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import argparse
import contextlib
import errno
import itertools
import os
import shutil
import subprocess
import sys
import tempfile
import threading
import time
import unittest

from grpc.framework.alpha import exceptions
from grpc.framework.foundation import future

# Identifiers of entities we expect to find in the generated module.
SERVICER_IDENTIFIER = 'EarlyAdopterTestServiceServicer'
SERVER_IDENTIFIER = 'EarlyAdopterTestServiceServer'
STUB_IDENTIFIER = 'EarlyAdopterTestServiceStub'
SERVER_FACTORY_IDENTIFIER = 'early_adopter_create_TestService_server'
STUB_FACTORY_IDENTIFIER = 'early_adopter_create_TestService_stub'

# The timeout used in tests of RPCs that are supposed to expire.
SHORT_TIMEOUT = 2
# The timeout used in tests of RPCs that are not supposed to expire. The
# absurdly large value doesn't matter since no passing execution of this test
# module will ever wait the duration.
LONG_TIMEOUT = 600
NO_DELAY = 0

# Build mode environment variable set by tools/run_tests/run_tests.py.
_build_mode = os.environ['CONFIG']


class _ServicerMethods(object):

  def __init__(self, test_pb2, delay):
    self._condition = threading.Condition()
    self._delay = delay
    self._paused = False
    self._fail = False
    self._test_pb2 = test_pb2

  @contextlib.contextmanager
  def pause(self):  # pylint: disable=invalid-name
    with self._condition:
      self._paused = True
    yield
    with self._condition:
      self._paused = False
      self._condition.notify_all()

  @contextlib.contextmanager
  def fail(self):  # pylint: disable=invalid-name
    with self._condition:
      self._fail = True
    yield
    with self._condition:
      self._fail = False

  def _control(self):  # pylint: disable=invalid-name
    with self._condition:
      if self._fail:
        raise ValueError()
      while self._paused:
        self._condition.wait()
    time.sleep(self._delay)

  def UnaryCall(self, request, unused_rpc_context):
    response = self._test_pb2.SimpleResponse()
    response.payload.payload_type = self._test_pb2.COMPRESSABLE
    response.payload.payload_compressable = 'a' * request.response_size
    self._control()
    return response

  def StreamingOutputCall(self, request, unused_rpc_context):
    for parameter in request.response_parameters:
      response = self._test_pb2.StreamingOutputCallResponse()
      response.payload.payload_type = self._test_pb2.COMPRESSABLE
      response.payload.payload_compressable = 'a' * parameter.size
      self._control()
      yield response

  def StreamingInputCall(self, request_iter, unused_rpc_context):
    response = self._test_pb2.StreamingInputCallResponse()
    aggregated_payload_size = 0
    for request in request_iter:
      aggregated_payload_size += len(request.payload.payload_compressable)
    response.aggregated_payload_size = aggregated_payload_size
    self._control()
    return response

  def FullDuplexCall(self, request_iter, unused_rpc_context):
    for request in request_iter:
      for parameter in request.response_parameters:
        response = self._test_pb2.StreamingOutputCallResponse()
        response.payload.payload_type = self._test_pb2.COMPRESSABLE
        response.payload.payload_compressable = 'a' * parameter.size
        self._control()
        yield response

  def HalfDuplexCall(self, request_iter, unused_rpc_context):
    responses = []
    for request in request_iter:
      for parameter in request.response_parameters:
        response = self._test_pb2.StreamingOutputCallResponse()
        response.payload.payload_type = self._test_pb2.COMPRESSABLE
        response.payload.payload_compressable = 'a' * parameter.size
        self._control()
        responses.append(response)
    for response in responses:
      yield response


@contextlib.contextmanager
def _CreateService(test_pb2, delay):
  """Provides a servicer backend and a stub.

  The servicer is just the implementation
  of the actual servicer passed to the face player of the python RPC
  implementation; the two are detached.

  Non-zero delay puts a delay on each call to the servicer, representative of
  communication latency. Timeout is the default timeout for the stub while
  waiting for the service.

  Args:
    test_pb2: The test_pb2 module generated by this test.
    delay: Delay in seconds per response from the servicer.

