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FreeDATA/arq.py
DJ2LS 2799e5b9fb
Improved N_FRAMES_LAST_BURST
2021-01-02 16:37:34 +01:00

322 lines
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Python
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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Sun Dec 27 20:43:40 2020
@author: DJ2LS
"""
# CRC aller payloads via XOR scrambeln und dann eine CRC8 mitsenden
import logging
import crcengine
import threading
import time
import static
import modem
import other
from random import randrange
modem = modem.RF()
crc_algorithm = crcengine.new('crc16-ccitt-false') #load crc16 library
static.ARQ_PAYLOAD_PER_FRAME = static.FREEDV_PAYLOAD_PER_FRAME - 3 #6?!
def data_received(data_in):
ARQ_N_RX_BURSTS = int.from_bytes(bytes(data_in[:1]), "big") - 10
static.ARQ_RX_BURST_BUFFER.append(data_in) #append data to RX BUFFER
print("WAITING FOR BURSTS: " + str(ARQ_N_RX_BURSTS))
print("ARQ_RX_BURST_BUFFER: " + str(len(static.ARQ_RX_BURST_BUFFER)))
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
#burst_total_payload = bytearray()
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
# ------------------ caculate CRC of BURST
#print(burst_total_payload)
burst_payload_crc = crc_algorithm(burst_total_payload)
burst_payload_crc = burst_payload_crc.to_bytes(2, byteorder='big')
#print(burst_payload_crc)
# IF BURST CRC IS CORRECT, APPEND BURST TO BUFFER AND SEND ACK FRAME
if burst_payload_crc == data_in[1:3]:
# WAIT SOME TIME TO PREVENT TIMING ISSUES --> NEEDS TO BE OPTIMIZED LATER
time.sleep(2)
logging.info("BURST CRC ARE EQUAL!")
logging.info("TX | SENDING ARQ BURST ACK [" + str(data_in[1:3]) +"]")
#print(burst_total_payload)
static.ARQ_RX_FRAME_BUFFER.append(burst_total_payload) # IF CRC TRUE APPEND burst_total_payload TO ARQ_RX_FRAME_BUFFER
#print(data_in[7:9])
#BUILDING ACK FRAME -----------------------------------------------
ack_frame = b'\7' + bytes(burst_payload_crc)
ack_buffer = bytearray(static.ARQ_PAYLOAD_PER_FRAME)
ack_buffer[:len(ack_frame)] = ack_frame # set buffersize to length of data which will be send
#TRANSMIT ACK FRAME -----------------------------------------------
modem.Transmit(ack_buffer)
static.ARQ_RX_BURST_BUFFER = [] # CLEAR RX BURST BUFFER
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 = []
# LOOP THOUGH FRAME BUFFER AND STICK EVERYTHING TOGETHER
# WE ALSO CHECK FOR FRAME HEADER AND LAST FRAME
complete_frame = bytearray()
print(static.ARQ_RX_FRAME_BUFFER)
for frame in range(len(static.ARQ_RX_FRAME_BUFFER)):
complete_frame = complete_frame + static.ARQ_RX_FRAME_BUFFER[frame]
print(complete_frame)
print(complete_frame[4:6])
# -------- DETECT IF WE ALREADY RECEIVED A FRAME HEADER THEN SAVE DATA TO GLOBALS
#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'):
print("DAS IST DER ERSTE BURST MIT BOF!!!")
#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")
# -------- DETECT IF WE HAVE ALREADY RECEIVED THE LAST FRAME
if burst_total_payload.rstrip(b'\x00').endswith(b'\xFF\xFF'):
print("DAS IST DER LETZTE BURST MIT EOF!!!")
# NOW WE TRY TO SEPARATE THE FRAME CRC FOR A CRC CALCULATION
frame_payload = complete_frame.rstrip(b'\x00') #REMOVE x00
frame_payload = frame_payload[6:-2] #THIS IS THE FRAME PAYLOAD
frame_payload_crc = crc_algorithm(frame_payload)
frame_payload_crc = frame_payload_crc.to_bytes(2, byteorder='big')
#IF THE FRAME PAYLOAD CRC IS EQUAL TO THE FRAME CRC WHICH IS KNOWN FROM THE HEADER --> SUCCESS
if frame_payload_crc == static.FRAME_CRC:
logging.info("RX | FILE SUCESSFULL RECEIVED! - TIME TO PARTY")
static.RX_BUFFER.append(frame_payload)
static.ARQ_RX_FRAME_BUFFER = []
#print(static.RX_BUFFER[-1])
