40 lines
1 KiB
TypeScript
40 lines
1 KiB
TypeScript
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import Sqids from "sqids";
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export type Slug = string & { readonly __tag: unique symbol };
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export class Slugs {
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private static instance: Slugs;
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private sqids!: Sqids;
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private constructor() {
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if (Slugs.instance) return Slugs.instance;
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Slugs.instance = this;
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this.sqids = new Sqids({
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alphabet: "dbnixSPYJNy5hvsqCWIHwEKTFutV6r4Xa32okL8RQUj7Am9DcpgfZezMBG",
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});
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}
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static encode(num: number | bigint): Slug {
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const sqids = new Slugs().sqids;
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const thirtyTwoBitMax = BigInt(0xffffffff);
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if (typeof num === "bigint" && num > thirtyTwoBitMax) {
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const arr = [];
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while (num > 0) {
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arr.push(Number(num & thirtyTwoBitMax));
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num >>= 32n;
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}
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return sqids.encode(arr) as Slug;
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} else {
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return sqids.encode([Number(num)]) as Slug;
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}
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}
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static decode(slug: Slug): number | bigint {
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const ns = new Slugs().sqids.decode(slug);
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if (ns.length === 1) return ns[0];
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return ns.reduceRight((big, each) => (big << 32n) + BigInt(each), 0n);
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}
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}
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