  Yields:
    A (servicer_methods, servicer, stub) three-tuple where servicer_methods is
      the back-end of the service bound to the stub and the server and stub
      are both activated and ready for use.
  """
  servicer_methods = _ServicerMethods(test_pb2, delay)

  class Servicer(getattr(test_pb2, SERVICER_IDENTIFIER)):

    def UnaryCall(self, request, context):
      return servicer_methods.UnaryCall(request, context)

    def StreamingOutputCall(self, request, context):
      return servicer_methods.StreamingOutputCall(request, context)

    def StreamingInputCall(self, request_iter, context):
      return servicer_methods.StreamingInputCall(request_iter, context)

    def FullDuplexCall(self, request_iter, context):
      return servicer_methods.FullDuplexCall(request_iter, context)

    def HalfDuplexCall(self, request_iter, context):
      return servicer_methods.HalfDuplexCall(request_iter, context)

  servicer = Servicer()
  server = getattr(
      test_pb2, SERVER_FACTORY_IDENTIFIER)(servicer, 0)
  with server:
    port = server.port()
    stub = getattr(test_pb2, STUB_FACTORY_IDENTIFIER)('localhost', port)
    with stub:
      yield servicer_methods, stub, server


def _streaming_input_request_iterator(test_pb2):
  for _ in range(3):
    request = test_pb2.StreamingInputCallRequest()
    request.payload.payload_type = test_pb2.COMPRESSABLE
    request.payload.payload_compressable = 'a'
    yield request


def _streaming_output_request(test_pb2):
  request = test_pb2.StreamingOutputCallRequest()
  sizes = [1, 2, 3]
  request.response_parameters.add(size=sizes[0], interval_us=0)
  request.response_parameters.add(size=sizes[1], interval_us=0)
  request.response_parameters.add(size=sizes[2], interval_us=0)
  return request


def _full_duplex_request_iterator(test_pb2):
  request = test_pb2.StreamingOutputCallRequest()
  request.response_parameters.add(size=1, interval_us=0)
  yield request
  request = test_pb2.StreamingOutputCallRequest()
  request.response_parameters.add(size=2, interval_us=0)
  request.response_parameters.add(size=3, interval_us=0)
  yield request


class PythonPluginTest(unittest.TestCase):
  """Test case for the gRPC Python protoc-plugin.

  While reading these tests, remember that the futures API
  (`stub.method.async()`) only gives futures for the *non-streaming* responses,
  else it behaves like its blocking cousin.
  """

  def setUp(self):
    protoc_command = '../../bins/%s/protobuf/protoc' % _build_mode
    protoc_plugin_filename = '../../bins/%s/grpc_python_plugin' % _build_mode
    test_proto_filename = './test.proto'
    if not os.path.isfile(protoc_command):
      # Assume that if we haven't built protoc that it's on the system.
      protoc_command = 'protoc'

    # Ensure that the output directory exists.
    self.outdir = tempfile.mkdtemp()

    # Invoke protoc with the plugin.
    cmd = [
        protoc_command,
        '--plugin=protoc-gen-python-grpc=%s' % protoc_plugin_filename,
        '-I %s' % os.path.dirname(test_proto_filename),
        '--python_out=%s' % self.outdir,
        '--python-grpc_out=%s' % self.outdir,
        os.path.basename(test_proto_filename),
    ]
    subprocess.call(' '.join(cmd), shell=True)
    sys.path.append(self.outdir)

  def tearDown(self):
    try:
      shutil.rmtree(self.outdir)
    except OSError as exc:
      if exc.errno != errno.ENOENT:
        raise

  # TODO(atash): Figure out which of these tests is hanging flakily with small
  # probability.

  def testImportAttributes(self):
    # check that we can access the generated module and its members.
    import test_pb2  # pylint: disable=g-import-not-at-top
    self.assertIsNotNone(getattr(test_pb2, SERVICER_IDENTIFIER, None))
    self.assertIsNotNone(getattr(test_pb2, SERVER_IDENTIFIER, None))
    self.assertIsNotNone(getattr(test_pb2, STUB_IDENTIFIER, None))
    self.assertIsNotNone(getattr(test_pb2, SERVER_FACTORY_IDENTIFIER, None))
    self.assertIsNotNone(getattr(test_pb2, STUB_FACTORY_IDENTIFIER, None))

  def testUpDown(self):
    import test_pb2
    with _CreateService(
        test_pb2, NO_DELAY) as (servicer, stub, unused_server):
      request = test_pb2.SimpleRequest(response_size=13)

  def testUnaryCall(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    with _CreateService(test_pb2, NO_DELAY) as (methods, stub, unused_server):
      timeout = 6  # TODO(issue 2039): LONG_TIMEOUT like the other methods.
      request = test_pb2.SimpleRequest(response_size=13)
      response = stub.UnaryCall(request, timeout)
    expected_response = methods.UnaryCall(request, 'not a real RpcContext!')
    self.assertEqual(expected_response, response)

