351 lines
7.1 KiB
Markdown
351 lines
7.1 KiB
Markdown
mqtt-packet [](https://travis-ci.org/mqttjs/mqtt-packet)
|
|
===========
|
|
|
|
Encode and Decode MQTT 3.1.1 packets the node way.
|
|
|
|
[](https://github.com/feross/standard)
|
|
|
|
* <a href="#installation">Installation</a>
|
|
* <a href="#examples">Examples</a>
|
|
* <a href="#packets">Packets</a>
|
|
* <a href="#api">API</a>
|
|
* <a href="#contributing">Contributing</a>
|
|
* <a href="#license">License & copyright</a>
|
|
|
|
This library is tested with node v4, v6 and v7. The last version to support
|
|
older versions of node was mqtt-packet@4.1.2.
|
|
|
|
Installation
|
|
------------
|
|
|
|
```bash
|
|
npm install mqtt-packet --save
|
|
```
|
|
|
|
Examples
|
|
--------
|
|
|
|
### Generating
|
|
|
|
```js
|
|
var mqtt = require('mqtt-packet')
|
|
var object = {
|
|
cmd: 'publish',
|
|
retain: false,
|
|
qos: 0,
|
|
dup: false,
|
|
length: 10,
|
|
topic: 'test',
|
|
payload: 'test' // Can also be a Buffer
|
|
}
|
|
|
|
console.log(mqtt.generate(object))
|
|
// Prints:
|
|
//
|
|
// <Buffer 30 0a 00 04 74 65 73 74 74 65 73 74>
|
|
//
|
|
// Which is the same as:
|
|
//
|
|
// new Buffer([
|
|
// 48, 10, // Header (publish)
|
|
// 0, 4, // Topic length
|
|
// 116, 101, 115, 116, // Topic (test)
|
|
// 116, 101, 115, 116 // Payload (test)
|
|
// ])
|
|
```
|
|
|
|
### Parsing
|
|
|
|
```js
|
|
var mqtt = require('mqtt-packet')
|
|
var parser = mqtt.parser()
|
|
|
|
// Synchronously emits all the parsed packets
|
|
parser.on('packet', function(packet) {
|
|
console.log(packet)
|
|
// Prints:
|
|
//
|
|
// {
|
|
// cmd: 'publish',
|
|
// retain: false,
|
|
// qos: 0,
|
|
// dup: false,
|
|
// length: 10,
|
|
// topic: 'test',
|
|
// payload: <Buffer 74 65 73 74>
|
|
// }
|
|
})
|
|
|
|
parser.parse(new Buffer([
|
|
48, 10, // Header (publish)
|
|
0, 4, // Topic length
|
|
116, 101, 115, 116, // Topic (test)
|
|
116, 101, 115, 116 // Payload (test)
|
|
])
|
|
// Returns the number of bytes left in the parser
|
|
```
|
|
|
|
API
|
|
---
|
|
|
|
* <a href="#generate"><code>mqtt#<b>generate()</b></code></a>
|
|
* <a href="#writeToStream"><code>mqtt#<b>writeToStream()</b></code></a>
|
|
* <a href="#parser"><code>mqtt#<b>parser()</b></code></a>
|
|
|
|
<a name="generate">
|
|
|
|
### mqtt.generate(object)
|
|
|
|
Generates a `Buffer` containing an MQTT packet.
|
|
The object must be one of the ones specified by the [packets](#packets)
|
|
section. Throws an `Error` if a packet cannot be generated.
|
|
|
|
<a name="writeToStream">
|
|
|
|
### mqtt.writeToStream(object, stream)
|
|
|
|
Writes the mqtt packet defined by `object` to the given stream.
|
|
The object must be one of the ones specified by the [packets](#packets)
|
|
section. Emits an `Error` on the stream if a packet cannot be generated.
|
|
On node >= 0.12, this function automatically calls `cork()` on your stream,
|
|
and then it calls `uncork()` on the next tick.
|
|
By default cache for number buffers is enabled.
|
|
It creates a list of buffers for faster write. To disable cache set `mqtt.writeToStream.cacheNumbers = false`.
|
|
Should be set before any `writeToStream` calls.
|
|
|
|
<a name="parser">
|
|
|
|
### mqtt.parser()
|
|
|
|
Returns a new `Parser` object. `Parser` inherits from `EventEmitter` and
|
|
will emit:
|
|
|
|
* `packet`, when a new packet is parsed, according to
|
|
[packets](#packets)
|
|
* `error`, if an error happens
|
|
|
|
<a name="parse">
|
|
|
|
#### Parser.parse(buffer)
|
|
|
|
Parses a given `Buffer` and emits synchronously all the MQTT packets that
|
|
are included. Returns the number of bytes left to parse.
|
|
|
|
If an error happens, an `error` event will be emitted, but no `packet` events
|
|
will be emitted after that. Calling `parse()` again clears the error and
|
|
previous buffer, as if you created a new `Parser`.
|
|
|
|
Packets
|
|
-------
|
|
|
|
This section describes the format of all packets emitted by the `Parser`
|
|
and that you can input to `generate`.
|
|
|
|
### Connect
|
|
|
|
```js
|
|
{
|
|
cmd: 'connect',
|
|
protocolId: 'MQTT', // Or 'MQIsdp' in MQTT 3.1
|
|
protocolVersion: 4, // Or 3 in MQTT 3.1
|
|
clean: true, // Can also be false
|
|
clientId: 'my-device',
|
|
keepalive: 0, // Seconds which can be any positive number, with 0 as the default setting
|
|
username: 'matteo',
|
|
password: new Buffer('collina'), // Passwords are buffers
|
|
will: {
|
|
topic: 'mydevice/status',
|
|
payload: new Buffer('dead') // Payloads are buffers
|
|
}
|
|
}
|
|
```
|
|
|
|
If `protocolVersion` is 3, `clientId` is mandatory and `generate` will throw if
|
|
missing.
