floodnet

fooldnet

A Mesh Network module for node.js that uses redis.

How To Install

npm install floodnet

API

.setup(config [*object], callback [function])

You MUST call this function in order to start the module correctly.

If config object is not given, the module will run with default values.

Config Object

{
    host: '127.0.0.1', // default
    port: 6379, // default
    prefix: '__floodnet__' // default
    reconnect: true // default
    heartbeatInterval: 0 // default
    logger: null // default
    options: null // default
}

host is the IP address that redis is running.

port is the port number that redis is listening to.

prefix is a string value to be used as a prefix for redis' pubsub key.

reconnect is a boolean value to switch on/off auto-reconnecting when the connection to redis is unexpectedly closed.

heartbeatInterval is a interval number in millisecond to check the availability of other mesh nodes in the same channel. By setting this to 0, you can turn this feature off.

logger is a logging module object that can be given to log internal logs.

NOTE: Supported logging modules:

1. winston

2. log4js

3. gracelog

Example for winston:

var winston = require('winston');
var flood = require('floodnet');
var config = {
    logger: winston
};
flood.setup(config, function () {
 
});

Example for log4js:

var log4 = require('log4js');
var flood = require('floodnet');
var config = {
    logger: log4.getLogger()
};
flood.setup(config, function () {
 
});

Example for winston:

var gracelog = require('gracelog');
var flood = require('floodnet');
var config = {
    logger: gracelog.create()
};
flood.setup(config, function () {
 
});

options is an object to configure redis client. The details are shown below.

Option Object

These optional values are used to optionally configure redis driver.

options: {
        parser: [javascript]
        return_buffers: [bool] // default to false: returns buffer all commands
        detect_buffers: [bool] // default to false: returns buffer per command
        socket_nodelay: [bool] // defaults to true: if set to false, it will not call setNoDelay() on the TCP stream resulting in more throughput at the cost of more latency
        socket_keepalive: [bool] // defaults to true
        no_ready_check: [bool] // defaults to false
        enable_offline_queue: [bool] // defaults to true
        retry_max_delay: [number] // defaults to null: provided in milliseconds
        connet_timeout: [number] // defaults to false: provided in milliseconds
        max_attemps: [number] // defaults to null
        auth_pass: [string] // defaults to null
        family: [string] // defaults to IPv4
}

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.id()

Returns a unique ID of floodnet module.

This ID is unique per process.

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.subscribe(channel [string], handler [function])

Joins a meshnet work channel.

handler function will be called on each message recieved in the channel from the other mesh nodes.

NOTE: When your application process successfully subscribes to a channel, it will publish a hello message to the other mesh nodes in the channel.

handler function

The module will be passing 2 arguments to handler function on each message recieved.

• key [string]: A key that is used to handle pub/sub for the message recieved.

• message [object]: A published message from another mesh node in the same channel.

message object

{
    id: 'xxxxxx-yyyyyyy-zzzzzzz' // an ID of the mesh node that published the message
    data: ''/{} // a data that is sent either a string or an object
}

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.unsubscribe(channel [string])

Leaves the channel and stops revieving messages from the other mesh nodes.

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.publish(channel [string], message [mix])

Sends a message to the other nodes in the same channel.

message can either be a string or an object.

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.exit(callback [function])

Gracefully closes the connection to redis and stops all pub/sub operations.

This function waits for all pending messages in the memory before it terminates the connection to redis.

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Events

floodnet module emits some events.

connect

connect event is emitted when the module is connected to redis and is ready to send and recieve packets.

The listener callback will have a string passed from the event.

The string values are either pub or sub to indicate either publish connection or subscribe connection.

NOTE: When the module is set up, both pub and sub will be emitted.

var flood = require('floodnet');
flood.on('connect', function (type) {
    console.log(type);
});

end

end event will be emitted when the module is closing the connection to redis.

Calling .exit() will also cause this event to be emitted.

The listener callback will have a string passed from the event.

The string values are either pub or sub to indicate either publish connection or subscribe connection.

NOTE: When the module is closing the connections, both pub and sub will be emitted.

var flood = require('floodnet');
flood.on('end', function (type) {
    console.log(type);
});

nodeAdded

nodeAdded event will be emitted when there is a new mesh node in the same channel.

The listener callback will have 1 argument which is the ID of the new added mesh node.

NOTE: Even if heartbeatInterval is set to 0, this event WILL be emitted

var flood = require('floodnet');
flood.on('nodeAdded', function (newNodeId) {
    // do something
});

nodeRemoved

nodeRemoved event will be emitted when a mesh node in the same channel has timed out and considered offline.

The listener callback will have 1 argument which is the ID of the removed mesh node.

NOTE: Even if heartbeatInterval is set to 0, this event WILL be emitted

var flood = require('floodnet');
flood.on('nodeRemoved', function (newNodeId) {
    // do something
});

error

error event will be emitted when there is an exception or when the module loses its connection to redis unexpectedly.

The listener callback will have 2 arguments passed. The first argument is an error object and the second argument is the connection type (pub/sub).

var flood = require('floodnet');
flood.on('error', function (error, type) {
    console.error(error, type);
});

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