use buffer mutate for polyfill

YGOProMessages.js

@@ -223,8 +223,8 @@ class YGOProMessagesHelper {
                         break;
                     }
                     let buffer = messageBuffer.slice(3, 2 + messageLength);
+                    let bufferMutated = false;
                     //console.log(l, direction, proto, cancel);
-                    let shrinkCount = 0;
                     for (let priority = 0; priority < 4; ++priority) {
                         if (cancel) {
                             break;
@@ -232,15 +232,20 @@ class YGOProMessagesHelper {
                         const handlerCollection = this.handlers[direction][priority];
                         if (proto && handlerCollection.has(bufferProto)) {
                             let struct = this.structs.get(this.proto_structs[direction][proto]);
-                            let info = null;
-                            if (struct) {
-                                struct._setBuff(buffer);
-                                info = underscore_1.default.clone(struct.fields);
-                            }
-                            for (let handler of handlerCollection.get(bufferProto)) {
+                            for (const handler of handlerCollection.get(bufferProto)) {
+                                let info = null;
+                                if (struct) {
+                                    struct._setBuff(buffer);
+                                    info = underscore_1.default.clone(struct.fields);
+                                }
                                 cancel = await handler.handle(buffer, info, datas, params);
                                 if (cancel) {
-                                    if (typeof cancel === "string") {
+                                    if (Buffer.isBuffer(cancel)) {
+                                        buffer = cancel;
+                                        bufferMutated = true;
+                                        cancel = false;
+                                    }
+                                    else if (typeof cancel === "string") {
                                         if (cancel === '_cancel') {
                                             return {
                                                 datas: [],
@@ -248,8 +253,15 @@ class YGOProMessagesHelper {
                                             };
                                         }
                                         else if (cancel.startsWith('_shrink_')) {
-                                            shrinkCount += parseInt(cancel.slice(8));
-                                            cancel = false;
+                                            const targetShrinkCount = parseInt(cancel.slice(8));
+                                            if (targetShrinkCount > buffer.length) {
+                                                cancel = true;
+                                            }
+                                            else {
+                                                buffer = buffer.slice(0, buffer.length - targetShrinkCount);
+                                                bufferMutated = true;
+                                                cancel = false;
+                                            }
                                         }
                                     }
                                     break;
@@ -257,14 +269,15 @@ class YGOProMessagesHelper {
                             }
                         }
                     }
-                    if (!cancel && shrinkCount <= messageLength) {
-                        if (shrinkCount > 0) {
-                            // rewrite first 2 bytes of length
-                            const oldLength = messageBuffer.readUInt16LE(0);
-                            const newLength = oldLength - shrinkCount;
+                    if (!cancel) {
+                        if (bufferMutated) {
+                            const newLength = buffer.length + 1;
                             messageBuffer.writeUInt16LE(newLength, 0);
+                            datas.push(Buffer.concat([messageBuffer.slice(0, 3), buffer]));
+                        }
+                        else {
+                            datas.push(messageBuffer.slice(0, 2 + messageLength));
                         }
-                        datas.push(messageBuffer.slice(0, 2 + messageLength - shrinkCount));
                     }
                     messageBuffer = messageBuffer.slice(2 + messageLength);
                     messageLength = 0;

YGOProMessages.ts

@@ -8,13 +8,13 @@ import net from "net";
 
