view tests/test-wireproto-serverreactor.py @ 44950:f9734b2d59cc

py3: make stdout line-buffered if connected to a TTY

Status messages that are to be shown on the terminal should be written to the
file descriptor before anything further is done, to keep the user updated.

One common way to achieve this is to make stdout line-buffered if it is
connected to a TTY. This is done on Python 2 (except on Windows, where libc,
which the CPython 2 streams depend on, does not properly support this).

Python 3 rolls it own I/O streams. On Python 3, buffered binary streams can't be
set line-buffered. The previous code (added in 227ba1afcb65) incorrectly
assumed that on Python 3, pycompat.stdout (sys.stdout.buffer) is already
line-buffered. However the interpreter initializes it with a block-buffered
stream or an unbuffered stream (when the -u option or the PYTHONUNBUFFERED
environment variable is set), never with a line-buffered stream.

One example where the current behavior is unacceptable is when running
`hg pull https://www.mercurial-scm.org/repo/hg` on Python 3, where the line
"pulling from https://www.mercurial-scm.org/repo/hg" does not appear on the
terminal before the hg process blocks while waiting for the server.

Various approaches to fix this problem are possible, including:

1. Weaken the contract of procutil.stdout to not give any guarantees about
   buffering behavior. In this case, users of procutil.stdout need to be
   changed to do enough flushes. In particular,
  1. either ui must insert enough flushes for ui.write() and friends, or
  2. ui.write() and friends get split into flushing and fully buffered
     methods, or
  3. users of ui.write() and friends must flush explicitly.
2. Make stdout unbuffered.
3. Make stdout line-buffered. Since Python 3 does not natively support that for
   binary streams, we must implement it ourselves.

(2.) is problematic because using unbuffered I/O changes the performance
characteristics significantly compared to line-buffered (which is used on
Python 2) and this would be a regression.

(1.2.) and (1.3) are a substantial amount of work. It’s unclear whether the
added complexity would be justified, given that raw performance doesn’t matter
that much when writing to a terminal much faster than the user could read it.

(1.1.) pushes complexity into the ui class instead of separating the concern of
how stdout is buffered. Other users of procutil.stdout would still need to take
care of the flushes.

This patch implements (3.). The general performance considerations are very
similar to (1.1.). The extra method invocation and method forwarding add a
little more overhead if the class is used. In exchange, it doesn’t add overhead
if not used.


For the benchmarks, I compared the previous implementation (incorrect on Python
3), (1.1.), (3.) and (2.). The command was chosen so that the streams were
configured as if they were writing to a TTY, but actually write to a pager,
which is also the default:
HGRCPATH=/dev/null python3 ./hg --cwd ~/vcs/mozilla-central --time --pager yes --config pager.pager='cat > /dev/null' status --all

previous:
time: real 7.880 secs (user 7.290+0.050 sys 0.580+0.170)
time: real 7.830 secs (user 7.220+0.070 sys 0.590+0.140)
time: real 7.800 secs (user 7.210+0.050 sys 0.570+0.170)

(1.1.) using Yuya Nishihara’s patch:
time: real 9.860 secs (user 8.670+0.350 sys 1.160+0.830)
time: real 9.540 secs (user 8.430+0.370 sys 1.100+0.770)
time: real 9.830 secs (user 8.630+0.370 sys 1.180+0.840)

(3.) using this patch:
time: real 9.580 secs (user 8.480+0.350 sys 1.090+0.770)
time: real 9.670 secs (user 8.480+0.330 sys 1.170+0.860)
time: real 9.640 secs (user 8.500+0.350 sys 1.130+0.810)

(2.) using a previous patch by me:
time: real 10.480 secs (user 8.850+0.720 sys 1.590+1.500)
time: real 10.490 secs (user 8.750+0.750 sys 1.710+1.470)
time: real 10.240 secs (user 8.600+0.700 sys 1.590+1.510)


