DfsFsck: refactor pack verify into its own method

This simplifies the logic about allocation of the DfsReader, and
clarifies the code considerably by using smaller scopes with less
indentation.

A few static imports from PackExt and slightly shorter variable names
make for a more understandable-at-glance implementation.

Change-Id: Iaf5a0e14fe0349215d9e44446f68d1129ad3bb3d

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsFsck.java

@@ -43,8 +43,11 @@
 
 package org.eclipse.jgit.internal.storage.dfs;
 
+import static org.eclipse.jgit.internal.storage.pack.PackExt.INDEX;
+import static org.eclipse.jgit.internal.storage.pack.PackExt.PACK;
+
+import java.io.FileNotFoundException;
 import java.io.IOException;
-import java.util.List;
 
 import org.eclipse.jgit.errors.CorruptPackIndexException;
 import org.eclipse.jgit.errors.MissingObjectException;
@@ -52,7 +55,6 @@ import org.eclipse.jgit.internal.JGitText;
 import org.eclipse.jgit.internal.fsck.FsckError;
 import org.eclipse.jgit.internal.fsck.FsckError.CorruptIndex;
 import org.eclipse.jgit.internal.fsck.FsckPackParser;
-import org.eclipse.jgit.internal.storage.pack.PackExt;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.NullProgressMonitor;
 import org.eclipse.jgit.lib.ObjectChecker;
@@ -60,16 +62,11 @@ import org.eclipse.jgit.lib.ProgressMonitor;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.revwalk.ObjectWalk;
 import org.eclipse.jgit.revwalk.RevObject;
-import org.eclipse.jgit.transport.PackedObjectInfo;
 
 /** Verify the validity and connectivity of a DFS repository. */
 public class DfsFsck {
 	private final DfsRepository repo;
-
 	private final DfsObjDatabase objdb;
-
-	private final DfsReader ctx;
-
 	private ObjectChecker objChecker = new ObjectChecker();
 
 	/**
@@ -81,10 +78,8 @@ public class DfsFsck {
 	public DfsFsck(DfsRepository repository) {
 		repo = repository;
 		objdb = repo.getObjectDatabase();
-		ctx = objdb.newReader();
 	}
 
-
 	/**
 	 * Verify the integrity and connectivity of all objects in the object
 	 * database.
@@ -101,42 +96,45 @@ public class DfsFsck {
 		}
 
 		FsckError errors = new FsckError();
-		try {
+		checkPacks(pm, errors);
+		checkConnectivity(pm, errors);
+		return errors;
+	}
+
+	private void checkPacks(ProgressMonitor pm, FsckError errors)
+			throws IOException, FileNotFoundException {
+		try (DfsReader ctx = objdb.newReader()) {
 			for (DfsPackFile pack : objdb.getPacks()) {
 				DfsPackDescription packDesc = pack.getPackDescription();
-				try (ReadableChannel channel = repo.getObjectDatabase()
-						.openFile(packDesc, PackExt.PACK)) {
-					List<PackedObjectInfo> objectsInPack;
-					FsckPackParser parser = new FsckPackParser(
-							repo.getObjectDatabase(), channel);
-					parser.setObjectChecker(objChecker);
-					parser.overwriteObjectCount(packDesc.getObjectCount());
-					parser.parse(pm);
-					errors.getCorruptObjects()
-							.addAll(parser.getCorruptObjects());
-					objectsInPack = parser.getSortedObjectList(null);
-					parser.verifyIndex(objectsInPack, pack.getPackIndex(ctx));
+				try (ReadableChannel rc = objdb.openFile(packDesc, PACK)) {
+					verifyPack(pm, errors, ctx, pack, rc);
 				} catch (MissingObjectException e) {
 					errors.getMissingObjects().add(e.getObjectId());
 				} catch (CorruptPackIndexException e) {
 					errors.getCorruptIndices().add(new CorruptIndex(
-							pack.getPackDescription()
-									.getFileName(PackExt.INDEX),
+							pack.getPackDescription().getFileName(INDEX),
 							e.getErrorType()));
 				}
 			}
-
-			checkConnectivity(pm, errors);
-		} finally {
-			ctx.close();
 		}
-		return errors;
+	}
+
+	private void verifyPack(ProgressMonitor pm, FsckError errors, DfsReader ctx,
+			DfsPackFile pack, ReadableChannel ch)
+					throws IOException, CorruptPackIndexException {
+		FsckPackParser fpp = new FsckPackParser(objdb, ch);
+		fpp.setObjectChecker(objChecker);
+		fpp.overwriteObjectCount(pack.getPackDescription().getObjectCount());
+		fpp.parse(pm);
+		errors.getCorruptObjects().addAll(fpp.getCorruptObjects());
+
+		fpp.verifyIndex(fpp.getSortedObjectList(null), pack.getPackIndex(ctx));
 	}
 
 	private void checkConnectivity(ProgressMonitor pm, FsckError errors)
 			throws IOException {
 		pm.beginTask(JGitText.get().countingObjects, ProgressMonitor.UNKNOWN);
-		try (ObjectWalk ow = new ObjectWalk(ctx)) {
+		try (ObjectWalk ow = new ObjectWalk(repo)) {
 			for (Ref r : repo.getAllRefs().values()) {
 				RevObject tip;
 				try {