4845 (not the committed/rebased version) diff --git: repo | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before ------+---+---+------------------------+-----------------------+------------ m-u | | | 1.329 s +- 0.011 s | 1.320 s +- 0.010 s | 99.3% m-u | | x | 1.316 s +- 0.005 s | 1.334 s +- 0.018 s | 101.4% m-u | x | | 1.330 s +- 0.021 s | 1.322 s +- 0.005 s | 99.4% m-u | x | x | 87.2 ms +- 0.7 ms | 86.9 ms +- 1.5 ms | 99.7% l-d-r | | | 203.3 ms +- 7.8 ms | 199.4 ms +- 1.8 ms | 98.1% l-d-r | | x | 204.6 ms +- 2.8 ms | 201.7 ms +- 2.1 ms | 98.6% l-d-r | x | | 90.5 ms +- 11.0 ms | 86.2 ms +- 1.0 ms | 95.2% l-d-r | x | x | 66.3 ms +- 2.0 ms | 66.4 ms +- 0.9 ms | 100.2% diff -c . --git: repo | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before ------+---+---+------------------------+-----------------------+------------ m-u | | | 239.4 ms +- 2.0 ms | 241.7 ms +- 4.6 ms | 101.0% m-u | | x | 128.9 ms +- 1.9 ms | 130.9 ms +- 7.7 ms | 101.6% m-u | x | | 241.1 ms +- 1.6 ms | 240.1 ms +- 1.4 ms | 99.6% m-u | x | x | 133.4 ms +- 1.5 ms | 133.4 ms +- 1.2 ms | 100.0% l-d-r | | | 84.3 ms +- 1.5 ms | 83.5 ms +- 1.0 ms | 99.1% l-d-r | | x | 200.9 ms +- 6.3 ms | 203.0 ms +- 4.4 ms | 101.0% l-d-r | x | | 108.1 ms +- 1.4 ms | 108.7 ms +- 2.1 ms | 100.6% l-d-r | x | x | 190.2 ms +- 4.8 ms | 191.6 ms +- 2.0 ms | 100.7% rebase -r . --keep -d .^^: repo | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before ------+---+---+------------------------+-----------------------+------------ m-u | | | 5.655 s +- 0.029 s | 5.640 s +- 0.036 s | 99.7% m-u | | x | 5.813 s +- 0.038 s | 5.773 s +- 0.028 s | 99.3% m-u | x | | 5.593 s +- 0.043 s | 5.589 s +- 0.028 s | 99.9% m-u | x | x | 648.2 ms +- 19.2 ms | 637.3 ms +- 27.7 ms | 98.3% l-d-r | | | 673.3 ms +- 8.0 ms | 673.2 ms +- 6.8 ms | 100.0% l-d-r | | x | 6.583 s +- 0.030 s | 5.721 s +- 0.028 s | 86.9% <-- l-d-r | x | | 277.8 ms +- 6.7 ms | 276.0 ms +- 2.7 ms | 99.4% l-d-r | x | x | 1.692 s +- 0.013 s | 720.9 ms +- 13.3 ms | 42.6% <-- status --change . --copies: repo | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before ------+---+---+------------------------+-----------------------+------------ m-u | | | 220.9 ms +- 1.6 ms | 219.9 ms +- 2.2 ms | 99.5% m-u | | x | 109.2 ms +- 1.0 ms | 109.4 ms +- 0.8 ms | 100.2% m-u | x | | 222.6 ms +- 1.7 ms | 221.4 ms +- 2.1 ms | 99.5% m-u | x | x | 113.4 ms +- 0.5 ms | 113.1 ms +- 1.1 ms | 99.7% l-d-r | | | 82.1 ms +- 1.7 ms | 82.1 ms +- 1.2 ms | 100.0% l-d-r | | x | 199.8 ms +- 4.0 ms | 200.7 ms +- 3.6 ms | 100.5% l-d-r | x | | 85.4 ms +- 1.5 ms | 85.2 ms +- 0.3 ms | 99.8% l-d-r | x | x | 202.6 ms +- 4.4 ms | 208.0 ms +- 4.0 ms | 102.7% status --copies: repo | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before ------+---+---+------------------------+-----------------------+------------ m-u | | | 1.941 s +- 0.014 s | 1.930 s +- 0.009 s | 99.4% m-u | | x | 1.924 s +- 0.007 s | 1.950 s +- 0.010 s | 101.4% m-u | x | | 1.959 s +- 0.085 s | 1.926 s +- 0.009 s | 98.3% m-u | x | x | 96.2 ms +- 1.0 ms | 96.4 ms +- 0.7 ms | 100.2% l-d-r | | | 604.4 ms +- 10.6 ms | 602.6 ms +- 7.1 ms | 99.7% l-d-r | | x | 605.7 ms +- 4.1 ms | 607.4 ms +- 6.1 ms | 100.3% l-d-r | x | | 182.4 ms +- 1.2 ms | 183.4 ms +- 1.2 ms | 100.5% l-d-r | x | x | 150.8 ms +- 2.0 ms | 150.6 ms +- 1.0 ms | 99.9% update $rev^; ~/src/hg/hg{hg}/hg update $rev: repo | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before ------+---+---+------------------------+-----------------------+------------ m-u | | | 3.185 s +- 0.027 s | 3.181 s +- 0.017 s | 99.9% m-u | | x | 3.028 s +- 0.021 s | 2.954 s +- 0.010 s | 97.6% m-u | x | | 3.168 s +- 0.010 s | 3.175 s +- 0.023 s | 100.2% m-u | x | x | 317.5 ms +- 3.5 ms | 313.2 ms +- 2.9 ms | 98.6% l-d-r | | | 456.2 ms +- 10.6 ms | 454.4 ms +- 5.8 ms | 99.6% l-d-r | | x | 9.236 s +- 0.063 s | 757.9 ms +- 9.2 ms | 8.2% <-- l-d-r | x | | 257.6 ms +- 2.3 ms | 261.2 ms +- 1.7 ms | 101.4% l-d-r | x | x | 1.614 s +- 0.013 s | 478.0 ms +- 14.3 ms | 29.6% <-- Differential Revision: https://phab.mercurial-scm.org/D4875

treemanifests: store whether a lazydirs entry needs copied after materializing Due to the way that things like manifestlog.get caches its values, without making a copy (if necessary) after calling readsubtree(), we might end up adjusting the state of the same object on different contexts, breaking things like dirty state tracking (and probably other things). Differential Revision: https://phab.mercurial-scm.org/D4874

treemanifests: extract _loaddifflazy from _diff, use in _filesnotin Differential Revision: https://phab.mercurial-scm.org/D4873

identify: show remote bookmarks in `hg id url -Tjson -B` I didn't display bookmarks when `default and not ui.quiet`: it seems strange for templates to depend on --id or -q, and it would take more code for `hg id url -T {node}` to not request remote bookmarks. An alternative I thought of was providing lazy data to the formatter, `fm.data(bookmarks=lambda: fm.formatlist(getbms(), name='bookmark'))`. The plainformatter would naturally not compute it, the templateformatter would compute only what it needs, and the other ones would compute everything, but that's not supported (or I don't see how), so I abandoned this idea. Differential Revision: https://phab.mercurial-scm.org/D4872

showstack: also handle SIGALRM This is looking *very* handy when debugging mysterious hangs in a test: you can wrap a hanging invocation in `perl -e 'alarm shift @ARGV; exec @ARGV' 1` for example, a hanging `hg pull` becomes `perl -e 'alarm shift @ARGV; exec @ARGV' 1 hg pull` where the `1` is the timeout in seconds before the process will be hit with SIGALRM. After making that edit to the test file, you can then use --extra-config-opt on run-tests.py to globaly enable showstack during the test run, so you'll get full stack traces as you force your hg to exit. I wonder (but only a little, not enough to take action just yet) if we should wire up some scaffolding in run-tests itself to automatically wrap all commands in alarm(3) somehow to avoid hangs in the future? Differential Revision: https://phab.mercurial-scm.org/D4870

exchangev2: add progress bar around manifest scanning This can take a long time on large repositories. Let's add a progress bar so we don't have long periods where it isn't obvious what is going on. Differential Revision: https://phab.mercurial-scm.org/D4859

httppeer: report http statistics Now that keepalive.py records HTTP request count and the number of bytes sent and received as part of performing those requests, we can easily print a report on the activity when closing a peer instance! Exact byte counts are globbed in tests because they are influenced by non-deterministic things, such as hostnames and port numbers. Plus, the exact byte count isn't too important anyway. I feel obliged to note that printing the byte count could have security implications. e.g. if sending a password via HTTP basic auth, the length of that password will influence the byte count and the reporting of the byte count could be a side-channel leak of the password length. I /think/ this is beyond our threshold for concern. But if we think it poses a problem, we can teach the byte count logging code to e.g. ignore sensitive HTTP request headers. We could also consider not reporting the byte count of request headers altogether. But since the wire protocol uses HTTP headers for sending command arguments, it is kind of important to report their size. Differential Revision: https://phab.mercurial-scm.org/D4858

keepalive: track number of bytes received from an HTTP response We also bubble the byte count up to the HTTPConnection instance and its parent opener at read time. Unlike sending, there isn't a clear "end of response" signal we can intercept to defer updating the accounting. Differential Revision: https://phab.mercurial-scm.org/D4857

keepalive: track request count and bytes sent I want wire protocol interactions to report the number of requests made and bytes transferred. This commit teaches the very low-level custom HTTPConnection class to track the number of bytes sent to the socket. This may vary from the number of bytes that go on the wire due to e.g. TLS. That's OK. KeepAliveHandler is taught to track the total number of requests and total number of bytes sent across all requests. Differential Revision: https://phab.mercurial-scm.org/D4856

url: have httpsconnection inherit from our custom HTTPConnection This will ensure that any customizations we perform to HTTPConnection will be available to httpsconnection. Differential Revision: https://phab.mercurial-scm.org/D4855

cborutil: change buffering strategy Profiling revealed that we were spending a lot of time on the line that was concatenating the old buffer with the incoming data when attempting to decode long byte strings, such as manifest revisions. Essentially, we were feeding N chunks of size len(X) << len(Y) into decode() and continuously allocating a new, larger buffer to hold the undecoded input. This created substantial memory churn and slowed down execution. Changing the code to aggregate pending chunks in a list until we have enough data to fully decode the next atom makes things much more efficient. I don't have exact data, but I recall the old code spending >1s on manifest fulltexts from the mozilla-unified repo. The new code doesn't significantly appear in profile output. Differential Revision: https://phab.mercurial-scm.org/D4854

cleanup: some Yoda conditions, this patch removes It seems the factor 20 is less than the frequency of " < \d" compared to " \d > ". Differential Revision: https://phab.mercurial-scm.org/D4862

streamclone: don't support stream clone unless repo feature present This change means custom repository types must opt in to enabling stream clone. This seems reasonable, as stream clones are a very low-level feature that has historically assumed the use of revlogs and the layout of .hg/ that they entail. Differential Revision: https://phab.mercurial-scm.org/D4853

