Add a basic API for retrieving spark statistics

1 files changed, 73 insertions, 0 deletions

diff --git a/spark-api/src/main/java/me/lucko/spark/api/gc/GarbageCollector.java b/spark-api/src/main/java/me/lucko/spark/api/gc/GarbageCollector.java
new file mode 100644
index 0000000..b2c8801
--- /dev/null
+++ b/spark-api/src/main/java/me/lucko/spark/api/gc/GarbageCollector.java
@@ -0,0 +1,73 @@
+/*
+ * 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.api.gc;
+
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+/**
+ * Statistics about a garbage collector.
+ *
+ * <p>All time durations are measured in milliseconds.</p>
+ */
+public interface GarbageCollector {
+
+    /**
+     * Gets the name of the garbage collector.
+     *
+     * @return the name
+     */
+    @NonNull String name();
+
+    /**
+     * Gets the total number of collections performed.
+     *
+     * @return the total number of collections
+     */
+    long totalCollections();
+
+    /**
+     * Gets the total amount of time spent performing collections.
+     *
+     * <p>Measured in milliseconds.</p>
+     *
+     * @return the total time spent collecting
+     */
+    long totalTime();
+
+    /**
+     * Gets the average amount of time spent performing each collection.
+     *
+     * <p>Measured in milliseconds.</p>
+     *
+     * @return the average collection time
+     */
+    double avgTime();
+
+    /**
+     * Gets the average frequency at which collections are performed.
+     *
+     * <p>Measured in milliseconds.</p>
+     *
+     * @return the average frequency of collections
+     */
+    long avgFrequency();
+
+}