1 files changed, 61 insertions, 0 deletions
diff --git a/src/com/jsyn/engine/LoadAnalyzer.java b/src/com/jsyn/engine/LoadAnalyzer.java
new file mode 100644
index 0000000..cbf7ed5
--- /dev/null
+++ b/src/com/jsyn/engine/LoadAnalyzer.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2009 Phil Burk, Mobileer Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.jsyn.engine;
+
+/** Measure CPU load. */
+public class LoadAnalyzer {
+    private long stopTime;
+    private long previousStopTime;
+    private long startTime;
+    private double averageTotalTime;
+    private double averageOnTime;
+
+    protected LoadAnalyzer() {
+        stopTime = System.nanoTime();
+    }
+
+    /**
+     * Call this when you stop doing something. Ideally all of the time since start() was spent on
+     * doing something without interruption.
+     */
+    public void stop() {
+        previousStopTime = stopTime;
+        stopTime = System.nanoTime();
+        long onTime = stopTime - startTime;
+        long totalTime = stopTime - previousStopTime;
+        if (totalTime > 0) {
+            // Recursive averaging filter.
+            double rate = 0.01;
+            averageOnTime = (averageOnTime * (1.0 - rate)) + (onTime * rate);
+            averageTotalTime = (averageTotalTime * (1.0 - rate)) + (totalTime * rate);
+        }
+    }
+
+    /** Call this when you start doing something. */
+    public void start() {
+        startTime = System.nanoTime();
+    }
+
+    /** Calculate, on average, how much of the time was spent doing something. */
+    public double getAverageLoad() {
+        if (averageTotalTime > 0.0) {
+            return averageOnTime / averageTotalTime;
+        } else {
+            return 0.0;
+        }
+    }
+}