localrepo: add repository feature when repo can be stream cloned Right now, the wire protocol server assumes all repository objects can be stream cloned (unless the stream clone feature is disabled via config option). But not all storage backends or repository objects may support stream clone. This commit defines a repository feature denoting whether stream clone is supported. The feature is defined for revlog-based repositories, which should currently be "all repositories." Differential Revision: https://phab.mercurial-scm.org/D4852

wireprotov2: client support for following content redirects And with the server actually sending content redirects, it is finally time to implement client support for following them! When a redirect response is seen, we wait until all data for that request has been received (it should be nearly immediate since no data is expected to follow the redirect message). Then we use a URL opener to make a request. We stuff that response into the client handler and construct a new response object to track it. When readdata() is called for servicing requests, we attempt to read data from the first redirected response. During data reading, data is processed similarly to as if it came from a frame payload. The existing test for the functionality demonstrates the client transparently following the redirect and obtaining the command response data from an alternate URL! There is still plenty of work to do here, including shoring up testing. I'm not convinced things will work in the presence of multiple redirect responses. And we don't yet implement support for integrity verification or configuring server certificates to validate the connection. But it's a start. And it should enable us to start experimenting with "real" caches. Differential Revision: https://phab.mercurial-scm.org/D4778

wireprotov2: server support for sending content redirects A "content redirect" can be sent in place of inline response content. In terms of code, we model a content redirect as a special type of response object holding the attributes describing that redirect. Sending a content redirect thus becomes as simple as the object emission layer sending an instance of that type. A cacher using externally-addressable content storage could replace the outgoing object stream with an object advertising its location. The bulk of the code in this commit is teaching the output layer which handles the object stream to recognize alternate location objects. The rules are that if an alternate location object is present, it must be the first and only object in the object stream. Otherwise the server emits an error. Differential Revision: https://phab.mercurial-scm.org/D4777

wireprotov2: client support for advertising redirect targets With the server now able to emit a redirect target descriptor, we can start to teach the client to recognize it. This commit implements support for filtering the advertised redirect targets against supported features and for advertising compatible redirect targets as part of command requests. It also adds the minimal boilerplate required to fail when a content redirect is seen. The server doesn't yet do anything with the advertised redirect targets. And the client can't yet follow redirects if it did. But at least we're putting bytes on the wire. Differential Revision: https://phab.mercurial-scm.org/D4776

wireprotov2: advertise redirect targets in capabilities This is pretty straightforward. Redirect targets will require an extension to support. So we've added a function that can be wrapped to define redirect targets. To test this, we teach our simple cache test extension to read redirect targets from a file. It's a bit hacky. But it gets the job done. Differential Revision: https://phab.mercurial-scm.org/D4775

wireprotov2: define semantics for content redirects When I implemented the clonebundles feature and deployed it on hg.mozilla.org using Amazon S3 as a content server, server-side CPU and bandwidth usage dropped off a cliff and a ton of server scaling headaches went away pretty much the instant clients with support for clonebundles were rolled out to Firefox CI. An obvious takeaway from that experience was that offloading server load to scalable file servers - potentially backed by a CDN - is a really good idea. Another takeaway was that Mercurial's wire protocol wasn't in a good position to support data offload generally. In wire protocol version 1, there isn't a mechanism in the protocol to say "grab the data from over here instead." For HTTP, we could teach the client to follow HTTP redirects. Or we could invent a media type that encoded redirects inline. But for SSH, we were pretty much out of luck because that protocol wasn't very flexible. Wire protocol version 2 offers the opportunity to do something better. The recent generic server-side content caching layer in the wire protocol version 2 server demonstrated that it is possible to have drop-in caching of responses to command requests. This by itself adds tons of value and already makes the built-in server much more scalable. But I don't want to stop there. The existing server-side caching implementation has a big weakness: it requires the server to send data to the client. This means that the Mercurial server is potentially sending gigabytes of data to thousands of clients. This is problematic because compared to scaling static file servers, scaling dynamic servers is *hard*. A solution to this is to "offload" serving of content to something that isn't the Mercurial server. By offloading content serving, you turn the Mercurial server from a centralized monolithic service to a distributed mostly-indexing service. Assuming high rates of content offload, this should drastically reduce the total work performed by the Mercurial server, both in terms of CPU and data transfer. This will make Mercurial servers vastly easier to scale. This commit defines the semantics for "content redirects" in wire protocol version 2. Essentially: * Servers advertise the set of locations a response could be served from. * When making requests, clients advertise the set of locations they are willing to fetch content from. * Servers can then replace the inline response with one that says "get the response from over here instead." This feature - when fully implemented - will allow extending the server-side caching layer to facilitate such things as integrating your server-side cache with a scalable blob store (such as S3 or a CDN) and offloading most data transfer to that external service. This feature could also be leveraged for load balancing. e.g. requests could come into a central server and then get redirected to an available mirror depending on server availability or locality. There's tons of potential :) Differential Revision: https://phab.mercurial-scm.org/D4774

wireprotov2: support response caching One of the things I've learned from managing VCS servers over the years is that they are hard to scale. It is well known that some companies have very beefy (read: very expensive) servers to power their VCS needs. It is also known that specialized servers for various VCS exist in order to facilitate scaling servers. (Mercurial is in this boat.) One of the aspects that make a VCS server hard to scale is the high CPU load incurred by constant client clone/pull operations. To alleviate the scaling pain associated with data retrieval operations, I want to integrate caching into the Mercurial wire protocol server as robustly as possible such that servers can aggressively cache responses and defer as much server load as possible. This commit represents the initial implementation of a general caching layer in wire protocol version 2. We define a new interface and behavior for a wire protocol cacher in repository.py. (This is probably where a reviewer should look first to understand what is going on.) The bulk of the added code is in wireprotov2server.py, where we define how a command can opt in to being cached and integrate caching into command dispatching. From a very high-level: * A command can declare itself as cacheable by providing a callable that can be used to derive a cache key. * At dispatch time, if a command is cacheable, we attempt to construct a cacher and use it for serving the request and/or caching the request. * The dispatch layer handles the bulk of the business logic for caching, making cachers mostly "dumb content stores." * The mechanism for invalidating cached entries (one of the harder parts about caching in general) is by varying the cache key when state changes. As such, cachers don't need to be concerned with cache invalidation. Initially, we've hooked up support for caching "manifestdata" and "filedata" commands. These are the simplest to cache, as they should be immutable over time. Caching of commands related to changeset data is a bit harder (because cache validation is impacted by changes to bookmarks, phases, etc). This will be implemented later. (Strictly speaking, censoring a file should invalidate caches. I've added an inline TODO to track this edge case.) To prove it works, this commit implements a test-only extension providing in-memory caching backed by an lrucachedict. A new test showing this extension behaving properly is added. FWIW, the cacher is ~50 lines of code, demonstrating the relative ease with which a cache can be added to a server. While the test cacher is not suitable for production workloads, just for kicks I performed a clone of just the changeset and manifest data for the mozilla-unified repository. With a fully warmed cache (of just the manifest data since changeset data is not cached), server-side CPU usage dropped from ~73s to ~28s. That's pretty significant and demonstrates the potential that response caching has on server scalability! Differential Revision: https://phab.mercurial-scm.org/D4773

wireprotov2: define type to represent pre-encoded object An upcoming commit will introduce a caching layer to command serving. This will require the ability to cache pre-encoded data. This commit introduces a type to represent pre-encoded data and teaches the output layer to not CBOR encode an instance of that type. Differential Revision: https://phab.mercurial-scm.org/D4772

wireprotov2: change name and behavior of readframe() In the near future, we will want to support performing I/O from other sources. Let's rename readframe() to readdata() and tweak its logic to support future growth. Differential Revision: https://phab.mercurial-scm.org/D4771

url: move _wraphttpresponse() from httpeer This is a generally useful function. Having it on the url module will make it more accessible outside of the HTTP peers. Differential Revision: https://phab.mercurial-scm.org/D4770

debugcommands: print all CBOR objects application/mercurial-cbor may contain multiple objects. Let's print all of them. Differential Revision: https://phab.mercurial-scm.org/D4769

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storageutil: pass nodes into emitrevisions() The main emitrevisions() uses nodes. So it makes sense to use nodes for the helper API. Not bothering with API since this function was introduced a few commits ago. Differential Revision: https://phab.mercurial-scm.org/D4805

storageutil: make all callables optional Not all storage backends may implement these callables. That's part of the reason these methods aren't exposed on the storage interface. Differential Revision: https://phab.mercurial-scm.org/D4804

storageutil: extract most of emitrevisions() to standalone function As part of implementing a storage backend, I found myself copying most of revlog.emitrevisions(). This code is highly nuanced and it bothered me greatly to be copying such low-level code. This commit extracts the bulk of revlog.emitrevisions() into a new standalone function. In order to make the function generally usable, all "self" function calls that aren't exposed on the ifilestorage interface are passed in via callable arguments. No meaningful behavior should have changed as part of the port. Upcoming commits will tweak behavior to make the code more generically usable. Differential Revision: https://phab.mercurial-scm.org/D4803

storageutil: invert logic of file data comparison IMO things make more sense when the function is explicitly a test for file data equivalence. Not bothering with API since the function was introduced by the previous commit. Differential Revision: https://phab.mercurial-scm.org/D4802

storageutil: extract filelog.cmp() to a standalone function As part of implementing an alternate storage backend, I found myself reimplementing this code. With a little massaging, we can extract filelog.cmp() to a standalone function. As part of this, the call to revlog.cmp() was inlined (it is just a 2-line function). I also tweaked some variable names to improve readability. I'll further tweak names in a subsequent commit. Differential Revision: https://phab.mercurial-scm.org/D4801

storageutil: extract copy metadata retrieval out of filelog As part of implementing an alternate storage backend, I found myself reinventing this wheel. Let's create a utility function for doing the work. Differential Revision: https://phab.mercurial-scm.org/D4800

storageutil: extract functionality for resolving strip revisions I found myself having to copy this method as part of implementing a new storage backend. With a little tweaking, we can extract it to a standalone function so it can be reused easily. We'll likely want to implement a better method for removing revisions on the storage interface someday. But until then, let's use what we have. Differential Revision: https://phab.mercurial-scm.org/D4799

storageutil: consistently raise LookupError (API) The interface docs say this is supposed to raise LookupError on failure. But for invalid revision number input, it could raise IndexError because ifileindex.node() is documented to raise IndexError. lookup() for files isn't used that much (pretty much just in basefilectx in core AFAICT). And callers should already be catching LookupError. So I don't anticipate that much fallout from this change. Differential Revision: https://phab.mercurial-scm.org/D4798

