changeset 11301:3d0591a66118

move discovery methods from localrepo into new discovery module
author Dirkjan Ochtman <dirkjan@ochtman.nl>
date Mon, 07 Jun 2010 18:35:54 +0200
parents 24eeca1f2791
children e1dde7363601
files hgext/graphlog.py hgext/patchbomb.py hgext/transplant.py mercurial/commands.py mercurial/discovery.py mercurial/localrepo.py mercurial/revset.py
diffstat 7 files changed, 376 insertions(+), 361 deletions(-) [+]
line wrap: on
line diff
--- a/hgext/graphlog.py	Mon Jun 07 16:29:06 2010 +0200
+++ b/hgext/graphlog.py	Mon Jun 07 18:35:54 2010 +0200
@@ -18,7 +18,7 @@
 from mercurial.i18n import _
 from mercurial.node import nullrev
 from mercurial import bundlerepo, changegroup, cmdutil, commands, extensions
-from mercurial import hg, url, util, graphmod
+from mercurial import hg, url, util, graphmod, discovery
 
 ASCIIDATA = 'ASC'
 
@@ -283,7 +283,7 @@
     if revs:
         revs = [repo.lookup(rev) for rev in revs]
     ui.status(_('comparing with %s\n') % url.hidepassword(dest))
-    o = repo.findoutgoing(other, force=opts.get('force'))
+    o = discovery.findoutgoing(repo, other, force=opts.get('force'))
     if not o:
         ui.status(_("no changes found\n"))
         return
@@ -311,7 +311,8 @@
     ui.status(_('comparing with %s\n') % url.hidepassword(source))
     if revs:
         revs = [other.lookup(rev) for rev in revs]
-    incoming = repo.findincoming(other, heads=revs, force=opts["force"])
+    incoming = discovery.findincoming(repo, other, heads=revs,
+                                      force=opts["force"])
     if not incoming:
         try:
             os.unlink(opts["bundle"])
--- a/hgext/patchbomb.py	Mon Jun 07 16:29:06 2010 +0200
+++ b/hgext/patchbomb.py	Mon Jun 07 18:35:54 2010 +0200
@@ -76,7 +76,7 @@
 import os, errno, socket, tempfile, cStringIO, time
 import email.MIMEMultipart, email.MIMEBase
 import email.Utils, email.Encoders, email.Generator
-from mercurial import cmdutil, commands, hg, mail, patch, util
+from mercurial import cmdutil, commands, hg, mail, patch, util, discovery
 from mercurial.i18n import _
 from mercurial.node import bin
 
@@ -244,7 +244,7 @@
             revs = [repo.lookup(rev) for rev in revs]
         other = hg.repository(hg.remoteui(repo, opts), dest)
         ui.status(_('comparing with %s\n') % dest)
-        o = repo.findoutgoing(other)
+        o = discovery.findoutgoing(repo, other)
         if not o:
             ui.status(_("no changes found\n"))
             return []
--- a/hgext/transplant.py	Mon Jun 07 16:29:06 2010 +0200
+++ b/hgext/transplant.py	Mon Jun 07 18:35:54 2010 +0200
@@ -16,7 +16,7 @@
 from mercurial.i18n import _
 import os, tempfile
 from mercurial import bundlerepo, changegroup, cmdutil, hg, merge, match
-from mercurial import patch, revlog, util, error
+from mercurial import patch, revlog, util, error, discovery
 
 class transplantentry(object):
     def __init__(self, lnode, rnode):
@@ -472,7 +472,8 @@
     def getremotechanges(repo, url):
         sourcerepo = ui.expandpath(url)
         source = hg.repository(ui, sourcerepo)
-        common, incoming, rheads = repo.findcommonincoming(source, force=True)
+        tmp = discovery.findcommonincoming(repo, source, force=True)
+        common, incoming, rheads = tmp
         if not incoming:
             return (source, None, None)
 
