Add getPackFile to ReceivePack to make PostReceiveHook more usable

Having access to the pack file that was created by the ReceivePack
may be useful for post receive hooks. For example, a hook may want
to check the size of the received pack and the created index.

Change-Id: I4d51758e4565d32c9f8892242947eb72644b847d
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

org.eclipse.jgit/.settings/.api_filters

@@ -8,6 +8,14 @@
             </message_arguments>
         </filter>
     </resource>
+    <resource path="src/org/eclipse/jgit/transport/BaseReceivePack.java" type="org.eclipse.jgit.transport.BaseReceivePack">
+        <filter comment="Method is only used by those subclassing BaseReceivePack, minor version are allowed to break implementer API according to OSGi semantic versioning (http://www.osgi.org/wiki/uploads/Links/SemanticVersioning.pdf)" id="338792546">
+            <message_arguments>
+                <message_argument value="org.eclipse.jgit.transport.BaseReceivePack"/>
+                <message_argument value="unlockPack()"/>
+            </message_arguments>
+        </filter>
+    </resource>
     <resource path="src/org/eclipse/jgit/transport/TransportHttp.java" type="org.eclipse.jgit.transport.TransportHttp">
         <filter comment="Method is only used by implementers of TransportHttp's API, minor version are allowed to break implementer API according to OSGi semantic versioning (http://www.osgi.org/wiki/uploads/Links/SemanticVersioning.pdf)" id="338792546">
             <message_arguments>

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackLock.java

@@ -54,6 +54,7 @@ import org.eclipse.jgit.util.FileUtils;
 public class PackLock {
 	private final File keepFile;
 	private final FS fs;
+	private final File packFile;
 
 	/**
 	 * Create a new lock for a pack file.
@@ -68,6 +69,7 @@ public class PackLock {
 		final String n = packFile.getName();
 		keepFile = new File(p, n.substring(0, n.length() - 5) + ".keep"); //$NON-NLS-1$
 		this.fs = fs;
+		this.packFile = packFile;
 	}
 
 	/**
@@ -100,4 +102,11 @@ public class PackLock {
 	public void unlock() throws IOException {
 		FileUtils.delete(keepFile);
 	}
+
+	/**
+	 * @return the pack file being held by this lock
+	 */
+	public File getPackFile() {
+		return packFile;
+	}
 }

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

@@ -51,6 +51,7 @@ import static org.eclipse.jgit.transport.SideBandOutputStream.CH_DATA;
 import static org.eclipse.jgit.transport.SideBandOutputStream.CH_PROGRESS;
 import static org.eclipse.jgit.transport.SideBandOutputStream.MAX_BUF;
 
+import java.io.File;
 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
@@ -804,14 +805,20 @@ public abstract class BaseReceivePack {
 	/**
 	 * Unlock the pack written by this object.
 	 *
+	 * @return the pack file that was unlocked, {@code null} if there was no
+	 *         lock
 	 * @throws IOException
 	 *             the pack could not be unlocked.
+	 * @since 3.3
 	 */
-	protected void unlockPack() throws IOException {
+	protected File unlockPack() throws IOException {
 		if (packLock != null) {
+			File packFile = packLock.getPackFile();
 			packLock.unlock();
 			packLock = null;
+			return packFile;
 		}
+		return null;
 	}
 
 	/**

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

@@ -45,6 +45,7 @@ package org.eclipse.jgit.transport;
 
 import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_REPORT_STATUS;
 
+import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -70,6 +71,9 @@ public class ReceivePack extends BaseReceivePack {
 
 	private boolean echoCommandFailures;
 
+	/** The pack file that was created by this receive pack */
+	private File packFile;
+
 	/**
 	 * Create a new pack receive for an open repository.
 	 *
@@ -167,6 +171,15 @@ public class ReceivePack extends BaseReceivePack {
 		}
 	}
 
+	/**
+	 * @return the pack file that was created by the
+	 *         {@link #receive(InputStream, OutputStream, OutputStream)} method
+	 * @since 3.3
+	 */
+	public File getPackFile() {
+		return packFile;
+	}
+
 	@Override
 	protected void enableCapabilities() {
 		reportStatus = isCapabilityEnabled(CAPABILITY_REPORT_STATUS);
@@ -203,7 +216,7 @@ public class ReceivePack extends BaseReceivePack {
 				preReceive.onPreReceive(this, filterCommands(Result.NOT_ATTEMPTED));
 				executeCommands();
 			}
-			unlockPack();
+			packFile = unlockPack();
 
 			if (reportStatus) {
 				if (echoCommandFailures && msgOut != null) {