testing: add interface unit tests for file storage Our strategy for supporting alternate storage backends is to define interfaces for everything then "code to the interface." We already have interfaces for various primitives, including file and manifest storage. What we don't have is generic unit tests for those interfaces. Up to this point we've been relying on high-level integration tests (mainly in the form of existing .t tests) to test alternate storage backends. And my experience with developing the "simple store" test extension is that such testing is very tedious: it takes several minutes to run all tests and when you find a failure, it is often non-trivial to debug. This commit starts to change that. This commit introduces the mercurial.testing.storage module. It contains testing code for storage. Currently, it defines some unittest.TestCase classes for testing the file storage interfaces. It also defines some factory functions that allow a caller to easily spawn a custom TestCase "bound" to a specific file storage backend implementation. A new .py test has been added. It simply defines a callable to produce filelog and transaction instances on demand and then "registers" the various test classes so the filelog class can be tested with the storage interface unit tests. As part of writing the tests, I identified a couple of apparent bugs in revlog.py and filelog.py! These are tracked with inline TODO comments. Writing the tests makes it more obvious where the storage interface is lacking. For example, we raise either IndexError or error.LookupError for missing revisions depending on whether we use an integer revision or a node. Also, we raise error.RevlogError in various places when we should be raising a storage-agnostic error type. The storage interfaces are currently far from perfect and there is much work to be done to improve them. But at least with this commit we finally have the start of unit tests that can be used to "qualify" the behavior of a storage backend. And when implementing and debugging new storage backends, we now have an obvious place to define new tests and have obvious places to insert breakpoints to facilitate debugging. This should be invaluable when implementing new storage backends. I added the mercurial.testing package because these interface conformance tests are generic and need to be usable by all storage backends. Having the code live in tests/ would make it difficult for storage backends implemented in extensions to test their interface conformance. First, it would require obtaining a copy of Mercurial's storage test code in order to test. Second, it would make testing against multiple Mercurial versions difficult, as you would need to import N copies of the storage testing code in order to achieve test coverage. By making the test code part of the Mercurial distribution itself, extensions can `import mercurial.testing.*` to access and run the test code. The test will run against whatever Mercurial version is active. FWIW I've always wanted to move parts of run-tests.py into the mercurial.* package to make the testing story simpler (e.g. imagine an `hg debugruntests` command that could invoke the test harness). While I have no plans to do that in the near future, establishing the mercurial.testing package does provide a natural home for that code should someone do this in the future. Differential Revision: https://phab.mercurial-scm.org/D4650

narrow: remove narrowrevlog Core now automatically enables ellipsis support on revlogs when repositories have narrow enabled. So, we no longer need to globally register the revlog flag as part of activating the narrow extension and this code can be deleted. A side effect of this change is that repositories will now raise an error on encountering an ellipsis flag when the narrow extension is loaded. Previously, loading the narrow extension on a non-narrow repo could result in silent usage of the ellipsis flag. This could lead to undetected bugs. I think the new behavior is more correct. Differential Revision: https://phab.mercurial-scm.org/D4649

localrepo: enable ellipsis flag on revlogs when repo is narrow If the narrow requirement is present, revlogs created for that repository will have the ellipsis flag enabled. This is the same behavior that the narrow extension exhibits. Except the ellipsis flag won't be enabled on repos/revlogs that don't have the narrow requirement. Differential Revision: https://phab.mercurial-scm.org/D4648

revlog: add opener option to enable ellipsis flag processor The ellipsis flag processor can now be registered by specifying an opener option when constructing a revlog instance. This allows us to enable ellipsis flags on a per-revlog basis. Differential Revision: https://phab.mercurial-scm.org/D4647

revlog: store flag processors per revlog Previously, revlog flag processing would consult a global dict when processing flags. This was simple. But it had the undesired side-effect that any extension could load flag processors once and those flag processors would be available to any revlog that was subsequent loaded in the process. e.g. in hgweb, if the narrow extension were loaded for repo A but not repo B, repo B would be able to decode ellipsis flags even though it shouldn't be able to. Making the flag processors dict per-revlog allows us to have per-revlog controls over what flag processors are available, thus preserving desired granular access to flag processors depending on the revlog's needs. If a flag processor is globally registered, it is still globally available. So this commit should not meaningfully change behavior. Differential Revision: https://phab.mercurial-scm.org/D4646

revlog: define ellipsis flag processors in core We will soon be teaching core to honor the ellipsis flag on revlogs. Moving the definition of the processor functions to core is the first step in this. The processor is still not registered unless the narrow extension is loaded. Differential Revision: https://phab.mercurial-scm.org/D4645

