Simplify message handling to avoid re-rendering

Only retrieve historical messages when starting the app.

This allows avoid re-rendering issues. This is an example dApp. No need
to waste time on React optimisation.

examples/web-chat/src/App.tsx

@@ -1,7 +1,7 @@
-import PeerId from 'peer-id';
-import { useEffect, useState } from 'react';
+import { useEffect, useReducer, useState } from 'react';
 import './App.css';
 import {
+  Direction,
   Environment,
   getStatusFleetNodes,
   StoreCodec,
@@ -48,7 +48,6 @@ export const ChatContentTopic = '/toy-chat/2/huilong/proto';
 
 async function retrieveStoreMessages(
   waku: Waku,
-  peerId: PeerId,
   setArchivedMessages: (value: Message[]) => void
 ): Promise<number> {
   const callback = (wakuMessages: WakuMessage[]): void => {
@@ -64,9 +63,9 @@ async function retrieveStoreMessages(
   };
 
   const res = await waku.store.queryHistory({
-    peerId,
     contentTopics: [ChatContentTopic],
     pageSize: 5,
+    direction: Direction.FORWARD,
     callback,
   });
 
@@ -74,13 +73,16 @@ async function retrieveStoreMessages(
 }
 
 export default function App() {
-  const [newMessages, setNewMessages] = useState<Message[]>([]);
-  const [archivedMessages, setArchivedMessages] = useState<Message[]>([]);
+  const [messages, dispatchMessages] = useReducer(reduceMessages, []);
   const [waku, setWaku] = useState<Waku | undefined>(undefined);
   const [nick, setNick] = useState<string>(() => {
     const persistedNick = window.localStorage.getItem('nick');
     return persistedNick !== null ? persistedNick : generate();
   });
+  const [
+    historicalMessagesRetrieved,
+    setHistoricalMessagesRetrieved,
+  ] = useState(false);
 
   useEffect(() => {
     localStorage.setItem('nick', nick);
@@ -94,12 +96,14 @@ export default function App() {
 
   useEffect(() => {
     if (!waku) return;
+    // Let's retrieve previous messages before listening to new messages
+    if (!historicalMessagesRetrieved) return;
 
     const handleRelayMessage = (wakuMsg: WakuMessage) => {
       console.log('Message received: ', wakuMsg);
       const msg = Message.fromWakuMessage(wakuMsg);
       if (msg) {
-        setNewMessages([msg]);
+        dispatchMessages([msg]);
       }
     };
 
@@ -108,45 +112,36 @@ export default function App() {
     return function cleanUp() {
       waku?.relay.deleteObserver(handleRelayMessage, [ChatContentTopic]);
     };
-  }, [waku]);
+  }, [waku, historicalMessagesRetrieved]);
 
   useEffect(() => {
     if (!waku) return;
+    if (historicalMessagesRetrieved) return;
 
-    const handleProtocolChange = async (
-      _waku: Waku,
-      { peerId, protocols }: { peerId: PeerId; protocols: string[] }
-    ) => {
-      if (protocols.includes(StoreCodec)) {
-        console.log(`${peerId.toB58String()}: retrieving archived messages}`);
-        try {
-          const length = await retrieveStoreMessages(
-            _waku,
-            peerId,
-            setArchivedMessages
-          );
-          console.log(`${peerId.toB58String()}: messages retrieved:`, length);
-        } catch (e) {
-          console.log(
-            `${peerId.toB58String()}: error encountered when retrieving archived messages`,
-            e
-          );
+    const connectedToStorePeer = new Promise((resolve) =>
+      waku.libp2p.peerStore.once(
+        'change:protocols',
+        ({ peerId, protocols }) => {
+          if (protocols.includes(StoreCodec)) {
+            resolve(peerId);
+          }
         }
-      }
-    };
-
-    waku.libp2p.peerStore.on(
-      'change:protocols',
-      handleProtocolChange.bind({}, waku)
+      )
     );
 
