134 lines
3.6 KiB
Python
134 lines
3.6 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
jishaku.shell
|
|
~~~~~~~~~~~~~
|
|
|
|
Tools related to interacting directly with the shell.
|
|
|
|
:copyright: (c) 2019 Devon (Gorialis) R
|
|
:license: MIT, see LICENSE for more details.
|
|
|
|
"""
|
|
|
|
import asyncio
|
|
import os
|
|
import re
|
|
import shlex
|
|
import subprocess
|
|
import sys
|
|
import time
|
|
|
|
SHELL = os.getenv("SHELL") or "/bin/bash"
|
|
WINDOWS = sys.platform == "win32"
|
|
|
|
|
|
def background_reader(stream, loop: asyncio.AbstractEventLoop, callback):
|
|
"""
|
|
Reads a stream and forwards each line to an async callback.
|
|
"""
|
|
|
|
for line in iter(stream.readline, b''):
|
|
loop.call_soon_threadsafe(loop.create_task, callback(line))
|
|
|
|
|
|
class ShellReader:
|
|
"""
|
|
A class that passively reads from a shell and buffers results for read.
|
|
|
|
Example
|
|
-------
|
|
|
|
.. code:: python3
|
|
|
|
# reader should be in a with statement to ensure it is properly closed
|
|
with ShellReader('echo one; sleep 5; echo two') as reader:
|
|
# prints 'one', then 'two' after 5 seconds
|
|
async for x in reader:
|
|
print(x)
|
|
"""
|
|
|
|
def __init__(self, code: str, timeout: int = 90, loop: asyncio.AbstractEventLoop = None):
|
|
if WINDOWS:
|
|
sequence = shlex.split(code)
|
|
else:
|
|
sequence = [SHELL, '-c', code]
|
|
|
|
self.process = subprocess.Popen(sequence, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
|
|
self.close_code = None
|
|
|
|
self.loop = loop or asyncio.get_event_loop()
|
|
self.timeout = timeout
|
|
|
|
self.stdout_task = self.make_reader_task(self.process.stdout, self.stdout_handler)
|
|
self.stderr_task = self.make_reader_task(self.process.stderr, self.stderr_handler)
|
|
|
|
self.queue = asyncio.Queue(maxsize=250)
|
|
|
|
@property
|
|
def closed(self):
|
|
"""
|
|
Are both tasks done, indicating there is no more to read?
|
|
"""
|
|
|
|
return self.stdout_task.done() and self.stderr_task.done()
|
|
|
|
async def executor_wrapper(self, *args, **kwargs):
|
|
"""
|
|
Call wrapper for stream reader.
|
|
"""
|
|
|
|
return await self.loop.run_in_executor(None, *args, **kwargs)
|
|
|
|
def make_reader_task(self, stream, callback):
|
|
"""
|
|
Create a reader executor task for a stream.
|
|
"""
|
|
|
|
return self.loop.create_task(self.executor_wrapper(background_reader, stream, self.loop, callback))
|
|
|
|
@staticmethod
|
|
def clean_bytes(line):
|
|
"""
|
|
Cleans a byte sequence of shell directives and decodes it.
|
|
"""
|
|
|
|
text = line.decode('utf-8').replace('\r', '').strip('\n')
|
|
return re.sub(r'\x1b[^m]*m', '', text).replace("``", "`\u200b`").strip('\n')
|
|
|
|
async def stdout_handler(self, line):
|
|
"""
|
|
Handler for this class for stdout.
|
|
"""
|
|
|
|
await self.queue.put(self.clean_bytes(line))
|
|
|
|
async def stderr_handler(self, line):
|
|
"""
|
|
Handler for this class for stderr.
|
|
"""
|
|
|
|
await self.queue.put(self.clean_bytes(b'[stderr] ' + line))
|
|
|
|
def __enter__(self):
|
|
return self
|
|
|
|
def __exit__(self, *args):
|
|
self.process.kill()
|
|
self.process.terminate()
|
|
self.close_code = self.process.wait(timeout=0.5)
|
|
|
|
def __aiter__(self):
|
|
return self
|
|
|
|
async def __anext__(self):
|
|
start_time = time.perf_counter()
|
|
|
|
while not self.closed or not self.queue.empty():
|
|
try:
|
|
return await asyncio.wait_for(self.queue.get(), timeout=1)
|
|
except asyncio.TimeoutError as exception:
|
|
if time.perf_counter() - start_time >= self.timeout:
|
|
raise exception
|
|
|
|
raise StopAsyncIteration()
|