aratz-lasa ef2e2487af Implemented PING fully-featured
First draft of PingService, which calculates RTT results
2020-02-27 09:12:09 +01:00

131 lines
3.9 KiB
Python

import logging
import math
import secrets
import time
from typing import Union
import trio
from libp2p.exceptions import ValidationError
from libp2p.host.host_interface import IHost
from libp2p.network.stream.exceptions import StreamClosed, StreamEOF, StreamReset
from libp2p.network.stream.net_stream_interface import INetStream
from libp2p.peer.id import ID as PeerID
from libp2p.typing import TProtocol
ID = TProtocol("/ipfs/ping/1.0.0")
PING_LENGTH = 32
RESP_TIMEOUT = 60
logger = logging.getLogger("libp2p.host.ping")
async def handle_ping(stream: INetStream) -> None:
"""``handle_ping`` responds to incoming ping requests until one side errors
or closes the ``stream``."""
peer_id = stream.muxed_conn.peer_id
while True:
try:
should_continue = await _handle_ping(stream, peer_id)
if not should_continue:
return
except Exception:
await stream.reset()
return
async def _handle_ping(stream: INetStream, peer_id: PeerID) -> bool:
"""Return a boolean indicating if we expect more pings from the peer at
``peer_id``."""
try:
with trio.fail_after(RESP_TIMEOUT):
payload = await stream.read(PING_LENGTH)
except trio.TooSlowError as error:
logger.debug("Timed out waiting for ping from %s: %s", peer_id, error)
raise
except StreamEOF:
logger.debug("Other side closed while waiting for ping from %s", peer_id)
return False
except StreamReset as error:
logger.debug(
"Other side reset while waiting for ping from %s: %s", peer_id, error
)
raise
except Exception as error:
logger.debug("Error while waiting to read ping for %s: %s", peer_id, error)
raise
logger.debug("Received ping from %s with data: 0x%s", peer_id, payload.hex())
try:
await stream.write(payload)
except StreamClosed:
logger.debug("Fail to respond to ping from %s: stream closed", peer_id)
raise
return True
class PingService:
"""PingService executes pings and returns RTT in miliseconds."""
def __init__(self, host: IHost):
self._host = host
async def ping(self, peer_id: PeerID) -> int:
stream = await self._host.new_stream(peer_id, (ID,))
try:
rtt = await _ping(stream)
await _close_stream(stream)
return rtt
except Exception:
await _close_stream(stream)
raise
async def ping_loop(
self, peer_id: PeerID, ping_amount: Union[int, float] = math.inf
) -> "PingIterator":
stream = await self._host.new_stream(peer_id, (ID,))
ping_iterator = PingIterator(stream, ping_amount)
return ping_iterator
class PingIterator:
def __init__(self, stream: INetStream, ping_amount: Union[int, float]):
self._stream = stream
self._ping_limit = ping_amount
self._ping_counter = 0
def __aiter__(self) -> "PingIterator":
return self
async def __anext__(self) -> int:
if self._ping_counter > self._ping_limit:
await _close_stream(self._stream)
raise StopAsyncIteration
self._ping_counter += 1
try:
return await _ping(self._stream)
except trio.EndOfChannel:
await _close_stream(self._stream)
raise StopAsyncIteration
async def _ping(stream: INetStream) -> int:
ping_bytes = secrets.token_bytes(PING_LENGTH)
before = int(time.time() * 10 ** 6) # convert float of seconds to int miliseconds
await stream.write(ping_bytes)
pong_bytes = await stream.read(PING_LENGTH)
rtt = int(time.time() * 10 ** 6) - before
if ping_bytes != pong_bytes:
raise ValidationError("Invalid PING response")
return rtt
async def _close_stream(stream: INetStream) -> None:
try:
await stream.close()
except Exception:
pass