wireproto: buffer output frames when in half duplex mode
Previously, when told that a response was ready, the server reactor
would instruct the caller to send frames immediately. This was OK
as an initial implementation. But it would not work for half-duplex
connections where the sender can't receive until all data has been
transmitted - such as httplib based clients.
In this commit, we teach the reactor that output frames should
be buffered until end of input is seen. This required a new
event to inform the reactor of end of input. The result from that
event will instruct the consumer to send all buffered frames.
The HTTP server is buffered by default.
This change effectively hides the complexity of buffering within
the reactor so that transports need not be concerned about it.
This helps keep the transports "dumb" and will make implementing
multiple requests-responses per atomic exchange (like an HTTP
request) much simpler.
Differential Revision: https://phab.mercurial-scm.org/D2860
from __future__ import absolute_import, print_function
import unittest
from mercurial import (
util,
wireprotoframing as framing,
)
ffs = framing.makeframefromhumanstring
def makereactor(deferoutput=False):
return framing.serverreactor(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:
frametype, frameflags, framelength = framing.parseheader(frame)
payload = frame[framing.FRAME_HEADER_SIZE:]
assert len(payload) == framelength
yield reactor.onframerecv(frametype, frameflags, payload)
def sendcommandframes(reactor, cmd, args, datafh=None):
"""Generate frames to run a command and send them to a reactor."""
return sendframes(reactor, framing.createcommandframes(cmd, args, datafh))
class FrameTests(unittest.TestCase):
def testdataexactframesize(self):
data = util.bytesio(b'x' * framing.DEFAULT_MAX_FRAME_SIZE)
frames = list(framing.createcommandframes(b'command', {}, data))
self.assertEqual(frames, [
ffs(b'command-name have-data command'),
ffs(b'command-data continuation %s' % data.getvalue()),
ffs(b'command-data eos ')
])
def testdatamultipleframes(self):
data = util.bytesio(b'x' * (framing.DEFAULT_MAX_FRAME_SIZE + 1))
frames = list(framing.createcommandframes(b'command', {}, data))
self.assertEqual(frames, [
ffs(b'command-name have-data command'),
ffs(b'command-data continuation %s' % (
b'x' * framing.DEFAULT_MAX_FRAME_SIZE)),
ffs(b'command-data eos x'),
])
def testargsanddata(self):
data = util.bytesio(b'x' * 100)
frames = list(framing.createcommandframes(b'command', {
b'key1': b'key1value',
b'key2': b'key2value',
b'key3': b'key3value',
}, data))
self.assertEqual(frames, [
ffs(b'command-name have-args|have-data command'),
ffs(br'command-argument 0 \x04\x00\x09\x00key1key1value'),
ffs(br'command-argument 0 \x04\x00\x09\x00key2key2value'),
ffs(br'command-argument eoa \x04\x00\x09\x00key3key3value'),
ffs(b'command-data eos %s' % data.getvalue()),
])
class ServerReactorTests(unittest.TestCase):
def _sendsingleframe(self, reactor, s):
results = list(sendframes(reactor, [ffs(s)]))
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()
results = list(sendcommandframes(reactor, b'mycommand', {}))
self.assertEqual(len(results), 1)
self.assertaction(results[0], 'runcommand')
self.assertEqual(results[0][1], {
'command': b'mycommand',
'args': {},
'data': None,
})
result = reactor.oninputeof()
self.assertaction(result, 'noop')
def test1argument(self):
reactor = makereactor()
results = list(sendcommandframes(reactor, b'mycommand',
{b'foo': b'bar'}))
self.assertEqual(len(results), 2)
self.assertaction(results[0], 'wantframe')
self.assertaction(results[1], 'runcommand')
self.assertEqual(results[1][1], {
'command': b'mycommand',
'args': {b'foo': b'bar'},
'data': None,
})
def testmultiarguments(self):
reactor = makereactor()
results = list(sendcommandframes(reactor, b'mycommand',
{b'foo': b'bar', b'biz': b'baz'}))
self.assertEqual(len(results), 3)
self.assertaction(results[0], 'wantframe')
self.assertaction(results[1], 'wantframe')
self.assertaction(results[2], 'runcommand')
self.assertEqual(results[2][1], {
'command': b'mycommand',
'args': {b'foo': b'bar', b'biz': b'baz'},
'data': None,
})
def testsimplecommanddata(self):
reactor = makereactor()
results = list(sendcommandframes(reactor, b'mycommand', {},
util.bytesio(b'data!')))
self.assertEqual(len(results), 2)
self.assertaction(results[0], 'wantframe')
self.assertaction(results[1], 'runcommand')
self.assertEqual(results[1][1], {
'command': b'mycommand',
'args': {},
'data': b'data!',
})
def testmultipledataframes(self):
frames = [
ffs(b'command-name have-data mycommand'),
ffs(b'command-data continuation data1'),
ffs(b'command-data continuation data2'),
ffs(b'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], 'wantframe')
self.assertaction(results[3], 'runcommand')
self.assertEqual(results[3][1], {
'command': b'mycommand',
'args': {},
'data': b'data1data2data3',
})
def testargumentanddata(self):
frames = [
ffs(b'command-name have-args|have-data command'),
ffs(br'command-argument 0 \x03\x00\x03\x00keyval'),
ffs(br'command-argument eoa \x03\x00\x03\x00foobar'),
ffs(b'command-data continuation value1'),
ffs(b'command-data eos value2'),
]
reactor = makereactor()
results = list(sendframes(reactor, frames))
self.assertaction(results[-1], 'runcommand')
self.assertEqual(results[-1][1], {
'command': b'command',
'args': {
b'key': b'val',
b'foo': b'bar',
},
'data': b'value1value2',
})
def testunexpectedcommandargument(self):
"""Command argument frame when not running a command is an error."""