--- a/mercurial/commands.py	Mon Jun 07 16:29:06 2010 +0200
+++ b/mercurial/commands.py	Mon Jun 07 18:35:54 2010 +0200
@@ -10,7 +10,7 @@
 from i18n import _, gettext
 import os, re, sys, difflib, time, tempfile
 import hg, util, revlog, bundlerepo, extensions, copies, error
-import patch, help, mdiff, url, encoding, templatekw
+import patch, help, mdiff, url, encoding, templatekw, discovery
 import archival, changegroup, cmdutil, sshserver, hbisect, hgweb, hgweb.server
 import merge as mergemod
 import minirst, revset
@@ -596,7 +596,7 @@
         dest, branches = hg.parseurl(dest, opts.get('branch'))
         other = hg.repository(hg.remoteui(repo, opts), dest)
         revs, checkout = hg.addbranchrevs(repo, other, branches, revs)
-        o = repo.findoutgoing(other, force=opts.get('force'))
+        o = discovery.findoutgoing(repo, other, force=opts.get('force'))
 
     if not o:
         ui.status(_("no changes found\n"))
@@ -2090,8 +2090,10 @@
     revs, checkout = hg.addbranchrevs(repo, other, branches, opts.get('rev'))
     if revs:
         revs = [other.lookup(rev) for rev in revs]
-    common, incoming, rheads = repo.findcommonincoming(other, heads=revs,
-                                                       force=opts["force"])
+
+    tmp = discovery.findcommonincoming(repo, other, heads=revs,
+                                       force=opts.get('force'))
+    common, incoming, rheads = tmp
     if not incoming:
         try:
             os.unlink(opts["bundle"])
@@ -2395,7 +2397,7 @@
 
