From 2d8a63f2008fa2ed0851f2e74ad9dceb79181202 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christoph=20L=C3=A4ubrich?= <laeubi@laeubi-soft.de>
Date: Mon, 16 Dec 2024 06:46:37 +0100
Subject: [PATCH] Add an option to print the java memory before/after mojo
 execution

---
 .../tycho/helper/MojoExecutionHelper.java     | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/tycho-spi/src/main/java/org/eclipse/tycho/helper/MojoExecutionHelper.java b/tycho-spi/src/main/java/org/eclipse/tycho/helper/MojoExecutionHelper.java
index 62ca69bbe5..f54f8d87f2 100644
--- a/tycho-spi/src/main/java/org/eclipse/tycho/helper/MojoExecutionHelper.java
+++ b/tycho-spi/src/main/java/org/eclipse/tycho/helper/MojoExecutionHelper.java
@@ -19,25 +19,41 @@
 import org.apache.maven.plugin.MojoExecution;
 import org.apache.maven.plugin.MojoExecutionException;
 import org.codehaus.plexus.component.annotations.Component;
+import org.codehaus.plexus.component.annotations.Requirement;
+import org.codehaus.plexus.logging.Logger;
 
 @Component(role = MojoExecutionListener.class, hint = "helper")
 public class MojoExecutionHelper implements MojoExecutionListener {
+    private static boolean printMemoryInfo = Boolean.getBoolean("tycho.printMemory");
+    private static boolean gc = Boolean.getBoolean("tycho.printMemory.gc");
 
     private static final ThreadLocal<MojoExecutionEvent> EVENT = new ThreadLocal<MojoExecutionEvent>();
 
+    @Requirement
+    private Logger logger;
+
     @Override
     public void beforeMojoExecution(MojoExecutionEvent event) throws MojoExecutionException {
         EVENT.set(event);
+        if (printMemoryInfo) {
+            printMemory("Before", gc, event);
+        }
     }
 
     @Override
     public void afterMojoExecutionSuccess(MojoExecutionEvent event) throws MojoExecutionException {
         EVENT.remove();
+        if (printMemoryInfo) {
+            printMemory("After", gc, event);
+        }
     }
 
     @Override
     public void afterExecutionFailure(MojoExecutionEvent event) {
         EVENT.remove();
+        if (printMemoryInfo) {
+            printMemory("After", gc, event);
+        }
     }
 
     public static Optional<MojoExecution> getExecution() {
@@ -48,4 +64,50 @@ public static Optional<MojoExecution> getExecution() {
         return Optional.ofNullable(executionEvent.getExecution());
     }
 
+    private void printMemory(String state, boolean gc, MojoExecutionEvent evt) {
+        Runtime runtime = Runtime.getRuntime();
+        double usedBefore;
+        if (gc) {
+            usedBefore = (runtime.totalMemory() - runtime.freeMemory()) / 1024 / 1024;
+            System.gc();
+        } else {
+            usedBefore = 0;
+        }
+        double totalMemory = runtime.totalMemory() / 1024 / 1024;
+        double freeMemory = runtime.freeMemory() / 1024 / 1024;
+        double usedMemory = totalMemory - freeMemory;
+        StringBuilder builder = new StringBuilder();
+        builder.append("---- ");
+        builder.append(state);
+        builder.append(" ");
+        builder.append(evt.getProject().getId());
+        builder.append(" - ");
+        MojoExecution execution = evt.getExecution();
+        builder.append(execution.getMojoDescriptor().getId());
+        builder.append(" [");
+        builder.append(execution.getExecutionId());
+        builder.append("] ----");
+        builder.append(System.lineSeparator());
+        builder.append("Total Memory: ");
+        builder.append(String.format("%.2f", totalMemory));
+        builder.append("mb");
+        builder.append(System.lineSeparator());
+        builder.append("Free Memory:  ");
+        builder.append(String.format("%.2f", freeMemory));
+        builder.append("mb");
+        builder.append(System.lineSeparator());
+        builder.append("Used Memory:  ");
+        builder.append(String.format("%.2f", usedMemory));
+        builder.append("mb");
+        builder.append(System.lineSeparator());
+        double reclaimed = usedBefore - usedMemory;
+        if (reclaimed > 0) {
+            builder.append("GC Reclaimed: ");
+            builder.append(String.format("%.2f", reclaimed));
+            builder.append("mb");
+            builder.append(System.lineSeparator());
+        }
+        logger.info(builder.toString());
+    }
+
 }