FreeDATA/arq.py
DJ2LS 06cb35276e
removed burst crc
the burst CRC is not needed, because we only receive frames with correct CRC. So its more important to create a correct ARQ algorithm. The 2byte CRC has been removed bei 2 x CRC8 for DX call sign and own callsign
2021-02-08 16:33:11 +01:00

352 lines
20 KiB
Python

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Sun Dec 27 20:43:40 2020
@author: DJ2LS
"""
import logging
import threading
import time
from random import randrange
import static
import modem
import helpers
import main
modem = modem.RF()
static.ARQ_PAYLOAD_PER_FRAME = static.FREEDV_DATA_PAYLOAD_PER_FRAME - 3 #6?!
static.ARQ_ACK_PAYLOAD_PER_FRAME = 14 - 2#
def arq_ack_timeout():
static.ARQ_ACK_TIMEOUT = 1
def data_received(data_in):
# arqframe = frame_type + \ # 1 [:1] # frame type and current number of arq frame of (current) burst
# bytes([static.ARQ_TX_N_FRAMES_PER_BURST]) + \ # 1 [1:2] # total number of arq frames per (current) burst
# static.ARQ_N_CURRENT_ARQ_FRAME + \ # 2 [2:4] # current arq frame number
# static.ARQ_N_TOTAL_ARQ_FRAMES + \ # 2 [4:6] # total number arq frames
# static.ARQ_BURST_PAYLOAD_CRC + \ # 2 [6:8] # arq crc
# payload_data # N [8:N] # payload data
static.ARQ_N_FRAME = int.from_bytes(bytes(data_in[:1]), "big") - 10 #get number of burst frame
static.ARQ_N_RX_FRAMES_PER_BURSTS = int.from_bytes(bytes(data_in[1:2]), "big") #get number of bursts from received frame
static.ARQ_RX_N_CURRENT_ARQ_FRAME = int.from_bytes(bytes(data_in[2:4]), "big") #get current number of total frames
static.ARQ_N_ARQ_FRAMES_PER_DATA_FRAME = int.from_bytes(bytes(data_in[4:6]), "big") # get get total number of frames
static.ARQ_BURST_PAYLOAD_CRC = data_in[6:8]
logging.debug("----------------------------------------------------------------")
logging.debug("ARQ_N_FRAME: " + str(static.ARQ_N_FRAME))
logging.debug("ARQ_N_RX_FRAMES_PER_BURSTS: " + str(static.ARQ_N_RX_FRAMES_PER_BURSTS))
logging.debug("ARQ_RX_N_CURRENT_ARQ_FRAME: " + str(static.ARQ_RX_N_CURRENT_ARQ_FRAME))
logging.debug("ARQ_N_ARQ_FRAMES_PER_DATA_FRAME: " + str(static.ARQ_N_ARQ_FRAMES_PER_DATA_FRAME))
logging.debug("static.ARQ_BURST_PAYLOAD_CRC: " + str(static.ARQ_BURST_PAYLOAD_CRC))
logging.debug("----------------------------------------------------------------")
arq_percent_burst = int((static.ARQ_N_FRAME / static.ARQ_N_RX_FRAMES_PER_BURSTS)*100)
arq_percent_frame = int(((static.ARQ_RX_N_CURRENT_ARQ_FRAME)/static.ARQ_N_ARQ_FRAMES_PER_DATA_FRAME)*100)
logging.info("ARQ | RX | ARQ FRAME [" + str(static.ARQ_N_FRAME) + "/" + str(static.ARQ_N_RX_FRAMES_PER_BURSTS) + "] [" + str(arq_percent_burst).zfill(3) + "%] --- TOTAL [" + str(static.ARQ_RX_N_CURRENT_ARQ_FRAME) + "/" + str(static.ARQ_N_ARQ_FRAMES_PER_DATA_FRAME) + "] [" + str(arq_percent_frame).zfill(3) + "%]" )
#allocate ARQ_RX_FRAME_BUFFER as a list with "None" if not already done. This should be done only once per burst!
