mirror of
https://github.com/swc-project/swc.git
synced 2024-12-21 04:32:01 +03:00
93 lines
2.0 KiB
TypeScript
93 lines
2.0 KiB
TypeScript
// Loaded from https://deno.land/x/crc32@v0.2.0/mod.ts
|
|
|
|
|
|
export function crc32(arr: Uint8Array | string): string {
|
|
if (typeof arr === "string") {
|
|
arr = new TextEncoder().encode(arr);
|
|
}
|
|
let crc = -1, i, j, l, temp, poly = 0xEDB88320;
|
|
|
|
for (i = 0, l = arr.length; i < l; i += 1) {
|
|
temp = (crc ^ arr[i]) & 0xff;
|
|
for (j = 0; j < 8; j += 1) {
|
|
if ((temp & 1) === 1) {
|
|
temp = (temp >>> 1) ^ poly;
|
|
} else {
|
|
temp = (temp >>> 1);
|
|
}
|
|
}
|
|
crc = (crc >>> 8) ^ temp;
|
|
}
|
|
|
|
return numberToHex(crc ^ -1);
|
|
}
|
|
|
|
export class Crc32Stream {
|
|
private bytes: number[] = [];
|
|
private poly = 0xEDB88320;
|
|
private crc = 0 ^ -1;
|
|
private encoder = new TextEncoder();
|
|
#crc32: string = "";
|
|
|
|
constructor() {
|
|
this.reset();
|
|
}
|
|
|
|
get crc32(): string {
|
|
return this.#crc32;
|
|
}
|
|
|
|
reset(): void {
|
|
this.#crc32 = "";
|
|
this.crc = 0 ^ -1;
|
|
|
|
for (let n = 0; n < 256; n += 1) {
|
|
let c = n;
|
|
for (let k = 0; k < 8; k += 1) {
|
|
if (c & 1) {
|
|
c = this.poly ^ (c >>> 1);
|
|
} else {
|
|
c = c >>> 1;
|
|
}
|
|
}
|
|
this.bytes[n] = c >>> 0;
|
|
}
|
|
}
|
|
|
|
append(arr: Uint8Array | string): string {
|
|
if (typeof arr === "string") {
|
|
arr = this.encoder.encode(arr);
|
|
}
|
|
|
|
let crc = this.crc;
|
|
|
|
for (let i = 0, l = arr.length; i < l; i += 1) {
|
|
crc = (crc >>> 8) ^ this.bytes[(crc ^ arr[i]) & 0xff];
|
|
}
|
|
|
|
this.crc = crc;
|
|
this.#crc32 = numberToHex(crc ^ -1);
|
|
return this.#crc32;
|
|
}
|
|
}
|
|
|
|
export function numberToHex(n: number): string {
|
|
return (n >>> 0).toString(16);
|
|
}
|
|
|
|
export function hexToUint8Array(str: string): Uint8Array {
|
|
if (str.length === 0 || str.length % 2 !== 0) {
|
|
throw new Error(`The string "${str}" is not valid hex.`);
|
|
}
|
|
return new Uint8Array(
|
|
str.match(/.{1,2}/g)!.map((byte) => parseInt(byte, 16)),
|
|
);
|
|
}
|
|
|
|
export function uint8ArrayToHex(bytes: Uint8Array): string {
|
|
return bytes.reduce(
|
|
(str, byte) => str + byte.toString(16).padStart(2, "0"),
|
|
"",
|
|
);
|
|
}
|