lj-clitools/generators/fromRedis.py

#!/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

Licensed under GNU GPLv3

by cocoa

'''

from __future__ import print_function
import ast
import argparse
import json
import redis
import sys
import time
from os import path, getcwd
abspath, filename = path.split(path.realpath(__file__ ))
sys.path.insert(0, path.join(abspath,"../lib"))
from clitools import Clitools 


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
cli                 = Clitools({
  "verbose"   : verbose,
  "looptime"  : 1 / fps,
  "name"      : "generator::fromRedis"
  })


r = redis.Redis( host=ip, port=port )

while True:

  cli.startFrame()
  # 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 )
  cli.debug(name,"Key:{} line:{}".format(key,line))
  print(line, flush=True);
  cli.endFrame()