Close gap to original pvws project

georgweiss · georgweiss · commit 850cf5330681 · 2025-04-17T15:44:01.000+02:00
diff --git a/src/main/java/org/phoebus/pvws/PvwsWebListener.java b/src/main/java/org/phoebus/pvws/PvwsWebListener.java
@@ -38,7 +38,6 @@ public class PvwsWebListener implements ServletContextListener {
 
     @Override
     public void contextDestroyed(ServletContextEvent event) {
-        System.out.println("sdjhgfdfugh");
         WebApplicationContext context = ContextLoader.getCurrentWebApplicationContext();
         sockets = (List<WebSocket>) context.getBean("sockets");
         if (sockets == null) {
diff --git a/src/main/java/org/phoebus/pvws/ws/Vtype2Json.java b/src/main/java/org/phoebus/pvws/ws/Vtype2Json.java
@@ -17,7 +17,9 @@
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.nio.DoubleBuffer;
+import java.nio.FloatBuffer;
 import java.nio.IntBuffer;
+import java.nio.ShortBuffer;
 import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.text.DecimalFormat;
@@ -58,15 +60,15 @@ else if (value instanceof VString)
         else if (value instanceof VEnum)
             handleEnum(g, (VEnum) value, last_value);
         else if (value instanceof VByteArray)
-            handleLongString(g, (VByteArray) value);
+            handleBytes(g, (VNumberArray) value, last_value);
 
         // Serialize double and float arrays as b64dbl
         else if (value instanceof VDoubleArray)
             handleDoubles(g, (VNumberArray) value, last_value);
         else if (value instanceof VFloatArray)
-            handleDoubles(g, (VNumberArray) value, last_value);
+            handleFloats(g, (VNumberArray) value, last_value);
 
-        // Serialize remaining number arrays (int, short) as b64int
+            // Serialize remaining number arrays (int) as b64int
         else if (value instanceof VNumberArray)
             handleInts(g, (VNumberArray) value, last_value);
 
@@ -239,7 +241,7 @@ private static void handleInts(final JsonGenerator g, final VNumberArray value,
         {
             // Add severity if it changed
             if ((last_value instanceof VNumber)  &&
-                ((VNumber) last_value).getAlarm().getSeverity() != severity)
+                    ((VNumber) last_value).getAlarm().getSeverity() != severity)
                 g.writeStringField("severity", severity.name());
         }
 
@@ -256,6 +258,7 @@ private static void handleInts(final JsonGenerator g, final VNumberArray value,
     }
 
 
+
     private static void handleEnum(final JsonGenerator g, final VEnum value, final VType last_value) throws Exception
     {
         final AlarmSeverity severity = value.getAlarm().getSeverity();
@@ -275,11 +278,98 @@ private static void handleEnum(final JsonGenerator g, final VEnum value, final V
         {
             // Add severity if it changed
             if ((last_value instanceof VNumber)  &&
-                ((VNumber) last_value).getAlarm().getSeverity() != severity)
+                    ((VNumber) last_value).getAlarm().getSeverity() != severity)
                 g.writeStringField("severity", severity.name());
         }
 