  def testUnaryCallAsync(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    request = test_pb2.SimpleRequest(response_size=13)
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      # Check that the call does not block waiting for the server to respond.
      with methods.pause():
        response_future = stub.UnaryCall.async(request, LONG_TIMEOUT)
      response = response_future.result()
    expected_response = methods.UnaryCall(request, 'not a real RpcContext!')
    self.assertEqual(expected_response, response)

  def testUnaryCallAsyncExpired(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      request = test_pb2.SimpleRequest(response_size=13)
      with methods.pause():
        response_future = stub.UnaryCall.async(request, SHORT_TIMEOUT)
        with self.assertRaises(exceptions.ExpirationError):
          response_future.result()

  @unittest.skip('TODO(atash,nathaniel): figure out why this flakily hangs '
                 'forever and fix.')
  def testUnaryCallAsyncCancelled(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    request = test_pb2.SimpleRequest(response_size=13)
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      with methods.pause():
        response_future = stub.UnaryCall.async(request, 1)
        response_future.cancel()
        self.assertTrue(response_future.cancelled())

  def testUnaryCallAsyncFailed(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    request = test_pb2.SimpleRequest(response_size=13)
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      with methods.fail():
        response_future = stub.UnaryCall.async(request, LONG_TIMEOUT)
        self.assertIsNotNone(response_future.exception())

  def testStreamingOutputCall(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    request = _streaming_output_request(test_pb2)
    with _CreateService(test_pb2, NO_DELAY) as (methods, stub, unused_server):
      responses = stub.StreamingOutputCall(request, LONG_TIMEOUT)
      expected_responses = methods.StreamingOutputCall(
          request, 'not a real RpcContext!')
      for expected_response, response in itertools.izip_longest(
          expected_responses, responses):
        self.assertEqual(expected_response, response)

  @unittest.skip('TODO(atash,nathaniel): figure out why this flakily hangs '
                 'forever and fix.')
  def testStreamingOutputCallExpired(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    request = _streaming_output_request(test_pb2)
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      with methods.pause():
        responses = stub.StreamingOutputCall(request, SHORT_TIMEOUT)
        with self.assertRaises(exceptions.ExpirationError):
          list(responses)

  @unittest.skip('TODO(atash,nathaniel): figure out why this flakily hangs '
                 'forever and fix.')
  def testStreamingOutputCallCancelled(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    request = _streaming_output_request(test_pb2)
    with _CreateService(test_pb2, NO_DELAY) as (
        unused_methods, stub, unused_server):
      responses = stub.StreamingOutputCall(request, SHORT_TIMEOUT)
      next(responses)
      responses.cancel()
      with self.assertRaises(future.CancelledError):
        next(responses)

  @unittest.skip('TODO(atash,nathaniel): figure out why this times out '
                 'instead of raising the proper error.')
  def testStreamingOutputCallFailed(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    request = _streaming_output_request(test_pb2)
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      with methods.fail():
        responses = stub.StreamingOutputCall(request, 1)
        self.assertIsNotNone(responses)
        with self.assertRaises(exceptions.ServicerError):
          next(responses)

  @unittest.skip('TODO(atash,nathaniel): figure out why this flakily hangs '
                 'forever and fix.')
  def testStreamingInputCall(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    with _CreateService(test_pb2, NO_DELAY) as (methods, stub, unused_server):
      response = stub.StreamingInputCall(
          _streaming_input_request_iterator(test_pb2), LONG_TIMEOUT)
    expected_response = methods.StreamingInputCall(
        _streaming_input_request_iterator(test_pb2), 'not a real RpcContext!')
    self.assertEqual(expected_response, response)

  def testStreamingInputCallAsync(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      with methods.pause():
        response_future = stub.StreamingInputCall.async(
            _streaming_input_request_iterator(test_pb2), LONG_TIMEOUT)
      response = response_future.result()
    expected_response = methods.StreamingInputCall(
        _streaming_input_request_iterator(test_pb2), 'not a real RpcContext!')
    self.assertEqual(expected_response, response)

  def testStreamingInputCallAsyncExpired(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      with methods.pause():
        response_future = stub.StreamingInputCall.async(
            _streaming_input_request_iterator(test_pb2), SHORT_TIMEOUT)
        with self.assertRaises(exceptions.ExpirationError):
          response_future.result()
        self.assertIsInstance(
            response_future.exception(), exceptions.ExpirationError)

