PreUploadHookChain: Use list instead of array internally

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

Update PostUploadHookChain to keep the hook chains implementation
consistent.

Change-Id: I5ae0c923f117ac48558a989464f5d5d868d81f76
Signed-off-by: Ivan Frade <ifrade@google.com>

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

@@ -0,0 +1,118 @@
+/*
+ * 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 java.util.Collection;
+
+import org.eclipse.jgit.lib.ObjectId;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class PreUploadHookChainTest {
+
+	@Test
+	public void testDefaultIfEmpty() {
+		PreUploadHook[] noHooks = {};
+		PreUploadHook newChain = PreUploadHookChain
+				.newChain(Arrays.asList(noHooks));
+		assertEquals(newChain, PreUploadHook.NULL);
+	}
+
+	@Test
+	public void testFlattenChainIfOnlyOne() {
+		FakePreUploadHook hook1 = new FakePreUploadHook();
+		PreUploadHook newChain = PreUploadHookChain
+				.newChain(Arrays.asList(PreUploadHook.NULL, hook1));
+		assertEquals(newChain, hook1);
+	}
+
+	@Test
+	public void testMultipleHooks() throws ServiceMayNotContinueException {
+		FakePreUploadHook hook1 = new FakePreUploadHook();
+		FakePreUploadHook hook2 = new FakePreUploadHook();
+
+		PreUploadHook chained = PreUploadHookChain
+				.newChain(Arrays.asList(hook1, hook2));
+		chained.onBeginNegotiateRound(null, null, 0);
+
+		assertTrue(hook1.wasInvoked());
+		assertTrue(hook2.wasInvoked());
+	}
+
+	private static final class FakePreUploadHook implements PreUploadHook {
+		boolean invoked;
+
+		@Override
+		public void onBeginNegotiateRound(UploadPack up,
+				Collection<? extends ObjectId> wants, int cntOffered)
+				throws ServiceMayNotContinueException {
+			invoked = true;
+		}
+
+		@Override
+		public void onEndNegotiateRound(UploadPack up,
+				Collection<? extends ObjectId> wants, int cntCommon,
+				int cntNotFound, boolean ready)
+				throws ServiceMayNotContinueException {
+			throw new UnsupportedOperationException();
+		}
+
+		@Override
+		public void onSendPack(UploadPack up,
+				Collection<? extends ObjectId> wants,
+				Collection<? extends ObjectId> haves)
+				throws ServiceMayNotContinueException {
+			throw new UnsupportedOperationException();
+		}
+
+		public boolean wasInvoked() {
+			return invoked;
+		}
+	}
+}

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

@@ -44,7 +44,9 @@
 package org.eclipse.jgit.transport;
 
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
+import java.util.stream.Collectors;
 
 import org.eclipse.jgit.lib.ObjectId;
 
@@ -56,8 +58,7 @@ import org.eclipse.jgit.lib.ObjectId;
  * one hook throws an exception, execution of remaining hook methods is aborted.
  */
 public class PreUploadHookChain implements PreUploadHook {
-	private final PreUploadHook[] hooks;
-	private final int count;
+	private final List<PreUploadHook> hooks;
 
 	/**
 	 * Create a new hook chaining the given hooks together.
@@ -66,18 +67,18 @@ public class PreUploadHookChain implements PreUploadHook {
 	 *            hooks to execute, in order.
 	 * @return a new hook chain of the given hooks.
 	 */
-	public static PreUploadHook newChain(List<? extends PreUploadHook> hooks) {
-		PreUploadHook[] newHooks = new PreUploadHook[hooks.size()];
-		int i = 0;
-		for (PreUploadHook hook : hooks)
-			if (hook != PreUploadHook.NULL)
-				newHooks[i++] = hook;
-		if (i == 0)
+	public static PreUploadHook newChain(List<PreUploadHook> hooks) {
+		List<PreUploadHook> newHooks = hooks.stream()
+				.filter(hook -> !hook.equals(PreUploadHook.NULL))
+				.collect(Collectors.toList());
+
+		if (newHooks.isEmpty()) {
 			return PreUploadHook.NULL;
-		else if (i == 1)
-			return newHooks[0];
-		else
-			return new PreUploadHookChain(newHooks, i);
+		} else if (newHooks.size() == 1) {
+			return newHooks.get(0);
+		} else {
+			return new PreUploadHookChain(newHooks);
+		}
 	}
 
 	/** {@inheritDoc} */
@@ -85,8 +86,9 @@ public class PreUploadHookChain implements PreUploadHook {
 	public void onBeginNegotiateRound(UploadPack up,
 			Collection<? extends ObjectId> wants, int cntOffered)
 			throws ServiceMayNotContinueException {
-		for (int i = 0; i < count; i++)
-			hooks[i].onBeginNegotiateRound(up, wants, cntOffered);
+		for (PreUploadHook hook : hooks) {
+			hook.onBeginNegotiateRound(up, wants, cntOffered);
+		}
 	}
 
 	/** {@inheritDoc} */
@@ -95,8 +97,9 @@ public class PreUploadHookChain implements PreUploadHook {
 			Collection<? extends ObjectId> wants, int cntCommon,
 			int cntNotFound, boolean ready)
 			throws ServiceMayNotContinueException {
-		for (int i = 0; i < count; i++)
-			hooks[i].onEndNegotiateRound(up, wants, cntCommon, cntNotFound, ready);
+		for (PreUploadHook hook : hooks) {
+			hook.onEndNegotiateRound(up, wants, cntCommon, cntNotFound, ready);
+		}
 	}
 
 	/** {@inheritDoc} */
@@ -105,12 +108,12 @@ public class PreUploadHookChain implements PreUploadHook {
 			Collection<? extends ObjectId> wants,
 			Collection<? extends ObjectId> haves)
 			throws ServiceMayNotContinueException {
-		for (int i = 0; i < count; i++)
-			hooks[i].onSendPack(up, wants, haves);
+		for (PreUploadHook hook : hooks) {
+			hook.onSendPack(up, wants, haves);
+		}
 	}
 
-	private PreUploadHookChain(PreUploadHook[] hooks, int count) {
-		this.hooks = hooks;
-		this.count = count;
+	private PreUploadHookChain(List<PreUploadHook> hooks) {
+		this.hooks = Collections.unmodifiableList(hooks);
 	}
 }