storageutil: implement file identifier resolution method (BC) revlog.lookup() has a number of advanced features, including partial node matching. These advanced features aren't needed for file id lookup because file identifiers are almost always from internal sources. (An exception to this is hgweb, which appears to have some code paths that attempt to resolve a user-supplied string to a node.) This commit implements a new function for resolving file identifiers to nodes. It behaves like revlog.lookup() but without the advanced features. Tests reveal behavior changes: * Partial hex nodes are no longer resolved to nodes. * "-1" now returns nullid instead of raising LookupError. * "0" on an empty store now raises LookupError instead of returning nullid. I'm not sure why "-1" wasn't recognized before. But it seems reasonable to accept it as a value since integer -1 resolves to nullid. These changes all seem reasonable to me. And with the exception of partial hex node matching, we may want to consider changing revlog.lookup() as well. Differential Revision: https://phab.mercurial-scm.org/D4797

testing: add more testing for ifileindex.lookup() The tests demonstrate some... questionable behavior of revlog.lookup(). Differential Revision: https://phab.mercurial-scm.org/D4796

dagop: extract DAG local heads functionality from revlog As part of implementing an alternate storage backend, I found myself having to reimplement this function. The DAG traversal logic is generic and can be factored out into a standalone function. We could probably combine this with headrevs(). But I'll leave that for another time. Differential Revision: https://phab.mercurial-scm.org/D4795

dagop: extract descendants() from revlog module This method needs to be implemented in other storage backends and is generic if we parameterize the functions for retrieving revision numbers and parent revision numbers. Let's extract it to dagop so backends don't need to reinvent the wheel. I'm not too worried about performance overhead of the extra function call because I don't expect anyone to be calling descendants() in a tight loop. Differential Revision: https://phab.mercurial-scm.org/D4794

filelog: remove checkhash() (API) It is unused. While a caller may want to ask the store to validate the hash of some provided text, since there are no in-core consumers of this method, let's drop it for now. Differential Revision: https://phab.mercurial-scm.org/D4793

filelog: remove revdiff() (API) This proxy method is no longer used. While it might be useful to query a storage backend for the delta between any 2 revisions because the store could have a delta cached and could compute it more efficiently than the caller calling revision() twice in order to compute a delta, since nothing in core is using this API now, I feel comfortable nuking it. Differential Revision: https://phab.mercurial-scm.org/D4792

localrepo: define storage backend in creation options (API) We add an experimental config option to define the storage backend for new repositories. By default, it uses "revlogv1," which maps to the current and only modern supported repository format. We add a "backend" creation option to control which backend to use. It defaults to using the value from the config option. newreporequirements() will now barf if it sees a "backend" value that isn't "revlogv1." This forces extensions to monkeypatch the function to handle requirements derivation for custom backends. In order for this to "just work," we factored out obtaining the default creation options into its own function and made callers of newreporequirements() responsible for passing in valid data. Without this, direct callers of newreporequirements() wouldn't get the proper results. Differential Revision: https://phab.mercurial-scm.org/D4791

wireprotov2: derive "required" from presence of default value If we define a default value for all optional arguments, we no longer need to explicitly declare whether the argument is required. Instead, we can derive it from the presence of a default value callable. Differential Revision: https://phab.mercurial-scm.org/D4790

localrepo: capture repo interface factory functions as lambas Previously, the list would hold a reference to the original function and attempting to wrap the module function via extension wouldn't result in the wrapped function being called, completely undermining the expected behavior. Differential Revision: https://phab.mercurial-scm.org/D4821

extensions: new closehead module for closing arbitrary heads ``hg close-head`` allows closing arbitrary heads. It is equivalent to checking out the given revisions and commit an empty change with ``hg commit --close-branch``. Differential Revision: https://phab.mercurial-scm.org/D3557

cext: use modern buffer protocol in mpatch_flist() Differential Revision: https://phab.mercurial-scm.org/D4841

cext: use modern buffer protocol in patches() PyObject_AsCharBuffer() is part of the "Old Buffer Protocol," which has been deprecated for years. Let's port away from it. PyBuffer_GetBuffer() must be paired with PyBuffer_Release(), hence the added "goto cleanup" in a failure case. We don't bump the extension version because the API has not changed. Differential Revision: https://phab.mercurial-scm.org/D4840

identify: when using -T, avoid unnecessary remote bookmarks query Differential Revision: https://phab.mercurial-scm.org/D4839

identify: only query remote bookmarks if needed Instead of all the time when operating on a remote repo. This perf regression was introduced in 15a79ac823e8, in 4.3. This datahint method returns nothing for -Tjson, -Tpickle, -Tdebug --config ui.formatdebug=true and --config ui.formatjson, so the bookmarks won't show up. I don't know what these formatters are for. plainformatter and templateformatter work properly, and the few other uses of datahint should have the same kind of problem. There is further weirdness where "--template '{node}'" is not enough to avoid querying the bookmarks, you also need to pass --id or -q. Differential Revision: https://phab.mercurial-scm.org/D4819

py3: whitelist another passing tests caught by buildbot I this indygreg recent patches made this test pass on Python 3. So thanks to him! Differential Revision: https://phab.mercurial-scm.org/D4848

manifest: remove an unused variable caught by pyflakes Uses of todel were removed in D4843 (19103e68a698). This patch will make buildbots green again. Differential Revision: https://phab.mercurial-scm.org/D4847

setup: ignore message about disabling 3rd party extensions because of version I started getting into a bind recently when switching between py2 and py3 because switching requires a `make clean`, which kills __version__.py. But then when running `make local`, it picks up the local hg.exe (MSYS seems to prefix $PATH with '.'), which doesn't know its version. That causes it to emit a warning about needing at least 4.3 to load evolve, which caused setup.py to fail saying there is no working hg executable to figure out the version. If we can ignore general extension import failures, we should be able to ignore this too.

narrow: avoid overwriting a variable I don't like to overwrite variables, especially not with a different type (because it makes it harder to explain what the variable is for, and, therefore, to name it well). Differential Revision: https://phab.mercurial-scm.org/D4846

treemanifests: remove _loadalllazy in _diff() The benchmarks below use a similar setup as in ee7ee0c516ca and my other recent commits. Yes, in some cases this runs in literally 5% of the time it previously took. before = a6f8ab53 diff --git: repo | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before ------+---+---+------------------------+-----------------------+------------ m-u | | | 1.301 s +- 0.004 s | 1.309 s +- 0.012 s | 100.6% m-u | | x | 1.303 s +- 0.009 s | 1.302 s +- 0.006 s | 99.9% m-u | x | | 1.308 s +- 0.006 s | 1.309 s +- 0.007 s | 100.1% m-u | x | x | 85.7 ms +- 0.6 ms | 86.0 ms +- 0.3 ms | 100.4% l-d-r | | | 197.5 ms +- 0.7 ms | 197.8 ms +- 2.2 ms | 100.2% l-d-r | | x | 199.4 ms +- 0.6 ms | 199.3 ms +- 0.9 ms | 99.9% l-d-r | x | | 86.1 ms +- 0.5 ms | 85.8 ms +- 0.9 ms | 99.7% l-d-r | x | x | 64.4 ms +- 0.4 ms | 64.4 ms +- 0.3 ms | 100.0% diff -c . --git: repo | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before ------+---+---+------------------------+-----------------------+------------ m-u | | | 236.7 ms +- 1.1 ms | 236.5 ms +- 1.3 ms | 99.9% m-u | | x | 158.7 ms +- 1.0 ms | 128.0 ms +- 1.0 ms | 80.7% <-- m-u | x | | 239.7 ms +- 1.8 ms | 238.1 ms +- 1.5 ms | 99.3% m-u | x | x | 132.4 ms +- 0.9 ms | 132.3 ms +- 0.6 ms | 99.9% l-d-r | | | 81.8 ms +- 0.4 ms | 81.8 ms +- 0.3 ms | 100.0% l-d-r | | x | 3.894 s +- 0.017 s | 193.6 ms +- 0.4 ms | 5.0% <-- l-d-r | x | | 106.9 ms +- 0.4 ms | 106.6 ms +- 0.3 ms | 99.7% l-d-r | x | x | 182.7 ms +- 0.8 ms | 183.3 ms +- 0.9 ms | 100.3% rebase -r . --keep -d .^^: repo | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before ------+---+---+------------------------+-----------------------+------------ m-u | | | 5.615 s +- 0.109 s | 5.562 s +- 0.015 s | 99.1% m-u | | x | 5.701 s +- 0.027 s | 5.715 s +- 0.023 s | 100.2% m-u | x | | 5.572 s +- 0.128 s | 5.613 s +- 0.182 s | 100.7% m-u | x | x | 633.3 ms +- 28.7 ms | 636.2 ms +- 13.8 ms | 100.5% l-d-r | | | 666.4 ms +- 17.0 ms | 658.5 ms +- 9.3 ms | 98.8% l-d-r | | x | 6.520 s +- 0.070 s | 6.505 s +- 0.026 s | 99.8% l-d-r | x | | 279.0 ms +- 13.0 ms | 276.5 ms +- 4.7 ms | 99.1% l-d-r | x | x | 1.636 s +- 0.058 s | 1.657 s +- 0.014 s | 101.3% status --change . --copies: repo | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before ------+---+---+------------------------+-----------------------+------------ m-u | | | 218.6 ms +- 1.4 ms | 217.9 ms +- 1.5 ms | 99.7% m-u | | x | 138.5 ms +- 0.4 ms | 108.4 ms +- 0.2 ms | 78.3% <-- m-u | x | | 220.1 ms +- 1.3 ms | 219.7 ms +- 1.5 ms | 99.8% m-u | x | x | 113.2 ms +- 0.4 ms | 112.4 ms +- 0.8 ms | 99.3% l-d-r | | | 80.2 ms +- 0.3 ms | 80.6 ms +- 0.6 ms | 100.5% l-d-r | | x | 3.899 s +- 0.020 s | 194.8 ms +- 4.0 ms | 5.0% <-- l-d-r | x | | 83.4 ms +- 0.8 ms | 83.2 ms +- 0.2 ms | 99.8% l-d-r | x | x | 732.2 ms +- 4.3 ms | 194.9 ms +- 1.0 ms | 26.6% <-- status --copies: repo | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before ------+---+---+------------------------+-----------------------+------------ m-u | | | 1.917 s +- 0.005 s | 1.914 s +- 0.004 s | 99.8% m-u | | x | 1.909 s +- 0.012 s | 1.934 s +- 0.004 s | 101.3% m-u | x | | 1.915 s +- 0.005 s | 1.904 s +- 0.004 s | 99.4% m-u | x | x | 94.8 ms +- 0.3 ms | 94.7 ms +- 0.2 ms | 99.9% l-d-r | | | 593.9 ms +- 1.2 ms | 594.6 ms +- 9.4 ms | 100.1% l-d-r | | x | 595.2 ms +- 3.8 ms | 597.2 ms +- 2.6 ms | 100.3% l-d-r | x | | 182.5 ms +- 1.6 ms | 182.1 ms +- 0.6 ms | 99.8% l-d-r | x | x | 149.6 ms +- 0.9 ms | 149.1 ms +- 0.8 ms | 99.7% update $rev^; ~/src/hg/hg{hg}/hg update $rev: repo | N | T | before (mean +- stdev) | after (mean +- stdev) | % of before ------+---+---+------------------------+-----------------------+------------ m-u | | | 3.121 s +- 0.007 s | 3.129 s +- 0.012 s | 100.3% m-u | | x | 2.972 s +- 0.011 s | 2.981 s +- 0.012 s | 100.3% m-u | x | | 3.144 s +- 0.014 s | 3.141 s +- 0.011 s | 99.9% m-u | x | x | 312.2 ms +- 2.4 ms | 312.3 ms +- 2.1 ms | 100.0% l-d-r | | | 444.4 ms +- 4.3 ms | 446.9 ms +- 5.3 ms | 100.6% l-d-r | | x | 9.159 s +- 0.069 s | 9.182 s +- 0.040 s | 100.3% l-d-r | x | | 254.6 ms +- 1.6 ms | 255.2 ms +- 1.6 ms | 100.2% l-d-r | x | x | 1.525 s +- 0.007 s | 1.577 s +- 0.007 s | 103.4% <--? Differential Revision: https://phab.mercurial-scm.org/D4845