|
|
|
|
If `password` or `will.payload` are passed as strings, they will
|
|
automatically be converted into a `Buffer`.
|
|
|
|
### Connack
|
|
|
|
```js
|
|
{
|
|
cmd: 'connack',
|
|
returnCode: 0, // Or whatever else you see fit
|
|
sessionPresent: false // Can also be true.
|
|
}
|
|
```
|
|
|
|
The only mandatory argument is `returnCode`, as `generate` will throw if
|
|
missing.
|
|
|
|
### Subscribe
|
|
|
|
```js
|
|
{
|
|
cmd: 'subscribe',
|
|
messageId: 42,
|
|
subscriptions: [{
|
|
topic: 'test',
|
|
qos: 0
|
|
}]
|
|
}
|
|
```
|
|
|
|
All properties are mandatory.
|
|
|
|
### Suback
|
|
|
|
```js
|
|
{
|
|
cmd: 'suback',
|
|
messageId: 42,
|
|
granted: [0, 1, 2, 128]
|
|
}
|
|
```
|
|
|
|
All the granted qos __must__ be < 256, as they are encoded as UInt8.
|
|
All properties are mandatory.
|
|
|
|
### Unsubscribe
|
|
|
|
```js
|
|
{
|
|
cmd: 'unsubscribe',
|
|
messageId: 42,
|
|
unsubscriptions: [
|
|
'test',
|
|
'a/topic'
|
|
]
|
|
}
|
|
```
|
|
|
|
All properties are mandatory.
|
|
|
|
### Unsuback
|
|
|
|
```js
|
|
{
|
|
cmd: 'unsuback',
|
|
messageId: 42
|
|
}
|
|
```
|
|
|
|
All properties are mandatory.
|
|
|
|
### Publish
|
|
|
|
```js
|
|
{
|
|
cmd: 'publish',
|
|
messageId: 42,
|
|
qos: 2,
|
|
dup: false,
|
|
topic: 'test',
|
|
payload: new Buffer('test'),
|
|
retain: false
|
|
}
|
|
```
|
|
|
|
Only the `topic` property is mandatory.
|
|
Both `topic` and `payload` can be `Buffer` objects instead of strings.
|
|
`messageId` is mandatory for `qos > 0`.
|
|
|
|
### Puback
|
|
|
|
```js
|
|
{
|
|
cmd: 'puback',
|
|
messageId: 42
|
|
}
|
|
```
|
|
|
|
The only mandatory property is `messageId`, as `generate` will throw if
|
|
missing.
|
|
|
|
### Pubrec
|
|
|
|
```js
|
|
{
|
|
cmd: 'pubcomp',
|
|
messageId: 42
|
|
}
|
|
```
|
|
|
|
The only mandatory property is `messageId`, as `generate` will throw if
|
|
missing.
|
|
|
|
### Pubrel
|
|
|
|
```js
|
|
{
|
|
cmd: 'pubrel',
|
|
messageId: 42
|
|
}
|
|
```
|
|
|
|
The only mandatory property is `messageId`, as `generate` will throw if
|
|
missing.
|
|
|
|
### Pubcomp
|
|
|
|
```js
|
|
{
|
|
cmd: 'pubcomp',
|
|
messageId: 42
|
|
}
|
|
```
|
|
|
|
The only mandatory property is `messageId`, as `generate` will throw if
|
|
missing.
|
|
|
|
### Pingreq
|
|
|
|
```js
|
|
{
|
|
cmd: 'pingreq'
|
|
}
|
|
```
|
|
|
|
### Pingresp
|
|
|
|
```js
|
|
{
|
|
cmd: 'pingresp'
|
|
}
|
|
```
|
|
|
|
### Disconnect
|
|
|
|
```js
|
|
{
|
|
cmd: 'disconnect'
|
|
}
|
|
```
|
|
|
|
<a name="contributing"></a>
|
|
|
|
Contributing
|
|
------------
|
|
|
|
mqtt-packet is an **OPEN Open Source Project**. This means that:
|
|
|
|
> Individuals making significant and valuable contributions are given commit-access to the project to contribute as they see fit. This project is more like an open wiki than a standard guarded open source project.
|
|
|
|
See the [CONTRIBUTING.md](https://github.com/mqttjs/mqtt-packet/blob/master/CONTRIBUTING.md) file for more details.
|
|
|
|
### Contributors
|
|
|
|
mqtt-packet is only possible due to the excellent work of the following contributors:
|
|
|
|
<table><tbody>
|
|
<tr><th align="left">Matteo Collina</th><td><a href="https://github.com/mcollina">GitHub/mcollina</a></td><td><a href="http://twitter.com/matteocollina">Twitter/@matteocollina</a></td></tr>
|
|
<tr><th align="left">Adam Rudd</th><td><a href="https://github.com/adamvr">GitHub/adamvr</a></td><td><a href="http://twitter.com/adam_vr">Twitter/@adam_vr</a></td></tr>
|
|
<tr><th align="left">Peter Sorowka</th><td><a href="https://github.com/psorowka">GitHub/psorowka</a></td><td><a href="http://twitter.com/psorowka">Twitter/@psorowka</a></td></tr>
|
|
</tbody></table>
|
|
|
|
License
|
|
-------
|
|
|
|
MIT
|