changegroup: clean up changelog callback changelog.read() calls changelog.changelogrevion() then turns it into a tuple. Let's call changelogrevision() directly and used named attributes to make code easier to read. While we're here, also change some variable names to make code easier to read. Differential Revision: https://phab.mercurial-scm.org/D4270

changegroup: call rev() on manifestlog instance rev() is part of the imanifestlog interface and should be used instead of using the private revlog instance, which is an implementation detail. Differential Revision: https://phab.mercurial-scm.org/D4269

manifest: rename dir to tree to avoid shadowing built-in And update the argument name in the imanifestlog interface. Differential Revision: https://phab.mercurial-scm.org/D4268

repository: remove candelta() from ifileindex candelta() was previously called by changegroup code. With delta generation moved to the storage API, there are no more external consumers of this method and it can be removed from the storage interface. Differential Revision: https://phab.mercurial-scm.org/D4236

changegroup: rename dir to tree to avoid shadowing a built-in Differential Revision: https://phab.mercurial-scm.org/D4235

repository: remove storedeltachains from ifilestorage The ifilestorage interface was bootstrapped from requirements of callers outside the storage implementation (revlogs). I believe we even made some members public so they could be part of the interface! Historically, the changegroup code was a gross offender when it came to accessing low-level storage primitives. There are a handful of members on the ifilestorage interface that are/were used only for changegroup code. With the recent refactor of changegroup code and the establishment of a formal API on the storage interface for producing revision deltas, the changegroup code is no longer accessing these low-level primitives related to delta generation directly. Instead, things are abstracted away in the storage implementation. This means we can remove elements from the storage interface that are no longer needed. We start with "storedeltachains." We remove it from the interface. Then we make it a private attribute and update all references. .. api:: storedeltachains has been dropped from ifilestorage interface .. api:: storedeltachains on revlog classes is now _storedeltachains Differential Revision: https://phab.mercurial-scm.org/D4227

repository: establish API for emitting revision deltas With our revision delta and revision delta request interfaces defined, it is now time to define a method on storage interfaces for using them. So far, the only storage interface that is well-defined and used is file storage. So that is the only interface we need to add a method on. We define an ``emitrevisiondeltas()`` method that takes an iterable of ``irevisiondeltarequest``s and turns them into ``irevisiondelta`` instances. changegroup._handlerevisiondeltarequest() and the looping logic from changegroup.deltagroup() has effectively been moved to revlog.emitrevisiondeltas(). Our filelog wrapper class proxies its emitrevisiondeltas() to the internal revlog instance. The simple store test extension used to verify sanity of storage abstractions has also implemented emitrevisiondeltas() for file storage and the test harness when run with this extension doesn't seem to exhibit any regressions. Rather than create a shared type to represent revision deltas, each storage backend has its own type and the class name identifies where the revision delta was derived from. Differential Revision: https://phab.mercurial-scm.org/D4226