narrow: remove custom filelog type This functionality is now handled by core as of the previous commit. I wanted this to be a standalone commit because the deleted code makes a reference to remotefilelog's file type missing a node() method and this may have implications to narrow+remotefilelog usage. The code in core doesn't perform this check and therefore behavior may be subtly different and buggy. But I /think/ the check is merely a performance optimization and nothing more. So I'm optimistic this will continue to "just work." Differential Revision: https://phab.mercurial-scm.org/D4644

filelog: custom filelog to be used with narrow repos Narrow repos may have file revisions whose copy/rename metadata references files not in the store. This can pose problems when consumers attempt to access a missing referenced file revision. The narrow extension hacks around this problem by implementing a derived filelog type that provides custom implementations of renamed(), size(), and cmp() which handle renames against files not in the narrow spec by silently removing the rename metadata. While silently dropping metadata isn't the most robust solution, it is the easiest to implement. This commit ports the custom narrow filelog class to core. When a narrow repo is constructed, its ifilestorage creation function will automatically use the new filelog type. This means the extra logic is 0 cost for non-narrow repos and shouldn't interfere with their operation. Differential Revision: https://phab.mercurial-scm.org/D4643

localrepo: iteratively derive local repository type This commit implements the dynamic local repository type derivation that was explained in the recent commit bfeab472e3c0 "localrepo: create new function for instantiating a local repo object." Instead of a static localrepository class/type which must be customized after construction, we now dynamically construct a type by building up base classes/types to represent specific repository interfaces. Conceptually, the end state is similar to what was happening when various extensions would monkeypatch the __class__ of newly-constructed repo instances. However, the approach is inverted. Instead of making the instance then customizing it, we do the customization up front by influencing the behavior of the type then we instantiate that custom type. This approach gives us much more flexibility. For example, we can use completely separate classes for implementing different aspects of the repository. For example, we could have one class representing revlog-based file storage and another representing non-revlog based file storage. When then choose which implementation to use based on the presence of repo requirements. A concern with this approach is that it creates a lot more types and complexity and that complexity adds overhead. Yes, it is true that this approach will result in more types being created. Yes, this is more complicated than traditional "instantiate a static type." However, I believe the alternatives to supporting alternate storage backends are just as complicated. (Before I arrived at this solution, I had patches storing factory functions on local repo instances for e.g. constructing a file storage instance. We ended up having a handful of these. And this was logically identical to assigning custom methods. Since we were logically changing the type of the instance, I figured it would be better to just use specialized types instead of introducing levels of abstraction at run-time.) On the performance front, I don't believe that having N base classes has any significant performance overhead compared to just a single base class. Intuition says that Python will need to iterate the base classes to find an attribute. However, CPython caches method lookups: as long as the __class__ or MRO isn't changing, method attribute lookup should be constant time after first access. And non-method attributes are stored in __dict__, of which there is only 1 per object, so the number of base classes for __dict__ is irrelevant. Anyway, this commit splits up the monolithic completelocalrepository interface into sub-interfaces: 1 for file storage and 1 representing everything else. We've taught ``makelocalrepository()`` to call a series of factory functions which will produce types implementing specific interfaces. It then calls type() to create a new type from the built-up list of base types. This commit should be considered a start and not the end state. I suspect we'll hit a number of problems as we start to implement alternate storage backends: * Passing custom arguments to __init__ and setting custom attributes on __dict__. * Customizing the set of interfaces that are needed. e.g. the "readonly" intent could translate to not requesting an interface providing methods related to writing. * More ergonomic way for extensions to insert themselves so their callbacks aren't unconditionally called. * Wanting to modify vfs instances, other arguments passed to __init__. That being said, this code is usable in its current state and I'm convinced future commits will demonstrate the value in this approach. Differential Revision: https://phab.mercurial-scm.org/D4642

localrepo: pass root manifest into manifestlog.__init__ Today, localrepository has a method that can be overloaded which returns an instance of the root manifest storage object. When a manifestlog is created, it calls this private method and stores the root manifest object on it. This "hook" on localrepository isn't part of the documented interface. It isn't compatible with our desire to make repo storage determined before the repo object is constructed. This commit changes manifestlog.__init__ to accept the root storage object instead of calling into the repo to construct it. By doing things this way, the repo instance is responsible for constructing the manifest storage object directly. This does mean that other derived repo types need to overload manifestlog(). But they should have been doing this already, as manifestlog() is typically decorated in a storage-specific way. e.g. localrepository.manifestlog() is decorated as @storecache('00manifest.i'). And this assumes that a 00manifest.i file exists in the store vfs. This condition may not hold for repository types using non-revlog storage. So it is important for special repo types to override manifestlog() to remove this file association. The code changed in perf is wrong because it isn't compatible with older Mercurial versions. But I'm pretty sure the code was broken on older versions before this commit. It only affects `hg perftags`. I don't care enough to fix that at this time. .. api:: ``manifest.manifestlog.__init__()`` now receives the root manifest storage instance instead of calling into a private method on the repo object to obtain it. Differential Revision: https://phab.mercurial-scm.org/D4641

