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