mercurial/loggingutil.py

sslutil: add support for clients to set TLSv1.3 as the minimum protocol

AFAICT, all of the TLS versions are supported by the server without doing any
explicit work, and there's only a `devel` config to specify an exact version on
the server side.  Clients would also use TLSv1.3 if available, but this prevents
the server from negotiating down.  This also causes "tls1.3" to be listed in
`hg debuginstall`, even though it was previously supported (if the Python
intepreter supported it- IDK if there's a good way to proactively test for and
show future protocols without requiring manual updates like this).

The v1.3 tests are nested inside the v1.2 tests for simplicity.  The v1.2 blocks
already assume v1.0 and v1.1 support, so this seems reasonable for now.  If/when
the older protocols start getting dropped, this will have to be reworked anyway.

# loggingutil.py - utility for logging events
#
# Copyright 2010 Nicolas Dumazet
# 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.

from __future__ import annotations

import errno

from . import (
    encoding,
)

from .utils import (
    dateutil,
    procutil,
    stringutil,
)


def openlogfile(ui, vfs, name, maxfiles=0, maxsize=0):
    """Open log file in append mode, with optional rotation

    If maxsize > 0, the log file will be rotated up to maxfiles.
    """

    def rotate(oldpath, newpath):
        try:
            vfs.unlink(newpath)
        except OSError as err:
            if err.errno != errno.ENOENT:
                ui.debug(
                    b"warning: cannot remove '%s': %s\n"
                    % (newpath, encoding.strtolocal(err.strerror))
                )
        try:
            if newpath:
                vfs.rename(oldpath, newpath)
        except OSError as err:
            if err.errno != errno.ENOENT:
                ui.debug(
                    b"warning: cannot rename '%s' to '%s': %s\n"
                    % (newpath, oldpath, encoding.strtolocal(err.strerror))
                )

    if maxsize > 0:
        try:
            st = vfs.stat(name)
        except OSError:
            pass
        else:
            if st.st_size >= maxsize:
                path = vfs.join(name)
                for i in range(maxfiles - 1, 1, -1):
                    rotate(
                        oldpath=b'%s.%d' % (path, i - 1),
                        newpath=b'%s.%d' % (path, i),
                    )
                rotate(oldpath=path, newpath=maxfiles > 0 and path + b'.1')
    return vfs(name, b'a', makeparentdirs=False)


def _formatlogline(msg):
    date = dateutil.datestr(format=b'%Y/%m/%d %H:%M:%S')
    pid = procutil.getpid()
    return b'%s (%d)> %s' % (date, pid, msg)


def _matchevent(event, tracked):
    return b'*' in tracked or event in tracked


class filelogger:
    """Basic logger backed by physical file with optional rotation"""

    def __init__(self, vfs, name, tracked, maxfiles=0, maxsize=0):
        self._vfs = vfs
        self._name = name
        self._trackedevents = set(tracked)
        self._maxfiles = maxfiles
        self._maxsize = maxsize

    def tracked(self, event):
        return _matchevent(event, self._trackedevents)

    def log(self, ui, event, msg, opts):
        line = _formatlogline(msg)
        try:
            with openlogfile(
                ui,
                self._vfs,
                self._name,
                maxfiles=self._maxfiles,
                maxsize=self._maxsize,
            ) as fp:
                fp.write(line)
        except IOError as err:
            ui.debug(
                b'cannot write to %s: %s\n'
                % (self._name, stringutil.forcebytestr(err))
            )


class fileobjectlogger:
    """Basic logger backed by file-like object"""

    def __init__(self, fp, tracked):
        self._fp = fp
        self._trackedevents = set(tracked)

    def tracked(self, event):
        return _matchevent(event, self._trackedevents)

    def log(self, ui, event, msg, opts):
        line = _formatlogline(msg)
        try:
            self._fp.write(line)
            self._fp.flush()
        except IOError as err:
            ui.debug(
                b'cannot write to %s: %s\n'
                % (
                    stringutil.forcebytestr(self._fp.name),
                    stringutil.forcebytestr(err),
                )
            )


class proxylogger:
    """Forward log events to another logger to be set later"""

    def __init__(self):
        self.logger = None

    def tracked(self, event):
        return self.logger is not None and self.logger.tracked(event)

    def log(self, ui, event, msg, opts):
        assert self.logger is not None
        self.logger.log(ui, event, msg, opts)