@geckos.io/typed-array-buffer-schema
Version:
A Schema based Object to Buffer converter
187 lines (136 loc) • 6.05 kB
Markdown
<div align="center">
<img src="readme/logo.png" alt="logo" height="150">
[](https://www.npmjs.com/package/@geckos.io/typed-array-buffer-schema)
[](https://github.com/geckosio/typed-array-buffer-schema/actions?query=workflow%3ACI)
[](https://github.com/geckosio/typed-array-buffer-schema/commits/master)
[](https://www.npmjs.com/package/@geckos.io/typed-array-buffer-schema)
[](https://codecov.io/gh/geckosio/typed-array-buffer-schema)
[](https://www.typescriptlang.org/)
</div>
---
Checkout this short introduction video on YouTube!
https://youtu.be/TBd1miOrLPQ
Install from npm.
```console
npm install @geckos.io/typed-array-buffer-schema
```
Or use the bundled version.
```html
<script src="https://unpkg.com/@geckos.io/typed-array-buffer-schema@1.0.2/bundle/typed-array-buffer-schema.js"></script>
<script>
const { BufferSchema, Model } = Schema
const { uint8, int16, uint16, int64, string8, ...more } Schema
</script>
```
You can easily combine this library with the Snapshot Interpolation library [@geckos.io/snapshot-interpolation](https://www.npmjs.com/package/@geckos.io/snapshot-interpolation).
```js
import { BufferSchema, Model } from '@geckos.io/typed-array-buffer-schema'
import { uint8, int16, uint16, int64, string8 } from '@geckos.io/typed-array-buffer-schema'
const playerSchema = BufferSchema.schema('player', {
id: uint8,
// The length parameter controls the length of a String8 or String16
name: { type: string8, length: 6 },
// The digits parameter controls where the decimal point is placed
// Therefore, it divides the maximum and minimum values by 10^n
x: { type: int16, digits: 2 },
y: { type: int16, digits: 2 }
})
const towerSchema = BufferSchema.schema('tower', {
id: uint8,
health: uint8,
team: uint8
})
const mainSchema = BufferSchema.schema('main', {
time: int64,
tick: uint16,
players: [playerSchema],
towers: [towerSchema]
})
export const mainModel = new Model(mainSchema)
// if you get the error "RangeError: Offset is outside the bounds of the DataView", increase the max. bufferSize.
// default is 8 (8KB).
export const mainModel = new Model(mainSchema, 8)
```
```js
import { mainModel } from './model'
const gameState = {
time: new Date().getTime(),
tick: 32580,
players: [
{ id: 0, name: 'Mistin', x: -14.43, y: 47.78 },
{ id: 1, name: 'Coobim', x: 21.85, y: -78.48 }
],
towers: [
{ id: 0, health: 100, team: 0 },
{ id: 1, health: 89, team: 0 },
{ id: 2, health: 45, team: 1 }
]
}
const buffer = mainModel.toBuffer(gameState)
// toBuffer() shrunk the byte size from 241 to only 56
// that is -77% compression!
console.log(JSON.stringify(gameState).length) // 241
console.log(buffer.byteLength) // 56
// send the buffer to the client (using geckos.io or any other library)
sendMessage(buffer)
```
```js
import { mainModel } from './model'
onMessage(buffer => {
// access your game state
const gameState = mainModel.fromBuffer(buffer)
})
```
Each Schema has an unique ID. To get the Schema ID from the Schema, Model or Buffer, use the helper functions listed below:
```ts
// get the schema id
const schemaId = BufferSchema.getIdFromSchema(schema)
// get the id of the top level schema (added via new Schema())
const modelId = BufferSchema.getIdFromModel(model)
// get the id of the top level schema
const bufferId = BufferSchema.getIdFromBuffer(buffer)
```
A list of all supported dataViews
```js
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Typed_arrays
/** -128 to 127 (1 byte) */
export const int8 = { _type: 'Int8Array', _bytes: 1 }
/** 0 to 255 (1 byte) */
export const uint8 = { _type: 'Uint8Array', _bytes: 1 }
/** -32768 to 32767 (2 bytes) */
export const int16 = { _type: 'Int16Array', _bytes: 2 }
/** 0 to 65535 (2 bytes) */
export const uint16 = { _type: 'Uint16Array', _bytes: 2 }
/** -2147483648 to 2147483647 (4 bytes) */
export const int32 = { _type: 'Int32Array', _bytes: 4 }
/** 0 to 4294967295 (4 bytes) */
export const uint32 = { _type: 'Uint32Array', _bytes: 4 }
/** -2^63 to 2^63-1 (8 bytes) */
export const int64 = { _type: 'BigInt64Array', _bytes: 8 }
/** 0 to 2^64-1 (8 bytes) */
export const uint64 = { _type: 'BigUint64Array', _bytes: 8 }
/** 1.2×10-38 to 3.4×1038 (7 significant digits e.g., 1.123456) (4 bytes) */
export const float32 = { _type: 'Float32Array', _bytes: 4 }
/** 5.0×10-324 to 1.8×10308 (16 significant digits e.g., 1.123...15) (8 bytes) */
export const float64 = { _type: 'Float64Array', _bytes: 8 }
/** 1 byte per character */
export const string8 = { _type: 'String8', _bytes: 1 }
/** 2 bytes per character */
export const string16 = { _type: 'String16', _bytes: 2 }
/** An array of 7 booleans */
export const bool8 = { _type: 'BitArray8', _bytes: 1 }
/** An array of 15 booleans */
export const bool16 = { _type: 'BitArray16', _bytes: 2 }
```