view tests/test-wireproto-clientreactor.py @ 51681:522b4d729e89

mmap: populate the mapping by default

Without pre-population, accessing all data through a mmap can result in many
pagefault, reducing performance significantly. If the mmap is prepopulated, the
performance can no longer get slower than a full read.
(See benchmark number below)

In some cases were very few data is read, prepopulating can be overkill and
slower than populating on access (through page fault). So that behavior can be
controlled when the caller can pre-determine the best behavior.
(See benchmark number below)

In addition, testing with populating in a secondary thread yield great result
combining the best of each approach. This might be implemented in later
changesets.

In all cases, using mmap has a great effect on memory usage when many processes
run in parallel on the same machine.

### Benchmarks

# What did I run

A couple of month back I ran a large benchmark campaign to assess the impact of
various approach for using mmap with the revlog (and other files), it
highlighted a few benchmarks that capture the impact of the changes well. So to
validate this change I checked the following:

- log command displaying various revisions
  (read the changelog index)
- log command displaying the patch of listed revisions
  (read the changelog index, the manifest index and a few files indexes)
- unbundling a few revisions
  (read and write changelog, manifest and few files indexes, and walk the graph
  to update some cache)
- pushing a few revisions
  (read and write changelog, manifest and few files indexes, walk the graph to
  update some cache, performs various accesses locally and remotely during
  discovery)

Benchmarks were run using the default module policy (c+py) and the rust one. No
significant difference were found between the two implementation, so we will
present result using the default policy (unless otherwise specified).

I ran them on a few repositories :

- mercurial: a "public changeset only" copy of mercurial from 2018-08-01 using
  zstd compression and sparse-revlog

- pypy: a copy of pypy from 2018-08-01 using zstd compression and sparse-revlog

- netbeans: a copy of netbeans from 2018-08-01 using zstd compression and
  sparse-revlog

- mozilla-try: a copy of mozilla-try from 2019-02-18 using zstd compression and
  sparse-revlog

- mozilla-try persistent-nodemap: Same as the above but with a persistent
  nodemap. Used for the log --patch benchmark only

# Results

For the smaller repositories (mercurial, pypy), the impact of mmap is almost
imperceptible, other cost dominating the operation. The impact of prepopulating
is undiscernible in the benchmark we ran.

For larger repositories the benchmark support explanation given above:

On netbeans, the log can be about 1% faster without repopulation (for a
difference < 100ms) but unbundle becomes a bit slower, even when small.

### data-env-vars.name                             = netbeans-2018-08-01-zstd-sparse-revlog
  # benchmark.name                                 = hg.command.unbundle
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.reuse-external-delta-parent = yes
  # benchmark.variants.revs                        = any-1-extra-rev
  # benchmark.variants.source                      = unbundle
  # benchmark.variants.verbosity                   = quiet
with-populate: 0.240157
no-populate:   0.265087  (+10.38%, +0.02)
  # benchmark.variants.revs                        = any-100-extra-rev
with-populate: 1.459518
no-populate:   1.481290   (+1.49%, +0.02)
 ## benchmark.name                                 = hg.command.push
  # benchmark.variants.explicit-rev                = none
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.protocol                    = ssh
  # benchmark.variants.reuse-external-delta-parent = yes
  # benchmark.variants.revs                        = any-1-extra-rev
with-populate: 0.771919
no-populate:   0.792025   (+2.60%, +0.02)
  # benchmark.variants.revs                        = any-100-extra-rev
with-populate: 1.459518
no-populate:   1.481290   (+1.49%, +0.02)


For mozilla-try, the "slow down" from pre-populate for small `hg log` is more
visible, but still small in absolute time. (using rust value for the persistent
nodemap value to be relevant).

### data-env-vars.name            = mozilla-try-2019-02-18-ds2-pnm
  # benchmark.name                = hg.command.log
  # bin-env-vars.hg.flavor        = rust
  # benchmark.variants.patch      = yes
  # benchmark.variants.limit-rev  = 1
with-populate: 0.237813
no-populate:   0.229452   (-3.52%, -0.01)
  # benchmark.variants.limit-rev  = 10
  # benchmark.variants.patch      = yes
with-populate: 1.213578
no-populate:   1.205189
### data-env-vars.name            = mozilla-try-2019-02-18-zstd-sparse-revlog
  # benchmark.variants.limit-rev  = 1000
  # benchmark.variants.patch      = no
  # benchmark.variants.rev        = tip
with-populate: 0.198607
no-populate:   0.195038   (-1.80%, -0.00)

