FreeDATA/arq.py

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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Sun Dec 27 20:43:40 2020
@author: DJ2LS
"""
import logging
import threading
import time
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from random import randrange
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import static
import modem
import helpers
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modem = modem.RF()
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static.ARQ_PAYLOAD_PER_FRAME = static.FREEDV_DATA_PAYLOAD_PER_FRAME - 3 #6?!
static.ARQ_ACK_PAYLOAD_PER_FRAME = 14 - 2# --> 700D
def arq_ack_timeout():
static.ACK_TIMEOUT = 1
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def data_received(data_in):
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ARQ_N_RX_BURSTS = int.from_bytes(bytes(data_in[:1]), "big") - 10 #get number of bursts from received frame
static.ARQ_RX_BURST_BUFFER.append(data_in) #append data to RX BUFFER
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print("WAITING FOR BURSTS: " + str(ARQ_N_RX_BURSTS))
print("ARQ_RX_BURST_BUFFER: " + str(len(static.ARQ_RX_BURST_BUFFER)))
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burst_total_payload = bytearray()
#while static.ACK_RX_TIMEOUT == 0: #define timeout where data has to be received untl error occurs
if len(static.ARQ_RX_BURST_BUFFER) == ARQ_N_RX_BURSTS: #if received bursts are equal to burst number in frame
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for n_raw_frame in range(0,len(static.ARQ_RX_BURST_BUFFER)):
burst_frame = static.ARQ_RX_BURST_BUFFER[n_raw_frame] #get burst frame
burst_payload = burst_frame[3:] #remove frame type and burst CRC
burst_total_payload = burst_total_payload + burst_payload #stick bursts together
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# ------------------ caculate CRC of BURST
burst_payload_crc = helpers.get_crc_16(burst_total_payload)
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# IF BURST CRC IS CORRECT, APPEND BURST TO BUFFER AND SEND ACK FRAME
if burst_payload_crc == data_in[1:3]:
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logging.info("BURST CRC ARE EQUAL!")
static.ARQ_RX_FRAME_BUFFER.append(burst_total_payload) # IF CRC TRUE APPEND burst_total_payload TO ARQ_RX_FRAME_BUFFER
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#BUILDING ACK FRAME -----------------------------------------------
ack_payload = bytes(burst_payload_crc)
#ack_frame = b'\7'+ bytes(burst_payload_crc)
ack_frame = b'<'+ bytes(burst_payload_crc) # < = 60
#ack_frame[1] = b'\7'
#ack_frame[2] = helpers.get_crc8(data)
#ack_frame[3:4] = bytes(burst_payload_crc)
frametype = int.from_bytes(bytes(ack_frame[:1]), "big")
print("ACK TYPE: " + str(frametype))
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ack_buffer = bytearray(static.ARQ_ACK_PAYLOAD_PER_FRAME)
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ack_buffer[:len(ack_frame)] = ack_frame # set buffersize to length of data which will be send
#TRANSMIT ACK FRAME -----------------------------------------------
logging.info("TX | SENDING ARQ BURST ACK [" + str(data_in[1:3]) +"]")
modem.transmit(7,ack_buffer)
print(ack_buffer)
# ------------------------------------------------------------
frametype = int.from_bytes(bytes(ack_buffer[:1]), "big")
print("ACK TYPE: " + str(frametype))
# ----------------------------------------------------------------
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static.ARQ_RX_BURST_BUFFER = [] # CLEAR RX BURST BUFFER
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else: #IF burst payload crc and input crc are NOT equal
print("CRC NOT EQUAL!!!!!")
print(data_in[1:3])
static.ARQ_RX_BURST_BUFFER = []
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# LOOP THOUGH FRAME BUFFER AND STICK EVERYTHING TOGETHER
# WE ALSO CHECK FOR FRAME HEADER AND LAST FRAME
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complete_frame = bytearray()
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print(static.ARQ_RX_FRAME_BUFFER)
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for frame in range(len(static.ARQ_RX_FRAME_BUFFER)):
complete_frame = complete_frame + static.ARQ_RX_FRAME_BUFFER[frame]
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print(complete_frame)
print(complete_frame[4:6])
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# -------- DETECT IF WE ALREADY RECEIVED A FRAME HEADER THEN SAVE DATA TO GLOBALS
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#if burst_total_payload[4:6].startswith(b'\xAA\xAA'):
if complete_frame[4:6].startswith(b'\xAA\xAA') or burst_total_payload[4:6].startswith(b'\xAA\xAA'):
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print("FRAME HEADER RECEIVED!")
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#print("FRAME BURSTS = " + str(complete_frame[:2]))
#print("FRAME CRC = " + str(complete_frame[2:4]))
static.FRAME_CRC = complete_frame[2:4]
static.ARQ_RX_FRAME_N_BURSTS = int.from_bytes(bytes(complete_frame[:2]), "big")
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# -------- DETECT IF WE HAVE ALREADY RECEIVED THE LAST FRAME
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if burst_total_payload.rstrip(b'\x00').endswith(b'\xFF\xFF'):
print("DAS IST DER LETZTE BURST MIT EOF!!!")
