optimize ygom 29 bit thing

src/ygom.ts

 import { fromBase64Url, toBase64Url } from "./base64";
 
-// === 常量区域 ===
+// === 常量 ===
 const QUERY_YGO_TYPE = 'ygotype';
 const QUERY_VERSION = 'v';
 const ARG_DECK = 'deck';
 const QUERY_DECK = 'd';
 const QUERY_NAME = 'name';
-
 const URL_SCHEME_HTTP = 'http';
 const URL_HOST_DECK = 'deck.ourygo.top';
 
-// === 工具函数 ===
-function toBinary(value: number, length: number): string {
-  return value.toString(2).padStart(length, '0');
-}
+// === BitWriter 类 ===
+class BitWriter {
+  private buffer: number[] = [];
+  private current = 0;
+  private bitPos = 0;
+
+  writeBits(value: number, length: number) {
+    while (length > 0) {
+      const remain = 8 - this.bitPos;
+      const take = Math.min(remain, length);
+      const shift = length - take;
+      this.current |= ((value >> shift) & ((1 << take) - 1)) << (remain - take);
+      this.bitPos += take;
+      length -= take;
+
+      if (this.bitPos === 8) {
+        this.buffer.push(this.current);
+        this.current = 0;
+        this.bitPos = 0;
+      }
+    }
+  }
 
-function encodeCards(cards: number[]): string {
-  const bits: string[] = [];
-  for (let i = 0; i < cards.length; ) {
-    const id = cards[i];
-    let count = 1;
-    while (i + count < cards.length && cards[i + count] === id && count < 3) count++;
-    const prefix = count === 2 ? '10' : count === 3 ? '11' : '01';
-    bits.push(prefix + toBinary(id, 27));
-    i += count;
+  finish(): Uint8Array {
+    if (this.bitPos > 0) this.buffer.push(this.current);
+    return new Uint8Array(this.buffer);
   }
-  return bits.join('');
 }
 
-function countUnique(cards: number[]): number {
-  let num = 0;
-  for (let i = 0; i < cards.length; i++) {
-    const id = cards[i];
-    if (id > 0) {
-      num++;
-      if (i < cards.length - 1 && cards[i + 1] === id) {
-        i++;
-        if (i < cards.length - 1 && cards[i + 1] === id) {
-          i++;
+// === BitReader 类 ===
+class BitReader {
+  private index = 0;
+  private bitPos = 0;
+
+  constructor(private bytes: Uint8Array) {}
+
+  readBits(length: number): number {
+    let result = 0;
+    while (length > 0) {
+      const remain = 8 - this.bitPos;
+      const take = Math.min(remain, length);
+      const bits = (this.bytes[this.index] >> (remain - take)) & ((1 << take) - 1);
+      result = (result << take) | bits;
+      this.bitPos += take;
+      length -= take;
+
+      if (this.bitPos === 8) {
+        this.bitPos = 0;
+        this.index++;
       }
     }
+    return result;
   }
-  }
-  return num;
 }
 
-// === 主函数 ===
+// === 工具函数 ===
+function countUnique(cards: number[]): number {
+  let count = 0;
+  for (let i = 0; i < cards.length; ) {
+    const id = cards[i];
+    count++;
+    while (i < cards.length && cards[i] === id) i++;
+  }
+  return count;
+}
 
+// === 主函数：编码 ===
 export function toYGOMobileDeckURL(
   main: number[],
   extra: number[],
@@ -57,20 +86,32 @@ export function toYGOMobileDeckURL(
   const eNum = countUnique(extra);
   const sNum = countUnique(side);
 
-  const header = toBinary(mNum, 8) + toBinary(eNum, 4) + toBinary(sNum, 4);
-  let bitString = header + encodeCards(main) + encodeCards(extra) + encodeCards(side);
-  while (bitString.length % 8 !== 0) bitString += '0';
+  const writer = new BitWriter();
+  writer.writeBits(mNum, 8);
+  writer.writeBits(eNum, 4);
+  writer.writeBits(sNum, 4);
 
-  const bytes = new Uint8Array(bitString.length / 8);
-  for (let i = 0; i < bytes.length; i++) {
-    bytes[i] = parseInt(bitString.slice(i * 8, i * 8 + 8), 2);
+  const encodeSection = (cards: number[]) => {
+    for (let i = 0; i < cards.length; ) {
+      const id = cards[i];
+      let count = 1;
+      while (i + count < cards.length && cards[i + count] === id && count < 3) count++;
+      const prefix = count === 2 ? 0b10 : count === 3 ? 0b11 : 0b01;
+      writer.writeBits(prefix, 2);
+      writer.writeBits(id, 27);
+      i += count;
     }
+  };
 
-  let encoded = toBase64Url(bytes)
+  encodeSection(main);
+  encodeSection(extra);
+  encodeSection(side);
+
+  const encoded = toBase64Url(writer.finish());
 
   const searchParams = new URLSearchParams();
-  for (const [key, value] of Object.entries(customParams)) {
-    searchParams.set(key, value);
+  for (const [k, v] of Object.entries(customParams)) {
+    searchParams.set(k, v);
   }
   searchParams.set(QUERY_YGO_TYPE, ARG_DECK);
   searchParams.set(QUERY_VERSION, '1');
@@ -79,7 +120,7 @@ export function toYGOMobileDeckURL(
   return `${URL_SCHEME_HTTP}://${URL_HOST_DECK}?${searchParams.toString()}`;
 }
 