treemanifests: skip extraneous check for item before calling _loadlazy Differential Revision: https://phab.mercurial-scm.org/D4844

treemanifests: make _loadchildrensetlazy just call _loadlazy This was suggested on the original review for _loadchildrensetlazy (D4370), it's taken me a while to get to it though. Differential Revision: https://phab.mercurial-scm.org/D4843

treemanifests: make _loadlazy tolerate item not on _lazydirs I'd like to clean up a few cases where we check for an item in _lazydirs before calling _loadlazy - this will remove an extraneous dict lookup and make it slightly more versatile. Differential Revision: https://phab.mercurial-scm.org/D4842

debugcommands: add a debugindexstats command Someone went through the trouble of recording these stats, so let's make them accessible. Differential Revision: https://phab.mercurial-scm.org/D4832

rust-chg: add main program It can at least connect to a *running* command server, and execute Mercurial command. No signal handling nor daemon management is implemented yet.

rust-chg: add interface to chdir the server

rust-chg: add Client extensions to run cHg-specific requests This just provides a nicer way to issue command-server requests.

rust-chg: port basic socket path handling from cHg of C This is basically modeled after setcmdserveropts() of chg.c.

rust-chg: add state machine to handle "runcommand" request with cHg extension This is modeled after tokio-hglib's RunCommand state to support the "S" channel message.

rust-chg: add callback to handle pager and shell command requests This could be inlined into the ChgRunCommand state to be introduced by the next patch, but it seemed good to separate any user interactions from the IPC code.

rust-chg: add low-level function to set pager fd blocking This is necessary because the server expects stdout/stderr to be blocking, whereas we'll use async library to spawn pager, which makes pipes unblocking.

rust-chg: add future that handles "attachio" request This is the sequence to send client-side stdio and pager stdin to the server.

rust-chg: add parser for request messages sent to "S" channel The data structure is documented at chgserver.py:channeledsystem().

rust-chg: add wrapper around C function

rust-chg: add function to send fds via domain socket As a beginning, I wrote some C. It's extracted from attachio() of contrib/chg/hgclient.c. Maybe it could be rewritten in Rust by using the libc (and/or nix) crates, but doing that wouldn't be trivial as the code depends on CMSG_*() macros. IMO, using C is better here.

rust-chg: update dependencies

rust-chg: add project skeleton This directory will host the reimplementation of cHg in Rust. It will use Tokio [1], and tokio-hglib [2] which I wrote for an oxidized CHg, no idea if there's such carbon bonding in nature btw. [1]: https://tokio.rs/ [2]: https://bitbucket.org/yuja/tokio-hglib/ The reasoning for depending on Tokio is that it will allow us to handle Unix signals in a safer way. Well, I believed that until I found a weird function, handlestopsignal(), in cHg codebase. It resends the same signal to the same process by temporarily masking the handler, which can't be inherently async. So the signal handlers will stay in C, which means there isn't actually much reason to write async code right now, other than I've already done most of the async stuff, and slightly easier pager handling. The reasoning for the rewrite is that it will eventually be possible to port server-side config validation back to the client side, which will reduce the complexity of the current daemon management. It will also encourage us to write frontend library (e.g. command line and config parsers) in Rust. The license is GPL2+ because it's likely to include derived work from the cHg of C. The rust/chg crate is excluded from the root workspace as it's unclear how the whole rust packages should be laid out. That can be revisited later.

narrow: move copies overrides to core The copies overrides seems to have been a little complicated just by not being in core. When moved to core, it becomes trivial (at least I think these overrides have the same effect). Differential Revision: https://phab.mercurial-scm.org/D4825

narrow: pass old includes and excludes to _widen() In future patches we will need to pass them in the widen wireprotocol command which we are building. Differential Revision: https://phab.mercurial-scm.org/D4812

narrow: check for servers' narrow support before doing anything (BC) Recently we introduced narrow capabilities for the server. So we can check whether a server has narrow clone support or not before doing anything. This is BC because new clients won't be able to extend from old narrow-enabled servers. I *think* narrow is not used much (maybe just inside Google), also it's experimental so I think we can change this. We will need to this someday anyway. The "doesn't" in error is changed to "does not" because I think that's we do in core. I also changed one more instance of the error message to use 'does not' for consistency. Differential Revision: https://phab.mercurial-scm.org/D4789

narrow: don't do the dirstate dance if ellipses is not enabled I believe we set dirstate parents to nullid before widening pull because in ellipses cases, the parent might be stripped off with a new changeset. However the second ds.setparents() call invalidate my assumption. I am not sure why we do this. So here is a patch. This patch also adds tests showing we break nothing in non-ellipses cases. Differential Revision: https://phab.mercurial-scm.org/D4788

narrow: pass 'narrow_widen' as source while generating changegroup Extensions inspect the `source` parameter and add some custom logic on the basis of value of that parameter. The parameter is also passed to hooks. So let's pass the value as 'narrow_widen' to differentiate widening from pull. Differential Revision: https://phab.mercurial-scm.org/D4787

narrow: factor out logic to create cg while widening into separate fn This patch takes out the logic which generates a changegroup for widening a narrow clone when ellipses are disabled. This is done because future patches will introduce a narrow_widen() wireprotocol command which will send a bundle2 with changegroup and will use this function. The new function for now returns just the changegroup for compatibility with existing code, but in future patches, when we establish a wireprotocol command and call this function from there, this will return the required bundle2. Differential Revision: https://phab.mercurial-scm.org/D4786

narrow: avoid looking up dirstate again when editing dirstate The narrow extension overrides the dirstate editing functions to restrict paths outside the narrowspec. These overrides access the dirstate from repo.dirstate instead of using the "self" reference passed to the overridden functions. I don't see a reason for this and it caused me problems with a later patch (it caused infinite recursion when I modified localrepo.dirstate()), so let's change it. Differential Revision: https://phab.mercurial-scm.org/D4829

repo: move unfiltered-repo optimization to workingctx localrepo.__getitem__ special-cased lookup of the working copy parent to avoid looking up obsmarkers. I think the reason for that code (which I once wrote myself) was to make `hg commit` not load obsmarkers, which it would otherwise do via ctx.p1() in localrepo.commitctx(). That had the somewhat unfortunate consequence of making lookup of an unrelated binary nodeid load the dirstate. Now that changectx's constructor is dumb, we can let workingctx._parents() have the opmtimization instead. This affects two tests, because they no longer end up loading the dirstate and their "warning: ignoring unknown working parent ..." messages therefore go way. Differential Revision: https://phab.mercurial-scm.org/D4828

context: move logic from changectx.__init__ to localrepo.__getitem__ (API) My motivation for this change was to make repo[node] not load the dirstate (more about that in the next patch), but I think it makes more sense this way too. For example, raising RepoLookupError seems to belong better in the repo lookup function (i.e. localrepo.__getitem__). This makes the changectx constructor very simple -- it just assigns the given repo, revnum, and nodeid to properties. Differential Revision: https://phab.mercurial-scm.org/D4827

context: reduce dependence of changectx constructor I want to change the constructor's signature and letting all creation of changectx instances go through the repo simplifies that. Differential Revision: https://phab.mercurial-scm.org/D4826

py3: use system strings for HTTP response header comparison res.headers is holding system strings. Attempting to compare against bytes always fails and we fail to print decoded CBOR responses on Python 3. After this change, various test-wireproto* tests are now properly printing CBOR response objects. Differential Revision: https://phab.mercurial-scm.org/D4835

py3: convert HTTP request headers to str The low-level request object ideally takes system strings for HTTP request headers and values. If we send in bytes, it works. But a duplicate header check fails and various tests emit duplicate user-agent headers. Differential Revision: https://phab.mercurial-scm.org/D4834

py3: use system strings in HTTP server code Previously the source transformer was converting some string literals to bytes and we were comparing a system native string to bytes and this was leading to sending the wrong HTTP response headers on Python 3. After this change, we now properly send Transfer-Encoding and Connection response headers on Python 3. Differential Revision: https://phab.mercurial-scm.org/D4833

py3: byteify test-storage.py The test now passed on Python 3. # skip-blame just b'' prefixes Differential Revision: https://phab.mercurial-scm.org/D4836

narrow: remove narrowpatch instead of narrowcopies 84092edd5c88 removed narrowpatch.py and wanted to drop narrowpatch from __init__.py but mistakenly removed narrowcopies. This will make buildbots green again. Differential Revision: https://phab.mercurial-scm.org/D4837

py3: suppress the output from .write() calls in more tests I missed these in 803b7569c9ea because I forgot about `...` lines.

py3: byteify test-lfs.t

lfs: explicitly name a key when sorting blob pointers This is needed to keep py3 happy. The other two instances of sorting already did this.

py3: byteify test-lock.py There's still a stacktrace about not being able to serialize _io.TextIOWrapper.

py3: byteify contrib/dumprevlog

py3: quote $PYTHON in test-merge-symlinks.t

copies: inline a variable that's used only once By inlining it, we also avoid calculating the value when "if of in seen" is false (probably not significant). Differential Revision: https://phab.mercurial-scm.org/D4831

bundlerepo: remove a variable alias "parentrepo" and "repo" were the same thing and I don't see much reason for it (unionrepo has similar structure and a similar alias but there are two repos there so at least it makes a little more sense there). Differential Revision: https://phab.mercurial-scm.org/D4830

merge with stable

Added signature for changeset 5405cb1a7901

Added tag 4.7.2 for changeset 5405cb1a7901

manifest: fix out-of-bounds read of corrupted manifest entry Spotted by ASAN.

manifest: rewrite pathlen() to not cross entry boundary Even though the entire manifest data should be terminated by '\0', it seems not nice to scan '\0' over the entry terminator, '\n'.

