Viewing file:  mesa-overlay-control.py (5.67 KB) -rwxr-xr-x
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#!/usr/bin/env python3
import os
import socket
import sys
import select
from select import EPOLLIN, EPOLLPRI, EPOLLERR
import time
from collections import namedtuple
import argparse
TIMEOUT = 1.0 # seconds
VERSION_HEADER = bytearray('MesaOverlayControlVersion', 'utf-8')
DEVICE_NAME_HEADER = bytearray('DeviceName', 'utf-8')
MESA_VERSION_HEADER = bytearray('MesaVersion', 'utf-8')
DEFAULT_SERVER_ADDRESS = "\0mesa_overlay"
class Connection:
def __init__(self, path):
# Create a Unix Domain socket and connect
sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
try:
sock.connect(path)
except socket.error as msg:
print(msg)
sys.exit(1)
self.sock = sock
# initialize poll interface and register socket
epoll = select.epoll()
epoll.register(sock, EPOLLIN | EPOLLPRI | EPOLLERR)
self.epoll = epoll
def recv(self, timeout):
'''
timeout as float in seconds
returns:
- None on error or disconnection
- bytes() (empty) on timeout
'''
events = self.epoll.poll(timeout)
for ev in events:
(fd, event) = ev
if fd != self.sock.fileno():
continue
# check for socket error
if event & EPOLLERR:
return None
# EPOLLIN or EPOLLPRI, just read the message
msg = self.sock.recv(4096)
# socket disconnected
if len(msg) == 0:
return None
return msg
return bytes()
def send(self, msg):
self.sock.send(msg)
class MsgParser:
MSGBEGIN = bytes(':', 'utf-8')[0]
MSGEND = bytes(';', 'utf-8')[0]
MSGSEP = bytes('=', 'utf-8')[0]
def __init__(self, conn):
self.cmdpos = 0
self.parampos = 0
self.bufferpos = 0
self.reading_cmd = False
self.reading_param = False
self.buffer = None
self.cmd = bytearray(4096)
self.param = bytearray(4096)
self.conn = conn
def readCmd(self, ncmds, timeout=TIMEOUT):
'''
returns:
- None on error or disconnection
- bytes() (empty) on timeout
'''
parsed = []
remaining = timeout
while remaining > 0 and ncmds > 0:
now = time.monotonic()
if self.buffer == None:
self.buffer = self.conn.recv(remaining)
self.bufferpos = 0
# disconnected or error
if self.buffer == None:
return None
for i in range(self.bufferpos, len(self.buffer)):
c = self.buffer[i]
self.bufferpos += 1
if c == self.MSGBEGIN:
self.cmdpos = 0
self.parampos = 0
self.reading_cmd = True
self.reading_param = False
elif c == self.MSGEND:
if not self.reading_cmd:
continue
self.reading_cmd = False
self.reading_param = False
cmd = self.cmd[0:self.cmdpos]
param = self.param[0:self.parampos]
self.reading_cmd = False
self.reading_param = False
parsed.append((cmd, param))
ncmds -= 1
if ncmds == 0:
break
elif c == self.MSGSEP:
if self.reading_cmd:
self.reading_param = True
else:
if self.reading_param:
self.param[self.parampos] = c
self.parampos += 1
elif self.reading_cmd:
self.cmd[self.cmdpos] = c
self.cmdpos += 1
# if we read the entire buffer and didn't finish the command,
# throw it away
self.buffer = None
# check if we have time for another iteration
elapsed = time.monotonic() - now
remaining = max(0, remaining - elapsed)
# timeout
return parsed
def control(args):
if args.socket:
address = '\0' + args.socket
else:
address = DEFAULT_SERVER_ADDRESS
conn = Connection(address)
msgparser = MsgParser(conn)
version = None
name = None
mesa_version = None
msgs = msgparser.readCmd(3)
for m in msgs:
cmd, param = m
if cmd == VERSION_HEADER:
version = int(param)
elif cmd == DEVICE_NAME_HEADER:
name = param.decode('utf-8')
elif cmd == MESA_VERSION_HEADER:
mesa_version = param.decode('utf-8')
if version != 1 or name == None or mesa_version == None:
print('ERROR: invalid protocol')
sys.exit(1)
if args.info:
info = "Protocol Version: {}\n"
info += "Device Name: {}\n"
info += "Mesa Version: {}"
print(info.format(version, name, mesa_version))
if args.cmd == 'start-capture':
conn.send(bytearray(':capture=1;', 'utf-8'))
elif args.cmd == 'stop-capture':
conn.send(bytearray(':capture=0;', 'utf-8'))
if __name__ == '__main__':
parser = argparse.ArgumentParser(description='MESA_overlay control client')
parser.add_argument('--info', action='store_true', help='Print info from socket')
parser.add_argument('--socket', '-s', type=str, help='Path to socket')
commands = parser.add_subparsers(help='commands to run', dest='cmd')
commands.add_parser('start-capture')
commands.add_parser('stop-capture')
args = parser.parse_args()
control(args)
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