refactor: re-order decryption factory

.env

@@ -1,4 +1,4 @@
 # Example environment file for vite to use.
 # For more information, see: https://vitejs.dev/guide/env-and-mode.html
 
-ENABLE_PERF_LOG=0
+VITE_ENABLE_PERF_LOG=0

src/decrypt-worker/crypto/CryptoFactory.ts

@@ -12,12 +12,7 @@ import { TransparentCrypto } from './transparent/transparent';
 import { QingTingFM$Device } from './qtfm/qtfm_device';
 
 export const allCryptoFactories: CryptoFactory[] = [
-  // Xiami (*.xm)
-  XiamiCrypto.make,
-
-  // QMCv2 (*.mflac)
-  QMC2CryptoWithKey.make,
-  QMC2Crypto.make,
+  /// File with fixed headers goes first.
 
   // NCM (*.ncm)
   NCMCrypto.make,
@@ -28,6 +23,17 @@ export const allCryptoFactories: CryptoFactory[] = [
   // KWMv1 (*.kwm)
   KWMCrypto.make,
 
+  // Xiami (*.xm)
+  XiamiCrypto.make,
+
+  /// File with a fixed footer goes second
+
+  // QMCv2 (*.mflac)
+  QMC2CryptoWithKey.make,
+  QMC2Crypto.make,
+
+  /// File without an obvious header or footer goes last.
+
   // Migu3D/Keyless (*.wav; *.m4a)
   MiguCrypto.make,
 

src/decrypt-worker/crypto/ncm/ncm_pc.ts

@@ -8,8 +8,13 @@ export class NCMCrypto implements CryptoBase {
   ncm = new NCMFile();
 
   async checkBySignature(buffer: ArrayBuffer) {
+    const data = new Uint8Array(buffer);
+    let len = 1024;
     try {
-      this.ncm.open(new Uint8Array(buffer));
+      while (len !== 0) {
+        console.debug('NCM/open: read %d bytes', len);
+        len = this.ncm.open(data.subarray(0, len));
+      }
     } catch (error) {
       return false;
     }

src/util/logUtils.ts

@@ -1,25 +1,25 @@
 import { wrapFunctionCall } from './fnWrapper';
 
 export function timedLogger<R = unknown>(label: string, fn: () => R): R {
-  if (import.meta.env.ENABLE_PERF_LOG !== '1') {
+  if (import.meta.env.VITE_ENABLE_PERF_LOG !== '1') {
     return fn();
   } else {
     return wrapFunctionCall(
       () => console.time(label),
       () => console.timeEnd(label),
-      fn
+      fn,
     );
   }
 }
 
 export function withGroupedLogs<R = unknown>(label: string, fn: () => R): R {
-  if (import.meta.env.ENABLE_PERF_LOG !== '1') {
+  if (import.meta.env.VITE_ENABLE_PERF_LOG !== '1') {
     return fn();
   } else {
     return wrapFunctionCall(
       () => console.group(label),
       () => (console.groupEnd as (label: string) => void)(label),
-      () => timedLogger(`${label}/total`, fn)
+      () => timedLogger(`${label}/total`, fn),
     );
   }
 }
@@ -37,7 +37,7 @@ const dummyLogger = {
 };
 
 export function getLogger() {
-  if (import.meta.env.ENABLE_PERF_LOG === '1') {
+  if (import.meta.env.VITE_ENABLE_PERF_LOG === '1') {
     return window.console;
   } else {
     return dummyLogger;