narrow: move support for `hg verify` into core Differential Revision: https://phab.mercurial-scm.org/D4824

narrow: drop unnecessary overrides of patch The patch overrides became unnecessary when I made context.status() filter by the narrowspec in e411774a2e0f (narrow: move status-filtering to core and to ctx, 2018-08-02). Differential Revision: https://phab.mercurial-scm.org/D4823

tests: add test showing that paths outside narrowspec are not added We had a test that shows that trying to explicitly add a file outside the narrowspec results in an error, but we didn't have a test that shows that paths from subdirectories outside the narrowspec are not added (on e.g. `hg add .`) but silently ignored. Differential Revision: https://phab.mercurial-scm.org/D4822

catapipe: fix bug introduced when switching to the timer api Differential Revision: https://phab.mercurial-scm.org/D4818

narrow: move the ellipses server capability to core This will be used in core logic to determining whether a server is ellipses enabled or not. And also this will ease moving narrow related things to core. Differential Revision: https://phab.mercurial-scm.org/D4809

narrow: move the wireprotocol narrow capability name to core We are trying to integrate the whole of narrow logic into core and it will be helpful for upcoming patches to have these capability names in core. The next patch will move the ellipses capability to core also. The exact motivation is to know whether we are cloning a ellipses repo or not and adding an ellipses repo requirement. Differential Revision: https://phab.mercurial-scm.org/D4808

help: document about "files" template keywords

formatter: remove experimental marker from -T option I think it's good enough to stabilize the feature, at least for the core and non-experimental commands.

grep: rename {line_number} to {lineno} as well (BC)

annotate: rename {line_number} to {lineno} (BC) I think {lineno} looks more like a common template keyword. It isn't called a {line} to avoid conflicts with the element name of {lines} and the {_|splitlines} filter. https://www.mercurial-scm.org/wiki/GenericTemplatingPlan#Dictionary

resolve: rename {status} to {mergestatus} to not shadow change status (BC) This is a part of the name unification. I think it's somewhat useful to provide a combined view of change/merge statuses. https://www.mercurial-scm.org/wiki/GenericTemplatingPlan#Dictionary

py3: whitelist one additional test Differential Revision: https://phab.mercurial-scm.org/D4817

logtoprocess: connect all fds to /dev/null to avoid bad interaction with pager We detected that pager is waiting for log-to-process script to finish, which is annoying when adding a script on commandfinish that does an HTTP push. There seems to be no workaround on the script side and it will make the behavior on Linux/MacOS closer to the Windows behavior. The drawback is that it makes the related tests more flaky as log-to-process outputs are now really asynchronous. If it's considered a BC change, another option would be to add a config option for this new behavior. I personally think that the different behavior between Windows and Linux is confusing and that it's a bug I would be fine with a new config option. Differential Revision: https://phab.mercurial-scm.org/D4816

logtoprocess: add a test to show pager and ltp bad interaction The next changeset will fix the bad interaction between the pager and log-to- process. Add a test first to make the next changeset easier to understand. Differential Revision: https://phab.mercurial-scm.org/D4815

py3: add one more passing test to whitelist caught by buildbot Thanks to Matt Harbison who fixed the remaining failures of this test. Differential Revision: https://phab.mercurial-scm.org/D4814

cleanupnodes: pass multiple predecessors to `createmarkers` directly

obsolete: allow multiple predecessors in createmarkers The logic for this change is similar to the change to `cleanupnodes` that we did earlier. Now that the rebase code is trying to record a fold, we need to actually record it in the markers. The first step is to have the markers creation API able to receive such fold data. To keep things sane, we restrict fold to on successors.

obsolete: preindent code in createmarkers This will help to make the next change clearer.

obsolete: explicitly pass relation items to effectflag computation To track folds, we are about to change the content of `rel`. To simplify this change, we update the `geteffectflag` function beforehand.

rebase: explicitly track collapses as fold A collapse is a large fold. It is now explicitly tracked (at the cleanupnodes API level).

rebase: use tuple as `replacement` keys Now that `cleanupnodes` support tuples as key, we update the rebase code to use them. No changes in the replacement tracked are introduced yet.

rebase: expand a long "one-liner" When a one-liner gets 3 lines longs, it lose its expressivity benefits. We expand it into a simple for loop. This makes future changes of the code in that area clearer.

cleanupnodes: drop special casing around prune markers (API) The `cleanupnodes` has logic to skip the creation of "prune" markers if the changeset is already obsolete. This feels strange and gets in the way of code changes to tracks folds. Now that callers no longer request such prune, we can drop this logic. In many cases, pruning through cleanupnodes should be replaced by internal phase usage.

rebase: don't try to prune obsolete changeset already in the destination With similar motivations to the previous changesets, we stop marking changeset from pruning when it is not the command intention. In this case, we still need to distinguish between the strip and the obsolete case.

histedit: don't cleanup nodes already disposed of If something else took care of these temporary nodes, we don't need to do anything about it. This less liberal usage of pruning through cleanup nodes will help us further cleanup on the road to explicitly tracks folds.

py3: avoid b'' output in test-hgweb-non-interactive.t I couldn't figure out how to get the list to print without b'' with pycompat.write(), without converted each element to str.

py3: convert print to a function call in a few tests I *think* this is the last of them.

py3: use util.forcebytestr() to convert push lock error to bytes

py3: byteify windows.shelltocmdexe() This makes test-doctest.py happy on Windows.

run-tests: flush output stream before prompting to accept changes With py3 on Windows, the prompt to accept changes in an --interactive run wasn't showing up until after the choice was read from stdin.

py3: use util.forcebytestr() to convert error messages to bytes This makes the python 3 buildbot green again. Differential Revision: https://phab.mercurial-scm.org/D4811

context: stop catching TypeError when converting hex nodeid to binary It has been a programming error to pass a 40-character string that is not a hex nodeid since 8b86acc7aa64 (context: drop support for looking up context by ambiguous changeid (API), 2018-04-28), so we can just let it raise a TypeError. Differential Revision: https://phab.mercurial-scm.org/D4807

context: stop catching and re-raising FilteredRepoLookupError FilteredRepoLookupError is only raised by changectx's constructor and the higher-level scmutil.revsymbol(), so there's no need to catch it in changectx's constructor. Differential Revision: https://phab.mercurial-scm.org/D4806

util: use a context manager in readlock()

py3: convert os.readlink() path to native strings on Windows Windows insisted that it needs to be str. I skipped the stuff in the posix module, and left `tests/f` and `run-tests.py` alone for now.

py3: suppress the output from .write() calls in the remaining tests

py3: conditionalize json float precision difference in test-debugcommands.t

py3: byteify extension in test-debugcommands.t

pullreport: rev duplicated and extinct into account If we already have some obsolete and hidden nodes locally and the server send them again to you, it seems useful to point it out instead of being silent about it.

pullreport: issue a message about "extinct" pulled changesets Changeset pulled from a remote repository while already obsolete locally can end up hidden after the pull. Hiding obsolete changesets is a good behavior but silently "skipping" some of the pulled content can get confusing. We now detect this situation and emit a message about it. The message is simple and the wording could be improved, however, we focus on the detection here. Evolution is still an experimental feature, so the output is open to changes. In particular, we could point out at the latest successors of the obsolete changesets, however, it can get tricky is there are many of them. So we delay these improvements to another adventure. Another easy improvement would be to merge this message with the previous line about the new nodes and their phases. This is a good example of cases where we can only transmit a limited amount of data to users by default. We need some sort of "transaction journal" we could point the user to.

pullreport: skip or rework some early return We are about to add more logic in this report. Before that, we need it to not quit so early.

pullreport: skip filtered revs instead of obsolete ones Obsolescence is closely related to visibility but still a distinct concept. We can receive changesets that are obsolete but visible (eg: when pulling orphans). Such changeset should be reported too. In addition, the filtering level can be anything, we should respect it.

pullreport: add a test to show misreporting of visible changeset The current code ignores all obsolete changesets including the visible one. We add a test showing this behavior before fixing the behavior.

repo: don't look up context for tip node if it's not needed We were doing repo['tip'].node() or similar in a few places where repo.changelog.tip() would be enough. Differential Revision: https://phab.mercurial-scm.org/D4781

repo: look up nullrev context by revnum, not symbolic name I think lookup of the 'null' symbol should be done via scmutil.revsymbol() and repo['null'] is only supported for historical reasons. However, repo[nullrev] is fine, so we can switch to that instead of switching to scmutil.revsymbol('null'). Differential Revision: https://phab.mercurial-scm.org/D4780

bundle: consistently put revnums in "base" collection The "base" collection contains revnums, except that it can also contain the "null" symbol. That's a little weird. Let's be consistent. Differential Revision: https://phab.mercurial-scm.org/D4779

py3: ensure printing to stdout uses str in test-hgweb-no-request-uri.t

scmutil: accept multiple predecessors in 'replacements' (API) This changeset makes 'cleanupnodes' accepts multiple predecessors as `replacements` keys. The same as it accepts multiple successors as `replacements` values. To avoid breaking all callers, the old and new ways are currently valid at the same time. We'll deprecate and drop the old way later. This change is the first step toward a better tracking of "fold" event in the evolution history. While working on the "rewind" command (in the evolve extension), we realized that first class tracking of folds are necessary. We already have good tracking of splits. When walking the evolution history from predecessors to successors, that makes for a clear distinction between having multiple successors because of the actual splitting of a changeset or content-divergences. The "rewind" command allows restoring older evolution of a stack of changesets. One of its mode walks the evolution history to automatically find appropriate predecessors. This means walking from successors to predecessors. In this case, we need to be able to make the same distinction between an actual fold and other cases. So we will have to track folds explicitly. This changesets only focus on making it possible to express fold at the `cleanupnodes` API level. The actual tracking will be implemented later.

scmutil: expand long "one-liner" When a one-liner gets 3 lines longs, it loses its expressivity benefits. We expand it into a simple for loop. This makes future changes of the code in that area clearer.

shelve: find shelvedctx from bundle even if they are already in the repo We use the new "duplicates" node tracking to find the tip of the bundle even if it already exists in the repository. Such logic is not supposed to be needed in theory. If the shelve was made using internal-phase, we already know its node. Otherwise, the bundle content should have been stripped. However, handling it makes the shelve code more robust and provide a good example of "revduplicates" usage.

shelve: return the shelved node as part of bundle application It make sense to have the function in charge of unbundling the shelved revision also return the node of that revision (when the data is in the bundle). This will help us to handle unnatural state where the unshelved change already exists in the repository.

changelog: keep track of duplicated node in the transaction adding them The transaction is already tracking the new nodes. We now tracks the "duplicates" in the same location.

revlog: add a callback "tracking" duplicate node addition If a changegroup contains node already added to the repository, they will be skipped. Skipping them is the right behavior (we don't need to store things twice), but it can hide some information to the code doing the unbundle (eg: shelve looking for the tip of the bundle). The first step to improve this situation is to add a low level callback. We do not need this tracking on all revlog, so actual tracking will be added in the next changeset.

logtoprocess: define $HG for children processes So they can compute the hg version for instance. Differential Revision: https://phab.mercurial-scm.org/D4768

py3: mask out None type when printing in `debuglocks` Apparently, %b doesn't allow None.

py3: ensure standard exceptions use `str` type strings in windows.py See also edaa40dc5fe5.

py3: replace a StandardError reference This doesn't exist on py3, and the standard way of handling this seems to be to catch both exceptions.