     other = hg.repository(hg.remoteui(repo, opts), dest)
     ui.status(_('comparing with %s\n') % url.hidepassword(dest))
-    o = repo.findoutgoing(other, force=opts.get('force'))
+    o = discovery.findoutgoing(repo, other, force=opts.get('force'))
     if not o:
         ui.status(_("no changes found\n"))
         return 1
@@ -3324,7 +3326,7 @@
         revs, checkout = hg.addbranchrevs(repo, other, branches, opts.get('rev'))
         ui.debug('comparing with %s\n' % url.hidepassword(source))
         repo.ui.pushbuffer()
-        common, incoming, rheads = repo.findcommonincoming(other)
+        common, incoming, rheads = discovery.findcommonincoming(repo, other)
         repo.ui.popbuffer()
         if incoming:
             t.append(_('1 or more incoming'))
@@ -3334,7 +3336,7 @@
         other = hg.repository(hg.remoteui(repo, {}), dest)
         ui.debug('comparing with %s\n' % url.hidepassword(dest))
         repo.ui.pushbuffer()
-        o = repo.findoutgoing(other)
+        o = discovery.findoutgoing(repo, other)
         repo.ui.popbuffer()
         o = repo.changelog.nodesbetween(o, None)[0]
         if o:
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mercurial/discovery.py	Mon Jun 07 18:35:54 2010 +0200
@@ -0,0 +1,350 @@
+# localrepo.py - read/write repository class for mercurial
+#
+# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+
+from node import nullid, short
+from i18n import _
+import util, error
+
+def findincoming(repo, remote, base=None, heads=None, force=False):
+    """Return list of roots of the subsets of missing nodes from remote
+
+    If base dict is specified, assume that these nodes and their parents
+    exist on the remote side and that no child of a node of base exists
+    in both remote and repo.
+    Furthermore base will be updated to include the nodes that exists
+    in repo and remote but no children exists in repo and remote.
+    If a list of heads is specified, return only nodes which are heads
+    or ancestors of these heads.
+
+    All the ancestors of base are in repo and in remote.
+    All the descendants of the list returned are missing in repo.
+    (and so we know that the rest of the nodes are missing in remote, see
+    outgoing)
+    """
+    return findcommonincoming(repo, remote, base, heads, force)[1]
+
+def findcommonincoming(repo, remote, base=None, heads=None, force=False):
+    """Return a tuple (common, missing roots, heads) used to identify
+    missing nodes from remote.
+
+    If base dict is specified, assume that these nodes and their parents
+    exist on the remote side and that no child of a node of base exists
+    in both remote and repo.
+    Furthermore base will be updated to include the nodes that exists
+    in repo and remote but no children exists in repo and remote.
+    If a list of heads is specified, return only nodes which are heads
+    or ancestors of these heads.
+
+    All the ancestors of base are in repo and in remote.
+    """
+    m = repo.changelog.nodemap
+    search = []
+    fetch = set()
+    seen = set()
+    seenbranch = set()
+    if base is None:
+        base = {}
+
+    if not heads:
+        heads = remote.heads()
+
+    if repo.changelog.tip() == nullid:
+        base[nullid] = 1
+        if heads != [nullid]:
+            return [nullid], [nullid], list(heads)
+        return [nullid], [], []
+
+    # assume we're closer to the tip than the root
+    # and start by examining the heads
+    repo.ui.status(_("searching for changes\n"))
+
+    unknown = []
+    for h in heads:
+        if h not in m:
+            unknown.append(h)
+        else:
+            base[h] = 1
+
+    heads = unknown
+    if not unknown:
+        return base.keys(), [], []
+
+    req = set(unknown)
+    reqcnt = 0
+
+    # search through remote branches
+    # a 'branch' here is a linear segment of history, with four parts:
+    # head, root, first parent, second parent
+    # (a branch always has two parents (or none) by definition)
+    unknown = remote.branches(unknown)
+    while unknown:
+        r = []
+        while unknown:
+            n = unknown.pop(0)
+            if n[0] in seen:
+                continue
+
+            repo.ui.debug("examining %s:%s\n"
+                          % (short(n[0]), short(n[1])))
+            if n[0] == nullid: # found the end of the branch
+                pass
+            elif n in seenbranch:
+                repo.ui.debug("branch already found\n")
+                continue
+            elif n[1] and n[1] in m: # do we know the base?
+                repo.ui.debug("found incomplete branch %s:%s\n"
+                              % (short(n[0]), short(n[1])))
+                search.append(n[0:2]) # schedule branch range for scanning
+                seenbranch.add(n)
+            else:
+                if n[1] not in seen and n[1] not in fetch:
+                    if n[2] in m and n[3] in m:
+                        repo.ui.debug("found new changeset %s\n" %
+                                      short(n[1]))
