From b8b511e1912e60163b4c3d73edad4a56ab74e512 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9mi=20Cocula?= <rcocula@gmail.com>
Date: Tue, 17 Jan 2017 23:30:54 +0100
Subject: [PATCH] WIP metrics

---
 .../player/filter/MetricsFilter.java          |  15 ++-
 .../player/monitor/MetricsManager.java        | 119 ++++++++++++++++++
 2 files changed, 128 insertions(+), 6 deletions(-)
 create mode 100644 libresonic-main/src/main/java/org/libresonic/player/monitor/MetricsManager.java

diff --git a/libresonic-main/src/main/java/org/libresonic/player/filter/MetricsFilter.java b/libresonic-main/src/main/java/org/libresonic/player/filter/MetricsFilter.java
index eb58b7bb..f3f87d74 100644
--- a/libresonic-main/src/main/java/org/libresonic/player/filter/MetricsFilter.java
+++ b/libresonic-main/src/main/java/org/libresonic/player/filter/MetricsFilter.java
@@ -1,12 +1,12 @@
 package org.libresonic.player.filter;
 
-import com.codahale.metrics.ConsoleReporter;
 import com.codahale.metrics.JmxReporter;
 import com.codahale.metrics.MetricRegistry;
-import com.codahale.metrics.Timer;
+import org.libresonic.player.monitor.MetricsManager;
 
 import javax.servlet.*;
 import javax.servlet.http.HttpServletRequest;
+
 import java.io.IOException;
 import java.util.concurrent.TimeUnit;
 
@@ -31,12 +31,15 @@ public class MetricsFilter implements Filter {
     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
 
         HttpServletRequest httpServletRequest = (HttpServletRequest)request;
-        Timer requestTimer = metrics.timer(MetricRegistry.name(MetricsFilter.class, httpServletRequest.getRequestURI()));
 
-        Timer.Context requestTimerContext =  requestTimer.time();
+        String timerName = httpServletRequest.getRequestURI();
+        try (MetricsManager.Timer t = MetricsManager.buildTimer(this,timerName).condition(timerName.contains("main.view")).timer()) {
+            chain.doFilter(request, response);
+        }
 
-        chain.doFilter(request, response);
-        requestTimerContext.stop();
+      /*  MetricsManager.buildTimer(MetricsFilter.class,timerName).condition(timerName.contains("main.view")).exec(() -> {
+            chain.doFilter(request,response);
+        }); */
     }
 
     @Override
diff --git a/libresonic-main/src/main/java/org/libresonic/player/monitor/MetricsManager.java b/libresonic-main/src/main/java/org/libresonic/player/monitor/MetricsManager.java
new file mode 100644
index 00000000..86512022
--- /dev/null
+++ b/libresonic-main/src/main/java/org/libresonic/player/monitor/MetricsManager.java
@@ -0,0 +1,119 @@
+package org.libresonic.player.monitor;
+
+import com.codahale.metrics.JmxReporter;
+import com.codahale.metrics.MetricRegistry;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Created by remi on 17/01/17.
+ */
+public class MetricsManager {
+
+    private static final MetricRegistry metrics = new MetricRegistry();
+    private static JmxReporter reporter;
+    private static final NullTimer nullTimerSingleton = new NullTimer(null);
+
+    static {
+        reporter = JmxReporter.forRegistry(metrics)
+                .convertRatesTo(TimeUnit.SECONDS.SECONDS)
+                .convertDurationsTo(TimeUnit.MILLISECONDS)
+                .build();
+        reporter.start();
+    }
+
+
+    public static TimerBuilder buildTimer(Class clazz, String name) {
+        return new TimerBuilder(clazz,name);
+    }
+
+    public static TimerBuilder buildTimer(Object ref, String name) {
+        return new TimerBuilder(ref.getClass(),name);
+    }
+
+    public interface TimerExecutor {
+        void doWithTimer() throws Exception;
+    }
+
+
+    public static class TimerBuilder {
+        private Timer theTimer;
+        private Class clazz;
+        private String name;
+
+        public TimerBuilder() {
+        }
+
+        public TimerBuilder(Timer theTimer) {
+            this.theTimer = theTimer;
+        }
+
+        public TimerBuilder(Class clazz, String name) {
+            this.clazz = clazz;
+            this.name = name;
+        }
+
+        public TimerBuilder condition(boolean ifTrue) {
+            if (ifTrue == false) {
+                theTimer = nullTimerSingleton;
+            }
+            return this;
+        }
+
+        public Timer timer() {
+            if (theTimer == null) {
+                com.codahale.metrics.Timer t = metrics.timer(MetricRegistry.name(clazz,name));
+                com.codahale.metrics.Timer.Context tContext =  t.time();
+                theTimer = new Timer(tContext);
+            }
+            return theTimer;
+        }
+
+        public void exec(TimerExecutor executor) throws Exception {
+            if (theTimer == null) {
+                com.codahale.metrics.Timer t = metrics.timer(MetricRegistry.name(clazz, name));
+                com.codahale.metrics.Timer.Context tContext = t.time();
+                theTimer = new Timer(tContext);
+            }
+
+            executor.doWithTimer();
+
+            theTimer.close();
+        }
+    }
+
+    /**
+     *
+     */
+    public static class Timer implements AutoCloseable {
+
+        private com.codahale.metrics.Timer.Context timerContext;
+
+        protected Timer(com.codahale.metrics.Timer.Context timerContext) {
+            this.timerContext = timerContext;
+        }
+
+        @Override
+        public void close() {
+            timerContext.stop();
+        }
+
+        public Timer condition() {
+            return null;
+        }
+    }
+
+    private static class NullTimer extends Timer {
+
+        protected NullTimer(com.codahale.metrics.Timer.Context timerContext) {
+            super(timerContext);
+        }
+
+        @Override
+        public void close()  {
+            // Does nothing
+        }
+    }
+
+
+}