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 logging 16 17import http2_base_server 18import messages_pb2 19 20# Set the number of padding bytes per data frame to be very large 21# relative to the number of data bytes for each data frame sent. 22_LARGE_PADDING_LENGTH = 255 23_SMALL_READ_CHUNK_SIZE = 5 24 25 26class TestDataFramePadding(object): 27 """ 28 In response to an incoming request, this test sends headers, followed by 29 data, followed by a reset stream frame. Client asserts that the RPC failed. 30 Client needs to deliver the complete message to the application layer. 31 """ 32 33 def __init__(self, use_padding=True): 34 self._base_server = http2_base_server.H2ProtocolBaseServer() 35 self._base_server._handlers["DataReceived"] = self.on_data_received 36 self._base_server._handlers["WindowUpdated"] = self.on_window_update 37 self._base_server._handlers[ 38 "RequestReceived" 39 ] = self.on_request_received 40 41 # _total_updates maps stream ids to total flow control updates received 42 self._total_updates = {} 43 # zero window updates so far for connection window (stream id '0') 44 self._total_updates[0] = 0 45 self._read_chunk_size = _SMALL_READ_CHUNK_SIZE 46 47 if use_padding: 48 self._pad_length = _LARGE_PADDING_LENGTH 49 else: 50 self._pad_length = None 51 52 def get_base_server(self): 53 return self._base_server 54 55 def on_data_received(self, event): 56 logging.info( 57 "on data received. Stream id: %d. Data length: %d" 58 % (event.stream_id, len(event.data)) 59 ) 60 self._base_server.on_data_received_default(event) 61 if len(event.data) == 0: 62 return 63 sr = self._base_server.parse_received_data(event.stream_id) 64 stream_bytes = "" 65 # Check if full grpc msg has been read into the recv buffer yet 66 if sr: 67 response_data = self._base_server.default_response_data( 68 sr.response_size 69 ) 70 logging.info( 71 "Stream id: %d. total resp size: %d" 72 % (event.stream_id, len(response_data)) 73 ) 74 # Begin sending the response. Add ``self._pad_length`` padding to each 75 # data frame and split the whole message into data frames each carrying 76 # only self._read_chunk_size of data. 77 # The purpose is to have the majority of the data frame response bytes 78 # be padding bytes, since ``self._pad_length`` >> ``self._read_chunk_size``. 79 self._base_server.setup_send( 80 response_data, 81 event.stream_id, 82 pad_length=self._pad_length, 83 read_chunk_size=self._read_chunk_size, 84 ) 85 86 def on_request_received(self, event): 87 self._base_server.on_request_received_default(event) 88 logging.info("on request received. Stream id: %s." % event.stream_id) 89 self._total_updates[event.stream_id] = 0 90 91 # Log debug info and try to resume sending on all currently active streams. 92 def on_window_update(self, event): 93 logging.info( 94 "on window update. Stream id: %s. Delta: %s" 95 % (event.stream_id, event.delta) 96 ) 97 self._total_updates[event.stream_id] += event.delta 98 total = self._total_updates[event.stream_id] 99 logging.info( 100 "... - total updates for stream %d : %d" % (event.stream_id, total) 101 ) 102 self._base_server.on_window_update_default( 103 event, 104 pad_length=self._pad_length, 105 read_chunk_size=self._read_chunk_size, 106 ) 107