Gregory Szorc <gregory.szorc@gmail.com> [Thu, 09 Aug 2018 16:11:24 -0700] rev 39260
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
Gregory Szorc <gregory.szorc@gmail.com> [Thu, 09 Aug 2018 16:02:14 -0700] rev 39259
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
Gregory Szorc <gregory.szorc@gmail.com> [Thu, 09 Aug 2018 15:40:14 -0700] rev 39258
repository: formalize interfaces for revision deltas and requests
Now that we've sufficiently abstracted how revision deltas are
produced in changegroup code, we can now start the process of
formalizing that as part of the interfaces defined in the
repository module.
This commit essentially converts the revisiondelta and
revisiondeltarequest classes into well-defined interfaces. This
is not strictly necessary. But I want all types formalized by the
storage interface to have interfaces. This makes it much easier
to test for interface conformance and for implementing new
storage backends.
Because the interface is documented, comments and docstrings from
changegroup.py have been dropped.
Differential Revision: https://phab.mercurial-scm.org/D4225
Gregory Szorc <gregory.szorc@gmail.com> [Thu, 09 Aug 2018 14:31:25 -0700] rev 39257
changegroup: move node sorting into deltagroup()
The 3 callers of deltagroup() all sort nodes and convert to
integer revs immediately before calling deltagroup().
Stepping back a bit, aside from the constraints on node ordering
that always apply (namely that a node must follow its ancestor),
it makes sense for sorting to be an implementation detail of the
store. Moving the sorting into deltagroup() will open the door
for moving sorting into a storage API.
The test for the changelog in deltagroup() to impact the sorting
method is a bit hacky. I suspect this will be resolved once
we establish a formal interface for delta group generation
and port changelog to it.
Differential Revision: https://phab.mercurial-scm.org/D4224