# here we will save the N frame of a data frame to N list position so we can explicit search for it
if static.ARQ_N_ARQ_FRAMES_PER_DATA_FRAME != len(static.ARQ_RX_FRAME_BUFFER) and static.ARQ_RX_N_CURRENT_ARQ_FRAME == 1:
for i in range(0,static.ARQ_N_ARQ_FRAMES_PER_DATA_FRAME+1):
static.ARQ_RX_FRAME_BUFFER.insert(i,None)
#allocate ARQ_RX_BURST_BUFFER as a list with "None" if not already done. This should be done only once per burst!
# here we will save the N frame of a burst to N list position so we can explicit search for it
if static.ARQ_N_RX_FRAMES_PER_BURSTS != len(static.ARQ_RX_BURST_BUFFER) and static.ARQ_N_FRAME == 1:
for i in range(0,static.ARQ_N_RX_FRAMES_PER_BURSTS+1):
static.ARQ_RX_BURST_BUFFER.insert(i,None)
# now we add the incoming data to the specified position in our lists
static.ARQ_RX_BURST_BUFFER[static.ARQ_N_FRAME] = bytes(data_in)
static.ARQ_RX_FRAME_BUFFER[static.ARQ_RX_N_CURRENT_ARQ_FRAME] = bytes(data_in)
# -------------------------- ARQ BURST CHECKER
# run only if we recieved all ARQ FRAMES per ARQ BURST
burst_total_payload = bytearray()
if static.ARQ_N_FRAME == static.ARQ_N_RX_FRAMES_PER_BURSTS and static.ARQ_RX_BURST_BUFFER.count(None) == 1: #if received bursts are equal to burst number in frame
# #here we get the total payload for the frame to calculate the crc
# for n_raw_frame in range(1,len(static.ARQ_RX_BURST_BUFFER)):
# # we need to check if we have a None or received data in list
# if static.ARQ_RX_BURST_BUFFER[n_raw_frame] != None:
# burst_frame = static.ARQ_RX_BURST_BUFFER[n_raw_frame] #get burst frame
# burst_payload = burst_frame[8:] #remove frame type and burst CRC #4
# burst_total_payload = burst_total_payload + burst_payload #stick bursts together
# ------------------ calculate CRC of BURST
# burst_payload_crc = helpers.get_crc_16(burst_total_payload)
# IF BURST CRC IS CORRECT, APPEND BURST TO BUFFER AND SEND ACK FRAME
# if burst_payload_crc == data_in[6:8]:
#BUILDING ACK FRAME FOR BURST -----------------------------------------------
# #ack_payload = bytes(burst_payload_crc)
# ack_frame = b'<'+ bytes(burst_payload_crc) # < = 60
# ack_buffer = bytearray(static.ARQ_ACK_PAYLOAD_PER_FRAME)
# ack_buffer[:len(ack_frame)] = ack_frame # set buffersize to length of data which will be send
#TRANSMIT ACK FRAME FOR BURST-----------------------------------------------
# logging.info("ARQ | TX | ARQ BURST ACK [" + str(data_in[6:8].hex()) +"]")
# modem.transmit_arq_ack(ack_buffer)
# ----------------------------------------------------------------
# static.ARQ_RX_BURST_BUFFER = [] # CLEAR RX BURST BUFFER AFTER SENDING DATA
# else: #IF burst payload crc and input crc are NOT equal
# logging.info("ARQ BURST CRC NOT EQUAL! [" + str(data_in[6:8]) + "]")
# static.ARQ_RX_BURST_BUFFER = [] #erase ARQ RX Burst buffer
# --------------- CHECK IF WE ARE MISSING FRAMES -------------------------------------------
for burst in range(1,len(static.ARQ_RX_BURST_BUFFER)):
if static.ARQ_RX_BURST_BUFFER[burst] == None:
print("Missing frames:" + str(burst))
