jsonschema-key-compression

jsonschema-key-compression

Compress json-data based on its json-schema while still having valid json. It works by compressing long attribute-names into smaller ones and backwards.

For example this:

{
    "firstName": "Corrine",
    "lastName": "Ziemann",
    "title": "Ms.",
    "gender": "f",
    "zipCode": 75963,
    "countryCode": "en",
    "birthYear": 1960,
    "active": false,
    "shoppingCartItems": [
        {
            "productNumber": 29857,
            "amount": 1
        },
        {
            "productNumber": 53409,
            "amount": 6
        }
    ]
}

becomes this:

{
    "|e": "Corrine",
    "|g": "Ziemann",
    "|j": "Ms.",
    "|f": "f",
    "|k": 75963,
    "|d": "en",
    "|c": 1960,
    "|a": false,
    "|i": [
        {
            "|h": 29857,
            "|b": 1
        },
        {
            "|h": 53409,
            "|b": 6
        }
    ]
}

Usage

Install

npm install jsonschema-key-compression --save

createCompressionTable

Creates a compression-table from the json-schema.

import {
    createCompressionTable
} from 'jsonschema-key-compression';
const compressionTable = createCompressionTable(jsonSchema);

compressObject

Compress a json-object based on its schema.

import {
    compressObject
} from 'jsonschema-key-compression';
const compressedObject = compressObject(
    compressionTable,
    jsonObject
);

decompressObject

Decompress a compressed object.

import {
    decompressObject
} from 'jsonschema-key-compression';
const jsonObject = decompressObject(
    compressionTable,
    compressedObject
);

compressedPath

Transform a chain of json-attributes into its compressed format.

import {
    compressedPath
} from 'jsonschema-key-compression';
const compressed = compressedPath(
    compressionTable,
    'whateverNested.firstName'
); // > '|a.|b'

decompressedPath

Decompress a compressed path.

import {
    decompressedPath
} from 'jsonschema-key-compression';
const decompressed = decompressedPath(
    compressionTable,
    '|a.|b' // from compressedPath
); // > 'whateverNested.firstName'

compressQuery

Compress a mango-query so that it can run over a NoSQL-database that has stored compressed documents.

import {
    compressQuery
} from 'jsonschema-key-compression';
const compressed = compressQuery(
    compressionTable,
    {
        selector: {
            active: {
                $eq: true
            }
        },
        skip: 1,
        limit: 1,
        fields: [
            'id',
            'name'
        ],
        sort: [
            'name'
        ]
    }
);