+                        fetch.add(n[1]) # earliest unknown
+                    for p in n[2:4]:
+                        if p in m:
+                            base[p] = 1 # latest known
+
+                for p in n[2:4]:
+                    if p not in req and p not in m:
+                        r.append(p)
+                        req.add(p)
+            seen.add(n[0])
+
+        if r:
+            reqcnt += 1
+            repo.ui.progress(_('searching'), reqcnt, unit=_('queries'))
+            repo.ui.debug("request %d: %s\n" %
+                        (reqcnt, " ".join(map(short, r))))
+            for p in xrange(0, len(r), 10):
+                for b in remote.branches(r[p:p + 10]):
+                    repo.ui.debug("received %s:%s\n" %
+                                  (short(b[0]), short(b[1])))
+                    unknown.append(b)
+
+    # do binary search on the branches we found
+    while search:
+        newsearch = []
+        reqcnt += 1
+        repo.ui.progress(_('searching'), reqcnt, unit=_('queries'))
+        for n, l in zip(search, remote.between(search)):
+            l.append(n[1])
+            p = n[0]
+            f = 1
+            for i in l:
+                repo.ui.debug("narrowing %d:%d %s\n" % (f, len(l), short(i)))
+                if i in m:
+                    if f <= 2:
+                        repo.ui.debug("found new branch changeset %s\n" %
+                                          short(p))
+                        fetch.add(p)
+                        base[i] = 1
+                    else:
+                        repo.ui.debug("narrowed branch search to %s:%s\n"
+                                      % (short(p), short(i)))
+                        newsearch.append((p, i))
+                    break
+                p, f = i, f * 2
+            search = newsearch
+
+    # sanity check our fetch list
+    for f in fetch:
+        if f in m:
+            raise error.RepoError(_("already have changeset ")
+                                  + short(f[:4]))
+
+    if base.keys() == [nullid]:
+        if force:
+            repo.ui.warn(_("warning: repository is unrelated\n"))
+        else:
+            raise util.Abort(_("repository is unrelated"))
+
+    repo.ui.debug("found new changesets starting at " +
+                 " ".join([short(f) for f in fetch]) + "\n")
+
+    repo.ui.progress(_('searching'), None)
+    repo.ui.debug("%d total queries\n" % reqcnt)
+
+    return base.keys(), list(fetch), heads
+
+def findoutgoing(repo, remote, base=None, heads=None, force=False):
+    """Return list of nodes that are roots of subsets not in remote
+
+    If base dict is specified, assume that these nodes and their parents
+    exist on the remote side.
+    If a list of heads is specified, return only nodes which are heads
+    or ancestors of these heads, and return a second element which
+    contains all remote heads which get new children.
+    """
+    if base is None:
+        base = {}
+        findincoming(repo, remote, base, heads, force=force)
+
+    repo.ui.debug("common changesets up to "
+                  + " ".join(map(short, base.keys())) + "\n")
+
+    remain = set(repo.changelog.nodemap)
+
+    # prune everything remote has from the tree
+    remain.remove(nullid)
+    remove = base.keys()
+    while remove:
+        n = remove.pop(0)
+        if n in remain:
+            remain.remove(n)
+            for p in repo.changelog.parents(n):
+                remove.append(p)
+
+    # find every node whose parents have been pruned
+    subset = []
+    # find every remote head that will get new children
+    updated_heads = set()
+    for n in remain:
+        p1, p2 = repo.changelog.parents(n)
+        if p1 not in remain and p2 not in remain:
+            subset.append(n)
+        if heads:
+            if p1 in heads:
+                updated_heads.add(p1)
+            if p2 in heads:
+                updated_heads.add(p2)
+
+    # this is the set of all roots we have to push
+    if heads:
+        return subset, list(updated_heads)
+    else:
+        return subset
+
+def prepush(repo, remote, force, revs, newbranch):
+    '''Analyze the local and remote repositories and determine which
+    changesets need to be pushed to the remote. Return value depends
+    on circumstances:
+
+    If we are not going to push anything, return a tuple (None,
+    outgoing) where outgoing is 0 if there are no outgoing
+    changesets and 1 if there are, but we refuse to push them
+    (e.g. would create new remote heads).
+
+    Otherwise, return a tuple (changegroup, remoteheads), where
+    changegroup is a readable file-like object whose read() returns
+    successive changegroup chunks ready to be sent over the wire and
+    remoteheads is the list of remote heads.'''
+    common = {}
+    remote_heads = remote.heads()
+    inc = findincoming(repo, remote, common, remote_heads, force=force)
+
+    cl = repo.changelog
+    update, updated_heads = findoutgoing(repo, remote, common, remote_heads)
