didier amyot
0d627c9051
The class was already implemented in "https://deno.land/std@0.144.0/streams/conversion.ts". So, I litterally lost 1 day of work! I hate myself.
45 lines
1.4 KiB
TypeScript
45 lines
1.4 KiB
TypeScript
// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
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// This module is browser compatible.
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/** Check whether binary arrays are equal to each other using 8-bit comparisons.
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* @private
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* @param a first array to check equality
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* @param b second array to check equality
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*/
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function equalsNaive(a: Uint8Array, b: Uint8Array): boolean {
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for (let i = 0; i < b.length; i++) {
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if (a[i] !== b[i]) return false;
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}
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return true;
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}
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/** Check whether binary arrays are equal to each other using 32-bit comparisons.
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* @private
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* @param a first array to check equality
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* @param b second array to check equality
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*/
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function equals32Bit(a: Uint8Array, b: Uint8Array): boolean {
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const len = a.length;
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const compressable = Math.floor(len / 4);
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const compressedA = new Uint32Array(a.buffer, 0, compressable);
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const compressedB = new Uint32Array(b.buffer, 0, compressable);
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for (let i = compressable * 4; i < len; i++) {
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if (a[i] !== b[i]) return false;
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}
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for (let i = 0; i < compressedA.length; i++) {
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if (compressedA[i] !== compressedB[i]) return false;
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}
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return true;
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}
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/** Check whether binary arrays are equal to each other.
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* @param a first array to check equality
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* @param b second array to check equality
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*/
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export function equals(a: Uint8Array, b: Uint8Array): boolean {
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if (a.length !== b.length) {
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return false;
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}
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return a.length < 1000 ? equalsNaive(a, b) : equals32Bit(a, b);
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}
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