commandserver: handle IOError related to flushing of streams
After dispatch, without chg we have handling of flushing of streams and
exception handling related to it. The exception handling part is important
because there can be exceptions when flushing fout or ferr.
One such case is in `test-basic.t` which was failing on python3+chg without this
patch as this handling was missing from chg.
Failure can be seen at
https://foss.heptapod.net/octobus/mercurial-devel/-/jobs/128399
Honestly I am not sure which one of `chgserver.py` or `commandserver.py` the
change should go in.
Differential Revision: https://phab.mercurial-scm.org/D9517
# discovery.py - protocol changeset discovery functions
#
# Copyright 2010 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 __future__ import absolute_import
import collections
from .i18n import _
from .node import (
nullid,
short,
)
from . import (
error,
pycompat,
)
def findcommonincoming(repo, remote, heads=None, force=False):
"""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 repo.changelog.tip() == nullid:
base.add(nullid)
if heads != [nullid]:
return [nullid], [nullid], list(heads)
return [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:
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] == 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:
reqcnt += 1
progress.increment()
repo.ui.debug(
b"request %d: %s\n" % (reqcnt, b" ".join(map(short, r)))
)
for p in pycompat.xrange(0, len(r), 10):
with remote.commandexecutor() as e:
branches = e.callcommand(
b'branches',
{
b'nodes': r[p : p + 10],
},
).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:
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 == [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