Add simple chain implementations of transport hooks and loggers

Allows callers to effectively run multiple hooks and loggers without
modifying the UploadPack/ReceivePack interface.

Change-Id: I5b388816b63036ffff08ef3a9b857ccb764cb8c4

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

@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2011, 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.Collection;
+import java.util.List;
+
+/**
+ * {@link PostReceiveHook} that delegates to a list of other hooks.
+ * <p>
+ * Hooks are run in the order passed to the constructor.
+ */
+public class PostReceiveHookChain implements PostReceiveHook {
+	private final PostReceiveHook[] 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 PostReceiveHook newChain(
+			List<? extends PostReceiveHook> hooks) {
+		PostReceiveHook[] newHooks = new PostReceiveHook[hooks.size()];
+		int i = 0;
+		for (PostReceiveHook hook : hooks)
+			if (hook != PostReceiveHook.NULL)
+				newHooks[i++] = hook;
+		if (i == 0)
+			return PostReceiveHook.NULL;
+		else if (i == 1)
+			return newHooks[0];
+		else
+			return new PostReceiveHookChain(newHooks, i);
+	}
+
+	public void onPostReceive(ReceivePack rp,
+			Collection<ReceiveCommand> commands) {
+		for (int i = 0; i < count; i++)
+			hooks[i].onPostReceive(rp, commands);
+	}
+
+	private PostReceiveHookChain(PostReceiveHook[] hooks, int count) {
+		this.hooks = hooks;
+		this.count = count;
+	}
+}

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

@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2011, 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.Collection;
+import java.util.List;
+
+/**
+ * {@link PreReceiveHook} that delegates to a list of other hooks.
+ * <p>
+ * Hooks are run in the order passed to the constructor.
+ */
+public class PreReceiveHookChain implements PreReceiveHook {
+	private final PreReceiveHook[] 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 PreReceiveHook newChain(List<? extends PreReceiveHook> hooks) {
+		PreReceiveHook[] newHooks = new PreReceiveHook[hooks.size()];
+		int i = 0;
+		for (PreReceiveHook hook : hooks)
+			if (hook != PreReceiveHook.NULL)
+				newHooks[i++] = hook;
+		if (i == 0)
+			return PreReceiveHook.NULL;
+		else if (i == 1)
+			return newHooks[0];
+		else
+			return new PreReceiveHookChain(newHooks, i);
+	}
+
+	public void onPreReceive(ReceivePack rp,
+			Collection<ReceiveCommand> commands) {
+		for (int i = 0; i < count; i++)
+			hooks[i].onPreReceive(rp, commands);
+	}
+
+	private PreReceiveHookChain(PreReceiveHook[] hooks, int count) {
+		this.hooks = hooks;
+		this.count = count;
+	}
+}

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

@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2011, 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.Collection;
+import java.util.List;
+
+import org.eclipse.jgit.lib.ObjectId;
+
+/**
+ * {@link PreUploadHook} that delegates to a list of other hooks.
+ * <p>
+ * Hooks are run in the order passed to the constructor. If running a method on
+ * 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;
+
+	/**
+	 * 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 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)
+			return PreUploadHook.NULL;
+		else if (i == 1)
+			return newHooks[0];
+		else
+			return new PreUploadHookChain(newHooks, i);
+	}
+
+	public void onPreAdvertiseRefs(UploadPack up)
+			throws UploadPackMayNotContinueException {
+		for (int i = 0; i < count; i++)
+			hooks[i].onPreAdvertiseRefs(up);
+	}
+
+	public void onBeginNegotiateRound(UploadPack up,
+			Collection<? extends ObjectId> wants, int cntOffered)
+			throws UploadPackMayNotContinueException {
+		for (int i = 0; i < count; i++)
+			hooks[i].onBeginNegotiateRound(up, wants, cntOffered);
+	}
+
+	public void onEndNegotiateRound(UploadPack up,
+			Collection<? extends ObjectId> wants, int cntCommon,
+			int cntNotFound, boolean ready)
+			throws UploadPackMayNotContinueException {
+		for (int i = 0; i < count; i++)
+			hooks[i].onEndNegotiateRound(up, wants, cntCommon, cntNotFound, ready);
+	}
+
+	public void onSendPack(UploadPack up,
+			Collection<? extends ObjectId> wants,
+			Collection<? extends ObjectId> haves)
+			throws UploadPackMayNotContinueException {
+		for (int i = 0; i < count; i++)
+			hooks[i].onSendPack(up, wants, haves);
+	}
+
+	private PreUploadHookChain(PreUploadHook[] hooks, int count) {
+		this.hooks = hooks;
+		this.count = count;
+	}
+}

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

@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2011, 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;
+
+import org.eclipse.jgit.storage.pack.PackWriter;
+
+/**
+ * {@link UploadPackLogger} that delegates to a list of other loggers.
+ * <p>
+ * loggers are run in the order passed to the constructor.
+ */
+public class UploadPackLoggerChain implements UploadPackLogger {
+	private final UploadPackLogger[] loggers;
+	private final int count;
+
+	/**
+	 * Create a new logger chaining the given loggers together.
+	 *
+	 * @param loggers
+	 *            loggers to execute, in order.
+	 * @return a new logger chain of the given loggers.
+	 */
+	public static UploadPackLogger newChain(
+			List<? extends UploadPackLogger> loggers) {
+		UploadPackLogger[] newLoggers = new UploadPackLogger[loggers.size()];
+		int i = 0;
+		for (UploadPackLogger logger : loggers)
+			if (logger != UploadPackLogger.NULL)
+				newLoggers[i++] = logger;
+		if (i == 0)
+			return UploadPackLogger.NULL;
+		else if (i == 1)
+			return newLoggers[0];
+		else
+			return new UploadPackLoggerChain(newLoggers, i);
+	}
+
+	public void onPackStatistics(PackWriter.Statistics stats) {
+		for (int i = 0; i < count; i++)
+			loggers[i].onPackStatistics(stats);
+	}
+
+	private UploadPackLoggerChain(UploadPackLogger[] loggers, int count) {
+		this.loggers = loggers;
+		this.count = count;
+	}
+}