As expected, there’s no difference on Python 2, as exactly the same code paths
are used:

previous:
time: real 6.950 secs (user 5.870+0.330 sys 1.070+0.770)
time: real 7.040 secs (user 6.040+0.360 sys 0.980+0.750)
time: real 7.070 secs (user 5.950+0.360 sys 1.100+0.760)

this patch:
time: real 7.010 secs (user 5.900+0.390 sys 1.070+0.730)
time: real 7.000 secs (user 5.850+0.350 sys 1.120+0.760)
time: real 7.000 secs (user 5.790+0.380 sys 1.170+0.710)

from __future__ import absolute_import, print_function

import unittest

from mercurial import (
    ui as uimod,
    util,
    wireprotoframing as framing,
)
from mercurial.utils import cborutil

ffs = framing.makeframefromhumanstring

OK = b''.join(cborutil.streamencode({b'status': b'ok'}))


def makereactor(deferoutput=False):
    ui = uimod.ui()
    return framing.serverreactor(ui, deferoutput=deferoutput)


def sendframes(reactor, gen):
    """Send a generator of frame bytearray to a reactor.

    Emits a generator of results from ``onframerecv()`` calls.
    """
    for frame in gen:
        header = framing.parseheader(frame)
        payload = frame[framing.FRAME_HEADER_SIZE :]
        assert len(payload) == header.length

        yield reactor.onframerecv(
            framing.frame(
                header.requestid,
                header.streamid,
                header.streamflags,
                header.typeid,
                header.flags,
                payload,
            )
        )


def sendcommandframes(reactor, stream, rid, cmd, args, datafh=None):
    """Generate frames to run a command and send them to a reactor."""
    return sendframes(
        reactor, framing.createcommandframes(stream, rid, cmd, args, datafh)
    )


class ServerReactorTests(unittest.TestCase):
    def _sendsingleframe(self, reactor, f):
        results = list(sendframes(reactor, [f]))
        self.assertEqual(len(results), 1)

        return results[0]

    def assertaction(self, res, expected):
        self.assertIsInstance(res, tuple)
        self.assertEqual(len(res), 2)
        self.assertIsInstance(res[1], dict)
        self.assertEqual(res[0], expected)

    def assertframesequal(self, frames, framestrings):
        expected = [ffs(s) for s in framestrings]
        self.assertEqual(list(frames), expected)

    def test1framecommand(self):
        """Receiving a command in a single frame yields request to run it."""
        reactor = makereactor()
        stream = framing.stream(1)
        results = list(sendcommandframes(reactor, stream, 1, b'mycommand', {}))
        self.assertEqual(len(results), 1)
        self.assertaction(results[0], b'runcommand')
        self.assertEqual(
            results[0][1],
            {
                b'requestid': 1,
                b'command': b'mycommand',
                b'args': {},
                b'redirect': None,
                b'data': None,
            },
        )

        result = reactor.oninputeof()
        self.assertaction(result, b'noop')

    def test1argument(self):
        reactor = makereactor()
        stream = framing.stream(1)
        results = list(
            sendcommandframes(
                reactor, stream, 41, b'mycommand', {b'foo': b'bar'}
            )
        )
        self.assertEqual(len(results), 1)
        self.assertaction(results[0], b'runcommand')
        self.assertEqual(
            results[0][1],
            {
                b'requestid': 41,
                b'command': b'mycommand',
                b'args': {b'foo': b'bar'},
                b'redirect': None,
                b'data': None,
            },
        )

    def testmultiarguments(self):
        reactor = makereactor()
        stream = framing.stream(1)
        results = list(
            sendcommandframes(
                reactor,
                stream,
                1,
                b'mycommand',
                {b'foo': b'bar', b'biz': b'baz'},
            )
        )
        self.assertEqual(len(results), 1)
        self.assertaction(results[0], b'runcommand')
        self.assertEqual(
            results[0][1],
            {
                b'requestid': 1,
                b'command': b'mycommand',
                b'args': {b'foo': b'bar', b'biz': b'baz'},
                b'redirect': None,
                b'data': None,
            },
        )

