-added arm_ros_conn

[arm_ros_conn.git] / scripts / json_client.py

diff --git a/scripts/json_client.py b/scripts/json_client.py
new file mode 100755 (executable)
index 0000000..4e2208e
--- /dev/null
+++ b/scripts/json_client.py
@@ -0,0 +1,61 @@
+#!/usr/bin/env python
+# -*- coding: iso-8859-15 -*-
+
+import sys
+import socket
+import json
+
+def set_keepalive(sock, after_idle_sec=1, interval_sec=3, max_fails=5):
+       """Set TCP keepalive on an open socket.
+
+       It activates after 1 second (after_idle_sec) of idleness,
+       then sends a keepalive ping once every 3 seconds (interval_sec),
+       and closes the connection after 5 failed ping (max_fails), or 15 seconds
+       """
+       sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
+       sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPIDLE, after_idle_sec)
+       sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPINTVL, interval_sec)
+       sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_KEEPCNT, max_fails)
+if not hasattr(socket, "set_keepalive"):
+       socket.set_keepalive = set_keepalive
+
+class JsonClient:
+       def __init__(self, addr = ("arm", 10002)):
+               self.pSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+               self.pSocket.settimeout(1)
+               socket.set_keepalive(self.pSocket)
+               self.pSocket.connect(addr)
+               self.lMsgs = []
+
+       def write(self, cmd):
+               data = {'command': cmd}
+               num = self.pSocket.sendall(json.dumps(data))
+               while True:
+                       msg = json.loads(self.pSocket.recv(4096))
+                       if msg.has_key("return"): return msg["return"]
+                       elif msg.has_key("error"): return msg["error"]
+                       self.lMsgs.insert(0, msg)
+
+       def read(self):
+               if len(self.lMsgs) > 0:
+                       return self.lMsgs.pop()
+               self.pSocket.setblocking(False)
+               try:
+                       return json.loads(self.pSocket.recv(4096))
+               except socket.error:
+                       pass
+               finally:
+                       self.pSocket.setblocking(True)
+
+if __name__ == "__main__":
+       print JsonClient().write(sys.argv[1])
+
+       #from datetime import datetime
+       #from time import sleep
+       #pClient = JsonClient()
+       #while True:
+       #       msg = pClient.read()
+       #       if msg:
+       #               print "Got async", msg
+       #       print datetime.now(), float(pClient.write("get distance forward lower"))
+       #       sleep(0.1)