However pre-populating provide a significant boost on more complex operations
like unbundle or push:

### data-env-vars.name                             = mozilla-try-2019-02-18-zstd-sparse-revlog
  # benchmark.name                                 = hg.command.push
  # benchmark.variants.explicit-rev                = none
  # benchmark.variants.issue6528                   = disabled
  # benchmark.variants.protocol                    = ssh
  # benchmark.variants.reuse-external-delta-parent = yes
  # benchmark.variants.revs                        = any-1-extra-rev
with-populate: 4.798632
no-populate:   4.953295   (+3.22%, +0.15)
  # benchmark.variants.revs                        = any-100-extra-rev
with-populate: 4.903618
no-populate:   5.014963   (+2.27%, +0.11)
 ## benchmark.name                                 = hg.command.unbundle
  # benchmark.variants.revs                        = any-1-extra-rev
with-populate: 1.423411
no-populate:   1.585365  (+11.38%, +0.16)
  # benchmark.variants.revs                        = any-100-extra-rev
with-populate: 1.537909
no-populate:   1.688489   (+9.79%, +0.15)

import sys
import unittest
import zlib

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

try:
    from mercurial import zstd

    zstd.__version__
except ImportError:
    zstd = None

ffs = framing.makeframefromhumanstring

globalui = uimod.ui()


def sendframe(reactor, frame):
    """Send a frame bytearray to a reactor."""
    header = framing.parseheader(frame)
    payload = frame[framing.FRAME_HEADER_SIZE :]
    assert len(payload) == header.length

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


class SingleSendTests(unittest.TestCase):
    """A reactor that can only send once rejects subsequent sends."""

    if not getattr(unittest.TestCase, 'assertRaisesRegex', False):
        # Python 3.7 deprecates the regex*p* version, but 2.7 lacks
        # the regex version.
        assertRaisesRegex = (  # camelcase-required
            unittest.TestCase.assertRaisesRegexp
        )

    def testbasic(self):
        reactor = framing.clientreactor(
            globalui, hasmultiplesend=False, buffersends=True
        )

        request, action, meta = reactor.callcommand(b'foo', {})
        self.assertEqual(request.state, b'pending')
        self.assertEqual(action, b'noop')

        action, meta = reactor.flushcommands()
        self.assertEqual(action, b'sendframes')

        for frame in meta[b'framegen']:
            self.assertEqual(request.state, b'sending')

        self.assertEqual(request.state, b'sent')

        with self.assertRaisesRegex(
            error.ProgrammingError, 'cannot issue new commands'
        ):
            reactor.callcommand(b'foo', {})

        with self.assertRaisesRegex(
            error.ProgrammingError, 'cannot issue new commands'
        ):
            reactor.callcommand(b'foo', {})


class NoBufferTests(unittest.TestCase):
    """A reactor without send buffering sends requests immediately."""

    def testbasic(self):
        reactor = framing.clientreactor(
            globalui, hasmultiplesend=True, buffersends=False
        )

        request, action, meta = reactor.callcommand(b'command1', {})
        self.assertEqual(request.requestid, 1)
        self.assertEqual(action, b'sendframes')

        self.assertEqual(request.state, b'pending')

        for frame in meta[b'framegen']:
            self.assertEqual(request.state, b'sending')

        self.assertEqual(request.state, b'sent')

        action, meta = reactor.flushcommands()
        self.assertEqual(action, b'noop')

        # And we can send another command.
        request, action, meta = reactor.callcommand(b'command2', {})
        self.assertEqual(request.requestid, 3)
        self.assertEqual(action, b'sendframes')

        for frame in meta[b'framegen']:
            self.assertEqual(request.state, b'sending')

        self.assertEqual(request.state, b'sent')


class BadFrameRecvTests(unittest.TestCase):
    if not getattr(unittest.TestCase, 'assertRaisesRegex', False):
        # Python 3.7 deprecates the regex*p* version, but 2.7 lacks
        # the regex version.
        assertRaisesRegex = (  # camelcase-required
            unittest.TestCase.assertRaisesRegexp
        )

    def testoddstream(self):
        reactor = framing.clientreactor(globalui)

        action, meta = sendframe(reactor, ffs(b'1 1 0 1 0 foo'))
        self.assertEqual(action, b'error')
        self.assertEqual(
            meta[b'message'], b'received frame with odd numbered stream ID: 1'
        )

    def testunknownstream(self):
        reactor = framing.clientreactor(globalui)

        action, meta = sendframe(reactor, ffs(b'1 0 0 1 0 foo'))
        self.assertEqual(action, b'error')
        self.assertEqual(
            meta[b'message'],
            b'received frame on unknown stream without beginning '
            b'of stream flag set',
        )

    def testunhandledframetype(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for frame in meta[b'framegen']:
            pass

        with self.assertRaisesRegex(
            error.ProgrammingError, 'unhandled frame type'
        ):
            sendframe(reactor, ffs(b'1 0 stream-begin text-output 0 foo'))


class StreamTests(unittest.TestCase):
    def testmultipleresponseframes(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})

        self.assertEqual(action, b'sendframes')
        for f in meta[b'framegen']:
            pass