+    outg, bases, heads = cl.nodesbetween(update, revs)
+
+    if not bases:
+        repo.ui.status(_("no changes found\n"))
+        return None, 1
+
+    if not force and remote_heads != [nullid]:
+
+        def fail_multiple_heads(unsynced, branch=None):
+            if branch:
+                msg = _("abort: push creates new remote heads"
+                        " on branch '%s'!\n") % branch
+            else:
+                msg = _("abort: push creates new remote heads!\n")
+            repo.ui.warn(msg)
+            if unsynced:
+                repo.ui.status(_("(you should pull and merge or"
+                                 " use push -f to force)\n"))
+            else:
+                repo.ui.status(_("(did you forget to merge?"
+                                 " use push -f to force)\n"))
+            return None, 0
+
+        if remote.capable('branchmap'):
+            # Check for each named branch if we're creating new remote heads.
+            # To be a remote head after push, node must be either:
+            # - unknown locally
+            # - a local outgoing head descended from update
+            # - a remote head that's known locally and not
+            #   ancestral to an outgoing head
+            #
+            # New named branches cannot be created without --force.
+
+            # 1. Create set of branches involved in the push.
+            branches = set(repo[n].branch() for n in outg)
+
+            # 2. Check for new branches on the remote.
+            remotemap = remote.branchmap()
+            newbranches = branches - set(remotemap)
+            if newbranches and not newbranch: # new branch requires --new-branch
+                branchnames = ', '.join("%s" % b for b in newbranches)
+                repo.ui.warn(_("abort: push creates "
+                               "new remote branches: %s!\n")
+                             % branchnames)
+                repo.ui.status(_("(use 'hg push --new-branch' to create new "
+                                 "remote branches)\n"))
+                return None, 0
+            branches.difference_update(newbranches)
+
+            # 3. Construct the initial oldmap and newmap dicts.
+            # They contain information about the remote heads before and
+            # after the push, respectively.
+            # Heads not found locally are not included in either dict,
+            # since they won't be affected by the push.
+            # unsynced contains all branches with incoming changesets.
+            oldmap = {}
+            newmap = {}
+            unsynced = set()
+            for branch in branches:
+                remoteheads = remotemap[branch]
+                prunedheads = [h for h in remoteheads if h in cl.nodemap]
+                oldmap[branch] = prunedheads
+                newmap[branch] = list(prunedheads)
+                if len(remoteheads) > len(prunedheads):
+                    unsynced.add(branch)
+
+            # 4. Update newmap with outgoing changes.
+            # This will possibly add new heads and remove existing ones.
+            ctxgen = (repo[n] for n in outg)
+            repo._updatebranchcache(newmap, ctxgen)
+
+            # 5. Check for new heads.
+            # If there are more heads after the push than before, a suitable
+            # warning, depending on unsynced status, is displayed.
+            for branch in branches:
+                if len(newmap[branch]) > len(oldmap[branch]):
+                    return fail_multiple_heads(branch in unsynced, branch)
+
+            # 6. Check for unsynced changes on involved branches.
+            if unsynced:
+                repo.ui.warn(_("note: unsynced remote changes!\n"))
+
+        else:
+            # Old servers: Check for new topological heads.
+            # Code based on _updatebranchcache.
+            newheads = set(h for h in remote_heads if h in cl.nodemap)
+            oldheadcnt = len(newheads)
+            newheads.update(outg)
+            if len(newheads) > 1:
+                for latest in reversed(outg):
+                    if latest not in newheads:
+                        continue
+                    minhrev = min(cl.rev(h) for h in newheads)
+                    reachable = cl.reachable(latest, cl.node(minhrev))
+                    reachable.remove(latest)
+                    newheads.difference_update(reachable)
+            if len(newheads) > oldheadcnt:
+                return fail_multiple_heads(inc)
+            if inc:
+                repo.ui.warn(_("note: unsynced remote changes!\n"))
+
+    if revs is None:
+        # use the fast path, no race possible on push
+        nodes = repo.changelog.findmissing(common.keys())
+        cg = repo._changegroup(nodes, 'push')
+    else:
+        cg = repo.changegroupsubset(update, revs, 'push')
+    return cg, remote_heads
--- a/mercurial/localrepo.py	Mon Jun 07 16:29:06 2010 +0200
+++ b/mercurial/localrepo.py	Mon Jun 07 18:35:54 2010 +0200
@@ -7,7 +7,7 @@
 
