example PoSy receiver
Stefan Schuermans commited on 2014-04-23 17:22:44
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+#! /usr/bin/env python |
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+ |
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+# Stage Director receiver |
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+# Copyright 2014 Stefan Schuermans <stefan@schuermans.info> |
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+# Copyleft: GNU public license - http://www.gnu.org/copyleft/gpl.html |
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+ |
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+import datetime |
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+import fcntl |
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+import os |
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+import select |
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+import socket |
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+import struct |
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+import sys |
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+import time |
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+ |
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+scriptdir = os.path.dirname(os.path.abspath(__file__)) |
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+ |
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+class Receiver: |
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+ |
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+ def __init__(self): |
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+ """construct a Stage Director Receiver object""" |
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+ # set constants |
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+ self.select_timeout = 0.1 # timeout (s) for select syscall |
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+ # create member variables |
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+ self.sock = None |
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+ # startup |
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+ self.sockSetup() |
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+ |
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+ def __del__(self): |
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+ """deconstruct object""" |
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+ self.sockClose() |
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+ |
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+ def posyParse(self, data): |
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+ """parse received PoSy packet""" |
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+ if len(data) < 76 or data[0:4] != "PoSy": |
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+ return False |
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+ flags, name, pos_ms = struct.unpack("!I64sI", data[4:76])
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+ name_end = name.find("\0")
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+ if name_end >= 0: |
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+ name = name[:name_end] |
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+ if flags & 1: |
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+ pause = True |
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+ else: |
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+ pause = False |
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+ # store info from PoSy packet |
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+ print("name=%s pos=%.3fs puase=%s" % (name, pos_ms * 1e-3, pause))
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+ |
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+ def run(self): |
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+ """run application""" |
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+ try: |
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+ while True: |
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+ self.waitForInput() |
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+ except KeyboardInterrupt: |
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+ pass |
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+ |
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+ def sockRecv(self): |
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+ """receive data from socket""" |
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+ if self.sock is None: |
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+ return |
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+ # receive message |
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+ data = self.sock.recv(4096) |
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+ print("data from socket: %d bytes" % len(data))
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+ # parse (ignore message on error) |
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+ self.posyParse(data) |
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+ |
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+ def sockClose(self): |
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+ """close UDP socket""" |
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+ if self.sock is not None: |
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+ self.sock.close() |
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+ self.sock = None |
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+ |
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+ def sockSetup(self): |
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+ """create a new UDP socket and bind it""" |
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+ self.sockClose() |
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+ try: |
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+ self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) |
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+ self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) |
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+ self.sock.bind(("0.0.0.0", 5740))
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+ except: |
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+ self.sockClose() |
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+ |
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+ def waitForInput(self): |
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+ """wait for input from UDP socket""" |
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+ # poll for data |
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+ inputs = [] |
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+ outputs = [] |
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+ errors = [] |
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+ wait_txt = "" |
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+ if self.sock is not None: |
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+ inputs.append(self.sock) |
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+ wait_txt += " socket" |
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+ print("waiting for input:" + wait_txt)
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+ rds, wrs, exs = select.select(inputs, outputs, errors, self.select_timeout) |
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+ # obtain available data |
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+ for rd in rds: |
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+ if self.sock is not None and rd is self.sock: |
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+ print("input from socket")
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+ self.sockRecv() |
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+ |
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+# main function |
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+def main(argv): |
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+ # run application |
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+ app = Receiver() |
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+ app.run() |
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+ # done |
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+ return 0 |
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+ |
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+# main application entry point |
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+if __name__ == "__main__": |
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+ sys.exit(main(sys.argv)) |
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+ |
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