Add an AdvertiseRefsHookChain, similar to the other hook chains

Change-Id: I3bb0dc86047fe0446d18e0055f714092a658d228

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

@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2012, Google Inc.
+ * 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 java.util.List;
+
+/**
+ * {@link AdvertiseRefsHook} that delegates to a list of other hooks.
+ * <p>
+ * Hooks are run in the order passed to the constructor. A hook may inspect or
+ * modify the results of the previous hooks in the chain by calling
+ * {@link UploadPack#getAdvertisedRefs()}, or
+ * {@link ReceivePack#getAdvertisedRefs()} or
+ * {@link ReceivePack#getAdvertisedObjects()}.
+ */
+public class AdvertiseRefsHookChain implements AdvertiseRefsHook {
+	private final AdvertiseRefsHook[] hooks;
+	private final int count;
+
+	/**
+	 * Create a new hook chaining the given hooks together.
+	 *
+	 * @param hooks
+	 *            hooks to execute, in order.
+	 * @return a new hook chain of the given hooks.
+	 */
+	public static AdvertiseRefsHook newChain(List<? extends AdvertiseRefsHook> hooks) {
+		AdvertiseRefsHook[] newHooks = new AdvertiseRefsHook[hooks.size()];
+		int i = 0;
+		for (AdvertiseRefsHook hook : hooks)
+			if (hook != AdvertiseRefsHook.DEFAULT)
+				newHooks[i++] = hook;
+		if (i == 0)
+			return AdvertiseRefsHook.DEFAULT;
+		else if (i == 1)
+			return newHooks[0];
+		else
+			return new AdvertiseRefsHookChain(newHooks, i);
+	}
+
+	public void advertiseRefs(ReceivePack rp)
+			throws ServiceMayNotContinueException {
+		for (int i = 0; i < count; i++)
+			hooks[i].advertiseRefs(rp);
+	}
+
+	public void advertiseRefs(UploadPack rp)
+			throws ServiceMayNotContinueException {
+		for (int i = 0; i < count; i++)
+			hooks[i].advertiseRefs(rp);
+	}
+
+	private AdvertiseRefsHookChain(AdvertiseRefsHook[] hooks, int count) {
+		this.hooks = hooks;
+		this.count = count;
+	}
+}