[WIP] Persist server state

server/FileUtils.js

@@ -0,0 +1,56 @@
+import fs from 'fs'
+
+export default class FileUtils {
+    constructor() {}
+
+    static readJSONFromPath(filepath) {
+        let retObj
+        try {
+            console.log(`Reading from ${filepath}...`)
+            let file = fs.readFileSync(filepath, 'utf8')
+            retObj = JSON.parse(file)
+            console.log(`Successfully parsed: ${JSON.stringify(retObj)}`)
+        } catch (e) {
+            console.log(`Error reading from ${filepath}}: ${e}`)
+        }
+        return retObj
+    }
+
+    static readJSONArray(filepath) {
+        let retArr = []
+        try {
+            console.log(`Reading from ${filepath}...`)
+            let data = fs.readFileSync(filepath, 'utf8')
+            let datArr = data.split("\n")
+            for (let i = 0; i < datArr.length; i++) {
+                try {
+                    retArr[i] = JSON.parse(datArr[i])
+                    console.log(`Item index ${i} of ${filepath}: ${datArr[i]}`)
+                } catch (e) {
+                    console.log(`Error parsing item ${i}: ${datArr[i]}`)
+                }
+            }
+            console.log(`Finished reading ${filepath}`)
+        } catch (e) {
+            console.log(`Error reading from ${filepath}}: ${e}`)
+        }
+        return retArr
+    }
+
+    static arrayOfJSONToString(arr) {
+        let retString = ""
+        for (const element of arr) {
+            retString += JSON.stringify(element) + "\n"
+        }
+        return retString.trimEnd()
+    }
+
+    static writeToPath(filepath, data) {
+        console.log(`Writing to ${filepath}`)
+        fs.writeFileSync(filepath, data, { flag: 'w' }, (err) => {
+            if (err) {
+                console.log(`Error writing ${data} to ${filepath}: ${err}`)
+            }
+        })
+    }
+}

server/PriorityQ.js

@@ -18,7 +18,15 @@ export default class PriorityQ {
     // 
     pollingRate = 50
 
-    constructor() { }
+    constructor() {}
+
+    initFromObject(object) {
+        // doesn't avoid deep copy issues. mostly for reading in from json object
+        this.qMap = object.qMap
+        this.users = object.users
+        this.head = object.head
+        this.length = object.length
+    }
 
     push(song) {
         if (!this.inUse) {

server/server.js

@@ -3,17 +3,23 @@ const { Server, OPEN } = pkg
 import fetch from 'node-fetch';
 import Song from './Song.js';
 import PriorityQ from './PriorityQ.js';
+import FileUtils from './FileUtils.js'
 
 const wss = new Server({ port: 3030 });
 
+const BASE_PATH = process.env.DSC_BASE_PATH
+const songQPath = `${BASE_PATH}/songq.json`
+const chatPath = `${BASE_PATH}/chat.txt`
+const songHistoryPath = `${BASE_PATH}/song_history.txt`
+
 const userList = [];
 
-const messages = [];
+var messages = [];
 const MAX_MESSAGES = 200;
 
-const songQueue = new PriorityQ(); //handle max song queue limit on frontend
+const songQueue = new PriorityQ() //handle max song queue limit on frontend
 
-const songHistory = []; 
+var songHistory = [];
 const MAX_SONGS_IN_HISTORY = 100;
 
 let nowPlaying = {};
@@ -34,6 +40,30 @@ const timerInterval = setInterval(() => {
   }
 }, 1000);
 
+{
+  // in method for single try/catch
+  try {
+    messages = FileUtils.readJSONArray(chatPath)
+    songHistory = FileUtils.readJSONArray(songHistoryPath)
+
+    const songQFromFile = FileUtils.readJSONFromPath(songQPath)
+    if (songQFromFile) { songQueue.initFromObject(songQFromFile) }
+  } catch (e) {
+    console.log(`Error reading state from files: ${e}`)
+  }
+}
+
+const persistChat = () => {
+  let messagesString = FileUtils.arrayOfJSONToString(messages)
+  FileUtils.writeToPath(chatPath, messagesString)
+}
+
+const persistSongState = () => {
+  let songHistoryString = FileUtils.arrayOfJSONToString(songHistory)
+  FileUtils.writeToPath(songHistoryPath, songHistoryString)
+  FileUtils.writeToPath(songQPath, JSON.stringify(songQueue))
+}
+
 const broadcast = (data) => {
   wss.clients.forEach((client) => {
     if (client.readyState === OPEN) {
@@ -104,14 +134,15 @@ const addMessage = (message) => {
     }
   );
 
