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 2020 Joerg Sonnenberger <joerg@bec.de>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""export repositories as git fast-import stream"""
# The format specification for fast-import streams can be found at
# https://git-scm.com/docs/git-fast-import#_input_format
import re
from mercurial.i18n import _
from mercurial.node import hex, nullrev
from mercurial.utils import stringutil
from mercurial import (
error,
logcmdutil,
pycompat,
registrar,
scmutil,
)
from .convert import convcmd
# Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = b"ships-with-hg-core"
cmdtable = {}
command = registrar.command(cmdtable)
GIT_PERSON_PROHIBITED = re.compile(b'[<>\n"]')
GIT_EMAIL_PROHIBITED = re.compile(b"[<> \n]")
def convert_to_git_user(authormap, user, rev):
mapped_user = authormap.get(user, user)
user_person = stringutil.person(mapped_user)
user_email = stringutil.email(mapped_user)
if GIT_EMAIL_PROHIBITED.match(user_email) or GIT_PERSON_PROHIBITED.match(
user_person
):
raise error.Abort(
_(b"Unable to parse user into person and email for revision %s")
% rev
)
if user_person:
return b'"' + user_person + b'" <' + user_email + b'>'
else:
return b"<" + user_email + b">"
def convert_to_git_date(date):
timestamp, utcoff = date
tzsign = b"+" if utcoff <= 0 else b"-"
if utcoff % 60 != 0:
raise error.Abort(
_(b"UTC offset in %b is not an integer number of seconds") % (date,)
)
utcoff = abs(utcoff) // 60
tzh = utcoff // 60
tzmin = utcoff % 60
return b"%d " % int(timestamp) + tzsign + b"%02d%02d" % (tzh, tzmin)
def convert_to_git_ref(branch):
# XXX filter/map depending on git restrictions
return b"refs/heads/" + branch
def write_data(buf, data, skip_newline):
buf.append(b"data %d\n" % len(data))
buf.append(data)
if not skip_newline or data[-1:] != b"\n":
buf.append(b"\n")
def export_commit(ui, repo, rev, marks, authormap):
ctx = repo[rev]
revid = ctx.hex()
if revid in marks:
ui.debug(b"warning: revision %s already exported, skipped\n" % revid)
return
parents = [p for p in ctx.parents() if p.rev() != nullrev]
for p in parents:
if p.hex() not in marks:
ui.warn(
_(b"warning: parent %s of %s has not been exported, skipped\n")
% (p, revid)
)
return
# For all files modified by the commit, check if they have already
# been exported and otherwise dump the blob with the new mark.
for fname in ctx.files():
if fname not in ctx:
continue
filectx = ctx.filectx(fname)
filerev = hex(filectx.filenode())
if filerev not in marks:
mark = len(marks) + 1
marks[filerev] = mark
data = filectx.data()
buf = [b"blob\n", b"mark :%d\n" % mark]
write_data(buf, data, False)
ui.write(*buf, keepprogressbar=True)
del buf
# Assign a mark for the current revision for references by
# latter merge commits.
mark = len(marks) + 1
marks[revid] = mark
ref = convert_to_git_ref(ctx.branch())
buf = [
b"commit %s\n" % ref,
b"mark :%d\n" % mark,
b"committer %s %s\n"
% (
convert_to_git_user(authormap, ctx.user(), revid),
convert_to_git_date(ctx.date()),
),
]
write_data(buf, ctx.description(), True)
if parents:
buf.append(b"from :%d\n" % marks[parents[0].hex()])
if len(parents) == 2:
buf.append(b"merge :%d\n" % marks[parents[1].hex()])
p0ctx = repo[parents[0]]
files = ctx.manifest().diff(p0ctx.manifest())
else:
files = ctx.files()
filebuf = []
for fname in files:
if fname not in ctx:
filebuf.append((fname, b"D %s\n" % fname))
else:
filectx = ctx.filectx(fname)
filerev = filectx.filenode()
fileperm = b"755" if filectx.isexec() else b"644"
changed = b"M %s :%d %s\n" % (fileperm, marks[hex(filerev)], fname)
filebuf.append((fname, changed))
filebuf.sort()
buf.extend(changed for (fname, changed) in filebuf)
del filebuf
buf.append(b"\n")
ui.write(*buf, keepprogressbar=True)
del buf
isrev = re.compile(b"^[0-9a-f]{40}$")
@command(
b"fastexport",
[
(b"r", b"rev", [], _(b"revisions to export"), _(b"REV")),
(b"i", b"import-marks", b"", _(b"old marks file to read"), _(b"FILE")),
(b"e", b"export-marks", b"", _(b"new marks file to write"), _(b"FILE")),
(
b"A",
b"authormap",
b"",
_(b"remap usernames using this file"),
_(b"FILE"),
),
],
_(b"[OPTION]... [REV]..."),
helpcategory=command.CATEGORY_IMPORT_EXPORT,
)
def fastexport(ui, repo, *revs, **opts):
"""export repository as git fast-import stream
This command lets you dump a repository as a human-readable text stream.
It can be piped into corresponding import routines like "git fast-import".
Incremental dumps can be created by using marks files.
"""
opts = pycompat.byteskwargs(opts)
revs += tuple(opts.get(b"rev", []))
if not revs:
revs = scmutil.revrange(repo, [b":"])
else:
revs = logcmdutil.revrange(repo, revs)
if not revs:
raise error.Abort(_(b"no revisions matched"))
authorfile = opts.get(b"authormap")
if authorfile:
authormap = convcmd.readauthormap(ui, authorfile)
else:
authormap = {}
import_marks = opts.get(b"import_marks")
marks = {}
if import_marks:
with open(import_marks, "rb") as import_marks_file:
for line in import_marks_file:
line = line.strip()
if not isrev.match(line) or line in marks:
raise error.Abort(_(b"Corrupted marks file"))
marks[line] = len(marks) + 1
revs.sort()
with ui.makeprogress(
_(b"exporting"), unit=_(b"revisions"), total=len(revs)
) as progress:
for rev in revs:
export_commit(ui, repo, rev, marks, authormap)
progress.increment()
export_marks = opts.get(b"export_marks")
if export_marks:
with open(export_marks, "wb") as export_marks_file:
output_marks = [None] * len(marks)
for k, v in marks.items():
output_marks[v - 1] = k
for k in output_marks:
export_marks_file.write(k + b"\n")