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updated reading to read until you see a message for your stream (#100)

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* updated reading to read until you see a message for your stream

* added timeout to decode uvarint

* resolved comments

* shortened long line
This commit is contained in:
Alex Haynes 2019-01-28 16:15:22 -05:00 committed by GitHub
parent fa4895dad8
commit 7736d2afd2
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 204 additions and 16 deletions
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35
libp2p/stream_muxer/mplex/mplex.py
View File

@ -29,7 +29,7 @@ class Mplex(IMuxedConn):
# The initiator of the raw connection need not read upon construction time.
# It should read when the user decides that it wants to read from the constructed stream.
if not self.initiator:
asyncio.ensure_future(self.handle_incoming())
asyncio.ensure_future(self.handle_incoming(None))
def close(self):
"""
@ -52,7 +52,7 @@ class Mplex(IMuxedConn):
# Empty buffer or nonexistent stream
# TODO: propagate up timeout exception and catch
if stream_id not in self.buffers or self.buffers[stream_id].empty():
await self.handle_incoming()
await self.handle_incoming(stream_id)
if stream_id in self.buffers:
return await self._read_buffer_exists(stream_id)
@ -126,20 +126,26 @@ class Mplex(IMuxedConn):
await self.raw_conn.writer.drain()
return len(_bytes)
async def handle_incoming(self):
async def handle_incoming(self, my_stream_id):
"""
Read a message off of the raw connection and add it to the corresponding message buffer
"""
# TODO Deal with other types of messages using flag (currently _)
# TODO call read_message in loop to handle case message for other stream was in conn
stream_id, _, message = await self.read_message()
continue_reading = True
i = 0
while continue_reading:
i += 1
stream_id, _, message = await self.read_message()
continue_reading = (stream_id is not None and
stream_id != my_stream_id and
my_stream_id is not None)
if stream_id not in self.buffers:
self.buffers[stream_id] = asyncio.Queue()
await self.stream_queue.put(stream_id)
if stream_id not in self.buffers:
self.buffers[stream_id] = asyncio.Queue()
await self.stream_queue.put(stream_id)
await self.buffers[stream_id].put(message)
await self.buffers[stream_id].put(message)
async def read_chunk(self):
"""
@ -158,12 +164,15 @@ class Mplex(IMuxedConn):
Read a single message off of the raw connection
:return: stream_id, flag, message contents
"""
# Timeout is set to a relatively small value to alleviate wait time to exit
# loop in handle_incoming
timeout = .1
try:
header = await decode_uvarint_from_stream(self.raw_conn.reader)
length = await decode_uvarint_from_stream(self.raw_conn.reader)
message = await asyncio.wait_for(self.raw_conn.reader.read(length), timeout=5)
header = await decode_uvarint_from_stream(self.raw_conn.reader, timeout)
length = await decode_uvarint_from_stream(self.raw_conn.reader, timeout)
message = await asyncio.wait_for(self.raw_conn.reader.read(length), timeout=timeout)
except asyncio.TimeoutError:
print("message malformed")
return None, None, None
flag = header & 0x07

5
libp2p/stream_muxer/mplex/utils.py
View File

@ -29,12 +29,11 @@ def decode_uvarint(buff, index):
return result, index + 1
async def decode_uvarint_from_stream(reader):
async def decode_uvarint_from_stream(reader, timeout):
shift = 0
result = 0
while True:
byte = await asyncio.wait_for(reader.read(1), timeout=5)
byte = await asyncio.wait_for(reader.read(1), timeout=timeout)
i = struct.unpack('>H', b'\x00' + byte)[0]
result |= (i & 0x7f) << shift
shift += 7

