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Module

std/encoding/hex.ts

The Deno Standard Library
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// Copyright 2009 The Go Authors. All rights reserved.// https://github.com/golang/go/blob/master/LICENSE// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
/** * Port of the Go * {@link https://github.com/golang/go/blob/go1.12.5/src/encoding/hex/hex.go | encoding/hex} * library. * * This module is browser compatible. * * ```ts * import { * decodeHex, * encodeHex, * } from "https://deno.land/std@$STD_VERSION/encoding/hex.ts"; * * const encoded = encodeHex("abc"); // "616263" * * decodeHex(encoded); // Uint8Array(3) [ 97, 98, 99 ] * ``` * * @module */
import { validateBinaryLike } from "./_util.ts";
const hexTable = new TextEncoder().encode("0123456789abcdef");const textEncoder = new TextEncoder();const textDecoder = new TextDecoder();
function errInvalidByte(byte: number) { return new TypeError(`Invalid byte '${String.fromCharCode(byte)}'`);}
function errLength() { return new RangeError("Odd length hex string");}
/** Converts a hex character into its value. */function fromHexChar(byte: number): number { // '0' <= byte && byte <= '9' if (48 <= byte && byte <= 57) return byte - 48; // 'a' <= byte && byte <= 'f' if (97 <= byte && byte <= 102) return byte - 97 + 10; // 'A' <= byte && byte <= 'F' if (65 <= byte && byte <= 70) return byte - 65 + 10;
throw errInvalidByte(byte);}
/** * Converts data into a hex-encoded string. * * @example * ```ts * import { encodeHex } from "https://deno.land/std@$STD_VERSION/encoding/hex.ts"; * * encodeHex("abc"); // "616263" * ``` */export function encodeHex(src: string | Uint8Array | ArrayBuffer): string { const u8 = validateBinaryLike(src);
const dst = new Uint8Array(u8.length * 2); for (let i = 0; i < dst.length; i++) { const v = u8[i]!; dst[i * 2] = hexTable[v >> 4]!; dst[i * 2 + 1] = hexTable[v & 0x0f]!; } return textDecoder.decode(dst);}
/** * Decodes the given hex-encoded string. If the input is malformed, an error is * thrown. * * @example * ```ts * import { decodeHex } from "https://deno.land/std@$STD_VERSION/encoding/hex.ts"; * * decodeHex("616263"); // Uint8Array(3) [ 97, 98, 99 ] * ``` */export function decodeHex(src: string): Uint8Array { const u8 = textEncoder.encode(src); const dst = new Uint8Array(u8.length / 2); for (let i = 0; i < dst.length; i++) { const a = fromHexChar(u8[i * 2]!); const b = fromHexChar(u8[i * 2 + 1]!); dst[i] = (a << 4) | b; }
if (u8.length % 2 === 1) { // Check for invalid char before reporting bad length, // since the invalid char (if present) is an earlier problem. fromHexChar(u8[dst.length * 2]!); throw errLength(); }
return dst;}