[GitHub] [cxf] rmannibucau commented on a change in pull request #721: [cxf-8340] add precompiled class for Graalvm native support

[GitBox <gi...@apache.org>]

rmannibucau commented on a change in pull request #721:
URL: https://github.com/apache/cxf/pull/721#discussion_r533129132



##########
File path: core/src/main/java/org/apache/cxf/common/spi/GeneratedClassClassLoader.java
##########
@@ -0,0 +1,118 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.cxf.common.spi;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.logging.Logger;
+
+import org.apache.cxf.Bus;
+import org.apache.cxf.common.classloader.ClassLoaderUtils;
+import org.apache.cxf.common.logging.LogUtils;
+import org.apache.cxf.common.util.StringUtils;
+
+public class GeneratedClassClassLoader {
+    private static final Logger LOG = LogUtils.getL7dLogger(ClassLoaderProxyService.class);
+    protected final Bus bus;
+
+    public GeneratedClassClassLoader(Bus bus) {
+        this.bus = bus;
+    }
+    protected Class<?> findClass(String className, Class<?> callingClass) {
+        ClassLoader cl = getClassLoader();
+        try {
+            return cl.loadClass(className);
+        } catch (ClassNotFoundException e) {
+            //ignore and try with other class loader
+        }
+        try {
+            return ClassLoaderUtils.loadClass(className, callingClass);
+        } catch (ClassNotFoundException e) {
+            LOG.fine("Failed to load class :" + e.toString());
+        }
+        return null;
+    }
+    public TypeHelperClassLoader getClassLoader() {
+        TypeHelperClassLoader loader = bus.getExtension(TypeHelperClassLoader.class);
+        if (loader == null) {
+            loader = bus.getExtension(TypeHelperClassLoader.class);
+            if (loader == null) {
+                ClassLoader parent = bus.getExtension(ClassLoader.class);
+                if (parent == null) {
+                    parent = Thread.currentThread().getContextClassLoader();
+                }
+                loader = new TypeHelperClassLoader(parent);
+                bus.setExtension(loader, TypeHelperClassLoader.class);
+            }
+        }
+        return loader;
+    }
+
+    public void restore(ClassGeneratorCapture capture) {

Review comment:
       Outside of a test you have written the .class in target/classes (maven/gradle) or in classloader singleton of quarkus (= it is int the future runtime classloader, no need to do anything special except have a stable name to reuse it and load it, xxhash64 of all parameters can help there, you can check the openwebbeans impl which has this option). The main trick is to ensure CXF uses a SPI to load the class. Generally the "write"/capture and "read"/load is the same SPI to ensure both sides match. One "already written" impl will throw an UnsupportedOperationException in write but it is a detail. In OWB the read/write methods are merged as a "defineAndLoad" ([1]) one but it is not required. The defineAndLoad deep implementation (actual classloader load) is either the one we currently have with a map in a classloader or a more aggressive one using Unsafe ([2]).
   
   [1] https://github.com/apache/openwebbeans/blob/master/webbeans-impl/src/main/java/org/apache/webbeans/service/ClassLoaderProxyService.java
   [2] https://github.com/apache/openwebbeans/blob/master/webbeans-impl/src/main/java/org/apache/webbeans/proxy/Unsafe.java#L132




----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
users@infra.apache.org