logging.info("ARQ | TX | ARQ BURST ACK")
ack_buffer = bytearray(static.ARQ_ACK_PAYLOAD_PER_FRAME)
modem.transmit_arq_ack(ack_buffer)
static.ARQ_RX_BURST_BUFFER = []
#if nframes are unequal to expected frames per burst #just a placeholder at this time
else:
pass
# ---------------------------- FRAME MACHINE
# --------------- CHECK IF WE ARE MISSING FRAMES -------------------------------------------
#for frame in range(1,len(static.ARQ_RX_FRAME_BUFFER)):
# if static.ARQ_RX_FRAME_BUFFER[frame] == None:
# print("Missing frames:" + str(frame))
# --------------- IF LIST NOT CONTAINS "None" stick everything together
complete_data_frame = bytearray()
if static.ARQ_RX_FRAME_BUFFER.count(None) == 1: ## 1 because position 0 of list will alaways be None in our case
for frame in range(1,len(static.ARQ_RX_FRAME_BUFFER)):
raw_arq_frame = static.ARQ_RX_FRAME_BUFFER[frame]
arq_frame_payload = raw_arq_frame[8:]
# -------- DETECT IF WE RECEIVED A FRAME HEADER THEN SAVE DATA TO GLOBALS
if arq_frame_payload[2:4].startswith(static.FRAME_BOF):
static.FRAME_CRC = arq_frame_payload[:2]
static.ARQ_FRAME_BOF_RECEIVED = True
arq_frame_payload = arq_frame_payload.split(static.FRAME_BOF)
arq_frame_payload = arq_frame_payload[1]
# -------- DETECT IF WE RECEIVED A FRAME FOOTER THEN SAVE DATA TO GLOBALS
if arq_frame_payload.rstrip(b'\x00').endswith(static.FRAME_EOF):
static.ARQ_FRAME_EOF_RECEIVED = True
arq_frame_payload = arq_frame_payload.split(static.FRAME_EOF)
arq_frame_payload = arq_frame_payload[0]
# --------- AFTER WE SEPARATED BOF AND EOF, STICK EVERYTHING TOGETHER
complete_data_frame = complete_data_frame + arq_frame_payload
#check if Begin of Frame BOF and End of Frame EOF are received, then start calculating CRC and sticking everything together
if static.ARQ_FRAME_BOF_RECEIVED == True and static.ARQ_FRAME_EOF_RECEIVED == True:
frame_payload_crc = helpers.get_crc_16(complete_data_frame)
#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("ARQ | RX | DATA FRAME SUCESSFULLY RECEIVED! - TIME TO PARTY")
#append received frame to RX_BUFFER
static.RX_BUFFER.append(complete_data_frame)
#BUILDING ACK FRAME FOR DATA FRAME -----------------------------------------------
ack_frame = b'='+ bytes(static.FRAME_CRC) # < = 61
ack_buffer = bytearray(static.ARQ_ACK_PAYLOAD_PER_FRAME)
ack_buffer[:len(ack_frame)] = ack_frame # set buffersize to length of data which will be send
#TRANSMIT ACK FRAME FOR BURST-----------------------------------------------
logging.info("ARQ | TX | ARQ DATA FRAME ACK [" + str(static.FRAME_CRC.hex()) +"]")
modem.transmit_arq_ack(ack_buffer)
# clearing buffers and resetting counters
static.ARQ_RX_BURST_BUFFER = []
static.ARQ_RX_FRAME_BUFFER = []
static.ARQ_FRAME_BOF_RECEIVED = False
static.ARQ_FRAME_EOF_RECEIVED = False
static.ARQ_N_ARQ_FRAMES_PER_DATA_FRAME = 0
#print("----------------------------------------------------------------")
#print(static.RX_BUFFER[-1])
#print("----------------------------------------------------------------")
else:
logging.info("ARQ | RX | DATA FRAME NOT SUCESSFULLY RECEIVED!")
