mirror of
https://github.com/denoland/std.git
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129 lines
3.5 KiB
TypeScript
129 lines
3.5 KiB
TypeScript
// Copyright 2009 The Go Authors. All rights reserved.
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// https://github.com/golang/go/blob/master/LICENSE
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// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
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// This module is browser compatible.
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import { validateBinaryLike } from "./_util.ts";
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/** Port of the Go
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* [encoding/hex](https://github.com/golang/go/blob/go1.12.5/src/encoding/hex/hex.go)
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* library.
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*
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* This module is browser compatible.
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*
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* @example
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* ```ts
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* import {
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* decodeHex,
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* encodeHex,
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* } from "https://deno.land/std@$STD_VERSION/encoding/hex.ts";
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*
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* const binary = new TextEncoder().encode("abc");
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* const encoded = encodeHex(binary);
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* console.log(encoded);
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* // => "616263"
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*
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* console.log(decodeHex(encoded));
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* // => Uint8Array(3) [ 97, 98, 99 ]
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* ```
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*
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* @module
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*/
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const hexTable = new TextEncoder().encode("0123456789abcdef");
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const textEncoder = new TextEncoder();
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const textDecoder = new TextDecoder();
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function errInvalidByte(byte: number) {
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return new TypeError(`Invalid byte '${String.fromCharCode(byte)}'`);
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}
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function errLength() {
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return new RangeError("Odd length hex string");
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}
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/** Converts a hex character into its value. */
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function fromHexChar(byte: number): number {
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// '0' <= byte && byte <= '9'
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if (48 <= byte && byte <= 57) return byte - 48;
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// 'a' <= byte && byte <= 'f'
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if (97 <= byte && byte <= 102) return byte - 97 + 10;
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// 'A' <= byte && byte <= 'F'
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if (65 <= byte && byte <= 70) return byte - 65 + 10;
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throw errInvalidByte(byte);
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}
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/**
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* @deprecated (will be removed in 0.210.0) Use {@linkcode encodeHex} instead.
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*
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* Encodes `src` into `src.length * 2` bytes.
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*/
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export function encode(src: Uint8Array): Uint8Array {
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const dst = new Uint8Array(src.length * 2);
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for (let i = 0; i < dst.length; i++) {
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const v = src[i];
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dst[i * 2] = hexTable[v >> 4];
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dst[i * 2 + 1] = hexTable[v & 0x0f];
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}
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return dst;
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}
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/** Encodes the source into hex string. */
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export function encodeHex(src: string | Uint8Array | ArrayBuffer): string {
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const u8 = validateBinaryLike(src);
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const dst = new Uint8Array(u8.length * 2);
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for (let i = 0; i < dst.length; i++) {
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const v = u8[i];
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dst[i * 2] = hexTable[v >> 4];
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dst[i * 2 + 1] = hexTable[v & 0x0f];
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}
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return textDecoder.decode(dst);
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}
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/**
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* @deprecated (will be removed in 0.210.0) Use {@linkcode decodeHex} instead.
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*
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* Decodes `src` into `src.length / 2` bytes.
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* If the input is malformed, an error will be thrown.
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*/
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export function decode(src: Uint8Array): Uint8Array {
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const dst = new Uint8Array(src.length / 2);
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for (let i = 0; i < dst.length; i++) {
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const a = fromHexChar(src[i * 2]);
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const b = fromHexChar(src[i * 2 + 1]);
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dst[i] = (a << 4) | b;
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}
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if (src.length % 2 === 1) {
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// Check for invalid char before reporting bad length,
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// since the invalid char (if present) is an earlier problem.
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fromHexChar(src[dst.length * 2]);
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throw errLength();
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}
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return dst;
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}
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/** Decodes the given hex string to Uint8Array.
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* If the input is malformed, an error will be thrown. */
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export function decodeHex(src: string): Uint8Array {
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const u8 = textEncoder.encode(src);
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const dst = new Uint8Array(u8.length / 2);
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for (let i = 0; i < dst.length; i++) {
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const a = fromHexChar(u8[i * 2]);
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const b = fromHexChar(u8[i * 2 + 1]);
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dst[i] = (a << 4) | b;
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}
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if (u8.length % 2 === 1) {
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// Check for invalid char before reporting bad length,
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// since the invalid char (if present) is an earlier problem.
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fromHexChar(u8[dst.length * 2]);
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throw errLength();
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}
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return dst;
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}
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