    def testsimplecommanddata(self):
        reactor = makereactor()
        stream = framing.stream(1)
        results = list(
            sendcommandframes(
                reactor, stream, 1, b'mycommand', {}, util.bytesio(b'data!')
            )
        )
        self.assertEqual(len(results), 2)
        self.assertaction(results[0], b'wantframe')
        self.assertaction(results[1], b'runcommand')
        self.assertEqual(
            results[1][1],
            {
                b'requestid': 1,
                b'command': b'mycommand',
                b'args': {},
                b'redirect': None,
                b'data': b'data!',
            },
        )

    def testmultipledataframes(self):
        frames = [
            ffs(
                b'1 1 stream-begin command-request new|have-data '
                b"cbor:{b'name': b'mycommand'}"
            ),
            ffs(b'1 1 0 command-data continuation data1'),
            ffs(b'1 1 0 command-data continuation data2'),
            ffs(b'1 1 0 command-data eos data3'),
        ]

        reactor = makereactor()
        results = list(sendframes(reactor, frames))
        self.assertEqual(len(results), 4)
        for i in range(3):
            self.assertaction(results[i], b'wantframe')
        self.assertaction(results[3], b'runcommand')
        self.assertEqual(
            results[3][1],
            {
                b'requestid': 1,
                b'command': b'mycommand',
                b'args': {},
                b'redirect': None,
                b'data': b'data1data2data3',
            },
        )

    def testargumentanddata(self):
        frames = [
            ffs(
                b'1 1 stream-begin command-request new|have-data '
                b"cbor:{b'name': b'command', b'args': {b'key': b'val',"
                b"b'foo': b'bar'}}"
            ),
            ffs(b'1 1 0 command-data continuation value1'),
            ffs(b'1 1 0 command-data eos value2'),
        ]

        reactor = makereactor()
        results = list(sendframes(reactor, frames))

        self.assertaction(results[-1], b'runcommand')
        self.assertEqual(
            results[-1][1],
            {
                b'requestid': 1,
                b'command': b'command',
                b'args': {b'key': b'val', b'foo': b'bar',},
                b'redirect': None,
                b'data': b'value1value2',
            },
        )

    def testnewandcontinuation(self):
        result = self._sendsingleframe(
            makereactor(),
            ffs(b'1 1 stream-begin command-request new|continuation '),
        )
        self.assertaction(result, b'error')
        self.assertEqual(
            result[1],
            {
                b'message': b'received command request frame with both new and '
                b'continuation flags set',
            },
        )

    def testneithernewnorcontinuation(self):
        result = self._sendsingleframe(
            makereactor(), ffs(b'1 1 stream-begin command-request 0 ')
        )
        self.assertaction(result, b'error')
        self.assertEqual(
            result[1],
            {
                b'message': b'received command request frame with neither new nor '
                b'continuation flags set',
            },
        )

    def testunexpectedcommanddata(self):
        """Command data frame when not running a command is an error."""
        result = self._sendsingleframe(
            makereactor(), ffs(b'1 1 stream-begin command-data 0 ignored')
        )
        self.assertaction(result, b'error')
        self.assertEqual(
            result[1],
            {
                b'message': b'expected sender protocol settings or command request '
                b'frame; got 2',
            },
        )

    def testunexpectedcommanddatareceiving(self):
        """Same as above except the command is receiving."""
        results = list(
            sendframes(
                makereactor(),
                [
                    ffs(
                        b'1 1 stream-begin command-request new|more '
                        b"cbor:{b'name': b'ignored'}"
                    ),
                    ffs(b'1 1 0 command-data eos ignored'),
                ],
            )
        )

        self.assertaction(results[0], b'wantframe')
        self.assertaction(results[1], b'error')
        self.assertEqual(
            results[1][1],
            {
                b'message': b'received command data frame for request that is not '
                b'expecting data: 1',
            },
        )

