Repository: camel Updated Branches: refs/heads/master a48ffc0eb -> 0f767091a
Add WeakThreadLocal utility class Project: http://git-wip-us.apache.org/repos/asf/camel/repo Commit: http://git-wip-us.apache.org/repos/asf/camel/commit/0f767091 Tree: http://git-wip-us.apache.org/repos/asf/camel/tree/0f767091 Diff: http://git-wip-us.apache.org/repos/asf/camel/diff/0f767091 Branch: refs/heads/master Commit: 0f767091a65f3e3004d8f4cc6ae7e4a94544fbec Parents: a48ffc0 Author: lburgazzoli <lburgazz...@gmail.com> Authored: Tue Dec 13 17:35:58 2016 +0100 Committer: lburgazzoli <lburgazz...@gmail.com> Committed: Tue Dec 13 17:35:58 2016 +0100 ---------------------------------------------------------------------- .../org/apache/camel/util/WeakThreadLocal.java | 51 ++++++++++++++++++++ 1 file changed, 51 insertions(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/camel/blob/0f767091/camel-core/src/main/java/org/apache/camel/util/WeakThreadLocal.java ---------------------------------------------------------------------- diff --git a/camel-core/src/main/java/org/apache/camel/util/WeakThreadLocal.java b/camel-core/src/main/java/org/apache/camel/util/WeakThreadLocal.java new file mode 100644 index 0000000..58959e8 --- /dev/null +++ b/camel-core/src/main/java/org/apache/camel/util/WeakThreadLocal.java @@ -0,0 +1,51 @@ +/** + * 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.camel.util; + +import java.lang.ref.WeakReference; +import java.util.function.Supplier; + +public final class WeakThreadLocal<T> implements Supplier<T> { + private final ThreadLocal<WeakReference<T>> cache; + private final Supplier<T> supplier; + + public WeakThreadLocal(Supplier<T> supplier) { + this.cache = new ThreadLocal<>(); + this.supplier = ObjectHelper.notNull(supplier, "value supplier"); + } + + @Override + public T get() { + T value = null; + WeakReference<T> ref = cache.get(); + + if (ref != null) { + value = ref.get(); + } + + if (value == null) { + value = supplier.get(); + cache.set(new WeakReference<>(value)); + } + + return value; + } + + public static <T> WeakThreadLocal<T> withSupplier(Supplier<T> supplier) { + return new WeakThreadLocal<>(supplier); + } +}
