1# Copyright 2016 gRPC authors. 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14 15import http2_base_server 16import logging 17import messages_pb2 18 19# Set the number of padding bytes per data frame to be very large 20# relative to the number of data bytes for each data frame sent. 21_LARGE_PADDING_LENGTH = 255 22_SMALL_READ_CHUNK_SIZE = 5 23 24 25class TestDataFramePadding(object): 26 """ 27 In response to an incoming request, this test sends headers, followed by 28 data, followed by a reset stream frame. Client asserts that the RPC failed. 29 Client needs to deliver the complete message to the application layer. 30 """ 31 32 def __init__(self, use_padding=True): 33 self._base_server = http2_base_server.H2ProtocolBaseServer() 34 self._base_server._handlers['DataReceived'] = self.on_data_received 35 self._base_server._handlers['WindowUpdated'] = self.on_window_update 36 self._base_server._handlers[ 37 'RequestReceived'] = self.on_request_received 38 39 # _total_updates maps stream ids to total flow control updates received 40 self._total_updates = {} 41 # zero window updates so far for connection window (stream id '0') 42 self._total_updates[0] = 0 43 self._read_chunk_size = _SMALL_READ_CHUNK_SIZE 44 45 if use_padding: 46 self._pad_length = _LARGE_PADDING_LENGTH 47 else: 48 self._pad_length = None 49 50 def get_base_server(self): 51 return self._base_server 52 53 def on_data_received(self, event): 54 logging.info('on data received. Stream id: %d. Data length: %d' % 55 (event.stream_id, len(event.data))) 56 self._base_server.on_data_received_default(event) 57 if len(event.data) == 0: 58 return 59 sr = self._base_server.parse_received_data(event.stream_id) 60 stream_bytes = '' 61 # Check if full grpc msg has been read into the recv buffer yet 62 if sr: 63 response_data = self._base_server.default_response_data( 64 sr.response_size) 65 logging.info('Stream id: %d. total resp size: %d' % 66 (event.stream_id, len(response_data))) 67 # Begin sending the response. Add ``self._pad_length`` padding to each 68 # data frame and split the whole message into data frames each carrying 69 # only self._read_chunk_size of data. 70 # The purpose is to have the majority of the data frame response bytes 71 # be padding bytes, since ``self._pad_length`` >> ``self._read_chunk_size``. 72 self._base_server.setup_send(response_data, 73 event.stream_id, 74 pad_length=self._pad_length, 75 read_chunk_size=self._read_chunk_size) 76 77 def on_request_received(self, event): 78 self._base_server.on_request_received_default(event) 79 logging.info('on request received. Stream id: %s.' % event.stream_id) 80 self._total_updates[event.stream_id] = 0 81 82 # Log debug info and try to resume sending on all currently active streams. 83 def on_window_update(self, event): 84 logging.info('on window update. Stream id: %s. Delta: %s' % 85 (event.stream_id, event.delta)) 86 self._total_updates[event.stream_id] += event.delta 87 total = self._total_updates[event.stream_id] 88 logging.info('... - total updates for stream %d : %d' % 89 (event.stream_id, total)) 90 self._base_server.on_window_update_default( 91 event, 92 pad_length=self._pad_length, 93 read_chunk_size=self._read_chunk_size) 94