comparison mercurial/sshpeer.py @ 36372:b8d0761a85c7

wireproto: document the wonky push protocol for SSH

It took me several minutes to figure out how the "unbundle"
protocol worked. It turns out that the SSH protocol handler
sends an empty reply that is interpreted as "OK to send" and
only then does the client send the bundle payload.

On top of that, the response is different depending on whether
the operation was successful or not. I nearly pulled out my hair
deciphering this.

Differential Revision: https://phab.mercurial-scm.org/D2385

36371:0c231df1ffdc

    def _call(self, cmd, **args):
        args = pycompat.byteskwargs(args)
        return self._sendrequest(cmd, args, framed=True).read()

    def _callpush(self, cmd, fp, **args):
        r = self._call(cmd, **args)
        if r:
            return '', r
        for d in iter(lambda: fp.read(4096), ''):
            self._writeframed(d)
        self._writeframed("", flush=True)
        r = self._readframed()
        if r:
            return '', r
        return self._readframed(), ''

    def _calltwowaystream(self, cmd, fp, **args):
        r = self._call(cmd, **args)
        if r:
            # XXX needs to be made better
            raise error.Abort(_('unexpected remote reply: %s') % r)
        for d in iter(lambda: fp.read(4096), ''):
            self._writeframed(d)
        self._writeframed("", flush=True)
        return self._pipei

    def _getamount(self):
        l = self._pipei.readline()
        if l == '\n':

36372:b8d0761a85c7

    def _call(self, cmd, **args):
        args = pycompat.byteskwargs(args)
        return self._sendrequest(cmd, args, framed=True).read()

    def _callpush(self, cmd, fp, **args):
        # The server responds with an empty frame if the client should
        # continue submitting the payload.
        r = self._call(cmd, **args)
        if r:
            return '', r

        # The payload consists of frames with content followed by an empty
        # frame.
        for d in iter(lambda: fp.read(4096), ''):
            self._writeframed(d)
        self._writeframed("", flush=True)

        # In case of success, there is an empty frame and a frame containing
        # the integer result (as a string).
        # In case of error, there is a non-empty frame containing the error.
        r = self._readframed()
        if r:
            return '', r
        return self._readframed(), ''

    def _calltwowaystream(self, cmd, fp, **args):
        # The server responds with an empty frame if the client should
        # continue submitting the payload.
        r = self._call(cmd, **args)
        if r:
            # XXX needs to be made better
            raise error.Abort(_('unexpected remote reply: %s') % r)

        # The payload consists of frames with content followed by an empty
        # frame.
        for d in iter(lambda: fp.read(4096), ''):
            self._writeframed(d)
        self._writeframed("", flush=True)

        return self._pipei

    def _getamount(self):
        l = self._pipei.readline()
        if l == '\n':