 
 class Handler {
-	private handler: (buffer: Buffer, info: any, datas: Buffer[], params: any) => Promise<boolean | string>;
+	private handler: (buffer: Buffer, info: any, datas: Buffer[], params: any) => Promise<boolean | string | Buffer>;
 	synchronous: boolean;
-	constructor(handler: (buffer: Buffer, info: any, datas: Buffer[], params: any) => Promise<boolean | string>, synchronous: boolean) {
+	constructor(handler: (buffer: Buffer, info: any, datas: Buffer[], params: any) => Promise<boolean | string | Buffer>, synchronous: boolean) {
 		this.handler = handler;
 		this.synchronous = synchronous || false;
 	}
-	async handle(buffer: Buffer, info: any, datas: Buffer[], params: any): Promise<boolean | string> {
+	async handle(buffer: Buffer, info: any, datas: Buffer[], params: any): Promise<boolean | string | Buffer> {
 		if (this.synchronous) {
 			return await this.handler(buffer, info, datas, params);
 		} else {
@@ -264,7 +264,7 @@ export class YGOProMessagesHelper {
 			} else {
 				if (messageBuffer.length >= 2 + messageLength) {
 					const proto = this.constants[direction][bufferProto];
-					let cancel: string | boolean = proto && protoFilter && !protoFilter.includes(proto);
+					let cancel: string | boolean | Buffer = proto && protoFilter && !protoFilter.includes(proto);
 					if (cancel && preconnect) {
 						feedback = {
 							type: "INVALID_PACKET",
@@ -273,8 +273,8 @@ export class YGOProMessagesHelper {
 						break;
 					}
 					let buffer = messageBuffer.slice(3, 2 + messageLength);
+					let bufferMutated = false;
 					//console.log(l, direction, proto, cancel);
-					let shrinkCount = 0;
 					for (let priority = 0; priority < 4; ++priority) {
 						if (cancel) {
 							break;
@@ -282,23 +282,33 @@ export class YGOProMessagesHelper {
 						const handlerCollection: Map<number, Handler[]> = this.handlers[direction][priority];
 						if (proto && handlerCollection.has(bufferProto)) {
 							let struct = this.structs.get(this.proto_structs[direction][proto]);
-							let info = null;
-							if (struct) {
-								struct._setBuff(buffer);
-								info = _.clone(struct.fields);
-							}
-							for (let handler of handlerCollection.get(bufferProto)) {
+							for (const handler of handlerCollection.get(bufferProto)) {
+								let info = null;
+								if (struct) {
+									struct._setBuff(buffer);
+									info = _.clone(struct.fields);
+								}
 								cancel = await handler.handle(buffer, info, datas, params);
 								if (cancel) {
-									if (typeof cancel === "string") { 
+									if (Buffer.isBuffer(cancel)) {
+										buffer = cancel as any;
+										bufferMutated = true;
+										cancel = false;
+									} else if (typeof cancel === "string") { 
 										if (cancel === '_cancel') {
 											return {
 												datas: [],
 												feedback
 											}
 										} else if (cancel.startsWith('_shrink_')) {
-											shrinkCount += parseInt(cancel.slice(8));
-											cancel = false;
+											const targetShrinkCount = parseInt(cancel.slice(8));
+											if (targetShrinkCount > buffer.length) {
+												cancel = true;
+											} else {
+												buffer = buffer.slice(0, buffer.length - targetShrinkCount);
+												bufferMutated = true;
+												cancel = false;
+											}
 										}
 									}
 									break;
@@ -306,14 +316,14 @@ export class YGOProMessagesHelper {
 							}
 						}
 					}
-					if (!cancel && shrinkCount <= messageLength) {
-						if (shrinkCount > 0) { 
-							// rewrite first 2 bytes of length
-							const oldLength = messageBuffer.readUInt16LE(0);
-							const newLength = oldLength - shrinkCount;
+					if (!cancel) {
+						if (bufferMutated) {
+							const newLength = buffer.length + 1;
 							messageBuffer.writeUInt16LE(newLength, 0);
+							datas.push(Buffer.concat([messageBuffer.slice(0, 3), buffer]));
+						} else {
+							datas.push(messageBuffer.slice(0, 2 + messageLength));
 						}
-						datas.push(messageBuffer.slice(0, 2 + messageLength - shrinkCount));
 					}
 					messageBuffer = messageBuffer.slice(2 + messageLength);
 					messageLength = 0;

