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Generic TCP Server for external requests
#1
I am not a big fan of the example : http://openrb.com/example-lm2-as-tcp-ser...-requests/

It uses the following principle :
- the resident script is the TCP server :
  - manages TCP clients
  - listen on UDP for internal LM requests
- the resident script do receive client request and process them
- other LM scripts/events use UDP to communicate to the TCP server and transmit data to be sent

For me, there is some limitations :
- only 5 messages per second are read by TCP server on the UDP side
- data can be lost with UDP

As I need to send a lot of data, I did use the internal storage instead of UDP.
I am sharing this as a generic TCP server that can be customized for every need.

So the idea is the following :
- the resident script is the TCP server :
  - manage TCP clients
  - read the internal storage for internal LM requests
- the resident script do receive client request and process them
- other LM scripts/events use internal storage to communicate to the TCP server and transmit data to be sent


First, the User Library :
Code:
-- TCP Server user library --general debug tcp_debug = false --networking debug tcp_debug_tcp = false -- additionnal debug tcp_debug_verbose = false --store a message to be send into the queue function tcp_queue(message)  if (tcp_debug_verbose) then    alert("tcp_queue : "..message)  end  local tcp_Q = storage.get('tcpQ')  table.insert(tcp_Q,message)     storage.set('tcpQ', tcp_Q) end

Now the resident script with sleep interval 0 :
Code:
require('copas') --[[ Resident script for TCP server Manage client connexions Receive requests from clients Also send events through tcpQ storage debug variables are set in the user library ]]-- --communication port to listen on local tcp_port = 6789 if (tcp_debug) then  alert ("TCP Server start") end -- send a message to the peers function tcp_sendmessage(message)  if (tcp_debug_tcp) then    alert ("tcp_sendmessage : ".. message)     end  for id, sock in pairs(tcp_clients) do    sock:send(message .. '\r\n')  end end     -- incoming data handler, manage each message sent by clients to LM function tcp_datahandler(sock, data)  local ip, port  ip, port = sock:getpeername()      if tcp_debug_tcp then    alert('tcp_datahandler receive data from %s:%d - %s', ip, port, data)  end -- add your code to process data end -- connection handler, manage new peers function tcp_connhandler(sock)  -- enable keep-alive to check for disconnect events  sock:setoption('keepalive', true)  local ip, port, data, err, id  -- get ip and port from socket  ip, port = sock:getpeername()  -- client id  id = string.format('%s:%d', ip, port)  alert('tcp_connhandler connection from %s', id)  -- save socket reference  tcp_clients[ id ] = sock  -- main reader loop  while true do    -- wait for single line of data (until \n, \r is ignored)    data, err = copas.receive(sock, '*l')    -- error while receiving    if err then      alert('tcp_connhandler closed connection from %s:%d', ip, port)      -- remove socket reference      tcp_clients[ id ] = nil      return    end    -- handle data frame    tcp_datahandler(sock, data)  end end -- init server handler if not tcp_ready then    if (tcp_debug) then    alert ("TCP Server init start")  end     -- list of client sockets  tcp_clients = {}  --variable for the queue  tcp_Q = {}  --empty the storage queue  storage.set('tcpQ', tcp_Q)  -- bind to port  tcp_tcpserver = socket.bind('*', tcp_port)  -- error while binding, try again later  if not tcp_tcpserver then    os.sleep(5)    error('tcp server realization init error: cannot bind')  end  -- set server connection handler  copas.addserver(tcp_tcpserver, tcp_connhandler)  tcp_ready = true    if (tcp_debug) then    alert ("TCP Server init end")     end end -- loop to manage packets while true do  --retreive the queue  tcp_Q = storage.get('tcpQ')  storage.set('tcpQ', {})  --sending the queue  for index, value in ipairs(tcp_Q) do    if tcp_debug then         alert("TCP Server sending item "..tostring(index).." : "..tostring(value))    end    tcp_sendmessage(value)  end  --wait for tcp request during 0.1s  copas.step(0.1) end if (tcp_debug) then  alert ("TCP Server closed") end

Event base script :
Code:
value = knxdatatype.decode(event.datahex, dt.bool) tcp_queue('Lamp is' .. (value and 'ON' or 'OFF'))

Matthieu
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Messages In This Thread
Generic TCP Server for external requests - by Matt - 14.07.2015, 06:57

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