lj-clitools/generators/fromRedis.py

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2020-11-11 16:31:08 +00:00
#!/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))