tests/test-wireproto-clientreactor.py

wireprotov2: define and use stream encoders

Now that we have basic support for defining stream encoding, it is
time to start doing something with it.

We define various classes implementing stream encoders/decoders for
the defined encoding profiles. This is relatively straightforward.

We teach the inputstream and outputstream classes how to encode,
decode, and flush data.

We then teach the clientreactor how to filter received data through
the inputstream decoder.

One of the features of the framing format is that streams can span
requests. This is a differentiating feature from say HTTP/2, which
associates streams with requests. By allowing streams to span requests,
we can reuse compression context data across requests/responses. But
in order to do this, we need a mechanism to "flush" the encoder at
logical boundaries so that receivers receive all data where it is
expected. And a "flush" event is distinct from a "finish" event from
the perspective of certain compressors because a "flush" will retain
compression context state whereas a "finish" operation will not. This
is why encoders have both a flush() and a finish() and each uses
specific flushing semantics on the underlying compressor.

The added tests verify various behavior of decoders via clientreactor.
These tests do test some compression behavior via use of outputstream.
But for all intents and purposes, server reactor support for encoding
is not yet implemented.

Differential Revision: https://phab.mercurial-scm.org/D4921

from __future__ import absolute_import

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__':
    import silenttestrunner
    silenttestrunner.main(__name__)