    def testconflictingrequestidallowed(self):
        """Multiple fully serviced commands with same request ID is allowed."""
        reactor = makereactor()
        results = []
        outstream = reactor.makeoutputstream()
        results.append(
            self._sendsingleframe(
                reactor,
                ffs(
                    b'1 1 stream-begin command-request new '
                    b"cbor:{b'name': b'command'}"
                ),
            )
        )
        result = reactor.oncommandresponsereadyobjects(
            outstream, 1, [b'response1']
        )
        self.assertaction(result, b'sendframes')
        list(result[1][b'framegen'])
        results.append(
            self._sendsingleframe(
                reactor,
                ffs(
                    b'1 1 stream-begin command-request new '
                    b"cbor:{b'name': b'command'}"
                ),
            )
        )
        result = reactor.oncommandresponsereadyobjects(
            outstream, 1, [b'response2']
        )
        self.assertaction(result, b'sendframes')
        list(result[1][b'framegen'])
        results.append(
            self._sendsingleframe(
                reactor,
                ffs(
                    b'1 1 stream-begin command-request new '
                    b"cbor:{b'name': b'command'}"
                ),
            )
        )
        result = reactor.oncommandresponsereadyobjects(
            outstream, 1, [b'response3']
        )
        self.assertaction(result, b'sendframes')
        list(result[1][b'framegen'])

        for i in range(3):
            self.assertaction(results[i], b'runcommand')
            self.assertEqual(
                results[i][1],
                {
                    b'requestid': 1,
                    b'command': b'command',
                    b'args': {},
                    b'redirect': None,
                    b'data': None,
                },
            )

    def testconflictingrequestid(self):
        """Request ID for new command matching in-flight command is illegal."""
        results = list(
            sendframes(
                makereactor(),
                [
                    ffs(
                        b'1 1 stream-begin command-request new|more '
                        b"cbor:{b'name': b'command'}"
                    ),
                    ffs(
                        b'1 1 0 command-request new '
                        b"cbor:{b'name': b'command1'}"
                    ),
                ],
            )
        )

        self.assertaction(results[0], b'wantframe')
        self.assertaction(results[1], b'error')
        self.assertEqual(
            results[1][1], {b'message': b'request with ID 1 already received',}
        )

    def testinterleavedcommands(self):
        cbor1 = b''.join(
            cborutil.streamencode(
                {
                    b'name': b'command1',
                    b'args': {b'foo': b'bar', b'key1': b'val',},
                }
            )
        )
        cbor3 = b''.join(
            cborutil.streamencode(
                {
                    b'name': b'command3',
                    b'args': {b'biz': b'baz', b'key': b'val',},
                }
            )
        )

        results = list(
            sendframes(
                makereactor(),
                [
                    ffs(
                        b'1 1 stream-begin command-request new|more %s'
                        % cbor1[0:6]
                    ),
                    ffs(b'3 1 0 command-request new|more %s' % cbor3[0:10]),
                    ffs(
                        b'1 1 0 command-request continuation|more %s'
                        % cbor1[6:9]
                    ),
                    ffs(
                        b'3 1 0 command-request continuation|more %s'
                        % cbor3[10:13]
                    ),
                    ffs(b'3 1 0 command-request continuation %s' % cbor3[13:]),
                    ffs(b'1 1 0 command-request continuation %s' % cbor1[9:]),
                ],
            )
        )

        self.assertEqual(
            [t[0] for t in results],
            [
                b'wantframe',
                b'wantframe',
                b'wantframe',
                b'wantframe',
                b'runcommand',
                b'runcommand',
            ],
        )

        self.assertEqual(
            results[4][1],
            {
                b'requestid': 3,
                b'command': b'command3',
                b'args': {b'biz': b'baz', b'key': b'val'},
                b'redirect': None,
                b'data': None,
            },
        )
        self.assertEqual(
            results[5][1],
            {
                b'requestid': 1,
                b'command': b'command1',
                b'args': {b'foo': b'bar', b'key1': b'val'},
                b'redirect': None,
                b'data': None,
            },
        )

    def testmissingcommanddataframe(self):
        # The reactor doesn't currently handle partially received commands.
        # So this test is failing to do anything with request 1.
        frames = [
            ffs(
                b'1 1 stream-begin command-request new|have-data '
                b"cbor:{b'name': b'command1'}"
            ),
            ffs(b'3 1 0 command-request new ' b"cbor:{b'name': b'command2'}"),
        ]
        results = list(sendframes(makereactor(), frames))
        self.assertEqual(len(results), 2)
        self.assertaction(results[0], b'wantframe')
        self.assertaction(results[1], b'runcommand')

