Report average collection frequency in '/spark gc'

3 files changed, 151 insertions, 18 deletions

diff --git a/spark-common/src/main/java/me/lucko/spark/common/SparkPlatform.java b/spark-common/src/main/java/me/lucko/spark/common/SparkPlatform.java
index 50ef7d8..4d6557b 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/SparkPlatform.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/SparkPlatform.java
@@ -21,6 +21,7 @@
 package me.lucko.spark.common;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import me.lucko.spark.common.activitylog.ActivityLog;
 import me.lucko.spark.common.command.Arguments;
 import me.lucko.spark.common.command.Command;
@@ -36,6 +37,7 @@ import me.lucko.spark.common.command.sender.CommandSender;
 import me.lucko.spark.common.command.tabcomplete.CompletionSupplier;
 import me.lucko.spark.common.command.tabcomplete.TabCompleter;
 import me.lucko.spark.common.monitor.cpu.CpuMonitor;
+import me.lucko.spark.common.monitor.memory.GarbageCollectorStatistics;
 import me.lucko.spark.common.monitor.tick.TickStatistics;
 import me.lucko.spark.common.sampler.tick.TickHook;
 import me.lucko.spark.common.sampler.tick.TickReporter;
@@ -50,6 +52,7 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 /**
@@ -71,6 +74,8 @@ public class SparkPlatform {
     private final TickHook tickHook;
     private final TickReporter tickReporter;
     private final TickStatistics tickStatistics;
+    private Map<String, GarbageCollectorStatistics> startupGcStatistics = ImmutableMap.of();
+    private long serverNormalOperationStartTime;
 
     public SparkPlatform(SparkPlugin plugin) {
         this.plugin = plugin;
@@ -108,6 +113,12 @@ public class SparkPlatform {
             this.tickReporter.start();
         }
         CpuMonitor.ensureMonitoring();
+
+        // poll startup GC statistics after plugins & the world have loaded
+        this.plugin.executeAsync(() -> {
+            this.startupGcStatistics = GarbageCollectorStatistics.pollStats();
+            this.serverNormalOperationStartTime = System.currentTimeMillis();
+        });
     }
 
     public void disable() {
@@ -143,6 +154,14 @@ public class SparkPlatform {
         return this.tickStatistics;
     }
 
+    public Map<String, GarbageCollectorStatistics> getStartupGcStatistics() {
+        return this.startupGcStatistics;
+    }
+
+    public long getServerNormalOperationStartTime() {
+        return this.serverNormalOperationStartTime;
+    }
+
     public void executeCommand(CommandSender sender, String[] args) {
         CommandResponseHandler resp = new CommandResponseHandler(this, sender);
 
diff --git a/spark-common/src/main/java/me/lucko/spark/common/command/modules/GcMonitoringModule.java b/spark-common/src/main/java/me/lucko/spark/common/command/modules/GcMonitoringModule.java
index 2e67a99..6330797 100644
--- a/spark-common/src/main/java/me/lucko/spark/common/command/modules/GcMonitoringModule.java
+++ b/spark-common/src/main/java/me/lucko/spark/common/command/modules/GcMonitoringModule.java
@@ -26,14 +26,13 @@ import me.lucko.spark.common.command.Command;
 import me.lucko.spark.common.command.CommandModule;
 import me.lucko.spark.common.command.CommandResponseHandler;
 import me.lucko.spark.common.monitor.memory.GarbageCollectionMonitor;
+import me.lucko.spark.common.monitor.memory.GarbageCollectorStatistics;
 import me.lucko.spark.common.util.FormatUtil;
 import net.kyori.text.Component;
 import net.kyori.text.TextComponent;
 import net.kyori.text.format.TextColor;
 import net.kyori.text.format.TextDecoration;
 
-import java.lang.management.GarbageCollectorMXBean;
-import java.lang.management.ManagementFactory;
 import java.lang.management.MemoryUsage;
 import java.text.DecimalFormat;
 import java.util.LinkedList;
@@ -60,26 +59,30 @@ public class GcMonitoringModule implements CommandModule {
         consumer.accept(Command.builder()
                 .aliases("gc")
                 .executor((platform, sender, resp, arguments) -> {
-                    resp.replyPrefixed(TextComponent.of("Calculating GC collection averages..."));
+                    resp.replyPrefixed(TextComponent.of("Calculating GC statistics..."));
 
