backport for issue helidon-io#7698

integrations/oci/tls-certificates/src/main/java/io/helidon/integrations/oci/tls/certificates/DefaultOciCertificatesTlsManagerProvider.java

@@ -43,7 +43,8 @@ public String configKey() {
     public TlsManager create(Config config,
                              String name) {
         OciCertificatesTlsManagerConfig cfg = OciCertificatesTlsManagerConfig.create(config);
-        return new DefaultOciCertificatesTlsManager(cfg, name, config);
+        return TlsManagerProvider.getOrCreate(cfg,
+                                              (c) -> new DefaultOciCertificatesTlsManager(cfg, name, config));
     }
 
 }

webserver/webserver/src/main/java/io/helidon/webserver/spi/TlsManagerCache.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2023 Oracle and/or its affiliates.
+ *
+ * Licensed 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 io.helidon.webserver.spi;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.function.Function;
+
+import io.helidon.webserver.TlsManager;
+
+class TlsManagerCache {
+    private static final ReentrantLock LOCK = new ReentrantLock();
+    private static final Map<Object, TlsManager> CACHE = new HashMap<>();
+
+    private TlsManagerCache() {
+    }
+
+    static <T> TlsManager getOrCreate(T configBean,
+                                      Function<T, TlsManager> creator) {
+        Objects.requireNonNull(configBean);
+        Objects.requireNonNull(creator);
+        LOCK.lock();
+        try {
+            TlsManager manager = CACHE.get(configBean);
+            if (manager != null) {
+                return manager;
+            }
+
+            manager = creator.apply(configBean);
+            Object existing = CACHE.put(configBean, manager);
+            assert (existing == null);
+
+            return manager;
+        } finally {
+            LOCK.unlock();
+        }
+    }
+
+}

webserver/webserver/src/main/java/io/helidon/webserver/spi/TlsManagerProvider.java

@@ -20,6 +20,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.ServiceLoader;
+import java.util.function.Function;
 
 import io.helidon.common.serviceloader.HelidonServiceLoader;
 import io.helidon.config.Config;
@@ -49,6 +50,19 @@ public interface TlsManagerProvider {
      */
     TlsManager create(Config config, String name);
 
+    /**
+     * Provides the ability to have a unique {@link TlsManager} per unique {@link Config} instance provided.
+     *
+     * @param configBean the config bean instance
+     * @param creator    the creator to apply if not already in cache, which takes the config bean instance
+     * @param <T>        the type of the config bean
+     * @return the tls manager instance from cache, defaulting to creation from the {@code creator} if not in cache
+     */
+    static <T> TlsManager getOrCreate(T configBean,
+                                      Function<T, TlsManager> creator) {
+        return TlsManagerCache.getOrCreate(configBean, creator);
+    }
+
     /**
      * Takes a configuration and looks for a suitable {@link TlsManager} instance based upon that configuration.
      *

webserver/webserver/src/test/java/io/helidon/webserver/spi/TlsManagerProviderTest.java

@@ -17,17 +17,23 @@
 package io.helidon.webserver.spi;
 
 import java.util.Map;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import io.helidon.config.Config;
 import io.helidon.config.ConfigSources;
 import io.helidon.webserver.ConfiguredTlsManager;
 import io.helidon.webserver.TlsManager;
 
 import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.instanceOf;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.not;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.hamcrest.Matchers.sameInstance;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 class TlsManagerProviderTest {
@@ -86,4 +92,33 @@ void goodConfig() {
                    equalTo("fake-type"));
     }
 
+    @Test
+    void caching() {
+        TlsManager mock = Mockito.mock(TlsManager.class);
+        AtomicInteger count = new AtomicInteger();
+
+        // we are using "1" and "2" here abstractly to stand in for Config beans, which would hash properly
+        TlsManager manager1 = TlsManagerProvider.getOrCreate("1", (c) -> {
+            count.incrementAndGet();
+            return mock;
+        });
+        assertThat(manager1, sameInstance(mock));
+        assertThat(count.get(), is(1));
+
+        TlsManager manager2 = TlsManagerProvider.getOrCreate("1", (c) -> {
+            count.incrementAndGet();
+            return Mockito.mock(TlsManager.class);
+        });
+        assertThat(manager2, sameInstance(mock));
+        assertThat(count.get(), is(1));
+
+        TlsManager manager3 = TlsManagerProvider.getOrCreate("2", (c) -> {
+            count.incrementAndGet();
+            return Mockito.mock(TlsManager.class);
+        });
+        assertThat(manager3, notNullValue());
+        assertThat(manager3, not(sameInstance(mock)));
+        assertThat(count.get(), is(2));
+    }
+
 }