    def testmissingcommanddataframeflags(self):
        frames = [
            ffs(
                b'1 1 stream-begin command-request new|have-data '
                b"cbor:{b'name': b'command1'}"
            ),
            ffs(b'1 1 0 command-data 0 data'),
        ]
        results = list(sendframes(makereactor(), frames))
        self.assertEqual(len(results), 2)
        self.assertaction(results[0], b'wantframe')
        self.assertaction(results[1], b'error')
        self.assertEqual(
            results[1][1], {b'message': b'command data frame without flags',}
        )

    def testframefornonreceivingrequest(self):
        """Receiving a frame for a command that is not receiving is illegal."""
        results = list(
            sendframes(
                makereactor(),
                [
                    ffs(
                        b'1 1 stream-begin command-request new '
                        b"cbor:{b'name': b'command1'}"
                    ),
                    ffs(
                        b'3 1 0 command-request new|have-data '
                        b"cbor:{b'name': b'command3'}"
                    ),
                    ffs(b'5 1 0 command-data eos ignored'),
                ],
            )
        )
        self.assertaction(results[2], b'error')
        self.assertEqual(
            results[2][1],
            {
                b'message': b'received frame for request that is not receiving: 5',
            },
        )

    def testsimpleresponse(self):
        """Bytes response to command sends result frames."""
        reactor = makereactor()
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'mycommand', {}))

        outstream = reactor.makeoutputstream()
        result = reactor.oncommandresponsereadyobjects(
            outstream, 1, [b'response']
        )
        self.assertaction(result, b'sendframes')
        self.assertframesequal(
            result[1][b'framegen'],
            [
                b'1 2 stream-begin stream-settings eos cbor:b"identity"',
                b'1 2 encoded command-response continuation %s' % OK,
                b'1 2 encoded command-response continuation cbor:b"response"',
                b'1 2 0 command-response eos ',
            ],
        )

    def testmultiframeresponse(self):
        """Bytes response spanning multiple frames is handled."""
        first = b'x' * framing.DEFAULT_MAX_FRAME_SIZE
        second = b'y' * 100

        reactor = makereactor()
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'mycommand', {}))

        outstream = reactor.makeoutputstream()
        result = reactor.oncommandresponsereadyobjects(
            outstream, 1, [first + second]
        )
        self.assertaction(result, b'sendframes')
        self.assertframesequal(
            result[1][b'framegen'],
            [
                b'1 2 stream-begin stream-settings eos cbor:b"identity"',
                b'1 2 encoded command-response continuation %s' % OK,
                b'1 2 encoded command-response continuation Y\x80d',
                b'1 2 encoded command-response continuation %s' % first,
                b'1 2 encoded command-response continuation %s' % second,
                b'1 2 0 command-response eos ',
            ],
        )

    def testservererror(self):
        reactor = makereactor()
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'mycommand', {}))

        outstream = reactor.makeoutputstream()
        result = reactor.onservererror(outstream, 1, b'some message')
        self.assertaction(result, b'sendframes')
        self.assertframesequal(
            result[1][b'framegen'],
            [
                b"1 2 stream-begin error-response 0 "
                b"cbor:{b'type': b'server', "
                b"b'message': [{b'msg': b'some message'}]}",
            ],
        )

    def test1commanddeferresponse(self):
        """Responses when in deferred output mode are delayed until EOF."""
        reactor = makereactor(deferoutput=True)
        instream = framing.stream(1)
        results = list(
            sendcommandframes(reactor, instream, 1, b'mycommand', {})
        )
        self.assertEqual(len(results), 1)
        self.assertaction(results[0], b'runcommand')

        outstream = reactor.makeoutputstream()
        result = reactor.oncommandresponsereadyobjects(
            outstream, 1, [b'response']
        )
        self.assertaction(result, b'noop')
        result = reactor.oninputeof()
        self.assertaction(result, b'sendframes')
        self.assertframesequal(
            result[1][b'framegen'],
            [
                b'1 2 stream-begin stream-settings eos cbor:b"identity"',
                b'1 2 encoded command-response continuation %s' % OK,
                b'1 2 encoded command-response continuation cbor:b"response"',
                b'1 2 0 command-response eos ',
            ],
        )

