Functional interfaces for caching and batching

Author: aschrijver

src/main/java/io/engagingspaces/vertx/dataloader/BatchLoader.java

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+/*
+ * Copyright (c) 2016 The original author or authors
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Apache License v2.0 which accompanies this distribution.
+ *
+ *      The Eclipse Public License is available at
+ *      http://www.eclipse.org/legal/epl-v10.html
+ *
+ *      The Apache License v2.0 is available at
+ *      http://www.opensource.org/licenses/apache2.0.php
+ *
+ * You may elect to redistribute this code under either of these licenses.
+ */
+
+package io.engagingspaces.vertx.dataloader;
+
+import io.vertx.core.CompositeFuture;
+
+import java.util.Collection;
+
+/**
+ * Function that is invoked for batch loading the list of data values indicated by the provided list of keys. The
+ * function returns a {@link CompositeFuture} to aggregate results of individual load requests.
+ *
+ * @param <K> type parameter indicating the type of keys to use for data load requests.
+ *
+ * @author <a href="https://github.com/aschrijver/">Arnold Schrijver</a>
+ */
+@FunctionalInterface
+public interface BatchLoader<K> {
+
+    /**
+     * Batch load the provided keys and return a composite future of the result.
+     *
+     * @param keys the list of keys to load
+     * @return the composite future
+     */
+    CompositeFuture load(Collection<K> keys);
+}

src/main/java/io/engagingspaces/vertx/dataloader/CacheKey.java

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+/*
+ * Copyright (c) 2016 The original author or authors
+ *
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * and Apache License v2.0 which accompanies this distribution.
+ *
+ *      The Eclipse Public License is available at
+ *      http://www.eclipse.org/legal/epl-v10.html
+ *
+ *      The Apache License v2.0 is available at
+ *      http://www.opensource.org/licenses/apache2.0.php
+ *
+ * You may elect to redistribute this code under either of these licenses.
+ */
+
+package io.engagingspaces.vertx.dataloader;
+
+/**
+ * Function that is invoked on input keys of type {@code K} to derive keys that are required by the {@link CacheMap}
+ * implementation.
+ *
+ * @author <a href="https://github.com/aschrijver/">Arnold Schrijver</a>
+ */
+@FunctionalInterface
+public interface CacheKey {
+
+    /**
+     * Returns the cache key that is created from the provided input key.
+     *
+     * @param input the input key
+     * @param <K>   type parameter indicating the type of the input key
+     * @param <U>   type parameter indicating the type of the cache key that is returned
+     * @return the cache key
+     */
+    <K, U> U getKey(K input);
+}