py3: create built in exceptions with str type messages in win32.py I hit an IOError in unlink() in test-pathconflicts-basic.t, that then crashed as it was handled: File "mercurial\dispatch.py", line 359, in _runcatch return _callcatch(ui, _runcatchfunc) File "mercurial\dispatch.py", line 367, in _callcatch return scmutil.callcatch(ui, func) File "mercurial\scmutil.py", line 252, in callcatch ui.error(_("abort: %s\n") % encoding.strtolocal(inst.strerror)) File "mercurial\encoding.py", line 205, in unitolocal return tolocal(u.encode('utf-8')) AttributeError: 'bytes' object has no attribute 'encode'

tests: stabilize test-shelve.t#phasebased for #no-symlink and #no-execbit The rev number ended up being 11 instead of 13 on Windows. If I ever get back to issue2020, this will go away.

debugdirstate: deprecate --nodates in favor of --no-dates We have supported 'no-' prefixes for boolean flag for a few years now, so I was expecting it to be --no-dates. I noticed that we have --nodates options for a few more commands (e.g. `hg diff`), but I'll leave that for another day. Differential Revision: https://phab.mercurial-scm.org/D4693

py3: fix a type error in hghave.has_hardlink test-hghave.t was failing with: feature hardlink failed: argument 1: <class 'TypeError'>: wrong type

narrow: remove hack to read narowspec from shared .hg directory This was another leftover from 576eef1ab43d (narrow: move .hg/narrowspec to .hg/store/narrowspec (BC), 2018-08-02), in addition to 623081f2abc2 (narrow: remove hack to write narrowspec to shared .hg directory, 2018-09-12). Differential Revision: https://phab.mercurial-scm.org/D4692

streamclone: reimplement nested context manager It's gone in Python 3, and you can't *ctxs into a with statement. Sigh. Differential Revision: https://phab.mercurial-scm.org/D4690

bundle2: grab kwarg using sysstr # skip-blame just an r prefix on a string Differential Revision: https://phab.mercurial-scm.org/D4691

py3: mark another passing test Differential Revision: https://phab.mercurial-scm.org/D4689

bookmarks: remove --active in favor of --list It's weird that we have both --active and --inactive options meaning completely different things. Instead of adding a one-off option, let's document the way to display the active bookmark by using -l/--list. No deprecated option is added since --active isn't released yet.

bookmarks: add explicit option to list bookmarks of the given names This is a generalized form of the --active option. A redundant sorted() call is removed. There was no point to update dict items in lexicographical order.

bookmarks: reject --delete with --inactive which makes no sense A deleted bookmark is neither active nor inactive.

bookmarks: parse out --inactive to action early The --inactive option can't be directly mapped to an action or a modifier. With any names, it means to add/rename to inactive bookmarks. Without names, it means to deactivate the current bookmark. This patch separates them to "inactive" flag and "action == 'inactive'".

bookmarks: parse out implicit "add" action early This prepares for adding -l/--list option, which can be combined with the positional arguments.

bookmarks: clarify that opts['rename'] points to an old bookmark to be renamed

bookmarks: refactor option checking to pick one from --delete/rename/active

bookmarks: convert opts to bytes dict early

bookmarks: pass in formatter to printbookmarks() instead of opts (API) This clarifies that user options have to be processed before calling printbookmarks().

strip: ignore orphaned internal changesets while computing safe strip roots Internal changeset can be safely garbage collected, so we can ignore them during safestrip. (Another phase for internal changeset that must be kept in the repository might be introduced later).

shelve: no longer strip internal commit when using internal phase When the internal phase is used, the internal commits we create during shelve will be automatically hidden, and we don't need to strip them. Avoiding strips gives much better performances and is less traumatic for caches. Test changes are all related to revision numbers increasing more quickly since we avoid stripping. At the end of `test-shelve.t` we now need manually strip the shelve-commit in addition to the x.shelve file deletion. This emulates a preexisting shelve after a repository upgrade. Note: The hidden internal commits confuses rebase a bit as shown by a new test added. This will happen when the user have shelve commits on top of a changeset to be rebased. We'll fix this in the next commit. As we still use a backup bundle, rebase can just strip the internal changesets and be fine.

meld: enable auto-merge This tells meld to resolve trivial conflicts before presenting the user with the remaining conflicts. This was attempted 5 years ago, but then --auto-merge was too new that the patch was rejected out of concern that users still had an older version of meld installed [1]. Maybe it's safe to assume that they have a newer version now. [1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2013-April/050084.html Differential Revision: https://phab.mercurial-scm.org/D4665