+  persistChat()
   broadcast(data);
 };
 
 const getOEmbedData = async (url) => {
   // hacky way to check if soundcloud
   if (url.includes('soundcloud.')) {
     const fetchUrl = `https://www.soundcloud.com/oembed?url=${url}&format=json`;
-    
+
     const response = await fetch(fetchUrl);
 
     return response.json();
@@ -128,8 +159,6 @@ const getOEmbedData = async (url) => {
 };
 
 const addSong = async (username, url, label, duration) => {
-  // TODO: order the queue so that each user takes turn playing songs, maybe not necessarily here
-
   // create song object
   let newSong = new Song(username, url, label, duration);
 
@@ -139,11 +168,11 @@ const addSong = async (username, url, label, duration) => {
 
     //hacky way to fix react-player not being able to play the same url twice in a row 
     // -- adding ?in to the end of the url seems to still let it play for both yt and sc
-    if (songQueue.length > 0 && songQueue.getSongAtIndex(songQueue.length - 1).url === url) { 
+    if (songQueue.length > 0 && songQueue.getSongAtIndex(songQueue.length - 1).url === url) {
       newSong.url = `${url}?in`;
       newSong.label = oEmbedData.title;
-    } 
-    
+    }
+
     else {
       newSong.label = oEmbedData.title
     };
@@ -154,13 +183,14 @@ const addSong = async (username, url, label, duration) => {
 
   let flatQ = songQueue.flatten()
   const data = JSON.stringify(
-    
+
     {
       type: 'addSong',
       songQueue: flatQ
     }
   );
 
+  persistSongState()
   broadcast(data);
 };
 
@@ -181,16 +211,17 @@ const removeSong = (index) => {
     }
   );
 
+  persistSongState()
   broadcast(data);
 };
 
 const nextSong = () => {
   nowPlaying = {};
   seekTime = 0;
 
-  const timestamp = new Date().toLocaleTimeString([], { hour12: false, hour: '2-digit', minute: '2-digit' }); 
-  songHistory.unshift({...songQueue.shift(), timestamp});
-  
+  const timestamp = new Date().toLocaleTimeString([], { hour12: false, hour: '2-digit', minute: '2-digit' });
+  songHistory.unshift({ ...songQueue.shift(), timestamp });
+
   if (songHistory.length > MAX_SONGS_IN_HISTORY) {
     songHistory.pop();
   };
@@ -205,6 +236,7 @@ const nextSong = () => {
     }
   );
 
+  persistSongState()
   broadcast(data);
 };
 
@@ -214,9 +246,9 @@ wss.on('connection', (ws) => {
 
   ws.on('message', (data) => {
     console.log(data);
-    
+
     // HH:mm format
-    const timestamp = new Date().toLocaleTimeString([], { hour12: false, hour: '2-digit', minute: '2-digit' }); 
+    const timestamp = new Date().toLocaleTimeString([], { hour12: false, hour: '2-digit', minute: '2-digit' });
 
     const clientMessage = JSON.parse(data);
     switch (clientMessage.type) {
@@ -235,7 +267,7 @@ wss.on('connection', (ws) => {
       case 'chat':
         addMessage({
           message: clientMessage.message,
-          username, 
+          username,
           type: 'chat',
           timestamp
         });
@@ -272,7 +304,7 @@ wss.on('connection', (ws) => {
 
   ws.on('close', () => {
     // HH:mm format
-    const timestamp = new Date().toLocaleTimeString([], { hour12: false, hour: '2-digit', minute: '2-digit' }); 
+    const timestamp = new Date().toLocaleTimeString([], { hour12: false, hour: '2-digit', minute: '2-digit' });
 
     addMessage({
       username,