comparison mercurial/repository.py @ 39230:b518d495a560

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

39229:2646b8d66b7b

            return

        raise error.CapabilityError(
            _('cannot %s; remote repository does not support the %r '
              'capability') % (purpose, name))

class ifilerevisionssequence(interfaceutil.Interface):
    """Contains index data for all revisions of a file.

    Types implementing this behave like lists of tuples. The index

39230:b518d495a560

            return

        raise error.CapabilityError(
            _('cannot %s; remote repository does not support the %r '
              'capability') % (purpose, name))

class irevisiondelta(interfaceutil.Interface):
    """Represents a delta between one revision and another.

    Instances convey enough information to allow a revision to be exchanged
    with another repository.

    Instances represent the fulltext revision data or a delta against
    another revision. Therefore the ``revision`` and ``delta`` attributes
    are mutually exclusive.

    Typically used for changegroup generation.
    """

    node = interfaceutil.Attribute(
        """20 byte node of this revision.""")

    p1node = interfaceutil.Attribute(
        """20 byte node of 1st parent of this revision.""")

    p2node = interfaceutil.Attribute(
        """20 byte node of 2nd parent of this revision.""")

    linknode = interfaceutil.Attribute(
        """20 byte node of the changelog revision this node is linked to.""")

    flags = interfaceutil.Attribute(
        """2 bytes of integer flags that apply to this revision.""")

    basenode = interfaceutil.Attribute(
        """20 byte node of the revision this data is a delta against.

        ``nullid`` indicates that the revision is a full revision and not
        a delta.
        """)

    baserevisionsize = interfaceutil.Attribute(
        """Size of base revision this delta is against.

        May be ``None`` if ``basenode`` is ``nullid``.
        """)

    revision = interfaceutil.Attribute(
        """Raw fulltext of revision data for this node.""")

    delta = interfaceutil.Attribute(
        """Delta between ``basenode`` and ``node``.

        Stored in the bdiff delta format.
        """)

class irevisiondeltarequest(interfaceutil.Interface):
    """Represents a request to generate an ``irevisiondelta``."""

    node = interfaceutil.Attribute(
        """20 byte node of revision being requested.""")

    p1node = interfaceutil.Attribute(
        """20 byte node of 1st parent of revision.""")

    p2node = interfaceutil.Attribute(
        """20 byte node of 2nd parent of revision.""")

    linknode = interfaceutil.Attribute(
        """20 byte node to store in ``linknode`` attribute.""")

    basenode = interfaceutil.Attribute(
        """Base revision that delta should be generated against.

        If ``nullid``, the derived ``irevisiondelta`` should have its
        ``revision`` field populated and no delta should be generated.

        If ``None``, the delta may be generated against any revision that
        is an ancestor of this revision. Or a full revision may be used.

        If any other value, the delta should be produced against that
        revision.
        """)

    ellipsis = interfaceutil.Attribute(
        """Boolean on whether the ellipsis flag should be set.""")

class ifilerevisionssequence(interfaceutil.Interface):
    """Contains index data for all revisions of a file.

    Types implementing this behave like lists of tuples. The index