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"""Tests server and client side compression."""

import unittest

import grpc
from grpc import _grpcio_metadata
from grpc.framework.foundation import logging_pool

from tests.unit import test_common
from tests.unit.framework.common import test_constants

_UNARY_UNARY = '/test/UnaryUnary'
_STREAM_STREAM = '/test/StreamStream'


def handle_unary(request, servicer_context):
  servicer_context.send_initial_metadata([
    ('grpc-internal-encoding-request', 'gzip')])
  return request


def handle_stream(request_iterator, servicer_context):
  # TODO(issue:#6891) We should be able to remove this loop,
  # and replace with return; yield
  servicer_context.send_initial_metadata([
    ('grpc-internal-encoding-request', 'gzip')])
  for request in request_iterator:
    yield request


class _MethodHandler(grpc.RpcMethodHandler):

  def __init__(self, request_streaming, response_streaming):
    self.request_streaming = request_streaming
    self.response_streaming = response_streaming
    self.request_deserializer = None
    self.response_serializer = None
    self.unary_unary = None
    self.unary_stream = None
    self.stream_unary = None
    self.stream_stream = None
    if self.request_streaming and self.response_streaming:
      self.stream_stream = lambda x, y: handle_stream(x, y)
    elif not self.request_streaming and not self.response_streaming:
      self.unary_unary = lambda x, y: handle_unary(x, y)


class _GenericHandler(grpc.GenericRpcHandler):

  def service(self, handler_call_details):
    if handler_call_details.method == _UNARY_UNARY:
      return _MethodHandler(False, False)
    elif handler_call_details.method == _STREAM_STREAM:
      return _MethodHandler(True, True)
    else:
      return None


class CompressionTest(unittest.TestCase):

  def setUp(self):
    self._server_pool = logging_pool.pool(test_constants.THREAD_CONCURRENCY)
    self._server = grpc.server(
        self._server_pool, handlers=(_GenericHandler(),))
    self._port = self._server.add_insecure_port('[::]:0')
    self._server.start()

  def testUnary(self):
    request = b'\x00' * 100

    # Client -> server compressed through default client channel compression
    # settings. Server -> client compressed via server-side metadata setting.
    # TODO(https://github.com/grpc/grpc/issues/4078): replace the "1" integer
    # literal with proper use of the public API.
    compressed_channel = grpc.insecure_channel('localhost:%d' % self._port,
        options=[('grpc.default_compression_algorithm', 1)])
    multi_callable = compressed_channel.unary_unary(_UNARY_UNARY)
    response = multi_callable(request)
    self.assertEqual(request, response)

    # Client -> server compressed through client metadata setting. Server ->
    # client compressed via server-side metadata setting.
    # TODO(https://github.com/grpc/grpc/issues/4078): replace the "0" integer
    # literal with proper use of the public API.
    uncompressed_channel = grpc.insecure_channel('localhost:%d' % self._port,
        options=[('grpc.default_compression_algorithm', 0)])
    multi_callable = compressed_channel.unary_unary(_UNARY_UNARY)
    response = multi_callable(request, metadata=[
      ('grpc-internal-encoding-request', 'gzip')])
    self.assertEqual(request, response)

  def testStreaming(self):
    request = b'\x00' * 100

    # TODO(https://github.com/grpc/grpc/issues/4078): replace the "1" integer
    # literal with proper use of the public API.
    compressed_channel = grpc.insecure_channel('localhost:%d' % self._port,
        options=[('grpc.default_compression_algorithm', 1)])
    multi_callable = compressed_channel.stream_stream(_STREAM_STREAM)
    call = multi_callable([request] * test_constants.STREAM_LENGTH)
    for response in call:
      self.assertEqual(request, response)


if __name__ == '__main__':
  unittest.main(verbosity=2)