                     List<Component> report = new LinkedList<>();
                     report.add(TextComponent.empty());
                     report.add(TextComponent.builder("")
                             .append(TextComponent.builder(">").color(TextColor.DARK_GRAY).decoration(TextDecoration.BOLD, true).build())
                             .append(TextComponent.space())
-                            .append(TextComponent.of("GC collection averages", TextColor.GOLD))
+                            .append(TextComponent.of("Garbage Collector statistics", TextColor.GOLD))
                             .build()
                     );
 
-                    for (GarbageCollectorMXBean collector : ManagementFactory.getGarbageCollectorMXBeans()) {
-                        double collectionTime = collector.getCollectionTime();
-                        long collectionCount = collector.getCollectionCount();
+                    long serverUptime = System.currentTimeMillis() - platform.getServerNormalOperationStartTime();
+                    Map<String, GarbageCollectorStatistics> collectorStats = GarbageCollectorStatistics.pollStatsSubtractInitial(platform.getStartupGcStatistics());
+
+                    for (Map.Entry<String, GarbageCollectorStatistics> collector : collectorStats.entrySet()) {
+                        String collectorName = collector.getKey();
+                        double collectionTime = collector.getValue().getCollectionTime();
+                        long collectionCount = collector.getValue().getCollectionCount();
 
                         report.add(TextComponent.empty());
 
                         if (collectionCount == 0) {
                             report.add(TextComponent.builder("    ")
-                                    .append(TextComponent.of(collector.getName() + " collector:", TextColor.GRAY))
+                                    .append(TextComponent.of(collectorName + " collector:", TextColor.GRAY))
                                     .build()
                             );
                             report.add(TextComponent.builder("      ")
@@ -91,9 +94,10 @@ public class GcMonitoringModule implements CommandModule {
                         }
 
                         double averageCollectionTime = collectionTime / collectionCount;
+                        double averageFrequency = (serverUptime - collectionTime) / collectionCount;
 
                         report.add(TextComponent.builder("    ")
-                                .append(TextComponent.of(collector.getName() + " collector:", TextColor.GRAY))
+                                .append(TextComponent.of(collectorName + " collector:", TextColor.GRAY))
                                 .build()
                         );
                         report.add(TextComponent.builder("      ")
@@ -104,6 +108,11 @@ public class GcMonitoringModule implements CommandModule {
                                 .append(TextComponent.of(" total collections", TextColor.GRAY))
                                 .build()
                         );
+                        report.add(TextComponent.builder("      ")
+                                .append(TextComponent.of(formatTime((long) averageFrequency), TextColor.WHITE))
+                                .append(TextComponent.of(" avg frequency", TextColor.GRAY))
+                                .build()
+                        );
                     }
 
                     if (report.size() == 1) {
@@ -130,6 +139,30 @@ public class GcMonitoringModule implements CommandModule {
         );
     }
 
