emitrevision: if we need to compute a delta on the fly, try p1 or p2 first
Falling back to `prev` does not yield any real value on modern storage and
result in pathological changes to be created on the other side. Doing a delta
against a parent will likely be smaller (helping the network) and will be safer
to apply on the client (helping future pulls by Triggering intermediate
snapshop where they will be needed by later deltas).
# discovery.py - protocol changeset discovery functions
#
# Copyright 2010 Olivia Mackall <olivia@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.
import collections
from .i18n import _
from .node import short
from . import (
error,
)
def findcommonincoming(repo, remote, heads=None, force=False, audit=None):
"""Return a tuple (common, fetch, heads) used to identify the common
subset of nodes between repo and remote.
"common" is a list of (at least) the heads of the common subset.
"fetch" is a list of roots of the nodes that would be incoming, to be
supplied to changegroupsubset.
"heads" is either the supplied heads, or else the remote's heads.
"""
knownnode = repo.changelog.hasnode
search = []
fetch = set()
seen = set()
seenbranch = set()
base = set()
if not heads:
with remote.commandexecutor() as e:
heads = e.callcommand(b'heads', {}).result()
if audit is not None:
audit[b'total-roundtrips'] = 1
audit[b'total-roundtrips-heads'] = 1
audit[b'total-roundtrips-branches'] = 0
audit[b'total-roundtrips-between'] = 0
audit[b'total-queries'] = 0
audit[b'total-queries-branches'] = 0
audit[b'total-queries-between'] = 0
if repo.changelog.tip() == repo.nullid:
base.add(repo.nullid)
if heads != [repo.nullid]:
return [repo.nullid], [repo.nullid], list(heads)
return [repo.nullid], [], heads
# assume we're closer to the tip than the root
# and start by examining the heads
repo.ui.status(_(b"searching for changes\n"))
unknown = []
for h in heads:
if not knownnode(h):
unknown.append(h)
else:
base.add(h)
if not unknown:
return list(base), [], list(heads)
req = set(unknown)
reqcnt = 0
progress = repo.ui.makeprogress(_(b'searching'), unit=_(b'queries'))
# 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)
with remote.commandexecutor() as e:
if audit is not None:
audit[b'total-queries'] += len(unknown)
audit[b'total-queries-branches'] += len(unknown)
audit[b'total-roundtrips'] += 1
audit[b'total-roundtrips-branches'] += 1
branches = e.callcommand(b'branches', {b'nodes': unknown}).result()
unknown = collections.deque(branches)
while unknown:
r = []
while unknown:
n = unknown.popleft()
if n[0] in seen:
continue
repo.ui.debug(b"examining %s:%s\n" % (short(n[0]), short(n[1])))
if n[0] == repo.nullid: # found the end of the branch
pass
elif n in seenbranch:
repo.ui.debug(b"branch already found\n")
continue
elif n[1] and knownnode(n[1]): # do we know the base?
repo.ui.debug(
b"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 knownnode(n[2]) and knownnode(n[3]):
repo.ui.debug(b"found new changeset %s\n" % short(n[1]))
fetch.add(n[1]) # earliest unknown
for p in n[2:4]:
if knownnode(p):
base.add(p) # latest known
for p in n[2:4]:
if p not in req and not knownnode(p):
r.append(p)
req.add(p)
seen.add(n[0])
if r:
for p in range(0, len(r), 10):
reqcnt += 1
progress.increment()
if repo.ui.debugflag:
msg = b"request %d: %s\n"
msg %= (reqcnt, b" ".join(map(short, r)))
repo.ui.debug(msg)
with remote.commandexecutor() as e:
subset = r[p : p + 10]
if audit is not None:
audit[b'total-queries'] += len(subset)
audit[b'total-queries-branches'] += len(subset)
audit[b'total-roundtrips'] += 1
audit[b'total-roundtrips-branches'] += 1
branches = e.callcommand(
b'branches',
{
b'nodes': subset,
},
).result()
for b in branches:
repo.ui.debug(
b"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
progress.increment()
with remote.commandexecutor() as e:
if audit is not None:
audit[b'total-queries'] += len(search)
audit[b'total-queries-between'] += len(search)
audit[b'total-roundtrips'] += 1
audit[b'total-roundtrips-between'] += 1
between = e.callcommand(b'between', {b'pairs': search}).result()
for n, l in zip(search, between):
l.append(n[1])
p = n[0]
f = 1
for i in l:
repo.ui.debug(b"narrowing %d:%d %s\n" % (f, len(l), short(i)))
if knownnode(i):
if f <= 2:
repo.ui.debug(
b"found new branch changeset %s\n" % short(p)
)
fetch.add(p)
base.add(i)
else:
repo.ui.debug(
b"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 knownnode(f):
raise error.RepoError(_(b"already have changeset ") + short(f[:4]))
base = list(base)
if base == [repo.nullid]:
if force:
repo.ui.warn(_(b"warning: repository is unrelated\n"))
else:
raise error.Abort(_(b"repository is unrelated"))
repo.ui.debug(
b"found new changesets starting at "
+ b" ".join([short(f) for f in fetch])
+ b"\n"
)
progress.complete()
repo.ui.debug(b"%d total queries\n" % reqcnt)
return base, list(fetch), heads