comparison mercurial/wireprotoserver.py @ 36066:2ad145fbde54

wireprotoserver: add context manager mechanism for redirecting stdio

Today, proto.redirect() sets up redirecting stdio and proto.restore()
undoes that. The API is a bit wonky because restore() is only
implemented on the HTTP protocol. Furthermore, not all calls to
redirect() are obviously paired with calls to restore(). For
example, the call to restore() for "unbundle" requests is handled
by the response handler for the HTTP protocol.

This commit introduces a new method on the protocol handler interface
to maybe capture stdio. It emits a file object or None depending on
whether stdio capture is used by the transport.

To prove it works, the "pushkey" wire protocol command has been
updated to use the new API.

I'm not convinced this is the best mechanism to capture stdio. I may
need to come up with something better once the new wire protocol
emerges into existence. But it is strictly better than before because
it removes variance in the wire protocol handler interface. It
therefore gets us closer to a unified interface between the SSH and
HTTP transports.

Differential Revision: https://phab.mercurial-scm.org/D2081

36065:bf676267f64f

from __future__ import absolute_import

import abc
import cgi
import struct
import sys

from .i18n import _
from . import (

        The file is in the form::

            (<chunk-size>\n<chunk>)+0\n

        chunk size is the ascii version of the int.
        """

    @abc.abstractmethod
    def redirect(self):
        """may setup interception for stdout and stderr

        # If httppostargs is used, we need to read Content-Length
        # minus the amount that was consumed by args.
        length -= int(self._req.env.get(r'HTTP_X_HGARGS_POST', 0))
        for s in util.filechunkiter(self._req, limit=length):
            fp.write(s)

    def redirect(self):
        self._oldio = self._ui.fout, self._ui.ferr
        self._ui.ferr = self._ui.fout = stringio()

        count = int(self._fin.readline())
        while count:
            fpout.write(self._fin.read(count))
            count = int(self._fin.readline())

    def redirect(self):
        pass

    def _client(self):
        client = encoding.environ.get('SSH_CLIENT', '').split(' ', 1)[0]

36066:2ad145fbde54

from __future__ import absolute_import

import abc
import cgi
import contextlib
import struct
import sys

from .i18n import _
from . import (

        The file is in the form::

            (<chunk-size>\n<chunk>)+0\n

        chunk size is the ascii version of the int.
        """

    @abc.abstractmethod
    def mayberedirectstdio(self):
        """Context manager to possibly redirect stdio.

        The context manager yields a file-object like object that receives
        stdout and stderr output when the context manager is active. Or it
        yields ``None`` if no I/O redirection occurs.

        The intent of this context manager is to capture stdio output
        so it may be sent in the response. Some transports support streaming
        stdio to the client in real time. For these transports, stdio output
        won't be captured.
        """

    @abc.abstractmethod
    def redirect(self):
        """may setup interception for stdout and stderr

        # If httppostargs is used, we need to read Content-Length
        # minus the amount that was consumed by args.
        length -= int(self._req.env.get(r'HTTP_X_HGARGS_POST', 0))
        for s in util.filechunkiter(self._req, limit=length):
            fp.write(s)

    @contextlib.contextmanager
    def mayberedirectstdio(self):
        oldout = self._ui.fout
        olderr = self._ui.ferr

        out = util.stringio()

        try:
            self._ui.fout = out
            self._ui.ferr = out
            yield out
        finally:
            self._ui.fout = oldout
            self._ui.ferr = olderr

    def redirect(self):
        self._oldio = self._ui.fout, self._ui.ferr
        self._ui.ferr = self._ui.fout = stringio()

        count = int(self._fin.readline())
        while count:
            fpout.write(self._fin.read(count))
            count = int(self._fin.readline())

    @contextlib.contextmanager
    def mayberedirectstdio(self):
        yield None

    def redirect(self):
        pass

    def _client(self):
        client = encoding.environ.get('SSH_CLIENT', '').split(' ', 1)[0]