def burst_ack_received():
logging.debug("ARQ | RX | BURST ACK RCVD!")
static.ARQ_ACK_TIMEOUT = 1 #Force timer to stop waiting
static.ARQ_ACK_RECEIVED = 1 #Force data loops of TNC to stop and continue with next frame
def frame_ack_received():
logging.debug("ARQ | RX | FRAME ACK RCVD!")
static.ARQ_ACK_TIMEOUT = 1 #Force timer to stop waiting
static.ARQ_FRAME_ACK_RECEIVED = 1 #Force data loops of TNC to stop and continue with next frame
def transmit(data_out):
static.ARQ_PAYLOAD_PER_FRAME = static.FREEDV_DATA_PAYLOAD_PER_FRAME - 8 #3 ohne ARQ_TX_N_FRAMES_PER_BURST
frame_header_length = 4
n_arq_frames_per_data_frame = (len(data_out)+frame_header_length) // static.ARQ_PAYLOAD_PER_FRAME + ((len(data_out)+frame_header_length) % static.ARQ_PAYLOAD_PER_FRAME > 0)
frame_payload_crc = helpers.get_crc_16(data_out)
# This is the total frame with frame header, which will be send
data_out = frame_payload_crc + static.FRAME_BOF + data_out + static.FRAME_EOF
# 2 2 N 2
# --------------------------------------------- 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("ARQ | TX | DATA FRAME --- BYTES: " + str(len(data_out)) + " ARQ FRAMES: " + str(static.TX_BUFFER_SIZE))
# --------------------------------------------- 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:
static.ARQ_TX_N_FRAMES_PER_BURST = get_n_frames_per_burst()
# ----------- CREATE FRAME TOTAL PAYLOAD TO BE ABLE TO CREATE CRC FOR IT
try: # DETECT IF LAST BURST TO PREVENT INDEX ERROR OF BUFFER
for i in range(static.ARQ_TX_N_FRAMES_PER_BURST): # Loop through TX_BUFFER LIST
len(static.TX_BUFFER[static.ARQ_N_SENT_FRAMES + i]) #we calculate the length to trigger a list index error
except IndexError: # IF LAST BURST DETECTED BUILD CRC WITH LESS FRAMES AND SET static.ARQ_TX_N_FRAMES_PER_BURST TO VALUE OF REST!
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
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
else:
static.ARQ_TX_N_FRAMES_PER_BURST = (static.TX_BUFFER_SIZE % static.ARQ_N_SENT_FRAMES)
# burst_total_payload = bytearray() # reset burst_total_payload because of possible input remaining of detecting loop one step above
# for i in range(static.ARQ_TX_N_FRAMES_PER_BURST): #bytearray(b'111111111111111111111111222222222222222222222222')
#
# # 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)
# 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
#
# # ----------- GENERATE PAYLOAD CRC FOR ARQ_TX_N_FRAMES_PER_BURST
# static.ARQ_BURST_PAYLOAD_CRC = helpers.get_crc_16(burst_total_payload)
#--------------------------------------------- N ATTEMPTS TO SEND BURSTS IF ACK RECEPTION FAILS
for static.TX_N_RETRIES in range(static.TX_N_MAX_RETRIES):
if static.ARQ_N_SENT_FRAMES+1 <= static.TX_BUFFER_SIZE:
