ARTEMIS-1783 Remove need for guava in client Refactor away from Guava memorize based on Guava Supplier to using java.util.Supplier and our own memorizer code.
Project: http://git-wip-us.apache.org/repos/asf/activemq-artemis/repo Commit: http://git-wip-us.apache.org/repos/asf/activemq-artemis/commit/19418630 Tree: http://git-wip-us.apache.org/repos/asf/activemq-artemis/tree/19418630 Diff: http://git-wip-us.apache.org/repos/asf/activemq-artemis/diff/19418630 Branch: refs/heads/master Commit: 19418630d4f9440b7bcbee78c9aad9202cdca02a Parents: 6904af8 Author: Michael André Pearce <[email protected]> Authored: Fri May 11 07:24:35 2018 +0100 Committer: Clebert Suconic <[email protected]> Committed: Mon May 14 09:45:41 2018 -0400 ---------------------------------------------------------------------- .../activemq/artemis/utils/Suppliers.java | 95 ++++++++++++++++++++ .../message/impl/CoreMessageObjectPools.java | 6 +- 2 files changed, 99 insertions(+), 2 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/activemq-artemis/blob/19418630/artemis-commons/src/main/java/org/apache/activemq/artemis/utils/Suppliers.java ---------------------------------------------------------------------- diff --git a/artemis-commons/src/main/java/org/apache/activemq/artemis/utils/Suppliers.java b/artemis-commons/src/main/java/org/apache/activemq/artemis/utils/Suppliers.java new file mode 100644 index 0000000..59ccd77 --- /dev/null +++ b/artemis-commons/src/main/java/org/apache/activemq/artemis/utils/Suppliers.java @@ -0,0 +1,95 @@ +/* + * 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.activemq.artemis.utils; + +import java.io.Serializable; +import java.util.function.Supplier; + +public class Suppliers { + + /** + * Returns a supplier which caches the instance retrieved during the first + * call to {@code get()} and returns that value on subsequent calls to + * {@code get()}. See: + * <a href="http://en.wikipedia.org/wiki/Memoization";>memoization</a> + * + * <p>The returned supplier is thread-safe. The delegate's {@code get()} + * method will be invoked at most once. The supplier's serialized form does + * not contain the cached value, which will be recalculated when {@code get()} + * is called on the reserialized instance. + * + * <p>If {@code delegate} is an instance created by an earlier call to {@code + * memoize}, it is returned directly. + */ + public static <T> Supplier<T> memoize(Supplier<T> delegate) { + return (delegate instanceof MemoizingSupplier) + ? delegate + : new MemoizingSupplier<T>(checkNotNull(delegate)); + } + + private static class MemoizingSupplier<T> implements Supplier<T>, Serializable { + final Supplier<T> delegate; + transient volatile boolean initialized; + // "value" does not need to be volatile; visibility piggy-backs + // on volatile read of "initialized". + transient T value; + + MemoizingSupplier(Supplier<T> delegate) { + this.delegate = delegate; + } + + @Override + public T get() { + // A 2-field variant of Double Checked Locking. + if (!initialized) { + synchronized (this) { + if (!initialized) { + T t = delegate.get(); + value = t; + initialized = true; + return t; + } + } + } + return value; + } + + @Override + public String toString() { + return "Suppliers.memoize(" + delegate + ")"; + } + + private static final long serialVersionUID = 0; + } + + /** + * Ensures that an object reference passed as a parameter to the calling method is not null. + * + * @param reference an object reference + * @return the non-null reference that was validated + * @throws NullPointerException if {@code reference} is null + */ + public static <T> T checkNotNull(T reference) { + if (reference == null) { + throw new NullPointerException(); + } + return reference; + } +} http://git-wip-us.apache.org/repos/asf/activemq-artemis/blob/19418630/artemis-core-client/src/main/java/org/apache/activemq/artemis/core/message/impl/CoreMessageObjectPools.java ---------------------------------------------------------------------- diff --git a/artemis-core-client/src/main/java/org/apache/activemq/artemis/core/message/impl/CoreMessageObjectPools.java b/artemis-core-client/src/main/java/org/apache/activemq/artemis/core/message/impl/CoreMessageObjectPools.java index d4e3ed1..7ee7d0a 100644 --- a/artemis-core-client/src/main/java/org/apache/activemq/artemis/core/message/impl/CoreMessageObjectPools.java +++ b/artemis-core-client/src/main/java/org/apache/activemq/artemis/core/message/impl/CoreMessageObjectPools.java @@ -16,11 +16,13 @@ */ package org.apache.activemq.artemis.core.message.impl; -import com.google.common.base.Supplier; -import com.google.common.base.Suppliers; + import org.apache.activemq.artemis.api.core.SimpleString; +import org.apache.activemq.artemis.utils.Suppliers; import org.apache.activemq.artemis.utils.collections.TypedProperties; +import java.util.function.Supplier; + public class CoreMessageObjectPools { private Supplier<SimpleString.ByteBufSimpleStringPool> addressDecoderPool = Suppliers.memoize(SimpleString.ByteBufSimpleStringPool::new);