-
+// === 主函数：解码 ===
 export function fromYGOMobileDeckURL(uri: string): {
   main: number[];
   extra: number[];
@@ -88,46 +129,39 @@ export function fromYGOMobileDeckURL(uri: string): {
 } {
   const url = new URL(uri);
   if (url.searchParams.get(QUERY_YGO_TYPE) !== ARG_DECK) {
-    throw new Error('Not a YGO Mobile deck URI');
+    throw new Error('Invalid deck URL');
   }
 
-  let encoded = url.searchParams.get(QUERY_DECK);
+  const encoded = url.searchParams.get(QUERY_DECK);
   if (!encoded) throw new Error('Missing deck data');
 
   const bytes = fromBase64Url(encoded);
+  const reader = new BitReader(bytes);
 
-  const bits = Array.from(bytes)
-    .map((b) => b.toString(2).padStart(8, '0'))
-    .join('');
-
-  const mNum = parseInt(bits.slice(0, 8), 2);
-  const eNum = parseInt(bits.slice(8, 12), 2);
-  const sNum = parseInt(bits.slice(12, 16), 2);
-
-  const all = mNum + eNum + sNum;
-  const cards: number[] = [];
-  let pos = 16;
+  const mNum = reader.readBits(8);
+  const eNum = reader.readBits(4);
+  const sNum = reader.readBits(4);
+  const total = mNum + eNum + sNum;
 
-  const res = {
+  const result = {
     main: [] as number[],
     extra: [] as number[],
     side: [] as number[],
-  }
-
-  let i = 0;
+  };
 
-  while (pos + 29 <= bits.length && cards.length < all) {
-    const countBits = bits.slice(pos, pos + 2);
-    const count = countBits === '10' ? 2 : countBits === '11' ? 3 : 1;
-    const id = parseInt(bits.slice(pos + 2, pos + 29), 2);
-    const field = i < mNum ? 'main' : i < mNum + eNum ? 'extra' : 'side';
-    res[field].push(...Array(count).fill(id));
-    pos += 29;
-    i++;
+  for (let i = 0; i < total; i++) {
+    const prefix = reader.readBits(2);
+    const count = prefix === 0b10 ? 2 : prefix === 0b11 ? 3 : 1;
+    const id = reader.readBits(27);
+    const target =
+      i < mNum ? result.main : i < mNum + eNum ? result.extra : result.side;
+    for (let j = 0; j < count; j++) {
+      target.push(id);
+    }
   }
 
   return {
-    ...res,
-    name: url.searchParams.get(QUERY_NAME),
+    ...result,
+    name: url.searchParams.get(QUERY_NAME) ?? undefined,
   };
 }

tests/sample.spec.ts

@@ -55,6 +55,98 @@ describe('Sample test.', () => {
 
   it('should encode and decode ygomobile', () => { 
     const uri = 'http://deck.ourygo.top?name=%E7%99%BD%E9%93%B6%E5%9F%8E%E7%A0%81&ygotype=deck&v=1&d=J-xK4Mka02AuEAMf2dV6mj7aRemuJNQJK8BwrcEYh0MqOJqBJSgYqUwxPEVhOG8R18WWVKmzkT-xEdwxbmGVkkOdrVIpufaYI3Hs8oOrcya8Bi40h9G79iFW80rq-o6P-AHsusPY5nmvHLol0DIqEykESVlf6VSbxVJp-j7XZtTE0XvmJW80rqH28R4rgyRovOusVJzbutenYFBA_cyK6d3UWcQkJQlLjaroWavH-INFA56k5DQNWOQ1gpvxrKVBLgEk1olpolKmSgriramLlgtBK1EQ6C6oi94ZyHe7N6T7mqE6peds7mahrORP6A';
+    const correctYdk = `#created by OURYGO
+#main
+22812963
+55410872
+102380
+89631139
+89631139
+89631139
+95718355
+95718355
+95718355
+59323650
+22938501
+96540807
+6637331
+33854624
+72656408
+63198739
+63198739
+14558127
+14558127
+23434538
+23434538
+94145021
+17947697
+17947697
+97268402
+17725109
+18144507
+25311006
+31786838
+31786838
+31786838
+80326401
+80326401
+80326401
+24224830
+24224830
+29095457
+29095457
+48130397
+65681983
+67171933
+67171933
+67171933
+71143015
+56506740
+56506740
+24382602
+10045474
+10045474
+22634473
+43219114
+27781371
+62089826
+85442146
+48130397
+8240199
+22812963
+22812963
+#extra
+12381100
+43228023
+56532353
+2129638
+11443677
+11765832
+21123811
+89604813
+63436931
+10515412
+59822133
+59822133
+74586817
+29301450
+42097666
+!side
+20292186
+85103922
+34267821
+87126721
+87126721
+84192580
+7608148
+12444060
+15693423
+15693423
+20899496
+30748475
+82732705
+94145021
+94145021`
     const deck = new YGOProDeck().fromYGOMobileDeckURL(uri);
     expect(deck.main).toHaveLength(58);
     expect(deck.extra).toHaveLength(15);
@@ -62,6 +154,12 @@ describe('Sample test.', () => {
     expect(deck.main[0]).toBe(22812963);
     expect(deck.extra[0]).toBe(12381100);
     expect(deck.side[0]).toBe(20292186);
+
+    const correctDeck = new YGOProDeck().fromYdkString(correctYdk);
+    expect(deck.main).toStrictEqual(correctDeck.main);
+    expect(deck.extra).toStrictEqual(correctDeck.extra);
+    expect(deck.side).toStrictEqual(correctDeck.side);
+
     const uri2 = deck.toYGOMobileDeckURL();
 
     expect(uri2).toBe(uri);