Files
poky/bitbake/lib/bb/asyncrpc/client.py
Paul Barker 244b044fd6 bitbake: asyncrpc: Common implementation of RPC using json & asyncio
The hashserv module implements a flexible RPC mechanism based on sending
json formatted messages over unix or tcp sockets and uses Python's
asyncio features to build an efficient message loop on both the client
and server side. Much of this implementation is not specific to the
hash equivalency service and can be extracted into a new module for
easy re-use elsewhere in bitbake.

(Bitbake rev: 4105ffd967fa86154ad67366aaf0f898abf78d14)

Signed-off-by: Paul Barker <pbarker@konsulko.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
2021-04-27 15:12:57 +01:00

146 lines
4.1 KiB
Python

#
# SPDX-License-Identifier: GPL-2.0-only
#
import abc
import asyncio
import json
import os
import socket
from . import chunkify, DEFAULT_MAX_CHUNK
class AsyncClient(object):
def __init__(self, proto_name, proto_version, logger):
self.reader = None
self.writer = None
self.max_chunk = DEFAULT_MAX_CHUNK
self.proto_name = proto_name
self.proto_version = proto_version
self.logger = logger
async def connect_tcp(self, address, port):
async def connect_sock():
return await asyncio.open_connection(address, port)
self._connect_sock = connect_sock
async def connect_unix(self, path):
async def connect_sock():
return await asyncio.open_unix_connection(path)
self._connect_sock = connect_sock
async def setup_connection(self):
s = '%s %s\n\n' % (self.proto_name, self.proto_version)
self.writer.write(s.encode("utf-8"))
await self.writer.drain()
async def connect(self):
if self.reader is None or self.writer is None:
(self.reader, self.writer) = await self._connect_sock()
await self.setup_connection()
async def close(self):
self.reader = None
if self.writer is not None:
self.writer.close()
self.writer = None
async def _send_wrapper(self, proc):
count = 0
while True:
try:
await self.connect()
return await proc()
except (
OSError,
ConnectionError,
json.JSONDecodeError,
UnicodeDecodeError,
) as e:
self.logger.warning("Error talking to server: %s" % e)
if count >= 3:
if not isinstance(e, ConnectionError):
raise ConnectionError(str(e))
raise e
await self.close()
count += 1
async def send_message(self, msg):
async def get_line():
line = await self.reader.readline()
if not line:
raise ConnectionError("Connection closed")
line = line.decode("utf-8")
if not line.endswith("\n"):
raise ConnectionError("Bad message %r" % msg)
return line
async def proc():
for c in chunkify(json.dumps(msg), self.max_chunk):
self.writer.write(c.encode("utf-8"))
await self.writer.drain()
l = await get_line()
m = json.loads(l)
if m and "chunk-stream" in m:
lines = []
while True:
l = (await get_line()).rstrip("\n")
if not l:
break
lines.append(l)
m = json.loads("".join(lines))
return m
return await self._send_wrapper(proc)
class Client(object):
def __init__(self):
self.client = self._get_async_client()
self.loop = asyncio.new_event_loop()
self._add_methods('connect_tcp', 'close')
@abc.abstractmethod
def _get_async_client(self):
pass
def _get_downcall_wrapper(self, downcall):
def wrapper(*args, **kwargs):
return self.loop.run_until_complete(downcall(*args, **kwargs))
return wrapper
def _add_methods(self, *methods):
for m in methods:
downcall = getattr(self.client, m)
setattr(self, m, self._get_downcall_wrapper(downcall))
def connect_unix(self, path):
# AF_UNIX has path length issues so chdir here to workaround
cwd = os.getcwd()
try:
os.chdir(os.path.dirname(path))
self.loop.run_until_complete(self.client.connect_unix(os.path.basename(path)))
self.loop.run_until_complete(self.client.connect())
finally:
os.chdir(cwd)
@property
def max_chunk(self):
return self.client.max_chunk
@max_chunk.setter
def max_chunk(self, value):
self.client.max_chunk = value