comparison mercurial/exchange.py @ 38791:7e66e7999bdd

exchange: move _computeellipsis() from narrow

This is also referenced as part of the narrow changegroup code and
therefore needs to move to core before we can integrate the narrow
changegroup code into core.

Differential Revision: https://phab.mercurial-scm.org/D4009

38790:3e7387337a3c

from .i18n import _
from .node import (
    bin,
    hex,
    nullid,
)
from .thirdparty import (
    attr,
)
from . import (
    bookmarks as bookmod,
    bundle2,
    changegroup,
    discovery,
    error,
    lock as lockmod,
    logexchange,
    narrowspec,

    new_args['includepats'] = req_includes
    if req_excludes:
        new_args['excludepats'] = req_excludes
    return new_args

def caps20to10(repo, role):
    """return a set with appropriate options to use bundle20 during getbundle"""
    caps = {'HG20'}
    capsblob = bundle2.encodecaps(bundle2.getrepocaps(repo, role=role))
    caps.add('bundle2=' + urlreq.quote(capsblob))

38791:7e66e7999bdd

from .i18n import _
from .node import (
    bin,
    hex,
    nullid,
    nullrev,
)
from .thirdparty import (
    attr,
)
from . import (
    bookmarks as bookmod,
    bundle2,
    changegroup,
    dagutil,
    discovery,
    error,
    lock as lockmod,
    logexchange,
    narrowspec,

    new_args['includepats'] = req_includes
    if req_excludes:
        new_args['excludepats'] = req_excludes
    return new_args

def _computeellipsis(repo, common, heads, known, match, depth=None):
    """Compute the shape of a narrowed DAG.

    Args:
      repo: The repository we're transferring.
      common: The roots of the DAG range we're transferring.
              May be just [nullid], which means all ancestors of heads.
      heads: The heads of the DAG range we're transferring.
      match: The narrowmatcher that allows us to identify relevant changes.
      depth: If not None, only consider nodes to be full nodes if they are at
             most depth changesets away from one of heads.

    Returns:
      A tuple of (visitnodes, relevant_nodes, ellipsisroots) where:

        visitnodes: The list of nodes (either full or ellipsis) which
                    need to be sent to the client.
        relevant_nodes: The set of changelog nodes which change a file inside
                 the narrowspec. The client needs these as non-ellipsis nodes.
        ellipsisroots: A dict of {rev: parents} that is used in
                       narrowchangegroup to produce ellipsis nodes with the
                       correct parents.
    """
    cl = repo.changelog
    mfl = repo.manifestlog

    cldag = dagutil.revlogdag(cl)
    # dagutil does not like nullid/nullrev
    commonrevs = cldag.internalizeall(common - set([nullid])) | set([nullrev])
    headsrevs = cldag.internalizeall(heads)
    if depth:
        revdepth = {h: 0 for h in headsrevs}

    ellipsisheads = collections.defaultdict(set)
    ellipsisroots = collections.defaultdict(set)

    def addroot(head, curchange):
        """Add a root to an ellipsis head, splitting heads with 3 roots."""
        ellipsisroots[head].add(curchange)
        # Recursively split ellipsis heads with 3 roots by finding the
        # roots' youngest common descendant which is an elided merge commit.
        # That descendant takes 2 of the 3 roots as its own, and becomes a
        # root of the head.
        while len(ellipsisroots[head]) > 2:
            child, roots = splithead(head)
            splitroots(head, child, roots)
            head = child  # Recurse in case we just added a 3rd root

    def splitroots(head, child, roots):
        ellipsisroots[head].difference_update(roots)
        ellipsisroots[head].add(child)
        ellipsisroots[child].update(roots)
        ellipsisroots[child].discard(child)

    def splithead(head):
        r1, r2, r3 = sorted(ellipsisroots[head])
        for nr1, nr2 in ((r2, r3), (r1, r3), (r1, r2)):
            mid = repo.revs('sort(merge() & %d::%d & %d::%d, -rev)',
                            nr1, head, nr2, head)
            for j in mid:
                if j == nr2:
                    return nr2, (nr1, nr2)
                if j not in ellipsisroots or len(ellipsisroots[j]) < 2:
                    return j, (nr1, nr2)
        raise error.Abort(_('Failed to split up ellipsis node! head: %d, '
                            'roots: %d %d %d') % (head, r1, r2, r3))

    missing = list(cl.findmissingrevs(common=commonrevs, heads=headsrevs))
    visit = reversed(missing)
    relevant_nodes = set()
    visitnodes = [cl.node(m) for m in missing]
    required = set(headsrevs) | known
    for rev in visit:
        clrev = cl.changelogrevision(rev)
        ps = cldag.parents(rev)
        if depth is not None:
            curdepth = revdepth[rev]
            for p in ps:
                revdepth[p] = min(curdepth + 1, revdepth.get(p, depth + 1))
        needed = False
        shallow_enough = depth is None or revdepth[rev] <= depth
        if shallow_enough:
            curmf = mfl[clrev.manifest].read()
            if ps:
                # We choose to not trust the changed files list in
                # changesets because it's not always correct. TODO: could
                # we trust it for the non-merge case?
                p1mf = mfl[cl.changelogrevision(ps[0]).manifest].read()
                needed = bool(curmf.diff(p1mf, match))
                if not needed and len(ps) > 1:
                    # For merge changes, the list of changed files is not
                    # helpful, since we need to emit the merge if a file
                    # in the narrow spec has changed on either side of the
                    # merge. As a result, we do a manifest diff to check.
                    p2mf = mfl[cl.changelogrevision(ps[1]).manifest].read()
                    needed = bool(curmf.diff(p2mf, match))
            else:
                # For a root node, we need to include the node if any
                # files in the node match the narrowspec.
                needed = any(curmf.walk(match))

        if needed:
            for head in ellipsisheads[rev]:
                addroot(head, rev)
            for p in ps:
                required.add(p)
            relevant_nodes.add(cl.node(rev))
        else:
            if not ps:
                ps = [nullrev]
            if rev in required:
                for head in ellipsisheads[rev]:
                    addroot(head, rev)
                for p in ps:
                    ellipsisheads[p].add(rev)
            else:
                for p in ps:
                    ellipsisheads[p] |= ellipsisheads[rev]

    # add common changesets as roots of their reachable ellipsis heads
    for c in commonrevs:
        for head in ellipsisheads[c]:
            addroot(head, c)
    return visitnodes, relevant_nodes, ellipsisroots

def caps20to10(repo, role):
    """return a set with appropriate options to use bundle20 during getbundle"""
    caps = {'HG20'}
    capsblob = bundle2.encodecaps(bundle2.getrepocaps(repo, role=role))
    caps.add('bundle2=' + urlreq.quote(capsblob))