        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 0 stream-begin command-response 0 foo' % request.requestid
            ),
        )
        self.assertEqual(action, b'responsedata')

        action, meta = sendframe(
            reactor, ffs(b'%d 0 0 command-response eos bar' % request.requestid)
        )
        self.assertEqual(action, b'responsedata')


class RedirectTests(unittest.TestCase):
    def testredirect(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        redirect = {
            b'targets': [b'a', b'b'],
            b'hashes': [b'sha256'],
        }

        request, action, meta = reactor.callcommand(
            b'foo', {}, redirect=redirect
        )

        self.assertEqual(action, b'sendframes')

        frames = list(meta[b'framegen'])
        self.assertEqual(len(frames), 1)

        self.assertEqual(
            frames[0],
            ffs(
                b'1 1 stream-begin command-request new '
                b"cbor:{b'name': b'foo', "
                b"b'redirect': {b'targets': [b'a', b'b'], "
                b"b'hashes': [b'sha256']}}"
            ),
        )


class StreamSettingsTests(unittest.TestCase):
    def testnoflags(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        action, meta = sendframe(
            reactor, ffs(b'1 2 stream-begin stream-settings 0 ')
        )

        self.assertEqual(action, b'error')
        self.assertEqual(
            meta,
            {
                b'message': b'stream encoding settings frame must have '
                b'continuation or end of stream flag set',
            },
        )

    def testconflictflags(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        action, meta = sendframe(
            reactor, ffs(b'1 2 stream-begin stream-settings continuation|eos ')
        )

        self.assertEqual(action, b'error')
        self.assertEqual(
            meta,
            {
                b'message': b'stream encoding settings frame cannot have both '
                b'continuation and end of stream flags set',
            },
        )

    def testemptypayload(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        action, meta = sendframe(
            reactor, ffs(b'1 2 stream-begin stream-settings eos ')
        )

        self.assertEqual(action, b'error')
        self.assertEqual(
            meta,
            {
                b'message': b'stream encoding settings frame did not contain '
                b'CBOR data'
            },
        )

    def testbadcbor(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        action, meta = sendframe(
            reactor, ffs(b'1 2 stream-begin stream-settings eos badvalue')
        )

        self.assertEqual(action, b'error')

    def testsingleobject(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        action, meta = sendframe(
            reactor,
            ffs(b'1 2 stream-begin stream-settings eos cbor:b"identity"'),
        )

        self.assertEqual(action, b'noop')
        self.assertEqual(meta, {})

    def testmultipleobjects(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        data = b''.join(
            [
                b''.join(cborutil.streamencode(b'identity')),
                b''.join(cborutil.streamencode({b'foo', b'bar'})),
            ]
        )

        action, meta = sendframe(
            reactor, ffs(b'1 2 stream-begin stream-settings eos %s' % data)
        )

        self.assertEqual(action, b'error')
        self.assertEqual(
            meta,
            {
                b'message': b'error setting stream decoder: identity decoder '
                b'received unexpected additional values',
            },
        )

    def testmultipleframes(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        data = b''.join(cborutil.streamencode(b'identity'))

        action, meta = sendframe(
            reactor,
            ffs(
                b'1 2 stream-begin stream-settings continuation %s' % data[0:3]
            ),
        )

        self.assertEqual(action, b'noop')
        self.assertEqual(meta, {})

        action, meta = sendframe(
            reactor, ffs(b'1 2 0 stream-settings eos %s' % data[3:])
        )

        self.assertEqual(action, b'noop')
        self.assertEqual(meta, {})

    def testinvalidencoder(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        action, meta = sendframe(
            reactor,
            ffs(b'1 2 stream-begin stream-settings eos cbor:b"badvalue"'),
        )

        self.assertEqual(action, b'error')
        self.assertEqual(
            meta,
            {
                b'message': b'error setting stream decoder: unknown stream '
                b'decoder: badvalue',
            },
        )

    def testzlibencoding(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 stream-begin stream-settings eos cbor:b"zlib"'
                % request.requestid
            ),
        )

        self.assertEqual(action, b'noop')
        self.assertEqual(meta, {})

        result = {
            b'status': b'ok',
        }
        encoded = b''.join(cborutil.streamencode(result))

        compressed = zlib.compress(encoded)
        self.assertEqual(zlib.decompress(compressed), encoded)