result = self._sendsingleframe(makereactor(),
b'command-argument 0 ignored')
self.assertaction(result, 'error')
self.assertEqual(result[1], {
'message': b'expected command frame; got 2',
})
def testunexpectedcommanddata(self):
"""Command argument frame when not running a command is an error."""
result = self._sendsingleframe(makereactor(),
b'command-data 0 ignored')
self.assertaction(result, 'error')
self.assertEqual(result[1], {
'message': b'expected command frame; got 3',
})
def testmissingcommandframeflags(self):
"""Command name frame must have flags set."""
result = self._sendsingleframe(makereactor(),
b'command-name 0 command')
self.assertaction(result, 'error')
self.assertEqual(result[1], {
'message': b'missing frame flags on command frame',
})
def testmissingargumentframe(self):
frames = [
ffs(b'command-name have-args command'),
ffs(b'command-name 0 ignored'),
]
results = list(sendframes(makereactor(), frames))
self.assertEqual(len(results), 2)
self.assertaction(results[0], 'wantframe')
self.assertaction(results[1], 'error')
self.assertEqual(results[1][1], {
'message': b'expected command argument frame; got 1',
})
def testincompleteargumentname(self):
"""Argument frame with incomplete name."""
frames = [
ffs(b'command-name have-args command1'),
ffs(br'command-argument eoa \x04\x00\xde\xadfoo'),
]
results = list(sendframes(makereactor(), frames))
self.assertEqual(len(results), 2)
self.assertaction(results[0], 'wantframe')
self.assertaction(results[1], 'error')
self.assertEqual(results[1][1], {
'message': b'malformed argument frame: partial argument name',
})
def testincompleteargumentvalue(self):
"""Argument frame with incomplete value."""
frames = [
ffs(b'command-name have-args command'),
ffs(br'command-argument eoa \x03\x00\xaa\xaafoopartialvalue'),
]
results = list(sendframes(makereactor(), frames))
self.assertEqual(len(results), 2)
self.assertaction(results[0], 'wantframe')
self.assertaction(results[1], 'error')
self.assertEqual(results[1][1], {
'message': b'malformed argument frame: partial argument value',
})
def testmissingcommanddataframe(self):
frames = [
ffs(b'command-name have-data command1'),
ffs(b'command-name eos command2'),
]
results = list(sendframes(makereactor(), frames))
self.assertEqual(len(results), 2)
self.assertaction(results[0], 'wantframe')
self.assertaction(results[1], 'error')
self.assertEqual(results[1][1], {
'message': b'expected command data frame; got 1',
})
def testmissingcommanddataframeflags(self):
frames = [
ffs(b'command-name have-data command1'),
ffs(b'command-data 0 data'),
]
results = list(sendframes(makereactor(), frames))
self.assertEqual(len(results), 2)
self.assertaction(results[0], 'wantframe')
self.assertaction(results[1], 'error')
self.assertEqual(results[1][1], {
'message': b'command data frame without flags',
})
def testsimpleresponse(self):
"""Bytes response to command sends result frames."""
reactor = makereactor()
list(sendcommandframes(reactor, b'mycommand', {}))
result = reactor.onbytesresponseready(b'response')
self.assertaction(result, 'sendframes')
self.assertframesequal(result[1]['framegen'], [
b'bytes-response eos response',
])
def testmultiframeresponse(self):
"""Bytes response spanning multiple frames is handled."""
first = b'x' * framing.DEFAULT_MAX_FRAME_SIZE
second = b'y' * 100
reactor = makereactor()
list(sendcommandframes(reactor, b'mycommand', {}))
result = reactor.onbytesresponseready(first + second)
self.assertaction(result, 'sendframes')
self.assertframesequal(result[1]['framegen'], [
b'bytes-response continuation %s' % first,
b'bytes-response eos %s' % second,
])
def testapplicationerror(self):
reactor = makereactor()
list(sendcommandframes(reactor, b'mycommand', {}))
result = reactor.onapplicationerror(b'some message')
self.assertaction(result, 'sendframes')
self.assertframesequal(result[1]['framegen'], [
b'error-response application some message',
])
def test1commanddeferresponse(self):
"""Responses when in deferred output mode are delayed until EOF."""
reactor = makereactor(deferoutput=True)
results = list(sendcommandframes(reactor, b'mycommand', {}))
self.assertEqual(len(results), 1)
self.assertaction(results[0], 'runcommand')
result = reactor.onbytesresponseready(b'response')
self.assertaction(result, 'noop')
result = reactor.oninputeof()
self.assertaction(result, 'sendframes')
self.assertframesequal(result[1]['framegen'], [
b'bytes-response eos response',
])
def testmultiplecommanddeferresponse(self):
reactor = makereactor(deferoutput=True)
list(sendcommandframes(reactor, b'command1', {}))
list(sendcommandframes(reactor, b'command2', {}))
result = reactor.onbytesresponseready(b'response1')
self.assertaction(result, 'noop')
result = reactor.onbytesresponseready(b'response2')
self.assertaction(result, 'noop')
result = reactor.oninputeof()
self.assertaction(result, 'sendframes')
self.assertframesequal(result[1]['framegen'], [
b'bytes-response eos response1',
b'bytes-response eos response2'
])
if __name__ == '__main__':
import silenttestrunner
silenttestrunner.main(__name__)