Don't fail when trying to prune pack which is already gone

Update the TestRepository.prunePacked so that it doesn't fail if a pack
to be pruned is already gone.
It is especially handy when the prunePacked function is called in
`TestRepository.packAndPrune` function after the repo moves on after
GC was performed.

Change-Id: I01b4ddbaddec1fdc24cfbb967e0edfe0de6c4b7c

org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/TestRepository.java

@@ -1020,7 +1020,8 @@ public void close() {
 	private static void prunePacked(ObjectDirectory odb) throws IOException {
 		for (Pack p : odb.getPacks()) {
 			for (MutableEntry e : p)
-				FileUtils.delete(odb.fileFor(e.toObjectId()));
+				FileUtils.delete(odb.fileFor(e.toObjectId()),
+						FileUtils.SKIP_MISSING);
 		}
 	}
 

org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/GcNumberOfPackFilesSinceBitmapStatisticsTest.java

@@ -12,25 +12,12 @@
 
 import static org.junit.Assert.assertEquals;
 
-import java.io.BufferedOutputStream;
-import java.io.FileOutputStream;
 import java.io.IOException;
-import java.io.OutputStream;
 import java.nio.file.Files;
-import java.util.HashSet;
-import java.util.Set;
 import java.util.stream.StreamSupport;
 
-import org.eclipse.jgit.internal.storage.file.PackIndex.MutableEntry;
-import org.eclipse.jgit.internal.storage.pack.PackExt;
-import org.eclipse.jgit.internal.storage.pack.PackWriter;
-import org.eclipse.jgit.junit.TestRepository;
-import org.eclipse.jgit.lib.NullProgressMonitor;
-import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.PersonIdent;
-import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.revwalk.RevCommit;
-import org.eclipse.jgit.util.FileUtils;
 import org.junit.Test;
 
 public class GcNumberOfPackFilesSinceBitmapStatisticsTest extends GcTestCase {
@@ -43,7 +30,7 @@ public void testShouldReportZeroObjectsForInitializedRepo()
 	@Test
 	public void testShouldReportAllPackFilesWhenNoGcWasPerformed()
 			throws Exception {
-		packAndPrune();
+		tr.packAndPrune();
 		long result = gc.getStatistics().numberOfPackFilesSinceBitmap;
 
 		assertEquals(repo.getObjectDatabase().getPacks().size(), result);
@@ -68,7 +55,7 @@ public void testShouldReportNewObjectsSinceGcWhenRepositoryProgresses()
 
 		// progress & pack
 		addCommit(parent);
-		packAndPrune();
+		tr.packAndPrune();
 
 		assertEquals(1L, gc.getStatistics().numberOfPackFilesSinceBitmap);
 	}
@@ -88,18 +75,11 @@ public void testShouldReportNewObjectsFromTheLatestBitmapWhenRepositoryProgresse
 
 		// progress & pack
 		addCommit(parent);
-		packAndPrune();
+		tr.packAndPrune();
 
 		assertEquals(1L, gc.getStatistics().numberOfPackFilesSinceBitmap);
 	}
 
-	private void packAndPrune() throws Exception {
-		try (SkipNonExistingFilesTestRepository testRepo = new SkipNonExistingFilesTestRepository(
-				repo)) {
-			testRepo.packAndPrune();
-		}
-	}
-
 	private RevCommit addCommit(RevCommit parent) throws Exception {
 		return tr.branch("master").commit()
 				.author(new PersonIdent("repo-metrics", "repo@metrics.com"))
@@ -114,60 +94,4 @@ private long repositoryBitmapFiles() throws IOException {
 						.spliterator(), false)
 				.count();
 	}
-
-	/**
-	 * The TestRepository has a {@link TestRepository#packAndPrune()} function
-	 * but it fails in the last step after GC was performed as it doesn't
-	 * SKIP_MISSING files. In order to circumvent it was copied and improved
-	 * here.
-	 */
-	private static class SkipNonExistingFilesTestRepository
-			extends TestRepository<FileRepository> {
-		private final FileRepository repo;
-
-		private SkipNonExistingFilesTestRepository(FileRepository db) throws IOException {
-			super(db);
-			repo = db;
-		}
-
-		@Override
-		public void packAndPrune() throws Exception {
-			ObjectDirectory odb = repo.getObjectDatabase();
-			NullProgressMonitor m = NullProgressMonitor.INSTANCE;
-
-			final PackFile pack, idx;
-			try (PackWriter pw = new PackWriter(repo)) {
-				Set<ObjectId> all = new HashSet<>();
-				for (Ref r : repo.getRefDatabase().getRefs())
-					all.add(r.getObjectId());
-				pw.preparePack(m, all, PackWriter.NONE);
-
-				pack = new PackFile(odb.getPackDirectory(), pw.computeName(),
-						PackExt.PACK);
-				try (OutputStream out = new BufferedOutputStream(
-						new FileOutputStream(pack))) {
-					pw.writePack(m, m, out);
-				}
-				pack.setReadOnly();
-
-				idx = pack.create(PackExt.INDEX);
-				try (OutputStream out = new BufferedOutputStream(
-						new FileOutputStream(idx))) {
-					pw.writeIndex(out);
-				}
-				idx.setReadOnly();
-			}
-
-			odb.openPack(pack);
-			updateServerInfo();
-
-			// alternative packAndPrune implementation that skips missing files
-			// after GC.
-			for (Pack p : odb.getPacks()) {
-				for (MutableEntry e : p)
-					FileUtils.delete(odb.fileFor(e.toObjectId()),
-							FileUtils.SKIP_MISSING);
-			}
-		}
-	}
 }