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#
# Copyright BitBake Contributors
#
# SPDX-License-Identifier: GPL-2.0-only
#
import asyncio
import itertools
import json
from .exceptions import ClientError, ConnectionClosedError
# The Python async server defaults to a 64K receive buffer, so we hardcode our
# maximum chunk size. It would be better if the client and server reported to
# each other what the maximum chunk sizes were, but that will slow down the
# connection setup with a round trip delay so I'd rather not do that unless it
# is necessary
DEFAULT_MAX_CHUNK = 32 * 1024
def chunkify(msg, max_chunk):
if len(msg) < max_chunk - 1:
yield "".join((msg, "\n"))
else:
yield "".join((json.dumps({"chunk-stream": None}), "\n"))
args = [iter(msg)] * (max_chunk - 1)
for m in map("".join, itertools.zip_longest(*args, fillvalue="")):
yield "".join(itertools.chain(m, "\n"))
yield "\n"
class StreamConnection(object):
def __init__(self, reader, writer, timeout, max_chunk=DEFAULT_MAX_CHUNK):
self.reader = reader
self.writer = writer
self.timeout = timeout
self.max_chunk = max_chunk
@property
def address(self):
return self.writer.get_extra_info("peername")
async def send_message(self, msg):
for c in chunkify(json.dumps(msg), self.max_chunk):
self.writer.write(c.encode("utf-8"))
await self.writer.drain()
async def recv_message(self):
l = await self.recv()
m = json.loads(l)
if not m:
return m
if "chunk-stream" in m:
lines = []
while True:
l = await self.recv()
if not l:
break
lines.append(l)
m = json.loads("".join(lines))
return m
async def send(self, msg):
self.writer.write(("%s\n" % msg).encode("utf-8"))
await self.writer.drain()
async def recv(self):
if self.timeout < 0:
line = await self.reader.readline()
else:
try:
line = await asyncio.wait_for(self.reader.readline(), self.timeout)
except asyncio.TimeoutError:
raise ConnectionError("Timed out waiting for data")
if not line:
raise ConnectionClosedError("Connection closed")
line = line.decode("utf-8")
if not line.endswith("\n"):
raise ConnectionError("Bad message %r" % (line))
return line.rstrip()
async def close(self):
self.reader = None
if self.writer is not None:
self.writer.close()
self.writer = None
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