Release Archive Tools 0.1.0

src/archive/checksums.ts

@@ -0,0 +1,25 @@
+const table = (() => {
+  const values = new Uint32Array(256);
+  for (let index = 0; index < values.length; index += 1) {
+    let value = index;
+    for (let bit = 0; bit < 8; bit += 1)
+      value = value & 1 ? 0xedb88320 ^ (value >>> 1) : value >>> 1;
+    values[index] = value >>> 0;
+  }
+  return values;
+})();
+
+export function crc32(bytes: Uint8Array): number {
+  let value = 0xffffffff;
+  for (const byte of bytes)
+    value = table[(value ^ byte) & 0xff]! ^ (value >>> 8);
+  return (value ^ 0xffffffff) >>> 0;
+}
+
+export function crc32Hex(bytes: Uint8Array): string {
+  return crc32(bytes).toString(16).padStart(8, "0");
+}
+
+export function uint32Hex(value: number): string {
+  return (value >>> 0).toString(16).padStart(8, "0");
+}