From b76370029fbfcc3fe72fb8492db6f444d1df3ef6 Mon Sep 17 00:00:00 2001
From: Vedran <vedran@Vedrans-iMac.local>
Date: Sat, 21 Apr 2018 16:01:13 +0200
Subject: [PATCH] future cancellation

---
 src/main/java/org/cactoos/func/TimedFunc.java | 27 +++++++++++++---
 .../java/org/cactoos/func/TimedFuncTest.java  | 31 +++++++++++++++++--
 2 files changed, 51 insertions(+), 7 deletions(-)

diff --git a/src/main/java/org/cactoos/func/TimedFunc.java b/src/main/java/org/cactoos/func/TimedFunc.java
index 0f5dacb05f..42f330d379 100644
--- a/src/main/java/org/cactoos/func/TimedFunc.java
+++ b/src/main/java/org/cactoos/func/TimedFunc.java
@@ -23,13 +23,15 @@
  */
 package org.cactoos.func;
 
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 import org.cactoos.Func;
 import org.cactoos.Proc;
 
 /**
  * Function that gets interrupted after a certain time has passed.
- *
  * @author Vedran Vatavuk (123vgv@gmail.com)
  * @version $Id$
  * @param <X> Type of input
@@ -41,7 +43,7 @@ public final class TimedFunc<X, Y> implements Func<X, Y> {
     /**
      * Origin function.
      */
-    private final Func<X, Y> origin;
+    private final Func<X, Future<Y>> func;
 
     /**
      * Milliseconds.
@@ -63,13 +65,28 @@ public TimedFunc(final Proc<X> proc, final long milliseconds) {
      * @param milliseconds Milliseconds
      */
     public TimedFunc(final Func<X, Y> function, final long milliseconds) {
-        this.origin = function;
+        this(milliseconds, new AsyncFunc<>(function));
+    }
+
+    /**
+     * Ctor.
+     * @param async Async function
+     * @param milliseconds Milliseconds
+     */
+    public TimedFunc(final long milliseconds, final Func<X, Future<Y>> async) {
+        this.func = async;
         this.time = milliseconds;
     }
 
     @Override
     public Y apply(final X input) throws Exception {
-        return new AsyncFunc<>(this.origin).apply(input)
-            .get(this.time, TimeUnit.MILLISECONDS);
+        final Future<Y> future = this.func.apply(input);
+        try {
+            return future.get(this.time, TimeUnit.MILLISECONDS);
+        } catch (final InterruptedException | ExecutionException
+            | TimeoutException exp) {
+            future.cancel(true);
+            throw exp;
+        }
     }
 }
diff --git a/src/test/java/org/cactoos/func/TimedFuncTest.java b/src/test/java/org/cactoos/func/TimedFuncTest.java
index 16dddb5310..82e71ecff7 100644
--- a/src/test/java/org/cactoos/func/TimedFuncTest.java
+++ b/src/test/java/org/cactoos/func/TimedFuncTest.java
@@ -23,6 +23,8 @@
  */
 package org.cactoos.func;
 
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
 import java.util.concurrent.TimeoutException;
 import org.cactoos.iterable.Endless;
 import org.cactoos.scalar.And;
@@ -32,7 +34,6 @@
 
 /**
  * Test case for {@link TimedFunc}.
- *
  * @author Vedran Vatavuk (123vgv@gmail.com)
  * @version $Id$
  * @since 0.29.3
@@ -67,7 +68,33 @@ public void procGetsInterrupted() throws Exception {
     }
 
     @Test
-    public void functionGetsExecuted() throws Exception {
+    @SuppressWarnings("PMD.AvoidCatchingGenericException")
+    public void futureTaskIsCancelled() {
+        final long period = 50L;
+        final long time = 2000L;
+        final Future<Boolean> future = Executors.newSingleThreadExecutor()
+            .submit(
+                () -> {
+                    Thread.sleep(time);
+                    return true;
+                }
+            );
+        try {
+            new TimedFunc<Boolean, Boolean>(
+                period,
+                input -> future
+            ).apply(true);
+                // @checkstyle IllegalCatchCheck (1 line)
+        } catch (final Exception exp) {
+            MatcherAssert.assertThat(
+                future.isCancelled(),
+                Matchers.equalTo(true)
+            );
+        }
+    }
+
+    @Test
+    public void functionIsExecuted() throws Exception {
         final long period = 3000L;
         MatcherAssert.assertThat(
             new TimedFunc<Boolean, Boolean>(