# HERE: SEND ACK FOR TOTAL FRAME!!!
#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))
#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
def transmit(data_out):
#static.ARQ_PAYLOAD_PER_FRAME = static.FREEDV_PAYLOAD_PER_FRAME - 3
#----------------------- BUILD A FRAME WITH CRC AND N BURSTS SO THE RECEIVER GETS THIS INFORMATION
frame_BOF = b'\xAA\xAA'
frame_EOF = b'\xFF\xFF'
frame_header_length = 8
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
n_bursts_prediction = n_bursts_prediction.to_bytes(2, byteorder='big') #65535
frame_payload_crc = crc_algorithm(data_out)
frame_payload_crc = frame_payload_crc.to_bytes(2, byteorder='big')
# This is the total frame with frame header, which will be send
data_out = n_bursts_prediction + frame_payload_crc + frame_BOF + data_out + frame_EOF
# 2 2 2 N 2
#print(data_out)
# --------------------------------------------- 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)
logging.info("TX | TOTAL PAYLOAD BYTES/FRAMES TO SEND: " + str(len(data_out)) + " / " + str(static.TX_BUFFER_SIZE))
###static.ACK_RECEIVED = 0 # SET ACK RECEIVED TO 0 IF NOT ALREADY DONE TO BE SURE WE HAVE A NEW CYCLE
# --------------------------------------------- THIS IS THE MAIN LOOP
static.ARQ_N_SENT_FRAMES = 0 # SET N SENT FRAMES TO 0 FOR A NEW SENDING CYCLE
while static.ARQ_N_SENT_FRAMES <= static.TX_BUFFER_SIZE:
print("static.ARQ_N_SENT_FRAMES: " + str(static.ARQ_N_SENT_FRAMES))
############################----------RANDOM FRAMES PER BURST MACHINE --> HELPER FOR SIMULATING DYNAMIC ARQ UNTIL BURST MACHINE IS BUILD
#static.ARQ_TX_N_FRAMES = get_n_frames_per_burst(len(data_out))
static.ARQ_TX_N_FRAMES = get_n_frames_per_burst()
static.ACK_RECEIVED = 0 # SET ACK RECEIVED TO 0 IF NOT ALREADY DONE TO BE SURE WE HAVE A NEW CYCLE
#################################################################
# ----------- SET FRAME PAYLOAD TO BE ABLE TO CREATE CRC
burst_total_payload = bytearray()
try: # DETECT IF LAST BURST TO PREVENT INDEX ERROR OF BUFFER
for i in range(static.ARQ_TX_N_FRAMES): #bytearray(b'111111111111111111111111222222222222222222222222')
# we need to make sure, payload data is always as long as static.ARQ_PAYLOAD_PER_FRAME beacuse of CRC!
burst_raw_payload = static.TX_BUFFER[static.ARQ_N_SENT_FRAMES + i]
burst_payload = bytearray(static.ARQ_PAYLOAD_PER_FRAME)
burst_payload[:len(burst_raw_payload)] = burst_raw_payload # set buffersize to length of data which will be send
burst_total_payload = burst_total_payload + burst_payload
except IndexError: # IF LAST BURST DETECTED BUILD CRC WITH LESS FRAMES AND SET static.ARQ_TX_N_FRAMES TO VALUE OF REST!
burst_total_payload = bytearray() # reset burst_total_payload because of possible input remaining of detecting loop one step above
if static.ARQ_N_SENT_FRAMES == 0 and (static.ARQ_TX_N_FRAMES > static.TX_BUFFER_SIZE): #WE CANT DO MODULO 0 --> CHECK IF FIRST FRAME == LAST FRAME
static.ARQ_TX_N_FRAMES = static.TX_BUFFER_SIZE
elif static.ARQ_N_SENT_FRAMES == 1 and (static.ARQ_TX_N_FRAMES > static.TX_BUFFER_SIZE): # MODULO 1 WILL ALWAYS BE 0 --> THIS FIXES IT
static.ARQ_TX_N_FRAMES = static.TX_BUFFER_SIZE - static.ARQ_N_SENT_FRAMES
else:
static.ARQ_TX_N_FRAMES = (static.TX_BUFFER_SIZE % static.ARQ_N_SENT_FRAMES)
#print("static.TX_BUFFER_SIZE: " + str(static.TX_BUFFER_SIZE))
#print("static.ARQ_N_SENT_FRAMES: " + str(static.ARQ_N_SENT_FRAMES))
print("ARQ_TX_N_FRAMES OF LAST BURST: " + str(static.ARQ_TX_N_FRAMES))
for i in range(static.ARQ_TX_N_FRAMES): #bytearray(b'111111111111111111111111222222222222222222222222')