         g.writeNumberField("value",  value.getIndex());
         g.writeStringField("text",  value.getValue());
     }
+
+    private static void handleFloats(final JsonGenerator g, final VNumberArray value, final VType last_value) throws Exception
+    {
+        final AlarmSeverity severity = value.getAlarm().getSeverity();
+        if (last_value == null)
+        {
+            // Initially, add complete metadata
+            g.writeStringField("vtype", VType.typeOf(value).getSimpleName());
+            handleDisplay(g, value.getDisplay());
+            // Initial severity
+            g.writeStringField("severity", severity.name());
+        }
+        else
+        {
+            // Add severity if it changed
+            if ((last_value instanceof VNumber)  &&
+                    ((VNumber) last_value).getAlarm().getSeverity() != severity)
+                g.writeStringField("severity", severity.name());
+        }
+
+        final ListNumber data = value.getData();
+        final int N = data.size();
+        final ByteBuffer buf = ByteBuffer.allocate(N * Float.BYTES);
+        buf.order(ByteOrder.LITTLE_ENDIAN);
+        final FloatBuffer fltbuf = buf.asFloatBuffer();
+        for (int i=0; i<N; ++i)
+            fltbuf.put(data.getFloat(i));
+        g.writeStringField("b64flt", Base64.getEncoder().encodeToString(buf.array()));
+    }
+
+    private static void handleShorts(final JsonGenerator g, final VNumberArray value, final VType last_value) throws Exception
+    {
+        final AlarmSeverity severity = value.getAlarm().getSeverity();
+        if (last_value == null)
+        {
+            // Initially, add complete metadata
+            g.writeStringField("vtype", VType.typeOf(value).getSimpleName());
+            handleDisplay(g, value.getDisplay());
+            // Initial severity
+            g.writeStringField("severity", severity.name());
+        }
+        else
+        {
+            // Add severity if it changed
+            if ((last_value instanceof VNumber)  &&
+                    ((VNumber) last_value).getAlarm().getSeverity() != severity)
+                g.writeStringField("severity", severity.name());
+        }
+
+        final ListNumber data = value.getData();
+        final int N = data.size();
+        final ByteBuffer buf = ByteBuffer.allocate(N * Short.BYTES);
+        buf.order(ByteOrder.LITTLE_ENDIAN);
+        final ShortBuffer srtbuf = buf.asShortBuffer();
+        for (int i=0; i<N; ++i)
+            srtbuf.put(data.getShort(i));
+        g.writeStringField("b64srt", Base64.getEncoder().encodeToString(buf.array()));
+    }
+
+    private static void handleBytes(final JsonGenerator g, final VNumberArray value, final VType last_value) throws Exception
+    {
+        final AlarmSeverity severity = value.getAlarm().getSeverity();
+        if (last_value == null)
+        {
+            // Initially, add complete metadata
+            g.writeStringField("vtype", VType.typeOf(value).getSimpleName());
+            handleDisplay(g, value.getDisplay());
+            // Initial severity
+            g.writeStringField("severity", severity.name());
+        }
+        else
+        {
+            // Add severity if it changed
+            if ((last_value instanceof VNumber)  &&
+                    ((VNumber) last_value).getAlarm().getSeverity() != severity)
+                g.writeStringField("severity", severity.name());
+        }
+
+        // Convert into Base64 int64 array
+        final ListNumber data = value.getData();
+        final int N = data.size();
+        final ByteBuffer buf = ByteBuffer.allocate(N * Byte.BYTES);
+        buf.order(ByteOrder.LITTLE_ENDIAN);
+        for (int i=0; i<N; ++i)
+            buf.put(data.getByte(i));
+        g.writeStringField("b64byt", Base64.getEncoder().encodeToString(buf.array()));
+    }
 }
diff --git a/src/main/resources/static/js/pvws.js b/src/main/resources/static/js/pvws.js
@@ -17,7 +17,21 @@ class PVWS
         this.url = url;
         this.connect_handler = connect_handler;
         this.message_handler = message_handler;
-        
+
+        // In local tests, the web socket tends to stay open indefinitely,
+        // but in production setups with proxies etc. they often time out
+        // after about a minute of inactivity.
+        // The server side could periodically 'ping' from the SessionManager,
+        // or the client could send periodic 'echo' messages.
+        // We combine both approaches by having the client send ping requests
+        // when the connection is idle. The server will then issue the ping,
+        // and the client should return a pong (but there's no way to see that ping/pong in javascript).
+
+        // Is the connection idle? Any received message marks as non-idle.
+        this.idle = true;
+        // While connected, call checkIdleTimeout() via this timer
+        this.idle_timer = null;
+
         // Map of PVs to last known value,
         // merging metadata and value updates.
         this.values = {}
@@ -29,21 +43,48 @@ class PVWS
         this.connect_handler(false);
         console.log("Opening " + this.url);
         this.socket = new WebSocket(this.url);
-        this.socket.onopen = event => this.handleConnection();
+        this.socket.onopen = event => this.handleConnection(event);
         this.socket.onmessage = event => this.handleMessage(event.data);
         this.socket.onclose = event => this.handleClose(event);
         this.socket.onerror = event => this.handleError(event);
     }
-    
-    handleConnection()
+
+    handleConnection(event)
     {
         console.log("Connected to " + this.url);
         this.connect_handler(true);
+
+        // Start idle check
+        if (this.idle_timer == null)
+            this.idle_timer = setInterval(() => this.checkIdleTimeout(), this.idle_check_ms);
     }
-    
+
+    checkIdleTimeout()
+    {
+        if (this.idle)
+        {
+            // console.log("Idle connection " + this.url);
+            this.ping();
+        }
+        else
+        {
+            // console.log("Active connection " + this.url);
+            // Reset to detect new messages
+            this.idle = true;
+        }
+    }
+
+    stopIdleCheck()
+    {
+        if (this.idle_timer != null)
+            clearInterval(this.idle_timer);
+        this.idle_timer = null;
+    }
+
     handleMessage(message)
     {
         // console.log("Received Message: " + message);
+        this.idle = false;
         let jm = JSON.parse(message);
         if (jm.type === "update")
         {
@@ -62,6 +103,22 @@ class PVWS
                 // console.log(JSON.stringify(jm.value));
                 delete jm.b64dbl;
             }
+            else if (jm.b64flt !== undefined)
+            {
+                let bytes = toByteArray(jm.b64flt);
+                jm.value = new Float32Array(bytes.buffer);
+                // Convert to plain array
+                jm.value = Array.prototype.slice.call(jm.value);
+                delete jm.b64flt;
+            }
+            else if (jm.b64srt !== undefined)
+            {
+                let bytes = toByteArray(jm.b64srt);
+                jm.value = new Int16Array(bytes.buffer);
+                // Convert to plain array
+                jm.value = Array.prototype.slice.call(jm.value);
+                delete jm.b64srt;
+            }
             else if (jm.b64int !== undefined)
             {
                 let bytes = toByteArray(jm.b64int);
@@ -70,14 +127,22 @@ class PVWS
                 jm.value = Array.prototype.slice.call(jm.value);
                 delete jm.b64int;
             }
-                
+            else if (jm.b64byt !== undefined)
+            {
+                let bytes = toByteArray(jm.b64byt);
+                jm.value = new Uint8Array(bytes.buffer);
+                // Convert to plain array, if necessary
+                jm.value = Array.prototype.slice.call(jm.value);
+                delete jm.b64byt;
+            }
+
             // Merge received data with last known value
             let value = this.values[jm.pv];
             // No previous value:
             // Default to read-only, no data
             if (value === undefined)
                 value = { pv: jm.pv, readonly: true };
-            
+
             // Update cached value with received changes
             Object.assign(value, jm);
             this.values[jm.pv] = value;
@@ -94,9 +159,10 @@ class PVWS
         console.error(event);
         this.close();
     }
-    
+
     handleClose(event)
     {
+        this.stopIdleCheck();
         this.connect_handler(false);
         let message = "Web socket closed (" +  event.code ;
         if (event.reason)
@@ -114,17 +180,17 @@ class PVWS
      */
     ping()
     {
+        console.log("Sending ping to " + this.url);
         this.socket.send(JSON.stringify({ type: "ping" }))
     }
-    
+
     /** Subscribe to one or more PVs
      *  @param pvs PV name or array of PV names
      */
     subscribe(pvs)
     {
         if (pvs.constructor !== Array)
             pvs = [ pvs ];
-        // TODO Remember all PVs so we can re-subscribe after close/re-open
         this.socket.send(JSON.stringify({ type: "subscribe", pvs: pvs }));
     }
 