 from node import bin, hex, nullid, nullrev, short
 from i18n import _
-import repo, changegroup, subrepo
+import repo, changegroup, subrepo, discovery
 import changelog, dirstate, filelog, manifest, context
 import lock, transaction, store, encoding
 import util, extensions, hook, error
@@ -1272,222 +1272,12 @@
 
         return r
 
-    def findincoming(self, remote, base=None, heads=None, force=False):
-        """Return list of roots of the subsets of missing nodes from remote
-
-        If base dict is specified, assume that these nodes and their parents
-        exist on the remote side and that no child of a node of base exists
-        in both remote and self.
-        Furthermore base will be updated to include the nodes that exists
-        in self and remote but no children exists in self and remote.
-        If a list of heads is specified, return only nodes which are heads
-        or ancestors of these heads.
-
-        All the ancestors of base are in self and in remote.
-        All the descendants of the list returned are missing in self.
-        (and so we know that the rest of the nodes are missing in remote, see
-        outgoing)
-        """
-        return self.findcommonincoming(remote, base, heads, force)[1]
-
-    def findcommonincoming(self, remote, base=None, heads=None, force=False):
-        """Return a tuple (common, missing roots, heads) used to identify
-        missing nodes from remote.
-
-        If base dict is specified, assume that these nodes and their parents
-        exist on the remote side and that no child of a node of base exists
-        in both remote and self.
-        Furthermore base will be updated to include the nodes that exists
-        in self and remote but no children exists in self and remote.
-        If a list of heads is specified, return only nodes which are heads
-        or ancestors of these heads.
-
-        All the ancestors of base are in self and in remote.
-        """
-        m = self.changelog.nodemap
-        search = []
-        fetch = set()
-        seen = set()
-        seenbranch = set()
-        if base is None:
-            base = {}
-
-        if not heads:
-            heads = remote.heads()
-
-        if self.changelog.tip() == nullid:
-            base[nullid] = 1
-            if heads != [nullid]:
-                return [nullid], [nullid], list(heads)
-            return [nullid], [], []
-
-        # assume we're closer to the tip than the root
-        # and start by examining the heads
-        self.ui.status(_("searching for changes\n"))
-
-        unknown = []
-        for h in heads:
-            if h not in m:
-                unknown.append(h)
-            else:
-                base[h] = 1
-
-        heads = unknown
-        if not unknown:
-            return base.keys(), [], []
-
-        req = set(unknown)
-        reqcnt = 0
-
-        # search through remote branches
-        # a 'branch' here is a linear segment of history, with four parts:
-        # head, root, first parent, second parent
-        # (a branch always has two parents (or none) by definition)
-        unknown = remote.branches(unknown)
-        while unknown:
-            r = []
-            while unknown:
-                n = unknown.pop(0)
-                if n[0] in seen:
-                    continue
-
-                self.ui.debug("examining %s:%s\n"
-                              % (short(n[0]), short(n[1])))
-                if n[0] == nullid: # found the end of the branch
-                    pass
-                elif n in seenbranch:
-                    self.ui.debug("branch already found\n")
-                    continue
-                elif n[1] and n[1] in m: # do we know the base?
-                    self.ui.debug("found incomplete branch %s:%s\n"
-                                  % (short(n[0]), short(n[1])))
-                    search.append(n[0:2]) # schedule branch range for scanning
-                    seenbranch.add(n)
-                else:
-                    if n[1] not in seen and n[1] not in fetch:
-                        if n[2] in m and n[3] in m:
-                            self.ui.debug("found new changeset %s\n" %
-                                          short(n[1]))
-                            fetch.add(n[1]) # earliest unknown
-                        for p in n[2:4]:
-                            if p in m:
-                                base[p] = 1 # latest known
-
-                    for p in n[2:4]:
-                        if p not in req and p not in m:
-                            r.append(p)
-                            req.add(p)
-                seen.add(n[0])
-
-            if r:
-                reqcnt += 1
