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.
# Copyright 2010-2011 Fog Creek Software
# Copyright 2010-2011 Unity Technologies
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''remote largefile store; the base class for wirestore'''
from mercurial.i18n import _
from mercurial import (
error,
util,
)
from mercurial.utils import (
stringutil,
urlutil,
)
from . import (
basestore,
lfutil,
localstore,
)
urlerr = util.urlerr
urlreq = util.urlreq
class remotestore(basestore.basestore):
'''a largefile store accessed over a network'''
def __init__(self, ui, repo, url):
super(remotestore, self).__init__(ui, repo, url)
self._lstore = None
if repo is not None:
self._lstore = localstore.localstore(self.ui, self.repo, self.repo)
def put(self, source, hash):
if self.sendfile(source, hash):
raise error.Abort(
_(b'remotestore: could not put %s to remote store %s')
% (source, urlutil.hidepassword(self.url))
)
self.ui.debug(
_(b'remotestore: put %s to remote store %s\n')
% (source, urlutil.hidepassword(self.url))
)
def exists(self, hashes):
return {
h: s == 0
for (h, s) in self._stat(hashes).items()
# dict-from-generator
}
def sendfile(self, filename, hash):
self.ui.debug(b'remotestore: sendfile(%s, %s)\n' % (filename, hash))
try:
with lfutil.httpsendfile(self.ui, filename) as fd:
return self._put(hash, fd)
except IOError as e:
raise error.Abort(
_(b'remotestore: could not open file %s: %s')
% (filename, stringutil.forcebytestr(e))
)
def _getfile(self, tmpfile, filename, hash):
try:
chunks = self._get(hash)
except urlerr.httperror as e:
# 401s get converted to error.Aborts; everything else is fine being
# turned into a StoreError
raise basestore.StoreError(
filename, hash, self.url, stringutil.forcebytestr(e)
)
except urlerr.urlerror as e:
# This usually indicates a connection problem, so don't
# keep trying with the other files... they will probably
# all fail too.
raise error.Abort(
b'%s: %s' % (urlutil.hidepassword(self.url), e.reason)
)
except IOError as e:
raise basestore.StoreError(
filename, hash, self.url, stringutil.forcebytestr(e)
)
return lfutil.copyandhash(chunks, tmpfile)
def _hashesavailablelocally(self, hashes):
existslocallymap = self._lstore.exists(hashes)
localhashes = [hash for hash in hashes if existslocallymap[hash]]
return localhashes
def _verifyfiles(self, contents, filestocheck):
failed = False
expectedhashes = [
expectedhash for cset, filename, expectedhash in filestocheck
]
localhashes = self._hashesavailablelocally(expectedhashes)
stats = self._stat(
[
expectedhash
for expectedhash in expectedhashes
if expectedhash not in localhashes
]
)
for cset, filename, expectedhash in filestocheck:
if expectedhash in localhashes:
filetocheck = (cset, filename, expectedhash)
verifyresult = self._lstore._verifyfiles(
contents, [filetocheck]
)
if verifyresult:
failed = True
else:
stat = stats[expectedhash]
if stat:
if stat == 1:
self.ui.warn(
_(b'changeset %s: %s: contents differ\n')
% (cset, filename)
)
failed = True
elif stat == 2:
self.ui.warn(
_(b'changeset %s: %s missing\n') % (cset, filename)
)
failed = True
else:
raise RuntimeError(
b'verify failed: unexpected response '
b'from statlfile (%r)' % stat
)
return failed
def _put(self, hash, fd):
'''Put file with the given hash in the remote store.'''
raise NotImplementedError(b'abstract method')
def _get(self, hash):
'''Get a iterator for content with the given hash.'''
raise NotImplementedError(b'abstract method')
def _stat(self, hashes):
"""Get information about availability of files specified by
hashes in the remote store. Return dictionary mapping hashes
to return code where 0 means that file is available, other
values if not."""
raise NotImplementedError(b'abstract method')