logging.info("ARQ | TX | F:[" + str(static.ARQ_N_SENT_FRAMES+1) + "-" + str(static.ARQ_N_SENT_FRAMES + static.ARQ_TX_N_FRAMES_PER_BURST) + "] | T:[" + str(static.ARQ_N_SENT_FRAMES) + "/" + str(static.TX_BUFFER_SIZE) + "] [" + str(int(static.ARQ_N_SENT_FRAMES/(static.TX_BUFFER_SIZE)*100)).zfill(3) + "%] | A:[" + str(static.TX_N_RETRIES+1) + "/" + str(static.TX_N_MAX_RETRIES) + "]")
# lets start a thread to transmit nonblocking
TRANSMIT_ARQ_BURST_THREAD = threading.Thread(target=modem.transmit_arq_burst, name="TRANSMIT_ARQ_BURST")
TRANSMIT_ARQ_BURST_THREAD.start()
# lets wait during sending. After sending is finished we will continue
while static.ARQ_STATE == 'SENDING_DATA':
time.sleep(0.05)
# --------------------------- START TIMER FOR WAITING FOR ACK ---> IF TIMEOUT REACHED, ACK_TIMEOUT = 1
#reset timer and ack state
static.ARQ_FRAME_ACK_RECEIVED = 0
static.ARQ_ACK_RECEIVED = 0
static.ARQ_ACK_TIMEOUT = 0
logging.debug("ARQ | RX | WAITING FOR BURST ACK")
static.ARQ_STATE = 'RECEIVING_ACK'
timer = threading.Timer(static.ARQ_ACK_TIMEOUT_SECONDS, arq_ack_timeout)
timer.start()
# --------------------------- WHILE TIMEOUT NOT REACHED AND NO ACK RECEIVED --> LISTEN
while static.ARQ_ACK_TIMEOUT == 0 and static.ARQ_ACK_RECEIVED == 0:
time.sleep(0.01) # lets reduce CPU load a little bit
#print(static.ARQ_STATE)
if static.ARQ_ACK_RECEIVED == 0 and static.ARQ_ACK_TIMEOUT == 1:
#logging.info("ARQ | RX | ACK TIMEOUT | SENDING ARQ BURST AGAIN")
pass
#--------------- BREAK LOOP IF ACK HAS BEEN RECEIVED OR FRAME ACK HAS BEEN RECEIVED
if static.ARQ_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_PER_BURST
break
#--------------- BREAK LOOP IF FRAME ACK HAS BEEN RECEIVED EARLIER AS EXPECTED
if static.ARQ_FRAME_ACK_RECEIVED == 1:
logging.info("ARQ | RX | EARLY FRAME ACK RECEIVED - STOPPING TX")
#static.ARQ_N_SENT_FRAMES = #static.TX_BUFFER_SIZE
static.ARQ_N_SENT_FRAMES = static.ARQ_N_SENT_FRAMES + static.ARQ_TX_N_FRAMES_PER_BURST
break
# ----------- if no ACK received and out of retries.....stop frame sending
if static.ARQ_ACK_RECEIVED == 0 and static.ARQ_FRAME_ACK_RECEIVED == 0 and static.ARQ_ACK_TIMEOUT == 1:
logging.info("ARQ | TX | NO BURST OR FRAME ACK RECEIVED | DATA SHOULD BE RESEND!")
break
#-------------------------BREAK TX BUFFER LOOP IF ALL PACKETS HAVE BEEN SENT AND WE GOT A FRAME ACK
if static.ARQ_N_SENT_FRAMES == static.TX_BUFFER_SIZE and static.ARQ_FRAME_ACK_RECEIVED == 1:
logging.info("ARQ | RX | REGULAR FRAME ACK RECEIVED - DATA TRANSMITTED!")
break
# IF TX BUFFER IS EMPTY / ALL FRAMES HAVE BEEN SENT --> HERE WE COULD ADD AN static.VAR for IDLE STATE
logging.info("ARQ | TX | BUFFER EMPTY")
# - RESET COUNTERS
static.ARQ_N_SENT_FRAMES = 0
static.ARQ_TX_N_FRAMES_PER_BURST = 0
static.ARQ_ACK_RECEIVED = 0
static.ARQ_FRAME_ACK_RECEIVED = 0
# 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(1,10)
#n_frames_per_burst = 1
return n_frames_per_burst