  def testStreamingInputCallAsyncCancelled(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      with methods.pause():
        timeout = 6  # TODO(issue 2039): LONG_TIMEOUT like the other methods.
        response_future = stub.StreamingInputCall.async(
            _streaming_input_request_iterator(test_pb2), timeout)
        response_future.cancel()
        self.assertTrue(response_future.cancelled())
      with self.assertRaises(future.CancelledError):
        response_future.result()

  def testStreamingInputCallAsyncFailed(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      with methods.fail():
        response_future = stub.StreamingInputCall.async(
            _streaming_input_request_iterator(test_pb2), SHORT_TIMEOUT)
        self.assertIsNotNone(response_future.exception())

  def testFullDuplexCall(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    with _CreateService(test_pb2, NO_DELAY) as (methods, stub, unused_server):
      responses = stub.FullDuplexCall(
          _full_duplex_request_iterator(test_pb2), LONG_TIMEOUT)
      expected_responses = methods.FullDuplexCall(
          _full_duplex_request_iterator(test_pb2), 'not a real RpcContext!')
      for expected_response, response in itertools.izip_longest(
          expected_responses, responses):
        self.assertEqual(expected_response, response)

  @unittest.skip('TODO(atash,nathaniel): figure out why this flakily hangs '
                 'forever and fix.')
  def testFullDuplexCallExpired(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    request_iterator = _full_duplex_request_iterator(test_pb2)
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      with methods.pause():
        responses = stub.FullDuplexCall(request_iterator, SHORT_TIMEOUT)
        with self.assertRaises(exceptions.ExpirationError):
          list(responses)

  @unittest.skip('TODO(atash,nathaniel): figure out why this flakily hangs '
                 'forever and fix.')
  def testFullDuplexCallCancelled(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    with _CreateService(test_pb2, NO_DELAY) as (methods, stub, unused_server):
      request_iterator = _full_duplex_request_iterator(test_pb2)
      responses = stub.FullDuplexCall(request_iterator, LONG_TIMEOUT)
      next(responses)
      responses.cancel()
      with self.assertRaises(future.CancelledError):
        next(responses)

  @unittest.skip('TODO(atash,nathaniel): figure out why this hangs forever '
                 'and fix.')
  def testFullDuplexCallFailed(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    request_iterator = _full_duplex_request_iterator(test_pb2)
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      with methods.fail():
        responses = stub.FullDuplexCall(request_iterator, LONG_TIMEOUT)
        self.assertIsNotNone(responses)
        with self.assertRaises(exceptions.ServicerError):
          next(responses)

  @unittest.skip('TODO(atash,nathaniel): figure out why this flakily hangs '
                 'forever and fix.')
  def testHalfDuplexCall(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    with _CreateService(test_pb2, NO_DELAY) as (
        methods, stub, unused_server):
      def half_duplex_request_iterator():
        request = test_pb2.StreamingOutputCallRequest()
        request.response_parameters.add(size=1, interval_us=0)
        yield request
        request = test_pb2.StreamingOutputCallRequest()
        request.response_parameters.add(size=2, interval_us=0)
        request.response_parameters.add(size=3, interval_us=0)
        yield request
      responses = stub.HalfDuplexCall(
          half_duplex_request_iterator(), LONG_TIMEOUT)
      expected_responses = methods.HalfDuplexCall(
          half_duplex_request_iterator(), 'not a real RpcContext!')
      for check in itertools.izip_longest(expected_responses, responses):
        expected_response, response = check
        self.assertEqual(expected_response, response)

  def testHalfDuplexCallWedged(self):
    import test_pb2  # pylint: disable=g-import-not-at-top
    condition = threading.Condition()
    wait_cell = [False]
    @contextlib.contextmanager
    def wait():  # pylint: disable=invalid-name
      # Where's Python 3's 'nonlocal' statement when you need it?
      with condition:
        wait_cell[0] = True
      yield
      with condition:
        wait_cell[0] = False
        condition.notify_all()
    def half_duplex_request_iterator():
      request = test_pb2.StreamingOutputCallRequest()
      request.response_parameters.add(size=1, interval_us=0)
      yield request
      with condition:
        while wait_cell[0]:
          condition.wait()
    with _CreateService(test_pb2, NO_DELAY) as (methods, stub, unused_server):
      with wait():
        responses = stub.HalfDuplexCall(
            half_duplex_request_iterator(), SHORT_TIMEOUT)
        # half-duplex waits for the client to send all info
        with self.assertRaises(exceptions.ExpirationError):
          next(responses)


if __name__ == '__main__':
  os.chdir(os.path.dirname(sys.argv[0]))
  unittest.main(verbosity=2)