# we need to make sure, payload data is always as long as static.ARQ_PAYLOAD_PER_FRAME beacuse of CRC!
burst_raw_payload = static.TX_BUFFER[static.ARQ_N_SENT_FRAMES + i]
burst_payload = bytearray(static.ARQ_PAYLOAD_PER_FRAME)
burst_payload[:len(burst_raw_payload)] = burst_raw_payload # set buffersize to length of data which will be send
burst_total_payload = burst_total_payload + burst_payload
# ----------- GENERATE PAYLOAD CRC FOR ARQ_TX_N_FRAMES
burst_payload_crc = crc_algorithm(burst_total_payload)
burst_payload_crc = burst_payload_crc.to_bytes(2, byteorder='big')
static.ARQ_ACK_WAITING_FOR_ID = burst_payload_crc #set the global variable so we know for which ACK we are waiting for
#------------------ BUILD ARQBURSTS---------------------------------------------
arqburst = []
for i in range(static.ARQ_TX_N_FRAMES):
frame_type = 10 + static.ARQ_TX_N_FRAMES
frame_type = bytes([frame_type])
payload_data = bytes(static.TX_BUFFER[static.ARQ_N_SENT_FRAMES + i])
arqframe = frame_type + burst_payload_crc + payload_data
buffer = bytearray(static.FREEDV_PAYLOAD_PER_FRAME) # create TX buffer
buffer[:len(arqframe)] = arqframe # set buffersize to length of data which will be send
arqburst.append(buffer) #append data to a buffer array, so we can loop through it
#--------------------------------------------- N ATTEMPTS TO SEND BURSTS IF ACK RECEPTION FAILS
for static.TX_N_RETRIES in range(static.TX_N_MAX_RETRIES):
static.ACK_RECEIVED = 0 #SET AGAIN ACK_RECEIVED TO 0 SO WE CAN BE SURE WE ARE WAITING FOR THE CORRECT ACK
# ----------------------- Loop through ARQ FRAMES BUFFER with N = Numbers of frames which will be send at once
for n in range(static.ARQ_TX_N_FRAMES):
logging.info("TX | SENDING BURST [" + str(n+1) + " / " + str(static.ARQ_TX_N_FRAMES) + "] [" + str(static.ARQ_N_SENT_FRAMES + n+1) + " / " + str(static.TX_BUFFER_SIZE) + "] [" + str(burst_payload_crc) + "]")
modem.Transmit(arqburst[n])
#LETS SLEEP SOME TIME FOR TX COOLDOWN --> CAN BE REMOVED LATER IF SYNC/UNSYNC OF FREEDV IS WORKING BETTER
time.sleep(4)
# --------------------------- START TIMER FOR WAITING FOR ACK ---> IF TIMEOUT REACHED, ACK_TIMEOUT = 1
static.ACK_TIMEOUT = 0
timer = threading.Timer(static.ACK_TIMEOUT_SECONDS * static.ARQ_TX_N_FRAMES, other.timeout)
timer.start()
logging.info("TX | WAITING FOR ACK")
# --------------------------- WHILE TIMEOUT NOT REACHED AND NO ACK RECEIVED --> LISTEN
while static.ACK_TIMEOUT == 0 and static.ACK_RECEIVED == 0:
static.MODEM_RECEIVE = True
#else:
#logging.info("TX | ACK TIMEOUT - SENDING AGAIN")
#pass
#--------------- BREAK LOOP IF ACK HAS BEEN RECEIVED
######if static.ACK_RECEIVED == 1:
if static.ACK_RECEIVED == 1:
#-----------IF ACK RECEIVED, INCREMENT ITERATOR FOR MAIN LOOP TO PROCEED WITH NEXT FRAMES/BURST
static.ARQ_N_SENT_FRAMES = static.ARQ_N_SENT_FRAMES + static.ARQ_TX_N_FRAMES
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
if static.ARQ_N_SENT_FRAMES == static.TX_BUFFER_SIZE:
break
# ------------ TIMER TO WAIT UNTIL NEXT PACKAGE WILL BE SEND TO PREVENT TIME ISSEUS --> NEEDS TO BE IMPROVED LATER
time.sleep(5)
# 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")
# 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():
n_frames_per_burst = randrange(1,5)
return n_frames_per_burst
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