+    private static String formatTime(long millis) {
+        if (millis <= 0) {
+            return "0ms";
+        }
+
+        long second = millis / 1000;
+        millis = millis % 1000;
+        long minute = second / 60;
+        second = second % 60;
+
+        StringBuilder sb = new StringBuilder();
+        if (minute != 0) {
+            sb.append(minute).append("m ");
+        }
+        if (second != 0) {
+            sb.append(second).append("s ");
+        }
+        if (millis != 0) {
+            sb.append(millis).append("ms");
+        }
+
+        return sb.toString().trim();
+    }
+
     private static class ReportingGcMonitor extends GarbageCollectionMonitor implements GarbageCollectionMonitor.Listener {
         private final SparkPlatform platform;
         private final CommandResponseHandler resp;
@@ -193,13 +226,13 @@ public class GcMonitoringModule implements CommandModule {
                                 .build()
                         );
                         report.add(TextComponent.builder("    ")
-                                .append(TextComponent.of(FormatUtil.formatBytes(before.getUsed()), TextColor.WHITE))
-                                .append(TextComponent.of(" → ", TextColor.GRAY))
-                                .append(TextComponent.of(FormatUtil.formatBytes(after.getUsed()), TextColor.WHITE))
+                                .append(TextComponent.of(FormatUtil.formatBytes(before.getUsed()), TextColor.GRAY))
+                                .append(TextComponent.of(" → ", TextColor.DARK_GRAY))
+                                .append(TextComponent.of(FormatUtil.formatBytes(after.getUsed()), TextColor.GRAY))
                                 .append(TextComponent.space())
-                                .append(TextComponent.of("(", TextColor.GRAY))
-                                .append(TextComponent.of(FormatUtil.percent(diff, before.getUsed()), TextColor.GREEN))
-                                .append(TextComponent.of(")", TextColor.GRAY))
+                                .append(TextComponent.of("(", TextColor.DARK_GRAY))
+                                .append(TextComponent.of(FormatUtil.percent(diff, before.getUsed()), TextColor.WHITE))
+                                .append(TextComponent.of(")", TextColor.DARK_GRAY))
                                 .build()
                         );
                     } else {
@@ -210,9 +243,9 @@ public class GcMonitoringModule implements CommandModule {
                                 .build()
                         );
                         report.add(TextComponent.builder("    ")
-                                .append(TextComponent.of(FormatUtil.formatBytes(before.getUsed()), TextColor.WHITE))
-                                .append(TextComponent.of(" → ", TextColor.GRAY))
-                                .append(TextComponent.of(FormatUtil.formatBytes(after.getUsed()), TextColor.WHITE))
+                                .append(TextComponent.of(FormatUtil.formatBytes(before.getUsed()), TextColor.GRAY))
+                                .append(TextComponent.of(" → ", TextColor.DARK_GRAY))
+                                .append(TextComponent.of(FormatUtil.formatBytes(after.getUsed()), TextColor.GRAY))
                                 .build()
                         );
                     }
diff --git a/spark-common/src/main/java/me/lucko/spark/common/monitor/memory/GarbageCollectorStatistics.java b/spark-common/src/main/java/me/lucko/spark/common/monitor/memory/GarbageCollectorStatistics.java
new file mode 100644
index 0000000..e875fd7
--- /dev/null
+++ b/spark-common/src/main/java/me/lucko/spark/common/monitor/memory/GarbageCollectorStatistics.java
@@ -0,0 +1,81 @@
+/*
+ * 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.monitor.memory;
+
+import com.google.common.collect.ImmutableMap;
+
+import java.lang.management.GarbageCollectorMXBean;
+import java.lang.management.ManagementFactory;
+import java.util.Map;
+
+/**
+ * Holder for {@link GarbageCollectorMXBean} statistics.
+ */
+public class GarbageCollectorStatistics {
+    public static final GarbageCollectorStatistics ZERO = new GarbageCollectorStatistics(0, 0);
+
+    public static Map<String, GarbageCollectorStatistics> pollStats() {
+        ImmutableMap.Builder<String, GarbageCollectorStatistics> stats = ImmutableMap.builder();
+        for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) {
+            stats.put(bean.getName(), new GarbageCollectorStatistics(bean));
+        }
+        return stats.build();
+    }
+
+    public static Map<String, GarbageCollectorStatistics> pollStatsSubtractInitial(Map<String, GarbageCollectorStatistics> initial) {
+        ImmutableMap.Builder<String, GarbageCollectorStatistics> stats = ImmutableMap.builder();
+        for (GarbageCollectorMXBean bean : ManagementFactory.getGarbageCollectorMXBeans()) {
+            stats.put(bean.getName(), new GarbageCollectorStatistics(bean).subtract(initial.getOrDefault(bean.getName(), ZERO)));
+        }
+        return stats.build();
+    }
+
+    private final long collectionCount;
+    private final long collectionTime;
+
+    public GarbageCollectorStatistics(long collectionCount, long collectionTime) {
+        this.collectionCount = collectionCount;
+        this.collectionTime = collectionTime;
+    }
+
+    public GarbageCollectorStatistics(GarbageCollectorMXBean bean) {
+        this(bean.getCollectionCount(), bean.getCollectionTime());
+    }
+
+    public long getCollectionCount() {
+        return this.collectionCount;
+    }
+
+    public long getCollectionTime() {
+        return this.collectionTime;
+    }
+
+    public GarbageCollectorStatistics subtract(GarbageCollectorStatistics other) {
+        if (other == ZERO || (other.collectionCount == 0 && other.collectionTime == 0)) {
+            return this;
+        }
+
+        return new GarbageCollectorStatistics(
+                this.collectionCount - other.collectionCount,
+                this.collectionTime - other.collectionTime
+        );
+    }
+}