msg-polyfill/base-polyfiller.js

@@ -2,33 +2,34 @@
 Object.defineProperty(exports, "__esModule", { value: true });
 exports.BasePolyfiller = void 0;
 class BasePolyfiller {
-    constructor() {
-        this.shrinkCount = 0;
+    async polyfillGameMsg(msgTitle, buffer) {
+        return;
+    }
+    async polyfillResponse(msgTitle, buffer) {
+        return;
     }
-    async polyfillGameMsg(msgTitle, buffer) { }
-    async polyfillResponse(msgTitle, buffer) { }
     splice(buf, offset, deleteCount = 1) {
         if (offset < 0 || offset >= buf.length)
             return Buffer.alloc(0);
         deleteCount = Math.min(deleteCount, buf.length - offset);
         const end = offset + deleteCount;
-        const deleted = Buffer.allocUnsafe(deleteCount);
-        buf.copy(deleted, 0, offset, end);
-        const moveLength = buf.length - end;
-        if (moveLength > 0) {
-            buf.copy(buf, offset, end, buf.length);
-        }
-        buf.fill(0, buf.length - deleteCount);
-        this.shrinkCount += deleteCount;
-        return deleted;
+        const newBuf = Buffer.concat([
+            buf.slice(0, offset),
+            buf.slice(end)
+        ]);
+        return newBuf;
     }
     insert(buf, offset, insertBuf) {
-        const availableSpace = buf.length - offset;
-        const insertLength = Math.min(insertBuf.length, availableSpace);
-        buf.copy(buf, offset + insertLength, offset, buf.length - insertLength);
-        insertBuf.copy(buf, offset, 0, insertLength);
-        this.shrinkCount -= insertLength;
-        return buf;
+        if (offset < 0)
+            offset = 0;
+        if (offset > buf.length)
+            offset = buf.length;
+        const newBuf = Buffer.concat([
+            buf.slice(0, offset),
+            insertBuf,
+            buf.slice(offset)
+        ]);
+        return newBuf;
     }
 }
 exports.BasePolyfiller = BasePolyfiller;

msg-polyfill/base-polyfiller.ts

 export class BasePolyfiller {
-  shrinkCount = 0;
 
-  async polyfillGameMsg(msgTitle: string, buffer: Buffer) {}
+  async polyfillGameMsg(msgTitle: string, buffer: Buffer): Promise<Buffer | undefined> {
+    return;
+  }
 
-  async polyfillResponse(msgTitle: string, buffer: Buffer) {}
+  async polyfillResponse(msgTitle: string, buffer: Buffer): Promise<Buffer | undefined> {
+    return;
+  }
 
   splice(buf: Buffer, offset: number, deleteCount = 1): Buffer {
     if (offset < 0 || offset >= buf.length) return Buffer.alloc(0);
@@ -11,31 +14,24 @@ export class BasePolyfiller {
     deleteCount = Math.min(deleteCount, buf.length - offset);
     const end = offset + deleteCount;
   
-    const deleted = Buffer.allocUnsafe(deleteCount);
-    buf.copy(deleted, 0, offset, end);
+    const newBuf = Buffer.concat([
+      buf.slice(0, offset),
+      buf.slice(end)
+    ]);
   
-    const moveLength = buf.length - end;
-    if (moveLength > 0) {
-      buf.copy(buf, offset, end, buf.length);
-    }
-  
-    buf.fill(0, buf.length - deleteCount);
-
-    this.shrinkCount += deleteCount;
-  
-    return deleted;
+    return newBuf;
   }
 
-  insert(buf: Buffer, offset: number, insertBuf: Buffer) {
-    const availableSpace = buf.length - offset;
-    const insertLength = Math.min(insertBuf.length, availableSpace);
+  insert(buf: Buffer, offset: number, insertBuf: Buffer): Buffer {
+    if (offset < 0) offset = 0;
+    if (offset > buf.length) offset = buf.length;
   
-    buf.copy(buf, offset + insertLength, offset, buf.length - insertLength);
-
-    insertBuf.copy(buf, offset, 0, insertLength);
-
-    this.shrinkCount -= insertLength;
+    const newBuf = Buffer.concat([
+      buf.slice(0, offset),
+      insertBuf,
+      buf.slice(offset)
+    ]);
   
