Change the way CPU monitoring is performed

1 files changed, 53 insertions, 0 deletions

diff --git a/spark-common/src/main/java/me/lucko/spark/common/util/RollingAverage.java b/spark-common/src/main/java/me/lucko/spark/common/util/RollingAverage.java
new file mode 100644
index 0000000..5b1fd21
--- /dev/null
+++ b/spark-common/src/main/java/me/lucko/spark/common/util/RollingAverage.java
@@ -0,0 +1,53 @@
+/*
+ * This file is part of spark.
+ *
+ *  Copyright (c) lucko (Luck) <luck@lucko.me>
+ *  Copyright (c) contributors
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package me.lucko.spark.common.util;
+
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+import java.util.ArrayDeque;
+import java.util.Queue;
+
+public class RollingAverage {
+
+    private final Queue<BigDecimal> samples = new ArrayDeque<>();
+    private final int size;
+    private BigDecimal total = BigDecimal.ZERO;
+
+    public RollingAverage(int size) {
+        this.size = size;
+    }
+
+    public void add(BigDecimal num) {
+        this.total = this.total.add(num);
+        this.samples.add(num);
+        if (this.samples.size() > this.size) {
+            this.total = this.total.subtract(this.samples.remove());
+        }
+    }
+
+    public double getAverage() {
+        if (this.samples.isEmpty()) {
+            return 0;
+        }
+        return this.total.divide(BigDecimal.valueOf(this.samples.size()), 30, RoundingMode.HALF_UP).doubleValue();
+    }
+
+}