-    return function cleanUp() {
-      waku?.libp2p.peerStore.removeListener(
-        'change:protocols',
-        handleProtocolChange.bind({}, waku)
-      );
-    };
-  }, [waku]);
+    connectedToStorePeer.then(() => {
+      console.log(`Retrieving archived messages}`);
+      setHistoricalMessagesRetrieved(true);
+
+      try {
+        retrieveStoreMessages(waku, dispatchMessages).then((length) =>
+          console.log(`Messages retrieved:`, length)
+        );
+      } catch (e) {
+        console.log(`Error encountered when retrieving archived messages`, e);
+      }
+    });
+  }, [waku, historicalMessagesRetrieved]);
 
   return (
     <div
@@ -157,14 +152,13 @@ export default function App() {
         <ThemeProvider theme={themes}>
           <Room
             nick={nick}
-            newMessages={newMessages}
-            archivedMessages={archivedMessages}
+            messages={messages}
             commandHandler={(input: string) => {
               const { command, response } = handleCommand(input, waku, setNick);
               const commandMessages = response.map((msg) => {
                 return Message.fromUtf8String(command, msg);
               });
-              setNewMessages(commandMessages);
+              dispatchMessages(commandMessages);
             }}
           />
         </ThemeProvider>
@@ -207,3 +201,7 @@ function selectFleetEnv() {
     return Environment.Prod;
   }
 }
+
+function reduceMessages(state: Message[], newMessages: Message[]) {
+  return state.concat(newMessages);
+}

examples/web-chat/src/ChatList.tsx

@@ -1,91 +1,43 @@
-import { useEffect, useRef, useState } from 'react';
+import { memo, useEffect, useRef } from 'react';
 import {
   Message as LiveMessage,
   MessageText,
-  MessageGroup,
   MessageList,
 } from '@livechat/ui-kit';
 import { Message } from './Message';
 
 interface Props {
-  archivedMessages: Message[];
-  newMessages: Message[];
+  messages: Message[];
 }
 
+memo(ChatList);
+
 export default function ChatList(props: Props) {
-  const [messages, setMessages] = useState<Message[]>([]);
-  const [groupedMessages, setGroupedMessages] = useState<Message[][]>([]);
-  let updatedMessages;
-
-  if (IsThereNewMessages(props.newMessages, messages)) {
-    updatedMessages = messages.concat(props.newMessages);
-    if (IsThereNewMessages(props.archivedMessages, updatedMessages)) {
-      updatedMessages = copyMergeUniqueReplace(
-        props.archivedMessages,
-        updatedMessages
-      );
-    }
-  } else {
-    if (IsThereNewMessages(props.archivedMessages, messages)) {
-      updatedMessages = copyMergeUniqueReplace(
-        props.archivedMessages,
-        messages
-      );
-    }
-  }
-
-  if (updatedMessages) {
-    setGroupedMessages(groupMessagesBySender(updatedMessages));
-    setMessages(updatedMessages);
-  }
-
-  const renderedGroupedMessages = groupedMessages.map((currentMessageGroup) => (
-    <MessageGroup onlyFirstWithMeta>
-      {currentMessageGroup.map((currentMessage) => (
-        <LiveMessage
-          key={
-            currentMessage.sentTimestamp
-              ? currentMessage.sentTimestamp.valueOf()
-              : '' +
-                currentMessage.timestamp.valueOf() +
-                currentMessage.nick +
-                currentMessage.payloadAsUtf8
-          }
-          authorName={currentMessage.nick}
-          date={formatDisplayDate(currentMessage)}
-        >
-          <MessageText>{currentMessage.payloadAsUtf8}</MessageText>
-        </LiveMessage>
-      ))}
-    </MessageGroup>
+  const renderedMessages = props.messages.map((message) => (
+    <LiveMessage
+      key={
+        message.sentTimestamp
+          ? message.sentTimestamp.valueOf()
+          : '' +
+            message.timestamp.valueOf() +
+            message.nick +
+            message.payloadAsUtf8
+      }
+      authorName={message.nick}
+      date={formatDisplayDate(message)}
+    >
+      <MessageText>{message.payloadAsUtf8}</MessageText>
+    </LiveMessage>
   ));
 