-                self.ui.progress(_('searching'), reqcnt, unit=_('queries'))
-                self.ui.debug("request %d: %s\n" %
-                            (reqcnt, " ".join(map(short, r))))
-                for p in xrange(0, len(r), 10):
-                    for b in remote.branches(r[p:p + 10]):
-                        self.ui.debug("received %s:%s\n" %
-                                      (short(b[0]), short(b[1])))
-                        unknown.append(b)
-
-        # do binary search on the branches we found
-        while search:
-            newsearch = []
-            reqcnt += 1
-            self.ui.progress(_('searching'), reqcnt, unit=_('queries'))
-            for n, l in zip(search, remote.between(search)):
-                l.append(n[1])
-                p = n[0]
-                f = 1
-                for i in l:
-                    self.ui.debug("narrowing %d:%d %s\n" % (f, len(l), short(i)))
-                    if i in m:
-                        if f <= 2:
-                            self.ui.debug("found new branch changeset %s\n" %
-                                              short(p))
-                            fetch.add(p)
-                            base[i] = 1
-                        else:
-                            self.ui.debug("narrowed branch search to %s:%s\n"
-                                          % (short(p), short(i)))
-                            newsearch.append((p, i))
-                        break
-                    p, f = i, f * 2
-                search = newsearch
-
-        # sanity check our fetch list
-        for f in fetch:
-            if f in m:
-                raise error.RepoError(_("already have changeset ")
-                                      + short(f[:4]))
-
-        if base.keys() == [nullid]:
-            if force:
-                self.ui.warn(_("warning: repository is unrelated\n"))
-            else:
-                raise util.Abort(_("repository is unrelated"))
-
-        self.ui.debug("found new changesets starting at " +
-                     " ".join([short(f) for f in fetch]) + "\n")
-
-        self.ui.progress(_('searching'), None)
-        self.ui.debug("%d total queries\n" % reqcnt)
-
-        return base.keys(), list(fetch), heads
-
-    def findoutgoing(self, remote, base=None, heads=None, force=False):
-        """Return list of nodes that are roots of subsets not in remote
-
-        If base dict is specified, assume that these nodes and their parents
-        exist on the remote side.
-        If a list of heads is specified, return only nodes which are heads
-        or ancestors of these heads, and return a second element which
-        contains all remote heads which get new children.
-        """
-        if base is None:
-            base = {}
-            self.findincoming(remote, base, heads, force=force)
-
-        self.ui.debug("common changesets up to "
-                      + " ".join(map(short, base.keys())) + "\n")
-
-        remain = set(self.changelog.nodemap)
-
-        # prune everything remote has from the tree
-        remain.remove(nullid)
-        remove = base.keys()
-        while remove:
-            n = remove.pop(0)
-            if n in remain:
-                remain.remove(n)
-                for p in self.changelog.parents(n):
-                    remove.append(p)
-
-        # find every node whose parents have been pruned
-        subset = []
-        # find every remote head that will get new children
-        updated_heads = set()
-        for n in remain:
-            p1, p2 = self.changelog.parents(n)
-            if p1 not in remain and p2 not in remain:
-                subset.append(n)
-            if heads:
-                if p1 in heads:
-                    updated_heads.add(p1)
-                if p2 in heads:
-                    updated_heads.add(p2)
-
-        # this is the set of all roots we have to push
-        if heads:
-            return subset, list(updated_heads)
-        else:
-            return subset
-
     def pull(self, remote, heads=None, force=False):
         lock = self.lock()
         try:
-            common, fetch, rheads = self.findcommonincoming(remote, heads=heads,
-                                                            force=force)
+            tmp = discovery.findcommonincoming(self, remote, heads=heads,
+                                               force=force)
+            common, fetch, rheads = tmp
             if not fetch:
                 self.ui.status(_("no changes found\n"))
                 return 0
@@ -1530,135 +1320,6 @@
             return self.push_unbundle(remote, force, revs, newbranch)
         return self.push_addchangegroup(remote, force, revs, newbranch)
 
