PostUploadHookChain: Use a list instead of array internally

The newly introduced ProtocolV2HookChain is implemented using lists
instead of arrays.

Update PostUploadHookChain to keep hook chain implementations
consistent.

Change-Id: Ic5694feab943e8949896b93103dbf427716c9bd7
Signed-off-by: Ivan Frade <ifrade@google.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/PostUploadHookChainTest.java

@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2019, Google LLC.
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.transport;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.util.Arrays;
+
+import org.eclipse.jgit.storage.pack.PackStatistics;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class PostUploadHookChainTest {
+
+	@Test
+	public void testDefaultIfEmpty() {
+		PostUploadHook[] noHooks = {};
+		PostUploadHook newChain = PostUploadHookChain
+				.newChain(Arrays.asList(noHooks));
+		assertEquals(newChain, PostUploadHook.NULL);
+	}
+
+	@Test
+	public void testFlattenChainIfOnlyOne() {
+		FakePostUploadHook hook1 = new FakePostUploadHook();
+		PostUploadHook newChain = PostUploadHookChain
+				.newChain(Arrays.asList(PostUploadHook.NULL, hook1));
+		assertEquals(newChain, hook1);
+	}
+
+	@Test
+	public void testMultipleHooks() {
+		FakePostUploadHook hook1 = new FakePostUploadHook();
+		FakePostUploadHook hook2 = new FakePostUploadHook();
+
+		PostUploadHook chained = PostUploadHookChain
+				.newChain(Arrays.asList(hook1, hook2));
+		chained.onPostUpload(null);
+
+		assertTrue(hook1.wasInvoked());
+		assertTrue(hook2.wasInvoked());
+	}
+
+	private static final class FakePostUploadHook implements PostUploadHook {
+		boolean invoked;
+
+		public boolean wasInvoked() {
+			return invoked;
+		}
+
+		@Override
+		public void onPostUpload(PackStatistics stats) {
+			invoked = true;
+		}
+	}
+}

org.eclipse.jgit/src/org/eclipse/jgit/transport/PostUploadHookChain.java

@@ -42,7 +42,9 @@
 
 package org.eclipse.jgit.transport;
 
+import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.eclipse.jgit.storage.pack.PackStatistics;
 
@@ -55,8 +57,7 @@ import org.eclipse.jgit.storage.pack.PackStatistics;
  * @since 4.1
  */
 public class PostUploadHookChain implements PostUploadHook {
-	private final PostUploadHook[] hooks;
-	private final int count;
+	private final List<PostUploadHook> hooks;
 
 	/**
 	 * Create a new hook chaining the given hooks together.
@@ -65,29 +66,29 @@ public class PostUploadHookChain implements PostUploadHook {
 	 *            hooks to execute, in order.
 	 * @return a new chain of the given hooks.
 	 */
-	public static PostUploadHook newChain(List<? extends PostUploadHook> hooks) {
-		PostUploadHook[] newHooks = new PostUploadHook[hooks.size()];
-		int i = 0;
-		for (PostUploadHook hook : hooks)
-			if (hook != PostUploadHook.NULL)
-				newHooks[i++] = hook;
-		if (i == 0)
+	public static PostUploadHook newChain(List<PostUploadHook> hooks) {
+		List<PostUploadHook> newHooks = hooks.stream()
+				.filter(hook -> !hook.equals(PostUploadHook.NULL))
+				.collect(Collectors.toList());
+
+		if (newHooks.isEmpty()) {
 			return PostUploadHook.NULL;
-		else if (i == 1)
-			return newHooks[0];
-		else
-			return new PostUploadHookChain(newHooks, i);
+		} else if (newHooks.size() == 1) {
+			return newHooks.get(0);
+		} else {
+			return new PostUploadHookChain(newHooks);
+		}
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void onPostUpload(PackStatistics stats) {
-		for (int i = 0; i < count; i++)
-			hooks[i].onPostUpload(stats);
+		for (PostUploadHook hook : hooks) {
+			hook.onPostUpload(stats);
+		}
 	}
 
-	private PostUploadHookChain(PostUploadHook[] hooks, int count) {
-		this.hooks = hooks;
-		this.count = count;
+	private PostUploadHookChain(List<PostUploadHook> hooks) {
+		this.hooks = Collections.unmodifiableList(hooks);
 	}
 }