180
stream_muxer/mplex/mplex.py Normal file
View File

@ -0,0 +1,180 @@
import asyncio
from .utils import encode_uvarint, decode_uvarint_from_stream
from .mplex_stream import MplexStream
from ..muxed_connection_interface import IMuxedConn
class Mplex(IMuxedConn):
# pylint: disable=too-many-instance-attributes
"""
reference: https://github.com/libp2p/go-mplex/blob/master/multiplex.go
"""
def __init__(self, conn):
"""
create a new muxed connection
:param conn: an instance of raw connection
:param initiator: boolean to prevent multiplex with self
"""
self.raw_conn = conn
self.initiator = conn.initiator
# Mapping from stream ID -> buffer of messages for that stream
self.buffers = {}
self.stream_queue = asyncio.Queue()
self.data_buffer = bytearray()
# The initiator of the raw connection need not read upon construction time.
# It should read when the user decides that it wants to read from the constructed stream.
if not self.initiator:
asyncio.ensure_future(self.handle_incoming(None))
def close(self):
"""
close the stream muxer and underlying raw connection
"""
self.raw_conn.close()
def is_closed(self):
"""
check connection is fully closed
:return: true if successful
"""
async def read_buffer(self, stream_id):
"""
Read a message from stream_id's buffer, check raw connection for new messages
:param stream_id: stream id of stream to read from
:return: message read
"""
# Empty buffer or nonexistent stream
# TODO: propagate up timeout exception and catch
if stream_id not in self.buffers or self.buffers[stream_id].empty():
await self.handle_incoming(stream_id)
if stream_id in self.buffers:
return await self._read_buffer_exists(stream_id)
return None
async def _read_buffer_exists(self, stream_id):
"""
Reads from raw connection with the assumption that the message buffer for stream_id exsits
:param stream_id: stream id of stream to read from
:return: message read
"""
try:
data = await asyncio.wait_for(self.buffers[stream_id].get(), timeout=5)
return data
except asyncio.TimeoutError:
return None
async def open_stream(self, protocol_id, peer_id, multi_addr):
"""
creates a new muxed_stream
:param protocol_id: protocol_id of stream
:param stream_id: stream_id of stream
:param peer_id: peer_id that stream connects to
:param multi_addr: multi_addr that stream connects to
:return: a new stream
"""
stream_id = self.raw_conn.next_stream_id()
stream = MplexStream(stream_id, multi_addr, self)
self.buffers[stream_id] = asyncio.Queue()
return stream
async def accept_stream(self):
"""
accepts a muxed stream opened by the other end
:return: the accepted stream
"""
# TODO update to pull out protocol_id from message
protocol_id = "/echo/1.0.0"
stream_id = await self.stream_queue.get()
stream = MplexStream(stream_id, False, self)
return stream, stream_id, protocol_id
async def send_message(self, flag, data, stream_id):
"""
sends a message over the connection
:param header: header to use
:param data: data to send in the message
:param stream_id: stream the message is in
:return: True if success
"""
# << by 3, then or with flag
header = (stream_id << 3) | flag
header = encode_uvarint(header)
if data is None:
data_length = encode_uvarint(0)
_bytes = header + data_length
else:
data_length = encode_uvarint(len(data))
_bytes = header + data_length + data
return await self.write_to_stream(_bytes)
async def write_to_stream(self, _bytes):
"""
writes a byte array to a raw connection
:param _bytes: byte array to write
:return: length written
"""
self.raw_conn.writer.write(_bytes)
await self.raw_conn.writer.drain()
return len(_bytes)
async def handle_incoming(self, my_stream_id):
"""
Read a message off of the raw connection and add it to the corresponding message buffer
"""
# TODO Deal with other types of messages using flag (currently _)
continue_reading = True
i = 0
while continue_reading:
i += 1
stream_id, _, message = await self.read_message()
continue_reading = (stream_id is not None and
stream_id != my_stream_id and
my_stream_id is not None)
if stream_id not in self.buffers:
self.buffers[stream_id] = asyncio.Queue()
await self.stream_queue.put(stream_id)
await self.buffers[stream_id].put(message)
async def read_chunk(self):
"""
Read a chunk of bytes off of the raw connection into data_buffer
"""
# unused now but possibly useful in the future
try:
chunk = await asyncio.wait_for(self.raw_conn.reader.read(-1), timeout=5)
self.data_buffer += chunk
except asyncio.TimeoutError:
print('timeout!')
return
async def read_message(self):
"""
Read a single message off of the raw connection
:return: stream_id, flag, message contents
"""
# Timeout is set to a relatively small value to alleviate wait time to exit
# loop in handle_incoming
timeout = .1
try:
header = await decode_uvarint_from_stream(self.raw_conn.reader, timeout)
length = await decode_uvarint_from_stream(self.raw_conn.reader, timeout)
message = await asyncio.wait_for(self.raw_conn.reader.read(length), timeout=timeout)
except asyncio.TimeoutError:
return None, None, None
flag = header & 0x07
stream_id = header >> 3
return stream_id, flag, message