    def testmultiplecommanddeferresponse(self):
        reactor = makereactor(deferoutput=True)
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'command1', {}))
        list(sendcommandframes(reactor, instream, 3, b'command2', {}))

        outstream = reactor.makeoutputstream()
        result = reactor.oncommandresponsereadyobjects(
            outstream, 1, [b'response1']
        )
        self.assertaction(result, b'noop')
        result = reactor.oncommandresponsereadyobjects(
            outstream, 3, [b'response2']
        )
        self.assertaction(result, b'noop')
        result = reactor.oninputeof()
        self.assertaction(result, b'sendframes')
        self.assertframesequal(
            result[1][b'framegen'],
            [
                b'1 2 stream-begin stream-settings eos cbor:b"identity"',
                b'1 2 encoded command-response continuation %s' % OK,
                b'1 2 encoded command-response continuation cbor:b"response1"',
                b'1 2 0 command-response eos ',
                b'3 2 encoded command-response continuation %s' % OK,
                b'3 2 encoded command-response continuation cbor:b"response2"',
                b'3 2 0 command-response eos ',
            ],
        )

    def testrequestidtracking(self):
        reactor = makereactor(deferoutput=True)
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'command1', {}))
        list(sendcommandframes(reactor, instream, 3, b'command2', {}))
        list(sendcommandframes(reactor, instream, 5, b'command3', {}))

        # Register results for commands out of order.
        outstream = reactor.makeoutputstream()
        reactor.oncommandresponsereadyobjects(outstream, 3, [b'response3'])
        reactor.oncommandresponsereadyobjects(outstream, 1, [b'response1'])
        reactor.oncommandresponsereadyobjects(outstream, 5, [b'response5'])

        result = reactor.oninputeof()
        self.assertaction(result, b'sendframes')
        self.assertframesequal(
            result[1][b'framegen'],
            [
                b'3 2 stream-begin stream-settings eos cbor:b"identity"',
                b'3 2 encoded command-response continuation %s' % OK,
                b'3 2 encoded command-response continuation cbor:b"response3"',
                b'3 2 0 command-response eos ',
                b'1 2 encoded command-response continuation %s' % OK,
                b'1 2 encoded command-response continuation cbor:b"response1"',
                b'1 2 0 command-response eos ',
                b'5 2 encoded command-response continuation %s' % OK,
                b'5 2 encoded command-response continuation cbor:b"response5"',
                b'5 2 0 command-response eos ',
            ],
        )

    def testduplicaterequestonactivecommand(self):
        """Receiving a request ID that matches a request that isn't finished."""
        reactor = makereactor()
        stream = framing.stream(1)
        list(sendcommandframes(reactor, stream, 1, b'command1', {}))
        results = list(sendcommandframes(reactor, stream, 1, b'command1', {}))

        self.assertaction(results[0], b'error')
        self.assertEqual(
            results[0][1], {b'message': b'request with ID 1 is already active',}
        )

    def testduplicaterequestonactivecommandnosend(self):
        """Same as above but we've registered a response but haven't sent it."""
        reactor = makereactor()
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'command1', {}))
        outstream = reactor.makeoutputstream()
        reactor.oncommandresponsereadyobjects(outstream, 1, [b'response'])

        # We've registered the response but haven't sent it. From the
        # perspective of the reactor, the command is still active.

