ISPN-5688 Add Functional Map simple tutorial as a test

core/src/test/java/org/infinispan/functional/FunctionalSimpleTutorialTest.java

@@ -0,0 +1,87 @@
+package org.infinispan.functional;
+
+import org.infinispan.AdvancedCache;
+import org.infinispan.commons.api.functional.EntryView.ReadEntryView;
+import org.infinispan.commons.api.functional.FunctionalMap.ReadOnlyMap;
+import org.infinispan.commons.api.functional.FunctionalMap.ReadWriteMap;
+import org.infinispan.commons.api.functional.FunctionalMap.WriteOnlyMap;
+import org.infinispan.commons.api.functional.MetaParam.MetaLifespan;
+import org.infinispan.commons.api.functional.Traversable;
+import org.infinispan.functional.impl.FunctionalMapImpl;
+import org.infinispan.functional.impl.ReadOnlyMapImpl;
+import org.infinispan.functional.impl.ReadWriteMapImpl;
+import org.infinispan.functional.impl.WriteOnlyMapImpl;
+import org.infinispan.manager.EmbeddedCacheManager;
+import org.infinispan.test.SingleCacheManagerTest;
+import org.infinispan.test.fwk.TestCacheManagerFactory;
+import org.testng.annotations.Test;
+
+import java.time.Duration;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.CompletableFuture;
+
+@Test(groups = "functional", testName = "functional.FunctionalSimpleTutorialTest")
+public class FunctionalSimpleTutorialTest extends SingleCacheManagerTest {
+
+   @Override
+   protected EmbeddedCacheManager createCacheManager() throws Exception {
+      return TestCacheManagerFactory.createCacheManager();
+   }
+
+   public void testSimpleTutorial() throws Exception {
+      AdvancedCache<String, String> cache = cacheManager.<String, String>getCache().getAdvancedCache();
+      FunctionalMapImpl<String, String> functionalMap = FunctionalMapImpl.create(cache);
+      WriteOnlyMap<String, String> writeOnlyMap = WriteOnlyMapImpl.create(functionalMap);
+      ReadOnlyMap<String, String> readOnlyMap = ReadOnlyMapImpl.create(functionalMap);
+
+      // Execute two parallel write-only operation to store key/value pairs
+      CompletableFuture<Void> writeFuture1 = writeOnlyMap.eval("key1", "value1",
+         (v, writeView) -> writeView.set(v));
+      CompletableFuture<Void> writeFuture2 = writeOnlyMap.eval("key2", "value2",
+         (v, writeView) -> writeView.set(v));
+
+      // When each write-only operation completes, execute a read-only operation to retrieve the value
+      CompletableFuture<String> readFuture1 =
+         writeFuture1.thenCompose(r -> readOnlyMap.eval("key1", ReadEntryView::get));
+      CompletableFuture<String> readFuture2 =
+         writeFuture2.thenCompose(r -> readOnlyMap.eval("key2", ReadEntryView::get));
+
+      // When the read-only operation completes, print it out
+      printf("Created entries: %n");
+      CompletableFuture<Void> end = readFuture1.thenAcceptBoth(readFuture2, (v1, v2) ->
+         printf("key1 = %s%nkey2 = %s%n", v1, v2));
+
+      // Wait for this read/write combination to finish
+      end.get();
+
+      // Create a read-write map
+      ReadWriteMap<String, String> readWriteMap = ReadWriteMapImpl.create(functionalMap);
+
+      // Use read-write multi-key based operation to write new values
+      // together with lifespan and return previous values
+      Map<String, String> data = new HashMap<>();
+      data.put("key1", "newValue1");
+      data.put("key2", "newValue2");
+      Traversable<String> previousValues = readWriteMap.evalMany(data, (v, readWriteView) -> {
+         String prev = readWriteView.find().orElse(null);
+         readWriteView.set(v, new MetaLifespan(Duration.ofHours(1).toMillis()));
+         return prev;
+      });
+
+      // Use read-only multi-key operation to read current values for multiple keys
+      Traversable<ReadEntryView<String, String>> entryViews =
+            readOnlyMap.evalMany(data.keySet(), readOnlyView -> readOnlyView);
+      printf("Updated entries: %n");
+      entryViews.forEach(view -> printf("%s%n", view));
+
+      // Finally, print out the previous entry values
+      printf("Previous entry values: %n");
+      previousValues.forEach(prev -> printf("%s%n", prev));
+   }
+
+   private void printf(String format, Object ... args) {
+      log.infof(format, args);
+   }
+
+}