[enh] clitools: Adds a redis generator

clitools/generators/fromRedis.py

@@ -0,0 +1,73 @@
+#!/usr/bin/python3
+# -*- coding: utf-8 -*-
+# -*- mode: Python -*-
+
+
+'''
+
+This generator reads a frame from redis
+v0.1.0
+
+Use it to create feedback loops by writing to the same frame 
+or to copy the frame from someone else
+
+LICENCE : CC
+
+by cocoa 
+
+'''
+
+from __future__ import print_function
+import ast
+import argparse
+import json
+import redis
+import sys
+import time
+name="generator::fromRedis"
+
+
+def debug(*args, **kwargs):
+    if( verbose == False ):
+        return
+    print(*args, file=sys.stderr, **kwargs)
+
+
+argsparser      = argparse.ArgumentParser(description="Dummy generator")
+argsparser.add_argument("-k","--key",required=True,help="Redis key to look after",default=30,type=str)
+argsparser.add_argument("-i","--ip",help="IP address of the Redis server ",default="127.0.0.1",type=str)
+argsparser.add_argument("-p","--port",help="Port of the Redis server ",default="6379",type=str)
+argsparser.add_argument("-f","--fps",help="Frame Per Second",default=30,type=int)
+argsparser.add_argument("-v","--verbose",action="store_true",help="Verbose output")
+args = argsparser.parse_args()
+
+fps                 = args.fps
+verbose             = args.verbose
+key                 = args.key
+ip                  = args.ip
+port                = args.port
+optimal_looptime    = 1 / fps
+debug(name+" optimal looptime "+str(optimal_looptime))
+
+r = redis.Redis(
+        host=ip,
+        port=port)
+
+while True:
+  start = time.time()
+  # Read from Redis
+  line = r.get(key)
+  # Decode as list of tuples
+  pointsList = ast.literal_eval(line.decode('ascii'))
+  # convert to list of lists
+  pointsList  = [list(elem) for elem in pointsList]
+  # Convert to JSON string
+  line = json.dumps( pointsList )
+  debug(name,"Key:{} line:{}".format(key,line))
+  print(line, flush=True);
+  looptime = time.time() - start
+  if( looptime < optimal_looptime ):
+    time.sleep( optimal_looptime - looptime)
+    debug(name+" micro sleep:"+str( optimal_looptime - looptime))
+  
+