storageutil: extract revision number iteration This code is a bit quirky (and possibly buggy). It will likely be used by multiple storage backends. Let's extract it so it is reusable. Differential Revision: https://phab.mercurial-scm.org/D4757

storageutil: new function for extracting metadata-less content from text Other storage backends will want to do this. I'm not concerned about Python function call overhead because I expect self.revision() to dwarf the function call overhead time, since self.revision() requires multiple function calls and may involve decompression in the common case. Differential Revision: https://phab.mercurial-scm.org/D4756

storageutil: move _censoredtext() from revlog This seems like generic functionality we'll want to use from non-revlog storage backends. Differential Revision: https://phab.mercurial-scm.org/D4755

storageutil: move metadata parsing and packing from revlog (API) Parsing and writing of revision text metadata is likely identical across storage backends. Let's move the code out of revlog so we don't need to import the revlog module in order to use it. Differential Revision: https://phab.mercurial-scm.org/D4754

storageutil: new module for storage primitives (API) There will exist common code between storage backends. It would be nice to have a central place to put that code. This commit attempts to create that place by creating the "storageutil" module. The first thing we move is revlog.hash(), which is the function for computing the SHA-1 hash of revision fulltext and parents. Differential Revision: https://phab.mercurial-scm.org/D4753

filelog: stop proxying deltaparent() (API) deltaparent() obtains the revision number of the base revision a delta in storage is stored against. It is highly revlog-centric and may not apply to other storage backends. As a result, it doesn't belong on the generic file storage interface. This method/proxy is no longer used in core. The last consumer was probably changegroup code and went away with the transition to emitrevisions(). Differential Revision: https://phab.mercurial-scm.org/D4751

filelog: stop proxying rawsize() (API) This method is no longer used by external consumers. The API is quite low-level and is effectively len(revision(raw=True)). I don't see a compelling reason to keep it around. Let's drop the API and make the file storage interface simpler. Differential Revision: https://phab.mercurial-scm.org/D4750

filelog: stop proxying "opener" (API) The last consumer of it in upgrade code was removed as part of the previous commit. This attribute is revlog specific (because it assumes the existence of a vfs for performing I/O on tracked file data) and therefore isn't appropriate for a generic storage interface. So nuke it. Differential Revision: https://phab.mercurial-scm.org/D4749

filelog: stop proxying flags() (API) Per-revision storage flags are kinda a revlog-centric API. (Except for the fact that changegroup uses the same integer flags as revlog does and there's minimal verification that the server's flags map to the client's storage flags - but that's another problem.) The last user of flags() was in verify.py and that code was just moved into revlog.py and is accessed behind the verifyintegrity() file storage API. Since there are no more consumers, let's drop the proxy and remove the method from the file storage interface. This commit only drops the dedicated API for reading a single revision's storage flags: we still support reading and writing flags through the bulk data retrieval and add revision APIs. And since changegroups encode revlog integer flags over the wire, we'll always need to support flags at some level. The removal of individual storage flags may be too premature. But since flags() is now unused, I'd like to see how far we can get without that dedicated API - especially since it uses revision numbers instead of nodes. Differential Revision: https://phab.mercurial-scm.org/D4746

revlog: move revision verification out of verify File revision verification is performing low-level checks of file storage, namely that flags are appropriate and revision data can be resolved. Since these checks are somewhat revlog-specific and may not be appropriate for alternate storage backends, this commit moves those checks from verify.py to revlog.py. Because we're now emitting warnings/errors that apply to specific revisions, we taught the iverifyproblem interface to expose the problematic node and to report this node in verify output. This was necessary to prevent unwanted test changes. After this change, revlog.verifyintegrity() and file verify code in verify.py both iterate over revisions and resolve their fulltext. But they do so in separate loops. (verify.py needs to resolve fulltexts as part of calling renamed() - at least when using revlogs.) This should add overhead. But on the mozilla-unified repo: $ hg verify before: time: real 700.640 secs (user 585.520+0.000 sys 23.480+0.000) after: time: real 682.380 secs (user 570.370+0.000 sys 22.240+0.000) I'm not sure what's going on. Maybe avoiding the filelog attribute proxies shaved off enough time to offset the losses? Maybe fulltext resolution has less overhead than I thought? I've left a comment indicating the potential for optimization. But because it doesn't produce a performance regression on a large repository, I'm not going to worry about it. Differential Revision: https://phab.mercurial-scm.org/D4745

tests: de-flake test-narrow-debugrebuilddirstate.t If the dirstate gets written much later (usually 1-2 s, depending on FS) than the working copy file (there's only one), then the `hg debugdirstate` command will include a timestamp. There's nothing wrong with that, so we should just allow it. Differential Revision: https://phab.mercurial-scm.org/D4758

upgrade: use storageinfo() for obtaining storage metadata Let's switch to our new API for obtaining information about storage. This eliminates the last consumer of rawsize() and the opener proxy from the file storage interface! Differential Revision: https://phab.mercurial-scm.org/D4748

revlog: add method for obtaining storage info (API) We currently have a handful of methods on the file and manifest storage interfaces for obtaining metadata about storage. e.g. files() is used to obtain the files backing storage. rawsize() is to quickly compute the size of tracked revisions without resolving their fulltext. Code in upgrade and stream clone make heavy use of these methods. The existing APIs are generic and don't necessarily have the specialization that we need going forward. For example, files() doesn't distinguish between exclusive storage and shared storage. This makes stream clone difficult to implement when e.g. there may be a single file backing storage for multiple tracked paths. It also makes reporting difficult, as we don't know how many bytes are actually used by storage since we can't easily identify shared files. This commit implements a new method for obtaining storage metadata. It is designed to accept arguments specifying what metadata to request and to return a dict with those fields populated. We /could/ make each of these attributes a separate method. But this is a specialized API and I'm trying to avoid method bloat on the interfaces. There is also the possibility that certain callers will want to obtain multiple fields in different combinations and some backends may have performance issues obtaining all that data via separate method calls. Simple storage integration tests have been added. For now, we assume fields can't be "None" (ignoring the interface documentation). We can revisit this later. Differential Revision: https://phab.mercurial-scm.org/D4747

lfs: drop unused import A recent change dropped the last user of this module. Differential Revision: https://phab.mercurial-scm.org/D4744

filelog: drop _generaldelta attribute (API) With changegroup moving to emitrevisions(), this revlog-specific attribute is no longer used and can be deleted. Good riddance. Differential Revision: https://phab.mercurial-scm.org/D4727

revlog: drop emitrevisiondeltas() and associated functionality (API) emitrevisions() is the future! Differential Revision: https://phab.mercurial-scm.org/D4726

changegroup: port to emitrevisions() (issue5976) We now have a unified API for emitting revision data from a storage backend. It handles sorting nodes and the complicated delta versus revision decisions for us. This commit ports changegroup to that API. There should be no behavior changes for changegroups not using ellipsis. And lack of test changes seems to confirm that. There are some changes for ellipsis mode, however. Before, when sending an ellipsis revision, we would always send a fulltext revision (as opposed to a delta). There was a TODO tracking this open item. One of the things the emitrevisions() API does for us is figure out whether we can safely emit a delta. So, it is now possible for ellipsis revisions to be sent as deltas! (It does this by not assuming parent/ancestor revisions are available and tracking which revisions have been sent out.) Because we eliminated the list of revision delta request objects, performance has improved substantially: $ hg perfchangegroupchangelog before: ! wall 24.348077 comb 24.330000 user 24.140000 sys 0.190000 (best of 3) after: ! wall 18.245911 comb 18.240000 user 18.100000 sys 0.140000 (best of 3) That's a lot of overhead for creating a few hundred thousand Python objects! This is still a little slower than 4.7. Probably due to 23d582ca introducing a type for the revision/delta results. There is potentially room to optimize. But at some point we need to abstract storage in order to support alternate storage backends. Unfortunately that means using a Python data structure to represent results. And unfortunately there is overhead with every new Python object created. Differential Revision: https://phab.mercurial-scm.org/D4725

wireprotov2server: port to emitrevisions() We now have a proper storage API to request data on multiple revisions. We can drop it into wire protocol version 2 with minimal effort. The new API handles pretty much everything we were doing manually to build up the delta request. So we were able to delete a lot of code. As a bonus, wireprotov2 code is no longer accessing some low-level storage APIs. This includes the assumption that a node has an associated numeric revision number! This should make it drastically simpler to implement a server that doesn't have the concept of revision numbers. Differential Revision: https://phab.mercurial-scm.org/D4724

tests: use more complex file storage test The previous test was attempting to to test delta storage behavior. It didn't do a very good job at it because there was a good chance a delta wasn't being used in storage. Let's switch the test to yield a delta in storage so an upcoming change to delegate delta logic to storage has the desired effect. Differential Revision: https://phab.mercurial-scm.org/D4723

revlog: new API to emit revision data I recently refactored changegroup generation code to make it more storage agnostic. I made significant progress. But there is still a bit of work to be done. Specifically: * Changegroup code is looking at low-level storage attributes to influence sorting. Sorting should be done at the storage layer. * The linknode lookup and sorting code for ellipsis is very complicated. * Linknodes are just generally wonky because e.g. file storage doesn't know how to translate a linkrev to a changelog node. * We regressed performance when introducing the request-response objects. Having thought about this problem a bit, I think I've come up with a better interface for emitting revision deltas. This commit defines and implements that interface. See the docstring in repository.py for more info. This API adds 3 notable features over the previous one. First, it defers node ordering to the storage implementation in the common case but allows overriding as necessary. We have a facility for requesting an exact ordering (used in ellipsis mode). We have another facility for storage order (used for changelog). Second, we have an argument specifying assumptions about parents revisions. This can be used to force a fulltext revision when we don't know the receiver has a parent revision to delta against. Third, we can control whether revision data is emitted. This makes the API suitable as a generic "index data retrieval" API as well as for producing revision deltas - possibly in the same operation! The new API is much simpler: we no longer need a complicated "request" object to encapsulate the delta generation request. I'm optimistic this will restore performance loss associated with emitrevisiondeltas(). Storage unit tests for the new API have been implemented. Future commits will port existing consumers of emitrevisiondeltas() to the new API then remove emitrevisiondeltas(). Differential Revision: https://phab.mercurial-scm.org/D4722