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print("WEITER GEHTS...")
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# NOW WE TRY TO SEPARATE THE FRAME CRC FOR A CRC CALCULATION
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frame_payload = complete_frame.rstrip(b'\x00') #REMOVE x00
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frame_payload = frame_payload[6:-2] #THIS IS THE FRAME PAYLOAD
frame_payload_crc = helpers.get_crc_16(frame_payload)
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#IF THE FRAME PAYLOAD CRC IS EQUAL TO THE FRAME CRC WHICH IS KNOWN FROM THE HEADER --> SUCCESS
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if frame_payload_crc == static.FRAME_CRC:
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logging.info("RX | FILE SUCESSFULL RECEIVED! - TIME TO PARTY")
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static.RX_BUFFER.append(frame_payload)
static.ARQ_RX_FRAME_BUFFER = []
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#print(static.RX_BUFFER[-1])
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# HERE: SEND ACK FOR TOTAL FRAME!!!
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#else:
#print("CRC FOR FRAME NOT EQUAL!")
# print("FRAME PAYLOAD CRC: " + str(frame_payload_crc))
# print("FRAME PAYLOAD: " + str(frame_payload))
#print("COMPLETE FRAME: " + str(complete_frame))
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#static.ARQ_RX_FRAME_BUFFER = [] # ---> BUFFER ERST LÖSCHEN WENN MINDESTANZAHL AN BURSTS ERHALTEN WORDEN SIND
def ack_received():
logging.info("RX | ACK RCVD!")
static.ACK_TIMEOUT = 1 #Force timer to stop waiting
static.ACK_RECEIVED = 1 #Force data loops of TNC to stop and continue with next frame
# static.ARQ_ACK_WAITING_FOR_ID
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def transmit(data_out):
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static.ARQ_PAYLOAD_PER_FRAME = static.FREEDV_DATA_PAYLOAD_PER_FRAME - 3
frame_header_length = 8
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n_bursts_prediction = (len(data_out)+frame_header_length) // static.ARQ_PAYLOAD_PER_FRAME + ((len(data_out)+frame_header_length) % static.ARQ_PAYLOAD_PER_FRAME > 0) # aufrunden 3.2 = 4
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print(static.FREEDV_DATA_PAYLOAD_PER_FRAME)
print(static.ARQ_PAYLOAD_PER_FRAME)
print(n_bursts_prediction)
n_bursts_prediction = n_bursts_prediction.to_bytes(2, byteorder='big') #65535
frame_payload_crc = helpers.get_crc_16(data_out)
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# This is the total frame with frame header, which will be send
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data_out = n_bursts_prediction + frame_payload_crc + static.FRAME_BOF + data_out + static.FRAME_EOF
# 2 2 2 N 2
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print(data_out)
print(len(data_out))
print(static.ARQ_PAYLOAD_PER_FRAME)
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# --------------------------------------------- LETS CREATE A BUFFER BY SPLITTING THE FILES INTO PEACES
static.TX_BUFFER = [data_out[i:i+static.ARQ_PAYLOAD_PER_FRAME] for i in range(0, len(data_out), static.ARQ_PAYLOAD_PER_FRAME)]
static.TX_BUFFER_SIZE = len(static.TX_BUFFER)
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print(static.TX_BUFFER)
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logging.info("TX | TOTAL PAYLOAD BYTES/FRAMES TO SEND: " + str(len(data_out)) + " / " + str(static.TX_BUFFER_SIZE))
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# --------------------------------------------- THIS IS THE MAIN LOOP-----------------------------------------------------------------
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static.ARQ_N_SENT_FRAMES = 0 # SET N SENT FRAMES TO 0 FOR A NEW SENDING CYCLE
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while static.ARQ_N_SENT_FRAMES <= static.TX_BUFFER_SIZE:
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print("static.ARQ_N_SENT_FRAMES: " + str(static.ARQ_N_SENT_FRAMES))
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static.ARQ_TX_N_FRAMES_PER_BURST = get_n_frames_per_burst()
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# ----------- CREATE FRAME TOTAL PAYLOAD TO BE ABLE TO CREATE CRC FOR IT
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burst_total_payload = bytearray()
try: # DETECT IF LAST BURST TO PREVENT INDEX ERROR OF BUFFER
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for i in range(static.ARQ_TX_N_FRAMES_PER_BURST): # Loop through TX_BUFFER LIST
# make sure we have always a filled buffer with the length of payload per frame
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burst_raw_payload = static.TX_BUFFER[static.ARQ_N_SENT_FRAMES + i]
burst_payload = bytearray(static.ARQ_PAYLOAD_PER_FRAME)
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burst_payload[:len(burst_raw_payload)] = burst_raw_payload # get frame from TX_BUFFER
burst_total_payload = burst_total_payload + burst_payload # append single frame to total payload buffer
except IndexError: # IF LAST BURST DETECTED BUILD CRC WITH LESS FRAMES AND SET static.ARQ_TX_N_FRAMES_PER_BURST TO VALUE OF REST!
