ComLib

A library for communicating between two computers in a server and client relation

Contents:

Dependencies
Functions

Dependencies

ecnet (Third Party)

Functions

open()
getAddress()
sendRequest()
sendResponse()
broadcast()

open()

Opens secure connection on modem on specified side

function comlib.open(side)
    ...
    return sModem
end

Arguments:

Name	Type	Default	Description
side	`string`	`nil`	Side of the modem for the secure connection.

Returns:

Type	Description
`table`	Instance of secure modem object.

Example:

local comlib = require("comlib")
local sModem = comlib.open("front")

This would open a secure connection on the modem at the front of the computer, accessible with the sModem variable.

getAddress()

Returns address of current computer

function comlib.getAddress()
    ...
    return address
end

Arguments: nil

Returns:

Type	Description
`string`	Address of current computer.

Example:

local comlib = require("comlib")
print(comlib.getAddress())

This would print the address of the current computer, e.g. b38a:a780:bd82:cd56:195f

sendRequest()

Creates a request packet with the status REQUEST, sends it to the specified address and will wait for and return a response packet. This function will return -1 if the receiving operation times out.

function sendRequest(address, header, contents, timeout)
    ...
    return response
end

Arguments:

Name	Type	Default	Description
address	`string`	`nil`	Address of the receiver.
header	`string`	`nil`	Header of the request packet.
contents	`table`	`nil`	Additional contents of the request packet.
timeout	`number`	`3`	Number of seconds before the timeout would get triggered.

Note

Additional contents depend on the type of request and what the receiver is expecting

Returns:

Type	Description
`table`	Received response packet.

Warning

This function returns -1 instead of the above, if one of these conditions is met:

Not being able to connect to the address.
Sender of the response packet is nil.
Deserialized response packet is nil.
If response header does not match request header.

Example:

local comlib = require("comlib")
comlib.sendRequest("873b:a87c:fe93:846:c9d3", "GET", {key = "Hello"}, 3)

In this example, a request packet with the header "GET" and the contents {key = "Hello"} will be sent to "873b:a87c:fe93:846:c9d3". For this example, we will assume that the receiver expects key in contents, which is why key = "Hello" is specified here. If no response is received within 3 seconds, the function would timeout and return -1.

Created packet: {head = "GET", status = "REQUEST", contents = {key = "Hello"}}

sendResponse()

Sends a response to the specified receiver with specified head, status and additional contents

function comlib.sendResponse(address, header, status, contents)
    ...
end

Arguments:

Name	Type	Default	Description
address	`string`	`nil`	Address of the receiver.
header	`string`	`nil`	Header of the response packet.
status	`string`	`nil`	Status of the response packet (e.g. “OK” or “FAIL”).
contents	`table`	`nil`	Additional contents to add to the packet.

Note

Additional contents depend on the type of response and what the receiver is expecting

Returns: nil

Example:

local comlib = require("comlib")
comlib.sendResponse("b38a:a780:bd82:cd56:195f", "GET", "OK", {value = "Test"})

In this example, a response packet with the header "GET" and the status "OK" will be sent to "b38a:a780:bd82:cd56:195f". For this example, we will assume that the receiver expects value in contents, which is why value = "Test" is specified here.

Created packet: {head = "GET", status = "OK", contents = {value = "Test"}}

broadcast()

Broadcasts a request to multiple receivers and collects all responses. If a response of a receiver fails (sendRequest returns -1), its response will fall back to this one: {head = header, status = "FAIL", contents = {}}.

Note

This function calls sendRequest() for each receiver.

function comlib.broadcast(addresses, header, contents, timeout)
  ...
  return responses
end

Arguments:

Name	Type	Default	Description
addresses	`table`	`nil`	Addresses of the receivers.
header	`string`	`nil`	Header of the response packet.
contents	`table`	`nil`	Additional contents to add to the packet.
timeout	`number`	`3`	Number of seconds before the timeout would get triggered.

Note

Additional contents depend on the type of response and what the receiver is expecting

Returns:

Type	Description
`table`	Received response packets.

Example:

local comlib = require("comlib")
local responses = {}
local receivers = {
  "01ae:4a1e:0195:6e6e:56af",
  "e990:4b07:961f:0b4b:c50a:",
  "7a57:2c08:9d08:7bac:91ff"
}

responses = comlib.broadcast(receivers, "TEST", {})

This would send the packet {head = "TEST", status = "REQUEST", contents = {}} to all three specified receivers and would store there responses in responses.