commit 1bbe2079c40ec6d6517c2125274e9b9510c09197 Author: Nick Mathewson nickm@torproject.org Date: Fri May 10 10:12:00 2019 -0400

Refactor Source and Sink to not know about their data

Now data is generated by a DataSource type, and consumed by a DataChecker type that compares its incoming data against the data in a DataSource. --- lib/chutney/Traffic.py | 113 +++++++++++++++++++++++++++++-------------------- 1 file changed, 68 insertions(+), 45 deletions(-)

diff --git a/lib/chutney/Traffic.py b/lib/chutney/Traffic.py index f877452..72b9ca3 100755 --- a/lib/chutney/Traffic.py +++ b/lib/chutney/Traffic.py @@ -107,7 +107,6 @@ class TestSuite(object): return('%s: %d/%d/%d' % (self.tests, self.not_done, self.successes, self.failures))

- class Listener(asyncore.dispatcher): "A TCP listener, binding, listening and accepting new connections."

@@ -132,14 +131,69 @@ class Listener(asyncore.dispatcher): def fileno(self): return self.socket.fileno()

+class DataSource(object): + """A data source generates some number of bytes of data, and then + returns None. + + For convenience, it conforms to the 'producer' api. + """ + def __init__(self, data, repetitions=1): + self.data = data + self.repetitions = repetitions + self.sent_any = False + + def copy(self): + assert not self.sent_any + return DataSource(self.data, self.repetitions) + + def more(self): + self.sent_any = True + if self.repetitions > 0: + self.repetitions -= 1 + return self.data + + return None + +class DataChecker(object): + """A data checker verifies its input against bytes in a stream.""" + def __init__(self, source): + self.source = source + self.pending = b"" + self.succeeded = False + self.failed = False + + def consume(self, inp): + if self.failed: + return + if self.succeeded and len(inp): + self.succeeded = False + self.failed = True + return + + while len(inp): + n = min(len(inp), len(self.pending)) + if inp[:n] != self.pending[:n]: + self.failed = True + return + inp = inp[n:] + self.pending = self.pending[n:] + if not self.pending: + self.pending = self.source.more() + + if self.pending is None: + if len(inp): + self.failed = True + else: + self.succeeded = True + return + class Sink(asynchat.async_chat): "A data sink, reading from its peer and verifying the data." def __init__(self, sock, tt): asynchat.async_chat.__init__(self, sock) - self.inbuf = b"" self.set_terminator(None) self.tt = tt - self.repetitions = tt.repetitions + self.data_checker = DataChecker(tt.data_source.copy()) self.testname = "recv-data%s"%id(self)

def get_test_names(self): @@ -148,33 +202,16 @@ class Sink(asynchat.async_chat): def collect_incoming_data(self, inp): # shortcut read when we don't ever expect any data

- self.inbuf += inp - data = self.tt.data - debug("successfully received (bytes=%d)" % len(self.inbuf)) - while len(self.inbuf) >= len(data): - assert(len(self.inbuf) <= len(data) or self.repetitions > 1) - if self.inbuf[:len(data)] != data: - debug("receive comparison failed (bytes=%d)" % len(data)) - self.tt.failure(self.testname) - self.close() - # if we're not debugging, print a dot every dot_repetitions reps - elif (not debug_flag and self.tt.dot_repetitions > 0 and - self.repetitions % self.tt.dot_repetitions == 0): - sys.stdout.write('.') - sys.stdout.flush() - # repeatedly check data against self.inbuf if required - debug("receive comparison success (bytes=%d)" % len(data)) - self.inbuf = self.inbuf[len(data):] - debug("receive leftover bytes (bytes=%d)" % len(self.inbuf)) - self.repetitions -= 1 - debug("receive remaining repetitions (reps=%d)" % self.repetitions) - if self.repetitions == 0 and len(self.inbuf) == 0: + debug("successfully received (bytes=%d)" % len(inp)) + self.data_checker.consume(inp) + if self.data_checker.succeeded: debug("successful verification") self.close() self.tt.success(self.testname) - # calculate the actual length of data remaining, including reps - debug("receive remaining bytes (bytes=%d)" - % (self.repetitions*len(data) - len(self.inbuf))) + elif self.data_checker.failed: + debug("receive comparison failed") + self.tt.failure(self.testname) + self.close()

def fileno(self): return self.socket.fileno() @@ -197,22 +234,13 @@ class Source(asynchat.async_chat):

def __init__(self, tt, server, buf, proxy=None, repetitions=1): asynchat.async_chat.__init__(self) - self.data = buf - self.outbuf = b'' + self.data_source = DataSource(buf, repetitions) self.inbuf = b'' self.proxy = proxy self.server = server - self.repetitions = repetitions - self._sent_no_bytes = 0 self.tt = tt self.testname = "send-data%s"%id(self)

- # sanity checks - if len(self.data) == 0: - self.repetitions = 0 - if self.repetitions == 0: - self.data = b"" - self.set_terminator(None) dest = (self.proxy or self.server) self.create_socket(addr_to_family(dest[0]), socket.SOCK_STREAM) @@ -251,8 +279,7 @@ class Source(asynchat.async_chat): self.close()

def push_output(self): - for _ in range(self.repetitions): - self.push_with_producer(asynchat.simple_producer(self.data)) + self.push_with_producer(self.data_source)

self.push_with_producer(CloseSourceProducer(self)) self.close_when_done() @@ -279,13 +306,9 @@ class TrafficTester(object): self.pending_close = [] self.timeout = timeout self.tests = TestSuite() - self.data = data - self.repetitions = repetitions + self.data_source = DataSource(data, repetitions) + # sanity checks - if len(self.data) == 0: - self.repetitions = 0 - if self.repetitions == 0: - self.data = b"" self.dot_repetitions = dot_repetitions debug("listener fd=%d" % self.listener.fileno())