-    return buf;
+    return newBuf;
   }
 }

msg-polyfill/index.js

@@ -15,17 +15,15 @@ const getPolyfillers = (version) => {
 };
 async function polyfillGameMsg(version, msgTitle, buffer) {
     const polyfillers = getPolyfillers(version);
-    let shrinkCount = 0;
+    let mutated = false;
     for (const polyfiller of polyfillers) {
-        await polyfiller.polyfillGameMsg(msgTitle, buffer);
-        if (polyfiller.shrinkCount > 0) {
-            if (polyfiller.shrinkCount === 0x3f3f3f3f) {
-                return 0x3f3f3f3f; // special case for cancel message
-            }
-            shrinkCount += polyfiller.shrinkCount;
+        const newBuf = await polyfiller.polyfillGameMsg(msgTitle, buffer);
+        if (newBuf) {
+            mutated = true;
+            buffer = newBuf;
         }
     }
-    return shrinkCount;
+    return mutated ? buffer : undefined;
 }
 async function polyfillResponse(version, msgTitle, buffer) {
     const polyfillers = getPolyfillers(version);

msg-polyfill/index.ts

@@ -15,17 +15,15 @@ const getPolyfillers = (version: number) => {
 
 export async function polyfillGameMsg(version: number, msgTitle: string, buffer: Buffer) {
   const polyfillers = getPolyfillers(version);
-  let shrinkCount = 0;
+  let mutated = false;
   for (const polyfiller of polyfillers) {
-    await polyfiller.polyfillGameMsg(msgTitle, buffer);
-    if (polyfiller.shrinkCount > 0) {
-      if (polyfiller.shrinkCount === 0x3f3f3f3f) {
-        return 0x3f3f3f3f; // special case for cancel message
-      }
-      shrinkCount += polyfiller.shrinkCount;
+    const newBuf = await polyfiller.polyfillGameMsg(msgTitle, buffer);
+    if (newBuf) {
+      mutated = true;
+      buffer = newBuf;
     }
   }
-  return shrinkCount;
+  return mutated ? buffer : undefined;
 }
 
 export async function polyfillResponse(version: number, msgTitle: string, buffer: Buffer) {

msg-polyfill/polyfillers/0x1361.js

@@ -17,7 +17,7 @@ class Polyfiller1361 extends base_polyfiller_1.BasePolyfiller {
             // buf[0]: MSG_CONFIRM_CARDS
             // buf[1]: playerid
             // buf[2]: ADDED skip_panel
-            this.splice(buffer, 2, 1);
+            return this.splice(buffer, 2, 1);
         }
         else if (msgTitle === 'SELECT_CHAIN') {
             // buf[0]: MSG_SELECT_CHAIN
@@ -46,10 +46,10 @@ class Polyfiller1361 extends base_polyfiller_1.BasePolyfiller {
             // 从后往前 splice 每个 item 的 forced 字段
             for (let i = size - 1; i >= 0; i--) {
                 const itemOffset = itemStartOffset + i * 14;
-                this.splice(buffer, itemOffset + 1, 1); // 删除每个 item 的 forced（第 1 字节）
+                buffer = this.splice(buffer, itemOffset + 1, 1); // 删除每个 item 的 forced（第 1 字节）
             }
             // 最后再插入旧版所需的 forced 标志
-            this.insert(buffer, 4, Buffer.from([anyForced ? 1 : 0]));
+            return this.insert(buffer, 4, Buffer.from([anyForced ? 1 : 0]));
         }
         else if (msgTitle === 'SELECT_SUM') {
             // buf[0]: MSG_SELECT_SUM

msg-polyfill/polyfillers/0x1361.ts

@@ -15,7 +15,7 @@ export class Polyfiller1361 extends BasePolyfiller {
       // buf[0]: MSG_CONFIRM_CARDS
       // buf[1]: playerid
       // buf[2]: ADDED skip_panel
-      this.splice(buffer, 2, 1);
+      return this.splice(buffer, 2, 1);
     } else if (msgTitle === 'SELECT_CHAIN') {
       // buf[0]: MSG_SELECT_CHAIN
       // buf[1]: playerid
@@ -46,11 +46,11 @@ export class Polyfiller1361 extends BasePolyfiller {
       // 从后往前 splice 每个 item 的 forced 字段
       for (let i = size - 1; i >= 0; i--) {
         const itemOffset = itemStartOffset + i * 14;
-        this.splice(buffer, itemOffset + 1, 1); // 删除每个 item 的 forced（第 1 字节）
+        buffer = this.splice(buffer, itemOffset + 1, 1); // 删除每个 item 的 forced（第 1 字节）
       }
     
