mercurial/utils/storageutil.py

49785:fa955e3f6aee

    if deltamode == repository.CG_DELTAMODE_PREV or assumehaveparentrevisions:
        prevrev = store.parentrevs(revs[0])[0]

    # Set of revs available to delta against.
    available = set()

    def is_usable_base(rev):
        return rev != nullrev and rev in available

    for rev in revs:
        if rev == nullrev:
            continue

        node = fnode(rev)
        p1rev, p2rev = store.parentrevs(rev)

        if deltaparentfn:
            deltaparentrev = deltaparentfn(rev)
        else:
            deltaparentrev = nullrev

        # There is a delta in storage. We try to use that because it
        # amounts to effectively copying data from storage and is
        # therefore the fastest.
        elif deltaparentrev != nullrev:
            # Base revision was already emitted in this group. We can
            # always safely use the delta.
            if is_usable_base(deltaparentrev):
                baserev = deltaparentrev

            # Base revision is a parent that hasn't been emitted already.
            # Use it if we can assume the receiver has the parent revision.
            elif assumehaveparentrevisions and deltaparentrev in (p1rev, p2rev):
                baserev = deltaparentrev

            # No guarantee the receiver has the delta parent. Send delta
            # against last revision (if possible), which in the common case
            # should be similar enough to this revision that the delta is
            # reasonable.
            elif prevrev is not None:

49786:0bda07f34c01

    if deltamode == repository.CG_DELTAMODE_PREV or assumehaveparentrevisions:
        prevrev = store.parentrevs(revs[0])[0]

    # Set of revs available to delta against.
    available = set()
    parents = []

    def is_usable_base(rev):
        """Is a delta against this revision usable over the wire"""
        if rev == nullrev:
            return False
        # Base revision was already emitted in this group.
        if rev in available:
            return True
        # Base revision is a parent that hasn't been emitted already.
        if assumehaveparentrevisions and rev in parents:
            return True
        return False

    for rev in revs:
        if rev == nullrev:
            continue

        node = fnode(rev)
        parents[:] = p1rev, p2rev = store.parentrevs(rev)

        if deltaparentfn:
            deltaparentrev = deltaparentfn(rev)
        else:
            deltaparentrev = nullrev

        # There is a delta in storage. We try to use that because it
        # amounts to effectively copying data from storage and is
        # therefore the fastest.
        elif deltaparentrev != nullrev:
            # If the stored delta works, let us use it !
            if is_usable_base(deltaparentrev):
                baserev = deltaparentrev
            # No guarantee the receiver has the delta parent. Send delta
            # against last revision (if possible), which in the common case
            # should be similar enough to this revision that the delta is
            # reasonable.
            elif prevrev is not None: