https://github.com/luxedo/node-spos
An specification and implementation of an encoder/decoder for serializing small payloads.
https://github.com/luxedo/node-spos
Last synced: 15 days ago
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An specification and implementation of an encoder/decoder for serializing small payloads.
- Host: GitHub
- URL: https://github.com/luxedo/node-spos
- Owner: luxedo
- License: mit
- Created: 2020-03-16T21:57:47.000Z (about 5 years ago)
- Default Branch: master
- Last Pushed: 2024-06-16T10:56:49.000Z (11 months ago)
- Last Synced: 2025-03-17T03:47:26.746Z (about 1 month ago)
- Language: JavaScript
- Size: 1.51 MB
- Stars: 0
- Watchers: 1
- Forks: 1
- Open Issues: 2
-
Metadata Files:
- Readme: README.md
- License: LICENSE.md
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README
# node-SPOS
> **SPOS** stands for **Small Payload Object Serializer**.
[](https://codecov.io/gh/luxedo/node-spos) [](https://www.codefactor.io/repository/github/luxedo/node-spos) [](https://badge.fury.io/js/spos) [](https://opensource.org/licenses/MIT)
> This is and implementation of the `SPOS` specification in `Javascript`. See
> HTTPS://github.com/luxedo/SPOS for details.
`SPOS` is a tool for serializing simple objects. This tool focuses in
maintaining a consistent payload size while sacrificing precision.
Applications with limited bandwidth like [LoRa](https://lora-alliance.org/)
or [Globalstar](https://www.globalstar.com/en-us/) are ideal candidates
for `SPOS`. `SPOS` has implementations for
python3 ([SPOS](https://github.com/luxedo/SPOS)) and
node.js ([node-SPOS](https://github.com/luxedo/node-SPOS)).
> In this document we will be using JSON notation to describe payload
> specifications and payload data. For each programming language there's
> usually an analogous data type for each notation. Eg:
> `object <=> dict`, `array <=> list`, etc.
## Quick Start
To encode data, `SPOS` needs two arguments to serialize the data: The `payload_data` to be serialized and the [payload specification](https://github.com/luxedo/SPOS#Payload-specification).
```javascript
const spos = require("spos")
payload_spec = {
name: "example payload",
version: 1,
body: [{
type: "integer",
key: "constant_data",
value: 2, // 10
bits: 2
}, {
type: "integer",
key: "int_data",
bits: 6
}, {
type: "float",
key: "float_data",
bits: 6
}]
payload_data = {
int_data: 13, // 001101
float_data: 0.6 // 010011 (19/32 or 0.59375)
// padding 000
}
message = spos.binEncode(payload_data, payload_spec, output="bin")
"1000110110011000"
```
Decoding data
```javascript
const spos = require("spos")
const payload_spec = {
name: "example payload",
version: 1,
body: [{
type: "integer",
key: "constant_data",
value: 2,
bits: 2
}, {
type: "integer",
key: "int_data",
bits: 6
}, {
type: "float",
key: "float_data",
bits: 6
}]
const message = "1000110110011000"
const decoded = spos.decode(message, payload_spec, input="bin")
decoded
{
meta: {
name: "example payload",
version: 1,
},
body: {
constant_data: 2,
int_data: 13,
float_data: 0.59375
}
}
```
## Installation
```bash
npm install spos
```
## Functions
```javascript
/*
* Encodes the payloadData according to payloadSpec.
* @param {array} payloadData The object containing the values to be encoded.
* @param {object} payloadSpec Payload specifications.
* @param {string} output the output message format (bytes|hex|bin)
* @return {Uint8Array|hex string|bin string} message
*/
function encode(payloadData, payloadSpec, output = "bytes")
```
```javascript
/*
* Decodes message according to payloadSpec.
* @param {Uint8Array|hex string|bin string} message
* @param {object} payloadSpec Payload specifications.
* @param {string} input the input message format (bytes|hex|bin)
* @return {object} decoded The object containing the decoded values.
*/
function decode(message, payloadSpec, input = "bytes")
```
```javascript
/*
* Decodes message according to one payloadSpec in payloadSpecs.
* @param {Uint8Array|hex string|bin string} message
* @param {array} payloadSpecs Array of payload specifications.
* @param {string} input the input message format (bytes|hex|bin)
* @return {object} decoded The object containing the decoded values.
*/
function decodeFromSpecs(message, payloadSpecs, input = "bytes")
```
```javascript
/*
* Validates a payload specification, throwing errors if it is malformed.
* @param {payloadSpec} block The block to be validated.
* @throws ReferenceError, RangeError
*/
function validatePayloadSpec(payloadSpec)
```
## License
> MIT License
>
> Copyright (c) 2020 [Luiz Eduardo Amaral]([email protected])
>
> Permission is hereby granted, free of charge, to any person obtaining a copy
> of this software and associated documentation files (the "Software"), to deal
> in the Software without restriction, including without limitation the rights
> to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> copies of the Software, and to permit persons to whom the Software is
> furnished to do so, subject to the following conditions:
>
> The above copyright notice and this permission notice shall be included in all
> copies or substantial portions of the Software.
>
> THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
> AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
> SOFTWARE.