changegroup: remove reordering control (BC) This logic - including the experimental bundle.reorder option - was originally added in a8e3931e3fb5 in 2011 and then later ported to changegroup.py. The intent of this option and associated logic is to control the ordering of revisions in deltagroups in changegroups. At the time it was implemented, only changegroup version 1 existed and generaldelta revlogs were just coming into the world. Changegroup version 1 requires that deltas be made against the last revision sent over the wire. Used with generaldelta, this created an impedance mismatch of sorts and resulted in changegroup producers spending a lot of time recomputing deltas. Revision reordering was introduced so outgoing revisions would be sent in "generaldelta order" and producers would be able to reuse internal deltas from storage. Later on, we introduced changegroup version 2. It supported denoting which revision a delta was against. So we no longer needed to sort outgoing revisions to ensure optimal delta generation from the producer. So, subsequent changegroup versions disabled reordering. We also later made the changelog not store deltas by default. And we also made the changelog send out deltas in storage order. Why we do this for changelog, I'm not sure. Maybe we want to preserve revision order across clones? It doesn't really matter for this commit. Fast forward to 2018. We want to abstract storage backends. And having changegroup code require knowledge about how deltas are stored internally interferes with that goal. This commit removes reordering control from changegroup generation. After this commit, the reordering behavior is: * The changelog is always sent out in storage order (no behavior change). * Non-changelog generaldelta revlogs are reordered to always be in DAG topological order (previously, generaldelta revlogs would be emitted in storage order for version 2 and 3 changegroups). * Non-changelog non-generaldelta revlogs are sent in storage order (no behavior change). * There exists no config option to override behavior. The big difference here is that generaldelta revlogs now *always* have their revisions sorted in DAG order before going out over the wire. This behavior was previously only done for changegroup version 1. Version 2 and version 3 changegroups disabled reordering because the interchange format supported encoding arbitrary delta parents, so reordering wasn't strictly necessary. I can think of a few significant implications for this change. Because changegroup receivers will now see non-changelog revisions in DAG order instead of storage order, the internal storage order of manifests and files may differ substantially between producer and consumer. I don't think this matters that much, since the storage order of manifests and files is largely hidden from users. Only the storage order of changelog matters (because `hg log` shows the changelog in storage order). I don't think there should be any controversy here. The reordering of revisions has implications for changegroup producers. Previously, generaldelta revlogs would be emitted in storage order. And in the common case, the internally-stored delta could effectively be copied from disk into the deltagroup delta. This meant that emitting delta groups for generaldelta revlogs would be mostly linear read I/O. This is desirable for performance. With us now reordering generaldelta revlog revisions in DAG order, the read operations may use more random I/O instead of sequential I/O. This could result in performance loss. But with the prevalence of SSDs and fast random I/O, I'm not too worried. (Note: the optimal emission order for revlogs is actually delta encoding order. But the changegroup code wasn't doing that before or after this change. We could potentially implement that in a later commit.) Changegroups in DAG order will have implications for receivers. Previously, receiving storage order might mean seeing a number of interleaved branches. This would mean long delta chains, sparse I/O, and possibly more fulltext revisions instead of deltas, blowing up storage storage. (This is the same set of problems that sparse revlogs aims to address.) With the producer now sending revisions in DAG order, the receiver also stores revisions in DAG order. That means revisions for the same DAG branch are all grouped together. And this should yield better storage outcomes. In other words, sending the reordered changegroup allows the receiver to have better storage order and for the producer to not propagate its (possibly sub-optimal) internal storage order. On the mozilla-unified repository, this change influences bundle generation: $ hg bundle -t none-v2 -a before: time: real 355.680 secs (user 256.790+0.000 sys 16.820+0.000) after: time: real 382.950 secs (user 281.700+0.000 sys 17.690+0.000) before: 7,150,228,967 bytes (uncompressed) after: 7,041,556,273 bytes (uncompressed) before: 1,669,063,234 bytes (zstd l=3) after: 1,628,598,830 bytes (zstd l=3) $ hg unbundle before: time: real 511.910 secs (user 466.750+0.000 sys 32.680+0.000) after: time: real 487.790 secs (user 443.940+0.000 sys 30.840+0.000) 00manifest.d size: source: 274,924,292 bytes before: 304,741,626 bytes after: 245,252,087 bytes .hg/store total file size: source: 2,649,133,490 before: 2,680,888,130 after: 2,627,875,673 We see the bundle size drop. That's probably because if a revlog internally isn't storing a delta, it will choose to delta against the last emitted revision. And on repos with interleaved branches (like mozilla-unified), the previous revision could be an unrelated branch and therefore be a large delta. But with this patch, the previous revision is likely p1 or p2 and a delta should be small. We also see the manifest size drop by ~50 MB. It's worth noting that the manifest actually *increased* in size by ~25 MB in the old strategy and decreased ~25 MB from its source in the new strategy. Again, my explanation for this is that the DAG ordering in the changegroup is resulting in better grouping of revisions in the receiver, which results in more compact delta chains and higher storage efficiency. Unbundle time also dropped. I suspect this is due to the revlog having to work less to compute deltas since the incoming deltas are more optimal. i.e. the receiver spends less time resolving fulltext revisions as incoming deltas bounce around between DAG branches and delta chains. We also see bundle generation time increase. This is not desirable. However, the regression is only significant on the original repository: if we generate a bundle from the repository created from the new, always reordered bundles, we're close to baseline (if not at it with expected noise): $ hg bundle -t none-v2 -a before (original): time: real 355.680 secs (user 256.790+0.000 sys 16.820+0.000) after (original): time: real 382.950 secs (user 281.700+0.000 sys 17.690+0.000) after (new repo): time: real 362.280 secs (user 260.300+0.000 sys 17.700+0.000) This regression is a bit worrying because it will impact serving canonical repositories (that don't have optimal internal storage unless they are reordered - possibly as part of running `hg debugupgraderepo`). However, this regression will only be noticed by very large changegroups. And I'm guessing/hoping that any repository that large is using clonebundles to mitigate server load. Again, sending DAG order isn't the optimal send order for servers: sending in storage-delta order is. But in order to enable storage-optimal send order, we'll need a storage API that handles sorting. Future commits will introduce such an API. Differential Revision: https://phab.mercurial-scm.org/D4721

filelog: drop index attribute (API) The previous commit removed the last consumer of the "index" attribute on the file storage interface. The index is an extremely low-level data structure that is revlog specific and isn't appropriate to expose as part of a generic storage API. There may be a market for an efficient data structure to obtain metadata on every revision for a file. But if there is, it should be designed using e.g. named attributes for lookup instead of a list-like of 8-tuples. Let's drop the attribute from filelog and remove the attribute from the file storage interface. Differential Revision: https://phab.mercurial-scm.org/D4720

upgrade: use rawsize() instead of revlog index The revlog index is a very low-level data structure and it shouldn't be exposed to the storage interface - at least not in its current form. upgrade.py is the only consumer of the index attribute on file storage in the repository. This commit rewrites that final consumer to use rawsize() instead of going through the index. This is actually the more proper API to use, as rawsize() will accurately report the size of revisions which have a negative size in the index. Differential Revision: https://phab.mercurial-scm.org/D4719

manifest: add rawsize() proxy (API) I'm not keen about doing this. But it unblocks efforts to remove "index" from the file storage interface. We will probably remove this once we have a better upgrade API in place. Differential Revision: https://phab.mercurial-scm.org/D4718

upgrade: report size of backing files, not internal storage size upgrade.py is the only consumer of filelog.index, which I'd like to eliminate from the file storage interface. This commit changes the upgrade code to report the storage size of files by looking at the size of the files backing its storage instead of looking at the index. I'm not convinced the approach in this patch will live very long because it is relying on low-level attributes like "opener" and "files," which may behave very differently on non-revlog storage. But the data is only used for reporting purposes and it does get us one step closer to eliminating "index." A side-effect of this change is we now report the size of the revlog index data - not just the revision data. I think this is more accurate. Differential Revision: https://phab.mercurial-scm.org/D4717

filelog: store filename directly on revlog instance This attribute is only used by LFS. It is used by one of the revlog flag processor functions, which gets an instance of the revlog - not the file storage type. So, it makes sense to store this attribute on the revlog instead of the filelog. With this change, I'm pretty confident that LFS is no longer directly accessing file storage interface members that are revlog centric. i.e. it gets us one step closer to eliminating revlog-centric APIs from the file storage interface! Differential Revision: https://phab.mercurial-scm.org/D4715

lfs: access revlog directly LFS is monkeypatching filelog.filelog and is then accessing various filelog attributes in the monkeypatched function. This is all fine. But some of the attributes being accessed by LFS are revlog centric and shouldn't be exposed on the file storage interface. This commit changes the monkeypatched functions to access proxied attributes on self._revlog instead of self. This should be safe to do because non-revlog repositories should not be using filelog instances: instead they should have a separate class to represent file storage. So it is reasonable for LFS to assume the _revlog attribute exists and points to a revlog. Differential Revision: https://phab.mercurial-scm.org/D4714

largefiles: automatically load largefiles extension when required (BC) This is very similar to what we just did for LFS but for largefiles. See recent commit messages for the rationale here. Differential Revision: https://phab.mercurial-scm.org/D4713

lfs: don't add extension to hgrc after clone or share (BC) Now that repository loading in core supports automatically loading the lfs extension when the "lfs" requirement is present, we no longer need to update the .hg/hgrc of newly-created repos to load the lfs extension! I'm marking this as BC because it is a change in behavior. But users should not notice unless they create an LFS repo with new Mercurial and then attempt to use it with an old versions that doesn't support automatic extension loading. Differential Revision: https://phab.mercurial-scm.org/D4712

localrepo: automatically load lfs extension when required (BC) If an unrecognized requirement is present (possibly due to an unloaded extension), the user will get an error message telling them to go to https://mercurial-scm.org/wiki/MissingRequirement for more info. And some requirements clearly map to known extensions shipped by Mercurial. This commit teaches repository loading to automatically map requirements to extensions. We implement support for loading the lfs extension when the "lfs" requirement is present. This behavior feels more user-friendly to me and I'm having trouble coming up with a compelling reason to not do it. The strongest argument I have against is that - strictly speaking - requirements are general repository features and there could be N providers of that feature. e.g. in the case of LFS, there could be another extension implementing LFS support. And the user would want to use this non-official extension rather than the built-in one. The way this patch implements things, the non-official extension could be missing and Mercurial would load the official lfs extension, leading to unexpected behavior. But this feels like a highly marginal use case to me and doesn't outweigh the user benefit of "it just works." If someone really wanted to e.g. use a custom LFS extension, they could prevent the built-in one from being loaded by either defining "extensions.lfs=/path/to/custom/extension" or "extensions.lfs=!", as the automatic extension loading only occurs if there is no config entry for that extension. Differential Revision: https://phab.mercurial-scm.org/D4711

lfs: add repository feature denoting the use of LFS Whether LFS is enabled seems like a useful feature to expose. This will also facilitate some future work around LFS feature compatibility. Differential Revision: https://phab.mercurial-scm.org/D4710

localrepo: define "features" on repository instances (API) There are a handful of attributes/methods on repository instances that describe the behavior of the repository. Furthermore, there is an unbound set of repository descriptors that we may wish to expose. For example, an extension may wish to add a descriptor and have monkeypatched functions look for the presence of an attribute before taking actions. This commit introduces a "features" mechanism to allow repositories to self-advertise an arbitrary set of strings that describe repository behavior or capabilities. We implement basic support for advertising a few features to give an idea of what I want to use this for. Differential Revision: https://phab.mercurial-scm.org/D4709

