Allow Snappy to be loaded from a shared classloader

This commit introduces a solution for loading the Snappy native library across multiple test profiles. Due to the constraint that native libraries can only be loaded from a single classloader, a shared classloader is now utilized for loading Snappy in test mode.

Please note, this feature is exclusively applicable when running tests.

Fixes: quarkusio#39767

extensions/kafka-client/deployment/src/main/java/io/quarkus/kafka/client/deployment/KafkaBuildTimeConfig.java

@@ -23,6 +23,14 @@ public class KafkaBuildTimeConfig {
     @ConfigItem(name = "snappy.enabled", defaultValue = "false")
     public boolean snappyEnabled;
 
+    /**
+     * Whether to load the Snappy native library from the shared classloader.
+     * This setting is only used in tests if the tests are using different profiles, which would lead to
+     * unsatisfied link errors when loading Snappy.
+     */
+    @ConfigItem(name = "snappy.load-from-shared-classloader", defaultValue = "false")
+    public boolean snappyLoadFromSharedClassLoader;
+
     /**
      * Configuration for DevServices. DevServices allows Quarkus to automatically start Kafka in dev and test mode.
      */

extensions/kafka-client/deployment/src/main/java/io/quarkus/kafka/client/deployment/KafkaProcessor.java

@@ -72,6 +72,7 @@
 import io.quarkus.deployment.builditem.ExtensionSslNativeSupportBuildItem;
 import io.quarkus.deployment.builditem.FeatureBuildItem;
 import io.quarkus.deployment.builditem.IndexDependencyBuildItem;
+import io.quarkus.deployment.builditem.LaunchModeBuildItem;
 import io.quarkus.deployment.builditem.LogCategoryBuildItem;
 import io.quarkus.deployment.builditem.RunTimeConfigurationDefaultBuildItem;
 import io.quarkus.deployment.builditem.RuntimeConfigSetupCompleteBuildItem;
@@ -304,8 +305,12 @@ public void handleSnappyInNative(NativeImageRunnerBuildItem nativeImageRunner,
 
     @BuildStep(onlyIf = HasSnappy.class)
     @Record(ExecutionTime.RUNTIME_INIT)
-    void loadSnappyIfEnabled(SnappyRecorder recorder, KafkaBuildTimeConfig config) {
-        recorder.loadSnappy();
+    void loadSnappyIfEnabled(LaunchModeBuildItem launch, SnappyRecorder recorder, KafkaBuildTimeConfig config) {
+        boolean loadFromSharedClassLoader = false;
+        if (launch.isTest()) {
+            loadFromSharedClassLoader = config.snappyLoadFromSharedClassLoader;
+        }
+        recorder.loadSnappy(loadFromSharedClassLoader);
     }
 
     @Consume(RuntimeConfigSetupCompleteBuildItem.class)

extensions/kafka-client/runtime/src/main/java/io/quarkus/kafka/client/runtime/SnappyLoader.java

@@ -0,0 +1,18 @@
+package io.quarkus.kafka.client.runtime;
+
+import java.io.File;
+
+public class SnappyLoader {
+
+    /*
+     * This class is intended to be loaded from a shared classloader (e.g., the system classloader) to avoid
+     * unsatisfied link errors when the native library is loaded from a different classloader.
+     * See https://github.com/quarkusio/quarkus/issues/39767.
+     *
+     * This class is only used in tests if the `quarkus.kafka.snappy.load-from-shared-classloader=true` is set.
+     */
+    static {
+        File out = SnappyRecorder.getLibraryFile();
+        System.load(out.getAbsolutePath());
+    }
+}

extensions/kafka-client/runtime/src/main/java/io/quarkus/kafka/client/runtime/SnappyRecorder.java

@@ -8,14 +8,32 @@
 import java.net.URL;
 
 import org.xerial.snappy.OSInfo;
-import org.xerial.snappy.SnappyLoader;
 
+import io.quarkus.runtime.Application;
 import io.quarkus.runtime.annotations.Recorder;
 
 @Recorder
 public class SnappyRecorder {
 
-    public void loadSnappy() {
+    public void loadSnappy(boolean loadFromSharedClassLoader) {
+        if (loadFromSharedClassLoader) {
+            try {
+                Application.class.getClassLoader().loadClass(SnappyLoader.class.getName());
+            } catch (ClassNotFoundException e) {
+                throw new RuntimeException(e);
+            }
+        } else {
+            File out = getLibraryFile();
+            try {
+                System.load(out.getAbsolutePath());
+            } catch (UnsatisfiedLinkError e) {
+                // Try to load the library from the system library path
+                throw new RuntimeException("Failed to load Snappy native library", e);
+            }
+        }
+    }
+
+    static File getLibraryFile() {
         // Resolve the library file name with a suffix (e.g., dll, .so, etc.)
         String snappyNativeLibraryName = System.mapLibraryName("snappyjava");
         String snappyNativeLibraryPath = "/org/xerial/snappy/native/" + OSInfo.getNativeLibFolderPathForCurrentOS();
@@ -27,18 +45,16 @@ public void loadSnappy() {
             throw new RuntimeException(errorMessage);
         }
 
-        File out = extractLibraryFile(
+        return extractLibraryFile(
                 SnappyLoader.class.getResource(snappyNativeLibraryPath + "/" + snappyNativeLibraryName),
                 snappyNativeLibraryName);
-
-        System.load(out.getAbsolutePath());
     }
 
-    private static boolean hasResource(String path) {
+    static boolean hasResource(String path) {
         return SnappyLoader.class.getResource(path) != null;
     }
 
-    private static File extractLibraryFile(URL library, String name) {
+    static File extractLibraryFile(URL library, String name) {
         String tmp = System.getProperty("java.io.tmpdir");
         File extractedLibFile = new File(tmp, name);