From 81e99a0e226839d26a3d9d6dcfb6f7d6599a8e29 Mon Sep 17 00:00:00 2001 From: Fabio Manganiello Date: Tue, 17 Oct 2023 20:12:48 +0200 Subject: [PATCH] [`shell`] Better buffering for the output sent to websockets. --- platypush/plugins/shell/__init__.py | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/platypush/plugins/shell/__init__.py b/platypush/plugins/shell/__init__.py index dbc9e800d..22487c086 100644 --- a/platypush/plugins/shell/__init__.py +++ b/platypush/plugins/shell/__init__.py @@ -1,7 +1,8 @@ from base64 import b64encode import json -import threading import subprocess +import threading +import time from typing import Callable, Optional from uuid import uuid1 @@ -54,16 +55,28 @@ class ShellPlugin(Plugin): shell=True, stdout=subprocess.PIPE, ) as proc: - while proc.poll() is None: - if not proc.stdout: - break + first_loop = True - while True: - buf = proc.stdout.read(1024) - if not buf: + while proc.poll() is None and proc.stdout and proc.stdout.readable(): + buf = b'' + bufsize = 1024 + + while len(buf) < bufsize: + ch = proc.stdout.read(1) + if not ch: break - self._send_ws_output(cmd_id, buf) + buf += ch + if ch in (b'\r', b'\n'): + break + + if first_loop: + first_loop = False + # An artificial delay to let the client connect to the websocket, + # otherwise the first few lines of output might be lost. + time.sleep(2) + + self._send_ws_output(cmd_id, buf) finally: self._send_ws_output(cmd_id, None)