Add support for pre-push hooks

When the file <git-dir>/hooks/pre-push exists make sure that is is
executing during a push. The pre-push hook runs during git push, after
the remote refs have been updated but before any objects have been
transferred.

Change-Id: Ibbb58ee3227742d1a2f913134ce11e7a135c7f4c

3 files changed, 191 insertions, 2 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/hooks/Hooks.java b/org.eclipse.jgit/src/org/eclipse/jgit/hooks/Hooks.java
index 1494576ab8..6f7a21a73f 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/hooks/Hooks.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/hooks/Hooks.java
@@ -74,4 +74,15 @@ public class Hooks {
 			PrintStream outputStream) {
 		return new CommitMsgHook(repo, outputStream);
 	}
+
+	/**
+	 * @param repo
+	 * @param outputStream
+	 *            The output stream, or {@code null} to use {@code System.out}
+	 * @return The pre-push hook for the given repository.
+	 * @since 4.2
+	 */
+	public static PrePushHook prePush(Repository repo, PrintStream outputStream) {
+		return new PrePushHook(repo, outputStream);
+	}
 }
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/hooks/PrePushHook.java b/org.eclipse.jgit/src/org/eclipse/jgit/hooks/PrePushHook.java
new file mode 100644
index 0000000000..2e6582819f
--- /dev/null
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/hooks/PrePushHook.java
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2015 Obeo.
+ * 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.hooks;
+
+import java.io.IOException;
+import java.io.PrintStream;
+import java.util.Collection;
+
+import org.eclipse.jgit.api.errors.AbortedByHookException;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.jgit.transport.RemoteRefUpdate;
+
+/**
+ * The <code>pre-push</code> hook implementation. The pre-push hook runs during
+ * git push, after the remote refs have been updated but before any objects have
+ * been transferred.
+ *
+ * @since 4.2
+ */
+public class PrePushHook extends GitHook<String> {
+
+	/**
+	 * Constant indicating the name of the pre-push hook.
+	 */
+	public static final String NAME = "pre-push"; //$NON-NLS-1$
+
+	private String remoteName;
+
+	private String remoteLocation;
+
+	private String refs;
+
+	/**
+	 * @param repo
+	 *            The repository
+	 * @param outputStream
+	 *            The output stream the hook must use. {@code null} is allowed,
+	 *            in which case the hook will use {@code System.out}.
+	 */
+	protected PrePushHook(Repository repo, PrintStream outputStream) {
+		super(repo, outputStream);
+	}
+
+	@Override
+	protected String getStdinArgs() {
+		return refs;
+	}
+
+	@Override
+	public String call() throws IOException, AbortedByHookException {
+		if (canRun()) {
+			doRun();
+		}
+		return ""; //$NON-NLS-1$
+	}
+
+	/**
+	 * @return {@code true}
+	 */
+	private boolean canRun() {
+		return true;
+	}
+
+	@Override
+	public String getHookName() {
+		return NAME;
+	}
+
+	/**
+	 * This hook receives two parameters, which is the name and the location of
+	 * the remote repository.
+	 */
+	@Override
+	protected String[] getParameters() {
+		return new String[] { remoteName, remoteLocation };
+	}
+
+	/**
+	 * @param name
+	 */
+	public void setRemoteName(String name) {
+		remoteName = name;
+	}
+
+	/**
+	 * @param location
+	 */
+	public void setRemoteLocation(String location) {
+		remoteLocation = location;
+	}
+
+	/**
+	 * @param toRefs
+	 */
+	public void setRefs(Collection<RemoteRefUpdate> toRefs) {
+		StringBuilder b = new StringBuilder();
+		boolean first = true;
+		for (RemoteRefUpdate u : toRefs) {
+			if (!first)
+				b.append("\n"); //$NON-NLS-1$
+			else
+				first = false;
+			b.append(u.getSrcRef());
+			b.append(" "); //$NON-NLS-1$
+			b.append(u.getNewObjectId().getName());
+			b.append(" "); //$NON-NLS-1$
+			b.append(u.getRemoteName());
+			b.append(" "); //$NON-NLS-1$
+			ObjectId ooid = u.getExpectedOldObjectId();
+			b.append((ooid == null) ? ObjectId.zeroId().getName() : ooid
+					.getName());
+		}
+		refs = b.toString();
+	}
+}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/Transport.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/Transport.java
index 218562254c..cc7db47df5 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/Transport.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/Transport.java
@@ -53,6 +53,7 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
+import java.io.PrintStream;
 import java.lang.ref.WeakReference;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
@@ -70,8 +71,11 @@ import java.util.Map;
 import java.util.Vector;
 import java.util.concurrent.CopyOnWriteArrayList;
 
+import org.eclipse.jgit.api.errors.AbortedByHookException;
 import org.eclipse.jgit.errors.NotSupportedException;
 import org.eclipse.jgit.errors.TransportException;
+import org.eclipse.jgit.hooks.Hooks;
+import org.eclipse.jgit.hooks.PrePushHook;
 import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.NullProgressMonitor;
@@ -557,8 +561,13 @@ public abstract class Transport {
 				continue;
 			}
 
-			if (proto.canHandle(uri, local, remoteName))
-				return proto.open(uri, local, remoteName);
+			if (proto.canHandle(uri, local, remoteName)) {
+				Transport tn = proto.open(uri, local, remoteName);
+				tn.prePush = Hooks.prePush(local, tn.hookOutRedirect);
+				tn.prePush.setRemoteLocation(uri.toString());
+				tn.prePush.setRemoteName(remoteName);
+				return tn;
+			}
 		}
 
 		throw new NotSupportedException(MessageFormat.format(JGitText.get().URINotSupported, uri));
@@ -761,6 +770,9 @@ public abstract class Transport {
 	/** Assists with authentication the connection. */
 	private CredentialsProvider credentialsProvider;
 
+	private PrintStream hookOutRedirect;
+
+	private PrePushHook prePush;
 	/**
 	 * Create a new transport instance.
 	 *
@@ -778,6 +790,7 @@ public abstract class Transport {
 		this.uri = uri;
 		this.objectChecker = tc.newObjectChecker();
 		this.credentialsProvider = CredentialsProvider.getDefault();
+		prePush = Hooks.prePush(local, hookOutRedirect);
 	}
 
 	/**
@@ -1196,6 +1209,15 @@ public abstract class Transport {
 			if (toPush.isEmpty())
 				throw new TransportException(JGitText.get().nothingToPush);
 		}
+		if (prePush != null) {
+			try {
+				prePush.setRefs(toPush);
+				prePush.call();
+			} catch (AbortedByHookException | IOException e) {
+				throw new TransportException(e.getMessage(), e);
+			}
+		}
+
 		final PushProcess pushProcess = new PushProcess(this, toPush, out);
 		return pushProcess.execute(monitor);
 	}