procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
# shallowrepo.py - shallow repository that uses remote filelogs
#
# Copyright 2013 Facebook, Inc.
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
import os
from mercurial.i18n import _
from mercurial.node import hex, nullrev
from mercurial import (
encoding,
error,
localrepo,
match,
scmutil,
sparse,
util,
)
from mercurial.utils import procutil
from . import (
connectionpool,
constants,
contentstore,
datapack,
fileserverclient,
historypack,
metadatastore,
remotefilectx,
remotefilelog,
shallowutil,
)
# These make*stores functions are global so that other extensions can replace
# them.
def makelocalstores(repo):
"""In-repo stores, like .hg/store/data; can not be discarded."""
localpath = os.path.join(repo.svfs.vfs.base, b'data')
if not os.path.exists(localpath):
os.makedirs(localpath)
# Instantiate local data stores
localcontent = contentstore.remotefilelogcontentstore(
repo, localpath, repo.name, shared=False
)
localmetadata = metadatastore.remotefilelogmetadatastore(
repo, localpath, repo.name, shared=False
)
return localcontent, localmetadata
def makecachestores(repo):
"""Typically machine-wide, cache of remote data; can be discarded."""
# Instantiate shared cache stores
cachepath = shallowutil.getcachepath(repo.ui)
cachecontent = contentstore.remotefilelogcontentstore(
repo, cachepath, repo.name, shared=True
)
cachemetadata = metadatastore.remotefilelogmetadatastore(
repo, cachepath, repo.name, shared=True
)
repo.sharedstore = cachecontent
repo.shareddatastores.append(cachecontent)
repo.sharedhistorystores.append(cachemetadata)
return cachecontent, cachemetadata
def makeremotestores(repo, cachecontent, cachemetadata):
"""These stores fetch data from a remote server."""
# Instantiate remote stores
repo.fileservice = fileserverclient.fileserverclient(repo)
remotecontent = contentstore.remotecontentstore(
repo.ui, repo.fileservice, cachecontent
)
remotemetadata = metadatastore.remotemetadatastore(
repo.ui, repo.fileservice, cachemetadata
)
return remotecontent, remotemetadata
def makepackstores(repo):
"""Packs are more efficient (to read from) cache stores."""
# Instantiate pack stores
packpath = shallowutil.getcachepackpath(repo, constants.FILEPACK_CATEGORY)
packcontentstore = datapack.datapackstore(repo.ui, packpath)
packmetadatastore = historypack.historypackstore(repo.ui, packpath)
repo.shareddatastores.append(packcontentstore)
repo.sharedhistorystores.append(packmetadatastore)
shallowutil.reportpackmetrics(
repo.ui, b'filestore', packcontentstore, packmetadatastore
)
return packcontentstore, packmetadatastore
def makeunionstores(repo):
"""Union stores iterate the other stores and return the first result."""
repo.shareddatastores = []
repo.sharedhistorystores = []
packcontentstore, packmetadatastore = makepackstores(repo)
cachecontent, cachemetadata = makecachestores(repo)
localcontent, localmetadata = makelocalstores(repo)
remotecontent, remotemetadata = makeremotestores(
repo, cachecontent, cachemetadata
)
# Instantiate union stores
repo.contentstore = contentstore.unioncontentstore(
packcontentstore,
cachecontent,
localcontent,
remotecontent,
writestore=localcontent,
)
repo.metadatastore = metadatastore.unionmetadatastore(
packmetadatastore,
cachemetadata,
localmetadata,
remotemetadata,
writestore=localmetadata,
)
fileservicedatawrite = cachecontent
fileservicehistorywrite = cachemetadata
repo.fileservice.setstore(
repo.contentstore,
repo.metadatastore,
fileservicedatawrite,
fileservicehistorywrite,
)
shallowutil.reportpackmetrics(
repo.ui, b'filestore', packcontentstore, packmetadatastore
)
def wraprepo(repo):
class shallowrepository(repo.__class__):
@util.propertycache
def name(self):
return self.ui.config(b'remotefilelog', b'reponame')
@util.propertycache
def fallbackpath(self):
path = repo.ui.config(
b"remotefilelog",
b"fallbackpath",
repo.ui.config(b'paths', b'default'),
)
if not path:
raise error.Abort(
b"no remotefilelog server "
b"configured - is your .hg/hgrc trusted?"
)
return path
def maybesparsematch(self, *revs, **kwargs):
"""
A wrapper that allows the remotefilelog to invoke sparsematch() if
this is a sparse repository, or returns None if this is not a
sparse repository.
"""
if revs:
ret = sparse.matcher(repo, revs=revs)
else:
ret = sparse.matcher(repo)
if ret.always():
return None
return ret
def file(self, f):
if f[0] == b'/':
f = f[1:]
if self.shallowmatch(f):
return remotefilelog.remotefilelog(self.svfs, f, self)
else:
return super(shallowrepository, self).file(f)
def filectx(self, path, *args, **kwargs):
if self.shallowmatch(path):
return remotefilectx.remotefilectx(self, path, *args, **kwargs)
else:
return super(shallowrepository, self).filectx(
path, *args, **kwargs
)
@localrepo.unfilteredmethod
def commitctx(self, ctx, error=False, origctx=None):
"""Add a new revision to current repository.