burst_total_payload = bytearray() # reset burst_total_payload because of possible input remaining of detecting loop one step above
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if static.ARQ_N_SENT_FRAMES == 0 and (static.ARQ_TX_N_FRAMES_PER_BURST > static.TX_BUFFER_SIZE): #WE CANT DO MODULO 0 --> CHECK IF FIRST FRAME == LAST FRAME
static.ARQ_TX_N_FRAMES_PER_BURST = static.TX_BUFFER_SIZE
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elif static.ARQ_N_SENT_FRAMES == 1 and (static.ARQ_TX_N_FRAMES_PER_BURST > static.TX_BUFFER_SIZE): # MODULO 1 WILL ALWAYS BE 0 --> THIS FIXES IT
static.ARQ_TX_N_FRAMES_PER_BURST = static.TX_BUFFER_SIZE - static.ARQ_N_SENT_FRAMES
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else:
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static.ARQ_TX_N_FRAMES_PER_BURST = (static.TX_BUFFER_SIZE % static.ARQ_N_SENT_FRAMES)
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print("ARQ_TX_N_FRAMES_PER_BURST OF LAST BURST: " + str(static.ARQ_TX_N_FRAMES_PER_BURST))
for i in range(static.ARQ_TX_N_FRAMES_PER_BURST): #bytearray(b'111111111111111111111111222222222222222222222222')
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# make sure we have always a filled buffer with the length of payload per frame
burst_raw_payload = static.TX_BUFFER[static.ARQ_N_SENT_FRAMES + i]
burst_payload = bytearray(static.ARQ_PAYLOAD_PER_FRAME)
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burst_payload[:len(burst_raw_payload)] = burst_raw_payload # get frame from TX_BUFFER
burst_total_payload = burst_total_payload + burst_payload # append single frame to total payload buffer
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# ----------- GENERATE PAYLOAD CRC FOR ARQ_TX_N_FRAMES_PER_BURST
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#burst_payload_crc = helpers.get_crc_16(burst_total_payload)
static.ARQ_BURST_PAYLOAD_CRC = helpers.get_crc_16(burst_total_payload)
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#--------------------------------------------- N ATTEMPTS TO SEND BURSTS IF ACK RECEPTION FAILS
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for static.TX_N_RETRIES in range(static.TX_N_MAX_RETRIES):
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print("SENDING")
modem.transmit_arq_burst()
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# --------------------------- START TIMER FOR WAITING FOR ACK ---> IF TIMEOUT REACHED, ACK_TIMEOUT = 1
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static.ACK_TIMEOUT = 0
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static.ARQ_STATE = 'RECEIVING_ACK'
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timer = threading.Timer(static.ACK_TIMEOUT_SECONDS * static.ARQ_TX_N_FRAMES_PER_BURST, arq_ack_timeout)
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timer.start()
logging.info("TX | WAITING FOR ACK")
#static.MODEM_RECEIVE = False
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# --------------------------- WHILE TIMEOUT NOT REACHED AND NO ACK RECEIVED --> LISTEN
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while static.ACK_TIMEOUT == 0 and static.ACK_RECEIVED == 0:
time.sleep(0.05) # here we reduce CPU load
#static.MODEM_RECEIVE = True
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#else:
#logging.info("TX | ACK TIMEOUT - SENDING AGAIN")
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#pass
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#static.MODEM_RECEIVE = False
#time.sleep(1)
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#--------------- BREAK LOOP IF ACK HAS BEEN RECEIVED
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######if static.ACK_RECEIVED == 1:
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if static.ACK_RECEIVED == 1:
#static.MODEM_RECEIVE = False
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#time.sleep(1)
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#-----------IF ACK RECEIVED, INCREMENT ITERATOR FOR MAIN LOOP TO PROCEED WITH NEXT FRAMES/BURST
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static.ARQ_N_SENT_FRAMES = static.ARQ_N_SENT_FRAMES + static.ARQ_TX_N_FRAMES_PER_BURST
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break
# ----------- if no ACK received and out of retries.....stop frame sending
if static.ACK_RECEIVED == 0:
logging.info("TX | NO ACK RECEIVED | FRAME NEEDS TO BE RESEND!")
break
#-------------------------BREAK TX BUFFER LOOP IF ALL PACKETS HAVE BEEN SENT
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if static.ARQ_N_SENT_FRAMES == static.TX_BUFFER_SIZE:
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break
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# ------------ TIMER TO WAIT UNTIL NEXT PACKAGE WILL BE SEND TO PREVENT TIME ISSEUS --> NEEDS TO BE IMPROVED LATER
time.sleep(5)
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# IF TX BUFFER IS EMPTY / ALL FRAMES HAVE BEEN SENT --> HERE WE COULD ADD AN static.VAR for IDLE STATE
logging.info("TX | BUFFER EMPTY")
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# BURST MACHINE TO DEFINE N BURSTS PER FRAME ---> LATER WE CAN USE CHANNEL MESSUREMENT TO SET FRAMES PER BURST
def get_n_frames_per_burst():
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n_frames_per_burst = randrange(1,5)
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return n_frames_per_burst