[JGIT PATCH 00/12] Extensions in core needed by PackWriter

@@ -45,9 +45,9 @@ import java.util.zip.DataFormatException;
 import org.spearce.jgit.util.NB;
 
 /**
- * A Git version 2 pack file representation. A pack file contains
- * Git objects in delta packed format yielding high compression of
- * lots of object where some objects are similar.
+ * A Git version 2 pack file representation. A pack file contains Git objects in
+ * delta packed format yielding high compression of lots of object where some
+ * objects are similar.
  */
 public class PackFile {
 	private static final byte[] SIGNATURE = { 'P', 'A', 'C', 'K' };

@@ -58,7 +58,7 @@ public class PackFile {
 
 	/**
 	 * Construct a reader for an existing, pre-indexed packfile.
-	 *
+	 * 
 	 * @param parentRepo
 	 *            Git repository holding this pack file
 	 * @param idxFile

@@ -188,13 +188,11 @@ public class PackFile {
 		if (idx.getObjectCount() != objectCnt)
 			throw new IOException("Pack index"
 					+ " object count mismatch; expected " + objectCnt
-					+ " found " + idx.getObjectCount() + ": "
-					+ pack.getName());
+					+ " found " + idx.getObjectCount() + ": " + pack.getName());
 	}
 
 	private PackedObjectLoader reader(final WindowCursor curs,
-			final long objOffset)
-			throws IOException {
+			final long objOffset) throws IOException {
 		long pos = objOffset;
 		int p = 0;
 		final byte[] ib = curs.tempId;

@@ -61,7 +61,7 @@ public abstract class PackIndex {
 	 * implementation for that format will be constructed and returned to the
 	 * caller. The file may or may not be held open by the returned instance.
 	 * </p>
-	 *
+	 * 
 	 * @param idxFile
 	 *            existing pack .idx to read.
 	 * @return access implementation for the requested file.

@@ -118,7 +118,7 @@ public abstract class PackIndex {
 
 	/**
 	 * Obtain the total number of objects described by this index.
-	 *
+	 * 
 	 * @return number of objects in this index, and likewise in the associated
 	 *         pack that this index was generated from.
 	 */

@@ -126,7 +126,7 @@ public abstract class PackIndex {
 
 	/**
 	 * Locate the file offset position for the requested object.
-	 *
+	 * 
 	 * @param objId
 	 *            name of the object to locate within the pack.
 	 * @return offset of the object's header and compressed content; -1 if the

@@ -64,9 +64,9 @@ class PackIndexV1 extends PackIndex {
 		for (int k = 0; k < idxHeader.length; k++) {
 			int n;
 			if (k == 0) {
-				n = (int)(idxHeader[k]);
+				n = (int) (idxHeader[k]);
 			} else {
-				n = (int)(idxHeader[k]-idxHeader[k-1]);
+				n = (int) (idxHeader[k] - idxHeader[k - 1]);
 			}
 			if (n > 0) {
 				idxdata[k] = new byte[n * (Constants.OBJECT_ID_LENGTH + 4)];

@@ -94,11 +94,11 @@ class PackIndexV1 extends PackIndex {
 			if (cmp < 0)
 				high = mid;
 			else if (cmp == 0) {
-				int b0 = data[pos-4] & 0xff;
-				int b1 = data[pos-3] & 0xff;
-				int b2 = data[pos-2] & 0xff;
-				int b3 = data[pos-1] & 0xff;
-				return (((long)b0) << 24) | ( b1 << 16 ) | ( b2 << 8 ) | (b3);
+				int b0 = data[pos - 4] & 0xff;
+				int b1 = data[pos - 3] & 0xff;
+				int b2 = data[pos - 2] & 0xff;
+				int b3 = data[pos - 1] & 0xff;
+				return (((long) b0) << 24) | (b1 << 16) | (b2 << 8) | (b3);
 			} else
 				low = mid + 1;
 		} while (low < high);

@@ -74,6 +74,35 @@ public class MutableObjectId extends AnyObjectId {
 	}
 
 	/**
+	 * Convert an ObjectId from binary representation expressed in integers.
+	 * 
+	 * @param ints
+	 *            the raw int buffer to read from. At least 5 integers must be
+	 *            available within this integers array.
+	 */
+	public void fromRaw(final int[] ints) {
+		fromRaw(ints, 0);
+	}
+
+	/**
+	 * Convert an ObjectId from binary representation expressed in integers.
+	 * 
+	 * @param ints
+	 *            the raw int buffer to read from. At least 5 integers after p
+	 *            must be available within this integers array.
+	 * @param p
+	 *            position to read the first integer of data from.
+	 * 
+	 */
+	public void fromRaw(final int[] ints, final int p) {
+		w1 = ints[p];
+		w2 = ints[p + 1];
+		w3 = ints[p + 2];
+		w4 = ints[p + 3];
+		w5 = ints[p + 4];
+	}
+
+	/**
 	 * Convert an ObjectId from hex characters (US-ASCII).
 	 * 
 	 * @param buf

