server chatches send errors and checks if the connection is still alive

bin/utils.js

@@ -7,6 +7,11 @@ const decoding = require('lib0/dist/decoding.js')
 const mutex = require('lib0/dist/mutex.js')
 const map = require('lib0/dist/map.js')
 
+const wsReadyStateConnecting = 0
+const wsReadyStateOpen = 1
+const wsReadyStateClosing = 2 // eslint-disable-line
+const wsReadyStateClosed = 3 // eslint-disable-line
+
 // disable gc when using snapshots!
 const gcEnabled = process.env.GC !== 'false' && process.env.GC !== '0'
 const persistenceDir = process.env.YPERSISTENCE
@@ -39,13 +44,17 @@ const afterTransaction = (transaction, doc) => {
     encoding.writeVarUint(encoder, messageSync)
     syncProtocol.writeUpdate(encoder, transaction.updateMessage)
     const message = encoding.toBuffer(encoder)
-    doc.conns.forEach((_, conn) => conn.send(message))
+    doc.conns.forEach((_, conn) => send(doc, conn, message))
   }
 }
 
 class WSSharedDoc extends Y.Y {
-  constructor () {
+  /**
+   * @param {string} name
+   */
+  constructor (name) {
     super({ gc: gcEnabled })
+    this.name = name
     this.mux = mutex.createMutex()
     /**
      * Maps from conn to set of controlled user ids. Delete all user ids from awareness when this conn is closed
@@ -78,7 +87,7 @@ const messageListener = (conn, doc, message) => {
       encoding.writeVarUint(encoder, messageSync)
       syncProtocol.readSyncMessage(decoder, encoder, doc, null)
       if (encoding.length(encoder) > 1) {
-        conn.send(encoding.toBuffer(encoder))
+        send(doc, conn, encoding.toBuffer(encoder))
       }
       break
     case messageAwareness: {
@@ -92,7 +101,7 @@ const messageListener = (conn, doc, message) => {
       })
       const buff = encoding.toBuffer(encoder)
       doc.conns.forEach((_, c) => {
-        c.send(buff)
+        send(doc, c, buff)
       })
       break
     }
@@ -100,26 +109,11 @@ const messageListener = (conn, doc, message) => {
 }
 
 /**
+ * @param {WSSharedDoc} doc
  * @param {any} conn
- * @param {any} req
  */
-exports.setupWSConnection = (conn, req) => {
-  conn.binaryType = 'arraybuffer'
-  // get doc, create if it does not exist yet
-  const docName = req.url.slice(1)
-  const doc = map.setIfUndefined(docs, docName, () => {
-    const doc = new WSSharedDoc()
-    if (persistence !== null) {
-      persistence.bindState(docName, doc)
-    }
-    docs.set(docName, doc)
-    return doc
-  })
-  doc.conns.set(conn, new Set())
-  // listen and reply to events
-  // @ts-ignore
-  conn.on('message', message => messageListener(conn, doc, message))
-  conn.on('close', () => {
+const closeConn = (doc, conn) => {
+  if (doc.conns.has(conn)) {
     /**
      * @type {Set<number>}
      */
@@ -135,20 +129,85 @@ exports.setupWSConnection = (conn, req) => {
       return { clientID, state: null, clock }
     }))
     const buf = encoding.toBuffer(encoder)
-    doc.conns.forEach((_, conn) => conn.send(buf))
+    doc.conns.forEach((_, conn) => {
+      send(doc, conn, buf)
+    })
     if (doc.conns.size === 0 && persistence !== null) {
       // if persisted, we store state and destroy ydocument
-      persistence.writeState(docName, doc).then(() => {
+      persistence.writeState(doc.name, doc).then(() => {
         doc.destroy()
       })
-      docs.delete(docName)
+      doc.conns.delete(doc.name)
     }
+  }
+  conn.close()
+}
+
+/**
+ * @param {WSSharedDoc} doc
+ * @param {any} conn
+ * @param {ArrayBuffer} m
+ */
+const send = (doc, conn, m) => {
+  if (conn.readyState !== wsReadyStateConnecting && conn.readyState !== wsReadyStateOpen) {
+    closeConn(doc, conn)
+  }
+  try {
+    conn.send(m, /** @param {any} err */ err => { err != null && closeConn(doc, conn) })
+  } catch (e) {
+    closeConn(doc, conn)
+  }
+}
+
+const pingTimeout = 30000
+
+/**
+ * @param {any} conn
+ * @param {any} req
+ */
+exports.setupWSConnection = (conn, req) => {
+  conn.binaryType = 'arraybuffer'
+  // get doc, create if it does not exist yet
+  const docName = req.url.slice(1)
+  const doc = map.setIfUndefined(docs, docName, () => {
+    const doc = new WSSharedDoc(docName)
+    if (persistence !== null) {
+      persistence.bindState(docName, doc)
+    }
+    docs.set(docName, doc)
+    return doc
+  })
+  doc.conns.set(conn, new Set())
+  // listen and reply to events
+  conn.on('message', /** @param {ArrayBuffer} message */ message => messageListener(conn, doc, message))
+  conn.on('close', () => {
+    closeConn(doc, conn)
+  })
+  // Check if connection is still alive
+  let pongReceived = true
+  const pingInterval = setInterval(() => {
+    if (!pongReceived) {
+      if (doc.conns.has(conn)) {
+        closeConn(doc, conn)
+      }
+      clearInterval(pingInterval)
+    } else if (doc.conns.has(conn)) {
+      pongReceived = false
+      try {
+        conn.ping()
+      } catch (e) {
+        closeConn(doc, conn)
+      }
+    }
+  }, pingTimeout)
+  conn.on('pong', () => {
+    pongReceived = true
   })
   // send sync step 1
   const encoder = encoding.createEncoder()
   encoding.writeVarUint(encoder, messageSync)
   syncProtocol.writeSyncStep1(encoder, doc.store)
-  conn.send(encoding.toBuffer(encoder))
+  send(doc, conn, encoding.toBuffer(encoder))
   if (doc.awareness.size > 0) {
     const encoder = encoding.createEncoder()
     /**
@@ -160,6 +219,6 @@ exports.setupWSConnection = (conn, req) => {
     })
     encoding.writeVarUint(encoder, messageAwareness)
     awarenessProtocol.writeUsersStateChange(encoder, userStates)
-    conn.send(encoding.toBuffer(encoder))
+    send(doc, conn, encoding.toBuffer(encoder))
   }
 }

package.json

@@ -34,17 +34,17 @@
   },
   "homepage": "https://github.com/y-js/y-websocket#readme",
   "dependencies": {
-    "y-protocols": "0.0.2"
+    "y-protocols": "0.0.3"
   },
   "devDependencies": {
     "rollup": "^1.1.2",
     "rollup-cli": "^1.0.9",
     "standard": "^12.0.1",
-    "yjs": "13.0.0-80"
+    "yjs": "13.0.0-81"
   },
   "peerDependenies": {
     "lib0": "*",
-    "yjs": "13.0.0-80"
+    "yjs": "13.0.0-81"
   },
   "optionalDependencies": {
     "ws": "^6.2.1"