int-compress-string

Compresses an array of integers in the following range into a URL-safe short string.

|min | max| | --- | --- | | 0 | Number.MAX_SAFE_INTEGER === 9007199254740991 |

I wrote this function to store a large amount of sequential ID in a lmited URL query string (up to 2048 characters in Internet Explorer).
When compressed, the size decreases by more than 80% on average, depending on the data characteristics.
When decompressed, the order is not preserved and is sorted.

import {compress, decompress} from "int-compress-string";
const original = [0,1,2,.......,99];
const compressed = compress(); //TURIZkFkOEIzd0hGQVN6ZEFRPT0=
const decompressed = decompress(compressed);
expect(decompressed).to.deep.equal(original); // true

How It Works

1. Sort the array.
2. Convert numbers to the difference between adjacent elements
3. Convert to 64-digit string
4. Grouped by digit length and replaced with an alias of 1 character allocated for each digit length
5. Concat and join each group and the replaced original array
6. Compress once again with lzw
7. Replace slash characters to underscore for using path parameter