localrepo: support writing shared file (API) Now that we can create a shared repository via creation options, we can handle other special actions related to share at repo creation time as well. One of the things we do after creating a shared repository is write out a .hg/shared file containing the list of additional things to share. Of which only "bookmarks" is supported. We add a creation option to hold the set of additional items to share. If items are defined, we write out the .hg/shared file at repo creation time. As part of this, we no longer hold the repo lock when writing the file. I'm pretty sure we don't care about the tiny race condition window. I'm also pretty sure the reason we used the lock was because the vfs auditor on the repo instance complained otherwise. Since the repo creation code doesn't have an audited vfs, we don't need to appease it. Because we no longer need to tell the post share hook what items are shared, the "bookmarks" argument to that function has been dropped, incurring an API change. Differential Revision: https://phab.mercurial-scm.org/D4708

localrepo: support shared repo creation Previously, hg.share() had its own logic for creating a new repository on the filesystem. With the recent introduction of the createopts dict for passing options to influence repository creation, it is now possible to consolidate the repo creation code for both the normal and shared use cases. This commit teaches the repo creation code in localrepo to recognize when we're creating a shared repo and to act appropriately. Meaningful behavior should be identical. However, there are a few subtle changes: * The .hg/requires file is written out in sorted order (rather than having share-related requirements appended at end). * The .hg directory is created with notindexed=True when a shared repo is being created. Differential Revision: https://phab.mercurial-scm.org/D4707

localrepo: validate directories before creating any There is no meaningful change in behavior because wdir would already exist in the case where we raised RepoError. But I think the code is easier to read if we do all validation first then take actions with side-effects. Differential Revision: https://phab.mercurial-scm.org/D4706

localrepo: add missing join() Differential Revision: https://phab.mercurial-scm.org/D4705

revlog: use proper version comparison during verify Verify appears to want to compare the changelog's revlog version number with the version number of filelogs and error if they are different. But what it was actually doing was comparing the full 32-bit header integer, which contains 2 shorts: 1 for the revlog version number and 1 for feature flags. This commit tweaks the verification code so it only looks at the version number component of the header and emits a warning if they differ. The new code is more robust because it accounts for future revlog version numbers without them needing to be special cased. Differential Revision: https://phab.mercurial-scm.org/D4704

filelog: stop proxying checksize() (API) This was only used by verify code. And the check using it is now implemented as part of verifyintegrity(). The method is unused and is revlog-centric, which means it isn't appropriate for the file storage interface. So remove it. Differential Revision: https://phab.mercurial-scm.org/D4703

filelog: remove version attribute (API) This was only used by verify code. The check it was used for is now implemented as part of the verifyintegrity() implementation. The attribute is now unused, is revlog-specific, and isn't appropriate to be exposing on the file storage interface. So drop it. Differential Revision: https://phab.mercurial-scm.org/D4702

verify: start to abstract file verification Currently, the file storage interface has a handful of attributes that are exclusively or near-exclusively used by repo verification code. In order to support verification on non-revlog/alternate storage backends, we'll need to abstract verification so it can be performed in a storage-agnostic way. This commit starts that process. We establish a new verifyintegrity() method on revlogs and expose it to the file storage interface. Most of verify.verifier.checklog() has been ported to this new method. We need a way to represent verification problems. So we invent an interface to represent a verification problem, invent a revlog type to implement that interface, and use it. The arguments to verifyintegrity() will almost certainly change in the future, once more functionality is ported from the verify code. And the "revlogv1" version check is very hacky. (The code in verify is actually buggy because it is comparing the full 32-bit header integer instead of just the revlog version short. I'll likely fix this in a subsequent commit.) Differential Revision: https://phab.mercurial-scm.org/D4701

unionrepo: remove _constructmanifest() It is unused after a previous refactor. Spotted in D4641. Differential Revision: https://phab.mercurial-scm.org/D4700

merge with stable

encoding: remove unnecessary lambdas from _encodingfixers They have been unnecessary since 1a3a08b5d4d5 (encoding: remove workaround for locale.getpreferredencoding(), 2017-05-13). Also rename the variable since "fixer" sounds like a function. Differential Revision: https://phab.mercurial-scm.org/D4743

py3: cast exception to bytes In order to appease Python 3. Differential Revision: https://phab.mercurial-scm.org/D4733

py3: cast exception to bytes This was raising a TypeError on Python 3 and preventing most (all?) wireprotov2 commands from working. Differential Revision: https://phab.mercurial-scm.org/D4731

py3: remove a couple of superfluous calls to pycompat.rapply() These places can only be strings.

py3: byteify an inline python test extension # skip-blame for b'' prefixing

py3: conditionalize access to socketserver.ForkingMixIn This is no longer exported on platforms that don't support forking, as of 3.6. https://github.com/python/cpython/commit/aadff9bea61a2fc9f4cf0f213f0ee50fc54d6574

convert: fix a file descriptor leak test-check-code flagged this after I changed this line for something unrelated.

merge with stable

revlog: catch more specific exception in shortest() Since revlog._partialmatch() catches RevlogError coming from cext and re-raises AmbiguousPrefixLookupError, catching RevlogError here seems less correct. Differential Revision: https://phab.mercurial-scm.org/D4735

py3: update missing module list in test-check-py3-compat.t for Windows

py3: add b'' prefixes to wire protocol test Otherwise the CBOR encoder fails on Python 3 due to lacking support for encoding str/unicode. # skip-blame just some b'' prefixes Differential Revision: https://phab.mercurial-scm.org/D4734

py3: use pycompat.strkwargs() Otherwise we get an error attempting to dispatch a command with arguments because we're passing a dict with bytes keys. Differential Revision: https://phab.mercurial-scm.org/D4732

py3: ensure _start_response() is called with system string This was preventing HTTP 500's from being sent in Python 3. Differential Revision: https://phab.mercurial-scm.org/D4730

py3: convert arguments, cwd and env to native strings when spawning subprocess This keeps Windows happy.

py3: apply byteskwargs to contrib/perf

py3: un-byteify strings around os.system() and os.devnull in contrib/perf

py3: work around the lack of sys.maxint in contrib/perf

py3: switch contrib/perf from xrange to pycompat.xrange

py3: handle sysstr conversion around get/set attr in contrib/perf

py3: proxy posixfile objects to re-add a useful 'name' attribute on Windows This file object is used in the vfs layer, so there are many errors like this: ... File "mercurial\localrepo.py", line 2569, in savecommitmessage return self.pathto(fp.name[len(self.root) + 1:]) TypeError: 'int' object is not subscriptable It looks like the 'name' value is actually the fileno() value, and the documentation says the name parameter to PyFile_FromFd() is ignored. [1] I tried just assigning the attribute after osutil.posixfile() returns, but that crashes saying that it's read-only. [1] https://docs.python.org/3.6/c-api/file.html

py3: don't use os.getcwdb() on Windows to avoid DeprecationWarnings See also ac32685011a3.

py3: rename pycompat.getcwd() to encoding.getcwd() (API) We need to avoid os.getcwdb() on Windows to avoid DeprecationWarnings, and we need encoding.strtolocal() to encode the result of os.getcwd().

py3: whitelist two more passing tests Caught by the ratchet, but initially only the non-legacy path of test-clone-uncompressed.t was passing. That required the preceding patch. Differential Revision: https://phab.mercurial-scm.org/D4729

keepalive: be more careful about self._rbuf when calling super impls In Python 3, HTTPResponse implements read() in terms of readinto(), which was calling back into our readinto(), which duplicates self._rbuf if it's not empty. Before calling into super's read(), ensure self._rbuf is empty. Inheritance is bad, and undocumented self-use of your public API is one of many reasons. Differential Revision: https://phab.mercurial-scm.org/D4728

wireprotov2: teach changesetdata to fetch ancestors until depth For shallow clone, it is useful to specify a starting node and tell the server to send up to N ancestors from that starting point. This enables the server to perform the DAG walk without the client having to discover the base/stop node(s) first. This commit implements support for said queries on the changesetdata command. Differential Revision: https://phab.mercurial-scm.org/D4621

wireprotov2: allow multiple fields to follow revision maps The *data wire protocol commands emit a series of CBOR values. Because revision/delta data may be large, their data is emitted outside the map as a top-level bytestring value. Before this commit, we'd emit a single optional bytestring value after the revision descriptor map. This got the job done. But it was limiting in that we could only send a single field. And, it required the consumer to know that the presence of a key in the map implied the existence of a following bytestring value. This commit changes the encoding strategy so top-level bytestring values in the stream are explicitly denoted in a "fieldsfollowing" key. This key contains an array defining what fields that follow and the expected size of each field. By defining things this way, we can easily send N bytestring values without any ambiguity about their order. In addition, clients only need to know how to parse ``fieldsfollowing`` to know if extra values are present. Because this breaks backwards compatibility, we've bumped the version number of the wire protocol version 2 API endpoint. Differential Revision: https://phab.mercurial-scm.org/D4620

wireprotov2: advertise set of valid values for requestable fields changesetdata, manifestdata, and filedata all allow the caller to specify what data fields to request. Data fields are extensible and may evolve over time. In order to prevent clients from making requests for fields that are not available, the client needs to know what fields are available. This commit teaches the server to declare a set of "valid values" for wire protocol command arguments. That set of values is exposed in the command's capabilities descriptor. The changesetdata, manifestdata, and filedata commands all declare their set of available "fields." Differential Revision: https://phab.mercurial-scm.org/D4619

wireprotov2: expose rich arguments metadata Now that we internally store rich metadata about arguments, it makes sense to make that metadata available to the client. This will allow clients to validate outgoing command requests before they are sent over the wire. Strictly speaking, we should bump the wire protocol version for this change since it is backwards incompatible. But no client-side code touches the arguments map and I don't want to incur the work. Differential Revision: https://phab.mercurial-scm.org/D4618

wireprotov2: advertise recognized path filter prefixes While the wire protocol doesn't yet support it, we'll eventually have commands that accept narrow patterns to specify the set of files relevant to a command. For security and performance reasons, only specific filter types are allowed. This commit teaches the server to advertise the set of allowed filter types. By doing so, clients can e.g. validate user-specified patterns against the server's abilities without having to send a command to retrieve data. Having the data in the capabilities data structure will also serve as a check against unwanted BC. Differential Revision: https://phab.mercurial-scm.org/D4616

wireprotov2: declare command arguments richly Previously, we declared command arguments with an example of their value. After this commit, we declare command arguments as a dict of metadata. This allows us to define the value type, whether the argument is required, and provide default values. This in turn allows us to have nice things, such as less boilerplate code in individual commands for validating input and assigning default values. It should also make command behavior more consistent as a result. Test output changed slightly because I realized that the "fields" argument wasn't being consistently defined as a set. Oops! Other test output changed because of slight differences in code performing type validation. Differential Revision: https://phab.mercurial-scm.org/D4615

chgserver: do not send system() back to client if stdio redirected (issue5992) As the chg client doesn't know server-side stdio redirection, the server shouldn't upcall on "runsystem" request if the stdio streams are redirected. This patch teaches ui to remember the redirection flag, which is updated by the caller right now. Future patches (for default) will add ui methods to manage this flag internally.