修复提交疏漏

修改在查询群历史消息时，如未提供msg_seq，则返回最新消息

src/common/utils/MessageUnique.ts

@@ -61,6 +61,10 @@ class LimitedHashTable<K, V> {
       this.valueToKey.delete(value);
     }
   }
+
+  getKeyList(): K[] {
+    return Array.from(this.keyToValue.keys());
+  }
 }
 
 class MessageUniqueWrapper {
@@ -111,6 +115,25 @@ class MessageUniqueWrapper {
     this.msgIdMap.resize(maxSize);
     this.msgDataMap.resize(maxSize);
   }
+  getNthLatestShortIdByPeer(peer: Peer, index: number = 1): number | undefined {
+    const peerUid = peer.peerUid;
+    const chatType = peer.chatType;
+    const keys = this.msgDataMap.getKeyList();
+    const matches: number[] = [];
+    for (const key of keys) {
+      const [msgId, chatTypeStr, peerUidStr] = key.split('|');
+      if (peerUidStr === peerUid && chatTypeStr === chatType.toString()) {
+        const shortId = this.msgDataMap.getValue(key);
+        if (shortId) {
+          matches.push(shortId);
+        }
+      }
+    }
+    if (matches.length >= index) {
+      return matches[matches.length - index];
+    }
+    return undefined;
+  }
 }
 
 export const MessageUnique: MessageUniqueWrapper = new MessageUniqueWrapper();