       // 最后再插入旧版所需的 forced 标志
-      this.insert(buffer, 4, Buffer.from([anyForced ? 1 : 0]));
+      return this.insert(buffer, 4, Buffer.from([anyForced ? 1 : 0]));
     } else if (msgTitle === 'SELECT_SUM') {
       // buf[0]: MSG_SELECT_SUM
       // buf[1]: 0 => equal, 1 => greater

ygopro-server.coffee

@@ -2594,11 +2594,11 @@ ygopro.stoc_follow 'GAME_MSG', true, (buffer, info, client, server, datas)->
   return unless room and !client.reconnecting
   msg = buffer.readInt8(0)
   msg_name = ygopro.constants.MSG[msg]
-  shrink_count = await msg_polyfill.polyfillGameMsg(client.actual_version, msg_name, buffer)
-  if shrink_count == 0x3f3f3f3f
-    return true
+  new_buf = await msg_polyfill.polyfillGameMsg(client.actual_version, msg_name, buffer)
+  if new_buf
+    buffer = new_buf
   record_last_game_msg = () ->
-    client.last_game_msg = Buffer.from(buffer.slice(0, buffer.length - shrink_count))
+    client.last_game_msg = new_buf or buffer
     client.last_game_msg_title = msg_name
   #console.log client.pos, "MSG", msg_name
   if msg_name == 'RETRY' and room.recovering
@@ -2873,8 +2873,8 @@ ygopro.stoc_follow 'GAME_MSG', true, (buffer, info, client, server, datas)->
       room.recover_buffers[client.pos].push(buffer)
     return true
 
-  if shrink_count > 0
-    return "_shrink_#{shrink_count}"
+  if new_buf
+    return buffer
   else
     return false
 

ygopro-server.js

@@ -3405,19 +3405,19 @@
   };
 
   ygopro.stoc_follow('GAME_MSG', true, async function(buffer, info, client, server, datas) {
-    var card, chain, check, count, cpos, deck_found, found, hint_type, i, id, j, l, len, len1, len2, len3, limbo_found, line, loc, m, max_loop, msg, msg_name, n, o, oppo_pos, phase, player, playertype, pos, ppos, reason, record_last_game_msg, ref, ref1, ref2, ref3, ref4, ref5, room, shrink_count, trigger_location, val, win_pos;
+    var card, chain, check, count, cpos, deck_found, found, hint_type, i, id, j, l, len, len1, len2, len3, limbo_found, line, loc, m, max_loop, msg, msg_name, n, new_buf, o, oppo_pos, phase, player, playertype, pos, ppos, reason, record_last_game_msg, ref, ref1, ref2, ref3, ref4, ref5, room, trigger_location, val, win_pos;
     room = ROOM_all[client.rid];
     if (!(room && !client.reconnecting)) {
       return;
     }
     msg = buffer.readInt8(0);
     msg_name = ygopro.constants.MSG[msg];
-    shrink_count = (await msg_polyfill.polyfillGameMsg(client.actual_version, msg_name, buffer));
-    if (shrink_count === 0x3f3f3f3f) {
-      return true;
+    new_buf = (await msg_polyfill.polyfillGameMsg(client.actual_version, msg_name, buffer));
+    if (new_buf) {
+      buffer = new_buf;
     }
     record_last_game_msg = function() {
-      client.last_game_msg = Buffer.from(buffer.slice(0, buffer.length - shrink_count));
+      client.last_game_msg = new_buf || buffer;
       return client.last_game_msg_title = msg_name;
     };
     //console.log client.pos, "MSG", msg_name
@@ -3792,8 +3792,8 @@
       }
       return true;
     }
-    if (shrink_count > 0) {
-      return `_shrink_${shrink_count}`;
+    if (new_buf) {
+      return buffer;
     } else {
       return false;
     }