compressed-json

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String base JSON compressor

If you seriously want to reduce your data size, consider using msgpack.

Use compressed-json only if you cannot handle binary for some reason.

Install

``bash
npm i compressed-json
`

Usage

`js
'use strict'

const cjson = require('compressed-json')

// Convert json object
const compressed = cjson.compress({ / Large json / })
const restored = cjson.decompress(compressed)

// Convert json string
const compressedString = cjson.compress.toString({ / Some large json / })
const restoredFromString = cjson.decompress.fromString(compressedString)

`

How It Works

compressed-json has two logics:

* Key-Compression
* String-Value-Pointing

$3

example-src.json

`json
{
"description": "This is example json",
"entities": [
{
"id": 100,
"name": "Dog",
"desc": "This is desc of dog",
"tag": ["animal"]
},
{
"id": 101,
"name": "Cat",
"desc": "This is desc of cat",
"tag": ["animal"]
}
],
"notes": [
"Unique string will be kept as is",
"Duplicated string will be combined",
"Duplicated string will be combined",
"p: string start with 'p:' will be escaped "
]
}

`

example-compressed.json

`json
{
"_": {
"0": "This is example json",
"1": [
{
"2": 100,
"3": "Dog",
"4": "This is desc of dog",
"5": [
"p:0"
]
},
{
"2": 101,
"3": "Cat",
"4": "This is desc of cat",
"5": [
"p:0"
]
}
],
"6": [
"Unique string will be kept as is",
"p:1",
"p:1",
"e:p: string start with 'p:' will be escaped "
]
},
"K": [
"description",
"entities",
"id",
"name",
"desc",
"tag",
"notes"
],
"P": [
"animal",
"Duplicated string will be combined"
]
}
`

$3

| Key | Description |
| --- | ----------- |
| K | Array of original keys. Object keys are replaced with index of K in the compressed json |
| P | Pointed string values. Values are replaced with index of P in the compressed json |
| _ | Compressed payload. Keeps original structure, but keys and values may be replaced with pointers to K or P |

$3

All object keys are replaced with index of array stored in K of compressed JSON.

The more same key appears in original json, the more better compression.

$3

String values appeared at least two will replaced with pointer string with contains index of array stored in P` of compressed JSON.

The more same string value appears in original json, the more better compression.