procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
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__)