        results = list(sendcommandframes(reactor, instream, 1, b'command1', {}))
        self.assertaction(results[0], b'error')
        self.assertEqual(
            results[0][1], {b'message': b'request with ID 1 is already active',}
        )

    def testduplicaterequestaftersend(self):
        """We can use a duplicate request ID after we've sent the response."""
        reactor = makereactor()
        instream = framing.stream(1)
        list(sendcommandframes(reactor, instream, 1, b'command1', {}))
        outstream = reactor.makeoutputstream()
        res = reactor.oncommandresponsereadyobjects(outstream, 1, [b'response'])
        list(res[1][b'framegen'])

        results = list(sendcommandframes(reactor, instream, 1, b'command1', {}))
        self.assertaction(results[0], b'runcommand')

    def testprotocolsettingsnoflags(self):
        result = self._sendsingleframe(
            makereactor(), ffs(b'0 1 stream-begin sender-protocol-settings 0 ')
        )
        self.assertaction(result, b'error')
        self.assertEqual(
            result[1],
            {
                b'message': b'sender protocol settings frame must have '
                b'continuation or end of stream flag set',
            },
        )

    def testprotocolsettingsconflictflags(self):
        result = self._sendsingleframe(
            makereactor(),
            ffs(b'0 1 stream-begin sender-protocol-settings continuation|eos '),
        )
        self.assertaction(result, b'error')
        self.assertEqual(
            result[1],
            {
                b'message': b'sender protocol settings frame cannot have both '
                b'continuation and end of stream flags set',
            },
        )

    def testprotocolsettingsemptypayload(self):
        result = self._sendsingleframe(
            makereactor(),
            ffs(b'0 1 stream-begin sender-protocol-settings eos '),
        )
        self.assertaction(result, b'error')
        self.assertEqual(
            result[1],
            {
                b'message': b'sender protocol settings frame did not contain CBOR '
                b'data',
            },
        )

    def testprotocolsettingsmultipleobjects(self):
        result = self._sendsingleframe(
            makereactor(),
            ffs(
                b'0 1 stream-begin sender-protocol-settings eos '
                b'\x46foobar\x43foo'
            ),
        )
        self.assertaction(result, b'error')
        self.assertEqual(
            result[1],
            {
                b'message': b'sender protocol settings frame contained multiple '
                b'CBOR values',
            },
        )

    def testprotocolsettingscontentencodings(self):
        reactor = makereactor()

        result = self._sendsingleframe(
            reactor,
            ffs(
                b'0 1 stream-begin sender-protocol-settings eos '
                b'cbor:{b"contentencodings": [b"a", b"b"]}'
            ),
        )
        self.assertaction(result, b'wantframe')

        self.assertEqual(reactor._state, b'idle')
        self.assertEqual(
            reactor._sendersettings[b'contentencodings'], [b'a', b'b']
        )

    def testprotocolsettingsmultipleframes(self):
        reactor = makereactor()

        data = b''.join(
            cborutil.streamencode(
                {b'contentencodings': [b'value1', b'value2'],}
            )
        )

        results = list(
            sendframes(
                reactor,
                [
                    ffs(
                        b'0 1 stream-begin sender-protocol-settings continuation %s'
                        % data[0:5]
                    ),
                    ffs(b'0 1 0 sender-protocol-settings eos %s' % data[5:]),
                ],
            )
        )

        self.assertEqual(len(results), 2)

        self.assertaction(results[0], b'wantframe')
        self.assertaction(results[1], b'wantframe')

        self.assertEqual(reactor._state, b'idle')
        self.assertEqual(
            reactor._sendersettings[b'contentencodings'], [b'value1', b'value2']
        )

    def testprotocolsettingsbadcbor(self):
        result = self._sendsingleframe(
            makereactor(),
            ffs(b'0 1 stream-begin sender-protocol-settings eos badvalue'),
        )
        self.assertaction(result, b'error')

    def testprotocolsettingsnoninitial(self):
        # Cannot have protocol settings frames as non-initial frames.
        reactor = makereactor()

        stream = framing.stream(1)
        results = list(sendcommandframes(reactor, stream, 1, b'mycommand', {}))
        self.assertEqual(len(results), 1)
        self.assertaction(results[0], b'runcommand')

        result = self._sendsingleframe(
            reactor, ffs(b'0 1 0 sender-protocol-settings eos ')
        )
        self.assertaction(result, b'error')
        self.assertEqual(
            result[1], {b'message': b'expected command request frame; got 8',}
        )


if __name__ == '__main__':
    import silenttestrunner

    silenttestrunner.main(__name__)