compressed-json
!npm VersionbdnpmshieldurlbdnpmurlString 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
npm i compressed-json
Usage
'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:Example compression
example-src.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
{
"_": {
"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"
]
}
Structure of compressed json
| 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
|Key-Compression logic
All object keys are replaced with index of array stored inK
of compressed JSON.The more same key appears in original json, the more better compression.
String-Value-Pointing
String values appeared at least two will replaced with pointer string with contains index of array stored inP
of compressed JSON.The more same string value appears in original json, the more better compression.