   return (
     <MessageList active containScrollInSubtree>
-      {renderedGroupedMessages}
-      <AlwaysScrollToBottom newMessages={props.newMessages} />
+      {renderedMessages}
+      <AlwaysScrollToBottom messages={props.messages} />
     </MessageList>
   );
 }
 
-function groupMessagesBySender(messageArray: Message[]): Message[][] {
-  let currentSender = -1;
-  let lastNick = '';
-  let messagesBySender: Message[][] = [];
-  let currentSenderMessage = 0;
-
-  for (let currentMessage of messageArray) {
-    if (lastNick !== currentMessage.nick) {
-      currentSender++;
-      messagesBySender[currentSender] = [];
-      currentSenderMessage = 0;
-      lastNick = currentMessage.nick;
-    }
-    messagesBySender[currentSender][currentSenderMessage++] = currentMessage;
-  }
-  return messagesBySender;
-}
-
 function formatDisplayDate(message: Message): string {
   return message.timestamp.toLocaleString([], {
     month: 'short',
@@ -96,49 +48,14 @@ function formatDisplayDate(message: Message): string {
   });
 }
 
-const AlwaysScrollToBottom = (props: { newMessages: Message[] }) => {
+const AlwaysScrollToBottom = (props: { messages: Message[] }) => {
   const elementRef = useRef<HTMLDivElement>();
 
   useEffect(() => {
     // @ts-ignore
     elementRef.current.scrollIntoView();
-  }, [props.newMessages]);
+  }, [props.messages]);
 
   // @ts-ignore
   return <div ref={elementRef} />;
 };
-
-function IsThereNewMessages(
-  newValues: Message[],
-  currentValues: Message[]
-): boolean {
-  if (newValues.length === 0) return false;
-  if (currentValues.length === 0) return true;
-
-  return !newValues.find((newMsg) =>
-    currentValues.find(isEqual.bind({}, newMsg))
-  );
-}
-
-function copyMergeUniqueReplace(
-  newValues: Message[],
-  currentValues: Message[]
-) {
-  const copy = currentValues.slice();
-  newValues.forEach((msg) => {
-    if (!copy.find(isEqual.bind({}, msg))) {
-      copy.push(msg);
-    }
-  });
-  copy.sort((a, b) => a.timestamp.valueOf() - b.timestamp.valueOf());
-  return copy;
-}
-
-function isEqual(lhs: Message, rhs: Message): boolean {
-  return (
-    lhs.nick === rhs.nick &&
-    lhs.payloadAsUtf8 === rhs.payloadAsUtf8 &&
-    lhs.timestamp.valueOf() === rhs.timestamp.valueOf() &&
-    lhs.sentTimestamp?.valueOf() === rhs.sentTimestamp?.valueOf()
-  );
-}

examples/web-chat/src/Room.tsx

@@ -7,8 +7,7 @@ import { TitleBar } from '@livechat/ui-kit';
 import { Message } from './Message';
 
 interface Props {
-  newMessages: Message[];
-  archivedMessages: Message[];
+  messages: Message[];
   commandHandler: (cmd: string) => void;
   nick: string;
 }
@@ -32,10 +31,7 @@ export default function Room(props: Props) {
         leftIcons={`Peers: ${relayPeers} relay, ${storePeers} store.`}
         title="Waku v2 chat app"
       />
-      <ChatList
-        newMessages={props.newMessages}
-        archivedMessages={props.archivedMessages}
-      />
+      <ChatList messages={props.messages} />
       <MessageInput
         sendMessage={
           waku