        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 encoded command-response eos %s'
                % (request.requestid, compressed)
            ),
        )

        self.assertEqual(action, b'responsedata')
        self.assertEqual(meta[b'data'], encoded)

    def testzlibencodingsinglebyteframes(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 stream-begin stream-settings eos cbor:b"zlib"'
                % request.requestid
            ),
        )

        self.assertEqual(action, b'noop')
        self.assertEqual(meta, {})

        result = {
            b'status': b'ok',
        }
        encoded = b''.join(cborutil.streamencode(result))

        compressed = zlib.compress(encoded)
        self.assertEqual(zlib.decompress(compressed), encoded)

        chunks = []

        for i in range(len(compressed)):
            char = compressed[i : i + 1]
            if char == b'\\':
                char = b'\\\\'
            action, meta = sendframe(
                reactor,
                ffs(
                    b'%d 2 encoded command-response continuation %s'
                    % (request.requestid, char)
                ),
            )

            self.assertEqual(action, b'responsedata')
            chunks.append(meta[b'data'])
            self.assertTrue(meta[b'expectmore'])
            self.assertFalse(meta[b'eos'])

        # zlib will have the full data decoded at this point, even though
        # we haven't flushed.
        self.assertEqual(b''.join(chunks), encoded)

        # End the stream for good measure.
        action, meta = sendframe(
            reactor,
            ffs(b'%d 2 stream-end command-response eos ' % request.requestid),
        )

        self.assertEqual(action, b'responsedata')
        self.assertEqual(meta[b'data'], b'')
        self.assertFalse(meta[b'expectmore'])
        self.assertTrue(meta[b'eos'])

    def testzlibmultipleresponses(self):
        # We feed in zlib compressed data on the same stream but belonging to
        # 2 different requests. This tests our flushing behavior.
        reactor = framing.clientreactor(
            globalui, buffersends=False, hasmultiplesend=True
        )

        request1, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        request2, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        outstream = framing.outputstream(2)
        outstream.setencoder(globalui, b'zlib')

        response1 = b''.join(
            cborutil.streamencode(
                {
                    b'status': b'ok',
                    b'extra': b'response1' * 10,
                }
            )
        )

        response2 = b''.join(
            cborutil.streamencode(
                {
                    b'status': b'error',
                    b'extra': b'response2' * 10,
                }
            )
        )

        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 stream-begin stream-settings eos cbor:b"zlib"'
                % request1.requestid
            ),
        )

        self.assertEqual(action, b'noop')
        self.assertEqual(meta, {})

        # Feeding partial data in won't get anything useful out.
        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 encoded command-response continuation %s'
                % (request1.requestid, outstream.encode(response1))
            ),
        )
        self.assertEqual(action, b'responsedata')
        self.assertEqual(meta[b'data'], b'')

        # But flushing data at both ends will get our original data.
        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 encoded command-response eos %s'
                % (request1.requestid, outstream.flush())
            ),
        )
        self.assertEqual(action, b'responsedata')
        self.assertEqual(meta[b'data'], response1)

        # We should be able to reuse the compressor/decompressor for the
        # 2nd response.
        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 encoded command-response continuation %s'
                % (request2.requestid, outstream.encode(response2))
            ),
        )
        self.assertEqual(action, b'responsedata')
        self.assertEqual(meta[b'data'], b'')

        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 encoded command-response eos %s'
                % (request2.requestid, outstream.flush())
            ),
        )
        self.assertEqual(action, b'responsedata')
        self.assertEqual(meta[b'data'], response2)

    @unittest.skipUnless(zstd, 'zstd not available')
    def testzstd8mbencoding(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 stream-begin stream-settings eos cbor:b"zstd-8mb"'
                % request.requestid
            ),
        )

        self.assertEqual(action, b'noop')
        self.assertEqual(meta, {})

        result = {
            b'status': b'ok',
        }
        encoded = b''.join(cborutil.streamencode(result))

        encoder = framing.zstd8mbencoder(globalui)
        compressed = encoder.encode(encoded) + encoder.finish()
        self.assertEqual(
            zstd.ZstdDecompressor().decompress(
                compressed, max_output_size=len(encoded)
            ),
            encoded,
        )