Revision information is passed via the context argument.
"""
# some contexts already have manifest nodes, they don't need any
# prefetching (for example if we're just editing a commit message
# we can reuse manifest
if not ctx.manifestnode():
# prefetch files that will likely be compared
m1 = ctx.p1().manifest()
files = []
for f in ctx.modified() + ctx.added():
fparent1 = m1.get(f, self.nullid)
if fparent1 != self.nullid:
files.append((f, hex(fparent1)))
self.fileservice.prefetch(files)
return super(shallowrepository, self).commitctx(
ctx, error=error, origctx=origctx
)
def backgroundprefetch(
self, revs, base=None, repack=False, pats=None, opts=None
):
"""Runs prefetch in background with optional repack"""
cmd = [procutil.hgexecutable(), b'-R', repo.origroot, b'prefetch']
if repack:
cmd.append(b'--repack')
if revs:
cmd += [b'-r', revs]
# We know this command will find a binary, so don't block
# on it starting.
kwargs = {}
if repo.ui.configbool(b'devel', b'remotefilelog.bg-wait'):
kwargs['record_wait'] = repo.ui.atexit
procutil.runbgcommand(
cmd, encoding.environ, ensurestart=False, **kwargs
)
def prefetch(self, revs, base=None, pats=None, opts=None):
"""Prefetches all the necessary file revisions for the given revs
Optionally runs repack in background
"""
with repo._lock(
repo.svfs,
b'prefetchlock',
True,
None,
None,
_(b'prefetching in %s') % repo.origroot,
):
self._prefetch(revs, base, pats, opts)
def _prefetch(self, revs, base=None, pats=None, opts=None):
fallbackpath = self.fallbackpath
if fallbackpath:
# If we know a rev is on the server, we should fetch the server
# version of those files, since our local file versions might
# become obsolete if the local commits are stripped.
localrevs = repo.revs(b'outgoing(%s)', fallbackpath)
if base is not None and base != nullrev:
serverbase = list(
repo.revs(
b'first(reverse(::%s) - %ld)', base, localrevs
)
)
if serverbase:
base = serverbase[0]
else:
localrevs = repo
mfl = repo.manifestlog
mfrevlog = mfl.getstorage(b'')
if base is not None:
mfdict = mfl[repo[base].manifestnode()].read()
skip = set(mfdict.items())
else:
skip = set()
# Copy the skip set to start large and avoid constant resizing,
# and since it's likely to be very similar to the prefetch set.
files = skip.copy()
serverfiles = skip.copy()
visited = set()
visited.add(nullrev)
revcount = len(revs)
progress = self.ui.makeprogress(_(b'prefetching'), total=revcount)
progress.update(0)
for rev in sorted(revs):
ctx = repo[rev]
if pats:
m = scmutil.match(ctx, pats, opts)
sparsematch = repo.maybesparsematch(rev)
mfnode = ctx.manifestnode()
mfrev = mfrevlog.rev(mfnode)
# Decompressing manifests is expensive.
# When possible, only read the deltas.
p1, p2 = mfrevlog.parentrevs(mfrev)
if p1 in visited and p2 in visited:
mfdict = mfl[mfnode].readfast()
else:
mfdict = mfl[mfnode].read()
diff = mfdict.items()
if pats:
diff = (pf for pf in diff if m(pf[0]))
if sparsematch:
diff = (pf for pf in diff if sparsematch(pf[0]))
if rev not in localrevs:
serverfiles.update(diff)
else:
files.update(diff)
visited.add(mfrev)
progress.increment()
files.difference_update(skip)
serverfiles.difference_update(skip)
progress.complete()
# Fetch files known to be on the server
if serverfiles:
results = [(path, hex(fnode)) for (path, fnode) in serverfiles]
repo.fileservice.prefetch(results, force=True)
# Fetch files that may or may not be on the server
if files:
results = [(path, hex(fnode)) for (path, fnode) in files]
repo.fileservice.prefetch(results)
def close(self):
super(shallowrepository, self).close()
self.connectionpool.close()
repo.__class__ = shallowrepository
repo.shallowmatch = match.always()
makeunionstores(repo)
repo.includepattern = repo.ui.configlist(
b"remotefilelog", b"includepattern", None
)
repo.excludepattern = repo.ui.configlist(
b"remotefilelog", b"excludepattern", None
)
if not util.safehasattr(repo, 'connectionpool'):
repo.connectionpool = connectionpool.connectionpool(repo)
if repo.includepattern or repo.excludepattern:
repo.shallowmatch = match.match(
repo.root, b'', None, repo.includepattern, repo.excludepattern
)