@@ -135,21 +201,20 @@ class PVWS
     {
         if (pvs.constructor !== Array)
             pvs = [ pvs ];
-        // TODO Forget PVs so we don't re-subscribe after close/re-open
         this.socket.send(JSON.stringify({ type: "clear", pvs: pvs }));
-        
+
         // Remove entry for cleared PVs from this.values
         let pv;
         for (pv of pvs)
             delete this.values[pv];
     }
-    
+
     /** Request list of PVs */
     list()
     {
         this.socket.send(JSON.stringify({ type: "list" }));
     }
-    
+
     /** Write to PV
      *  @param pvs PV name
      *  @param value number or string
@@ -158,17 +223,20 @@ class PVWS
     {
         this.socket.send(JSON.stringify({ type: "write", pv: pv, value: value }));
     }
-    
+
     /** Close the web socket.
-     * 
+     *
      *  <p>Socket will automatically re-open,
      *  similar to handling an error.
      */
     close()
     {
+        this.stopIdleCheck();
         this.socket.close();
     }
 }
 
-// TODO Larger timeout for production setup
-PVWS.prototype.reconnect_ms = 5000;
+// Attempt re-connect after 10 seconds
+PVWS.prototype.reconnect_ms = 10000;
+// Perform idle check every 30 secs
+PVWS.prototype.idle_check_ms = 30000;