        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 encoded command-response eos %s'
                % (request.requestid, compressed)
            ),
        )

        self.assertEqual(action, b'responsedata')
        self.assertEqual(meta[b'data'], encoded)

    @unittest.skipUnless(zstd, 'zstd not available')
    def testzstd8mbencodingsinglebyteframes(self):
        reactor = framing.clientreactor(globalui, buffersends=False)

        request, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 stream-begin stream-settings eos cbor:b"zstd-8mb"'
                % request.requestid
            ),
        )

        self.assertEqual(action, b'noop')
        self.assertEqual(meta, {})

        result = {
            b'status': b'ok',
        }
        encoded = b''.join(cborutil.streamencode(result))

        compressed = zstd.ZstdCompressor().compress(encoded)
        self.assertEqual(
            zstd.ZstdDecompressor().decompress(compressed), encoded
        )

        chunks = []

        for i in range(len(compressed)):
            char = compressed[i : i + 1]
            if char == b'\\':
                char = b'\\\\'
            action, meta = sendframe(
                reactor,
                ffs(
                    b'%d 2 encoded command-response continuation %s'
                    % (request.requestid, char)
                ),
            )

            self.assertEqual(action, b'responsedata')
            chunks.append(meta[b'data'])
            self.assertTrue(meta[b'expectmore'])
            self.assertFalse(meta[b'eos'])

        # zstd decompressor will flush at frame boundaries.
        self.assertEqual(b''.join(chunks), encoded)

        # End the stream for good measure.
        action, meta = sendframe(
            reactor,
            ffs(b'%d 2 stream-end command-response eos ' % request.requestid),
        )

        self.assertEqual(action, b'responsedata')
        self.assertEqual(meta[b'data'], b'')
        self.assertFalse(meta[b'expectmore'])
        self.assertTrue(meta[b'eos'])

    @unittest.skipUnless(zstd, 'zstd not available')
    def testzstd8mbmultipleresponses(self):
        # We feed in zstd compressed data on the same stream but belonging to
        # 2 different requests. This tests our flushing behavior.
        reactor = framing.clientreactor(
            globalui, buffersends=False, hasmultiplesend=True
        )

        request1, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        request2, action, meta = reactor.callcommand(b'foo', {})
        for f in meta[b'framegen']:
            pass

        outstream = framing.outputstream(2)
        outstream.setencoder(globalui, b'zstd-8mb')

        response1 = b''.join(
            cborutil.streamencode(
                {
                    b'status': b'ok',
                    b'extra': b'response1' * 10,
                }
            )
        )

        response2 = b''.join(
            cborutil.streamencode(
                {
                    b'status': b'error',
                    b'extra': b'response2' * 10,
                }
            )
        )

        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 stream-begin stream-settings eos cbor:b"zstd-8mb"'
                % request1.requestid
            ),
        )

        self.assertEqual(action, b'noop')
        self.assertEqual(meta, {})

        # Feeding partial data in won't get anything useful out.
        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 encoded command-response continuation %s'
                % (request1.requestid, outstream.encode(response1))
            ),
        )
        self.assertEqual(action, b'responsedata')
        self.assertEqual(meta[b'data'], b'')

        # But flushing data at both ends will get our original data.
        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 encoded command-response eos %s'
                % (request1.requestid, outstream.flush())
            ),
        )
        self.assertEqual(action, b'responsedata')
        self.assertEqual(meta[b'data'], response1)

        # We should be able to reuse the compressor/decompressor for the
        # 2nd response.
        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 encoded command-response continuation %s'
                % (request2.requestid, outstream.encode(response2))
            ),
        )
        self.assertEqual(action, b'responsedata')
        self.assertEqual(meta[b'data'], b'')

        action, meta = sendframe(
            reactor,
            ffs(
                b'%d 2 encoded command-response eos %s'
                % (request2.requestid, outstream.flush())
            ),
        )
        self.assertEqual(action, b'responsedata')
        self.assertEqual(meta[b'data'], response2)


if __name__ == '__main__':
    if (3, 6, 0) <= sys.version_info < (3, 6, 4):
        # Python 3.6.0 through 3.6.3 inclusive shipped with
        # https://bugs.python.org/issue31825 and we can't run these
        # tests on those specific versions of Python. Sigh.
        sys.exit(80)
    import silenttestrunner

    silenttestrunner.main(__name__)