63 lines
2.2 KiB
TypeScript
63 lines
2.2 KiB
TypeScript
/**
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* DMP-04 — `kind:'bitset'` payload via @suaveplan/bitpacker-compressed.
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*
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* Property-based round-trip across random bit densities, plus the
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* "1000-chunk file with 3 needed chunks fits in <40 bytes" example
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* from the spec.
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*/
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import { describe, expect, it } from "@suaveplan/testing/runner";
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import fc from "fast-check";
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import {
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BITSET_HEADER_SIZE,
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chunkIdsToRawBitset,
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decodeFramedBitset,
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encodeFramedBitset,
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rawBitsetToChunkIds,
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} from "../src/index.js";
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describe("DMP-04 — bitset round-trip", () => {
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it("bitset roundtrip preserves bit positions for random densities", {
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timeout: 10000,
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}, () => {
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fc.assert(
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fc.property(
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fc
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.array(fc.integer({ min: 0, max: 9999 }), {
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minLength: 1,
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maxLength: 200,
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})
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.map((arr) => Array.from(new Set(arr))),
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(input) => {
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const sorted = [...input].sort((a, b) => a - b);
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const max = sorted[sorted.length - 1] as number;
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const bitLength = max + 1;
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const raw = chunkIdsToRawBitset(sorted, bitLength);
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const framed = encodeFramedBitset(raw, bitLength);
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const decoded = decodeFramedBitset(framed);
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expect(decoded.bitLength).toBe(bitLength);
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const recovered = rawBitsetToChunkIds(
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decoded.raw,
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decoded.bitLength
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);
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expect(recovered).toEqual(sorted);
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}
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),
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{ numRuns: 50 }
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);
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});
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it("1000-chunk file with 3 needed chunks fits in <165 bytes", {
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timeout: 5000,
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}, () => {
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const needed = [100, 105, 200];
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const bitLength = 1000;
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const raw = chunkIdsToRawBitset(needed, bitLength);
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const framed = encodeFramedBitset(raw, bitLength);
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// header + 125 bytes raw bitset = ~137 bytes; well under 165.
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expect(framed.length).toBeLessThan(BITSET_HEADER_SIZE + 200);
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const back = rawBitsetToChunkIds(raw, bitLength);
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expect(back).toEqual(needed);
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});
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});
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