-    def prepush(self, remote, force, revs, newbranch):
-        '''Analyze the local and remote repositories and determine which
-        changesets need to be pushed to the remote. Return value depends
-        on circumstances:
-
-        If we are not going to push anything, return a tuple (None,
-        outgoing) where outgoing is 0 if there are no outgoing
-        changesets and 1 if there are, but we refuse to push them
-        (e.g. would create new remote heads).
-
-        Otherwise, return a tuple (changegroup, remoteheads), where
-        changegroup is a readable file-like object whose read() returns
-        successive changegroup chunks ready to be sent over the wire and
-        remoteheads is the list of remote heads.'''
-        common = {}
-        remote_heads = remote.heads()
-        inc = self.findincoming(remote, common, remote_heads, force=force)
-
-        cl = self.changelog
-        update, updated_heads = self.findoutgoing(remote, common, remote_heads)
-        outg, bases, heads = cl.nodesbetween(update, revs)
-
-        if not bases:
-            self.ui.status(_("no changes found\n"))
-            return None, 1
-
-        if not force and remote_heads != [nullid]:
-
-            def fail_multiple_heads(unsynced, branch=None):
-                if branch:
-                    msg = _("abort: push creates new remote heads"
-                            " on branch '%s'!\n") % branch
-                else:
-                    msg = _("abort: push creates new remote heads!\n")
-                self.ui.warn(msg)
-                if unsynced:
-                    self.ui.status(_("(you should pull and merge or"
-                                     " use push -f to force)\n"))
-                else:
-                    self.ui.status(_("(did you forget to merge?"
-                                     " use push -f to force)\n"))
-                return None, 0
-
-            if remote.capable('branchmap'):
-                # Check for each named branch if we're creating new remote heads.
-                # To be a remote head after push, node must be either:
-                # - unknown locally
-                # - a local outgoing head descended from update
-                # - a remote head that's known locally and not
-                #   ancestral to an outgoing head
-                #
-                # New named branches cannot be created without --force.
-
-                # 1. Create set of branches involved in the push.
-                branches = set(self[n].branch() for n in outg)
-
-                # 2. Check for new branches on the remote.
-                remotemap = remote.branchmap()
-                newbranches = branches - set(remotemap)
-                if newbranches and not newbranch: # new branch requires --new-branch
-                    branchnames = ', '.join("%s" % b for b in newbranches)
-                    self.ui.warn(_("abort: push creates "
-                                   "new remote branches: %s!\n")
-                                 % branchnames)
-                    self.ui.status(_("(use 'hg push --new-branch' to create new "
-                                     "remote branches)\n"))
-                    return None, 0
-                branches.difference_update(newbranches)
-
-                # 3. Construct the initial oldmap and newmap dicts.
-                # They contain information about the remote heads before and
-                # after the push, respectively.
-                # Heads not found locally are not included in either dict,
-                # since they won't be affected by the push.
-                # unsynced contains all branches with incoming changesets.
-                oldmap = {}
-                newmap = {}
-                unsynced = set()
-                for branch in branches:
-                    remoteheads = remotemap[branch]
-                    prunedheads = [h for h in remoteheads if h in cl.nodemap]
-                    oldmap[branch] = prunedheads
-                    newmap[branch] = list(prunedheads)
-                    if len(remoteheads) > len(prunedheads):
-                        unsynced.add(branch)
-
-                # 4. Update newmap with outgoing changes.
-                # This will possibly add new heads and remove existing ones.
-                ctxgen = (self[n] for n in outg)
-                self._updatebranchcache(newmap, ctxgen)
-
-                # 5. Check for new heads.
-                # If there are more heads after the push than before, a suitable
-                # warning, depending on unsynced status, is displayed.
-                for branch in branches:
-                    if len(newmap[branch]) > len(oldmap[branch]):
-                        return fail_multiple_heads(branch in unsynced, branch)
-
-                # 6. Check for unsynced changes on involved branches.
-                if unsynced:
-                    self.ui.warn(_("note: unsynced remote changes!\n"))
-
-            else:
-                # Old servers: Check for new topological heads.
-                # Code based on _updatebranchcache.
-                newheads = set(h for h in remote_heads if h in cl.nodemap)
-                oldheadcnt = len(newheads)
-                newheads.update(outg)
-                if len(newheads) > 1:
-                    for latest in reversed(outg):
-                        if latest not in newheads:
-                            continue
-                        minhrev = min(cl.rev(h) for h in newheads)
-                        reachable = cl.reachable(latest, cl.node(minhrev))
-                        reachable.remove(latest)
-                        newheads.difference_update(reachable)
-                if len(newheads) > oldheadcnt:
-                    return fail_multiple_heads(inc)
-                if inc:
-                    self.ui.warn(_("note: unsynced remote changes!\n"))
-
-        if revs is None:
-            # use the fast path, no race possible on push
-            nodes = self.changelog.findmissing(common.keys())
-            cg = self._changegroup(nodes, 'push')
-        else:
-            cg = self.changegroupsubset(update, revs, 'push')
-        return cg, remote_heads
-
     def push_addchangegroup(self, remote, force, revs, newbranch):
         '''Push a changegroup by locking the remote and sending the
         addchangegroup command to it. Used for local and old SSH repos.
@@ -1666,7 +1327,7 @@
         '''
         lock = remote.lock()
         try:
-            ret = self.prepush(remote, force, revs, newbranch)
+            ret = discovery.prepush(self, remote, force, revs, newbranch)
             if ret[0] is not None:
                 cg, remote_heads = ret
                 # here, we return an integer indicating remote head count change
@@ -1685,7 +1346,7 @@
         # different heads (someone else won commit/push race), server
         # aborts.
 
-        ret = self.prepush(remote, force, revs, newbranch)
+        ret = discovery.prepush(self, remote, force, revs, newbranch)
         if ret[0] is not None:
             cg, remote_heads = ret
             if force:
--- a/mercurial/revset.py	Mon Jun 07 16:29:06 2010 +0200
+++ b/mercurial/revset.py	Mon Jun 07 18:35:54 2010 +0200
@@ -6,7 +6,7 @@
 # GNU General Public License version 2 or any later version.
 
 import re
-import parser, util, error
+import parser, util, error, discovery
 import match as _match
 
 elements = {
@@ -420,7 +420,7 @@
     dest, branches = hg.parseurl(dest)
     other = hg.repository(hg.remoteui(repo, {}), dest)
     repo.ui.pushbuffer()
-    o = repo.findoutgoing(other)
+    o = discovery.findoutgoing(repo, other)
     repo.ui.popbuffer()
     cl = repo.changelog
     o = set([cl.rev(r) for r in repo.changelog.nodesbetween(o, None)[0]])