view tests/test-wireproto-serverreactor.py @ 44118:f81c17ec303c

hgdemandimport: apply lazy module loading to sys.meta_path finders

Python's `sys.meta_path` finders are the primary objects whose job it
is to find a module at import time. When `import` is called, Python
iterates objects in this list and calls `o.find_spec(...)` to find
a `ModuleSpec` (or None if the module couldn't be found by that
finder). If no meta path finder can find a module, import fails.

One of the default meta path finders is `PathFinder`. Its job is to
import modules from the filesystem and is probably the most important
importer. This finder looks at `sys.path` and `sys.path_hooks` to do
its job.

The `ModuleSpec` returned by `MetaPathImporter.find_spec()` has a
`loader` attribute, which defines the concrete module loader to use.
`sys.path_hooks` is a hook point for teaching `PathFinder` to
instantiate custom loader types.

Previously, we injected a custom `sys.path_hook` that told `PathFinder`
to wrap the default loaders with a loader that creates a module object
that is lazy.

This approach worked. But its main limitation was that it only applied
to the `PathFinder` meta path importer. There are other meta path
importers that are registered. And in the case of PyOxidizer loading
modules from memory, `PathFinder` doesn't come into play since
PyOxidizer's own meta path importer was handling all imports.

This commit changes our approach to lazy module loading by proxying
all meta path importers. Specifically, we overload the `find_spec()`
method to swap in a wrapped loader on the `ModuleSpec` before it
is returned. The end result of this is all meta path importers should
be lazy.

As much as I would have loved to utilize .__class__ manipulation to
achieve this, some meta path importers are implemented in C/Rust
in such a way that they cannot be monkeypatched. This is why we
use __getattribute__ to define a proxy.

Also, this change could theoretically open us up to regressions in
meta path importers whose loader is creating module objects which
can't be monkeypatched. But I'm not aware of any of these in the
wild. So I think we'll be safe.

According to hyperfine, this change yields a decent startup time win of
5-6ms:

```
Benchmark #1: ~/.pyenv/versions/3.6.10/bin/python ./hg version
  Time (mean ± σ):      86.8 ms ±   0.5 ms    [User: 78.0 ms, System: 8.7 ms]
  Range (min … max):    86.0 ms …  89.1 ms    50 runs

  Time (mean ± σ):      81.1 ms ±   2.7 ms    [User: 74.5 ms, System: 6.5 ms]
  Range (min … max):    77.8 ms …  90.5 ms    50 runs

Benchmark #2: ~/.pyenv/versions/3.7.6/bin/python ./hg version
  Time (mean ± σ):      78.9 ms ±   0.6 ms    [User: 70.2 ms, System: 8.7 ms]
  Range (min … max):    78.1 ms …  81.2 ms    50 runs

  Time (mean ± σ):      73.4 ms ±   0.6 ms    [User: 65.3 ms, System: 8.0 ms]
  Range (min … max):    72.4 ms …  75.7 ms    50 runs

Benchmark #3: ~/.pyenv/versions/3.8.1/bin/python ./hg version
  Time (mean ± σ):      78.1 ms ±   0.6 ms    [User: 70.2 ms, System: 7.9 ms]
  Range (min … max):    77.4 ms …  80.9 ms    50 runs

  Time (mean ± σ):      72.1 ms ±   0.4 ms    [User: 64.4 ms, System: 7.6 ms]
  Range (min … max):    71.4 ms …  74.1 ms    50 runs
```

Differential Revision: https://phab.mercurial-scm.org/D7954

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__)