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 2017 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.
from mercurial.i18n import _
from mercurial.node import hex
from mercurial import (
bundle2,
changegroup,
error,
extensions,
revsetlang,
util,
)
from . import common
isremotebooksenabled = common.isremotebooksenabled
scratchbranchparttype = b'b2x:infinitepush'
def getscratchbranchparts(repo, peer, outgoing, ui, bookmark):
if not outgoing.missing:
raise error.Abort(_(b'no commits to push'))
if scratchbranchparttype not in bundle2.bundle2caps(peer):
raise error.Abort(
_(b'no server support for %r') % scratchbranchparttype
)
_validaterevset(
repo, revsetlang.formatspec(b'%ln', outgoing.missing), bookmark
)
supportedversions = changegroup.supportedoutgoingversions(repo)
# Explicitly avoid using '01' changegroup version in infinitepush to
# support general delta
supportedversions.discard(b'01')
cgversion = min(supportedversions)
_handlelfs(repo, outgoing.missing)
cg = changegroup.makestream(repo, outgoing, cgversion, b'push')
params = {}
params[b'cgversion'] = cgversion
if bookmark:
params[b'bookmark'] = bookmark
# 'prevbooknode' is necessary for pushkey reply part
params[b'bookprevnode'] = b''
bookmarks = repo._bookmarks
if bookmark in bookmarks:
params[b'bookprevnode'] = hex(bookmarks[bookmark])
# Do not send pushback bundle2 part with bookmarks if remotenames extension
# is enabled. It will be handled manually in `_push()`
if not isremotebooksenabled(ui):
params[b'pushbackbookmarks'] = b'1'
parts = []
# .upper() marks this as a mandatory part: server will abort if there's no
# handler
parts.append(
bundle2.bundlepart(
scratchbranchparttype.upper(),
advisoryparams=params.items(),
data=cg,
)
)
return parts
def _validaterevset(repo, revset, bookmark):
"""Abort if the revs to be pushed aren't valid for a scratch branch."""
if not repo.revs(revset):
raise error.Abort(_(b'nothing to push'))
if bookmark:
# Allow bundle with many heads only if no bookmark is specified
heads = repo.revs(b'heads(%r)', revset)
if len(heads) > 1:
raise error.Abort(
_(b'cannot push more than one head to a scratch branch')
)
def _handlelfs(repo, missing):
"""Special case if lfs is enabled
If lfs is enabled then we need to call prepush hook
to make sure large files are uploaded to lfs
"""
try:
lfsmod = extensions.find(b'lfs')
lfsmod.wrapper.uploadblobsfromrevs(repo, missing)
except KeyError:
# Ignore if lfs extension is not enabled
return
class copiedpart:
"""a copy of unbundlepart content that can be consumed later"""
def __init__(self, part):
# copy "public properties"
self.type = part.type
self.id = part.id
self.mandatory = part.mandatory
self.mandatoryparams = part.mandatoryparams
self.advisoryparams = part.advisoryparams
self.params = part.params
self.mandatorykeys = part.mandatorykeys
# copy the buffer
self._io = util.stringio(part.read())
def consume(self):
return
def read(self, size=None):
if size is None:
return self._io.read()
else:
return self._io.read(size)