@@ -188,6 +188,14 @@ public final class Constants {
 	 */
 	public static final int OBJ_REF_DELTA = 7;
 
+	/**
+	 * Pack file signature that occurs at file header - identifies file as Git
+	 * packfile formatted.
+	 * <p>
+	 * <b>This constant is fixed and is defined by the Git packfile format.</b>
+	 */
+	public static final byte[] PACK_SIGNATURE = { 'P', 'A', 'C', 'K' };
+	
 	/** Native character encoding for commit messages, file names... */
 	public static final String CHARACTER_ENCODING = "UTF-8";
 

@@ -50,8 +50,6 @@ import org.spearce.jgit.util.NB;
  * objects are similar.
  */
 public class PackFile {
-	private static final byte[] SIGNATURE = { 'P', 'A', 'C', 'K' };
-
 	private final WindowedFile pack;
 
 	private final PackIndex idx;

@@ -165,17 +163,17 @@ public class PackFile {
 	private void readPackHeader() throws IOException {
 		final WindowCursor curs = new WindowCursor();
 		long position = 0;
-		final byte[] sig = new byte[SIGNATURE.length];
+		final byte[] sig = new byte[Constants.PACK_SIGNATURE.length];
 		final byte[] intbuf = new byte[4];
 		final long vers;
 
-		if (pack.read(position, sig, curs) != SIGNATURE.length)
+		if (pack.read(position, sig, curs) != Constants.PACK_SIGNATURE.length)
 			throw new IOException("Not a PACK file.");
-		for (int k = 0; k < SIGNATURE.length; k++) {
-			if (sig[k] != SIGNATURE[k])
+		for (int k = 0; k < Constants.PACK_SIGNATURE.length; k++) {
+			if (sig[k] != Constants.PACK_SIGNATURE[k])
 				throw new IOException("Not a PACK file.");
 		}
-		position += SIGNATURE.length;
+		position += Constants.PACK_SIGNATURE.length;
 
 		pack.readFully(position, intbuf, curs);
 		vers = NB.decodeUInt32(intbuf, 0);

@@ -74,8 +74,6 @@ public class IndexPack {
 	/** Progress message when computing names of delta compressed objects. */
 	public static final String PROGRESS_RESOLVE_DELTA = "Resolving deltas";
 
-	private static final byte[] SIGNATURE = { 'P', 'A', 'C', 'K' };
-
 	private static final int BUFFER_SIZE = 2048;
 
 	/**

@@ -477,10 +475,10 @@ public class IndexPack {
 	}
 
 	private void readPackHeader() throws IOException {
-		final int hdrln = SIGNATURE.length + 4 + 4;
+		final int hdrln = Constants.PACK_SIGNATURE.length + 4 + 4;
 		final int p = fillFromInput(hdrln);
-		for (int k = 0; k < SIGNATURE.length; k++)
-			if (buf[p + k] != SIGNATURE[k])
+		for (int k = 0; k < Constants.PACK_SIGNATURE.length; k++)
+			if (buf[p + k] != Constants.PACK_SIGNATURE[k])
 				throw new IOException("Not a PACK file.");
 
 		final long vers = NB.decodeUInt32(buf, p + 4);

@@ -145,6 +145,16 @@ public class PackFile {
 		pack.close();
 	}
 
+	/**
+	 * Obtain the total number of objects available in this pack. This method
+	 * relies on pack index, giving number of effectively available objects.
+	 * 
+	 * @return number of objects in index of this pack, likewise in this pack
+	 */
+	long getObjectCount() {
+		return idx.getObjectCount();
+	}
+
 	final UnpackedObjectCache.Entry readCache(final long position) {
 		return UnpackedObjectCache.get(pack, position);
 	}

@@ -66,7 +66,6 @@ import org.spearce.jgit.lib.Ref;
 import org.spearce.jgit.lib.Repository;
 import org.spearce.jgit.lib.UnpackedObjectLoader;
 import org.spearce.jgit.revwalk.DateRevQueue;
-import org.spearce.jgit.revwalk.RevBlob;
 import org.spearce.jgit.revwalk.RevCommit;
 import org.spearce.jgit.revwalk.RevFlag;
 import org.spearce.jgit.revwalk.RevObject;

@@ -251,20 +250,22 @@ class WalkFetchConnection extends FetchConnection {
 		//
 		obj.dispose();
 
-		if (obj instanceof RevBlob)
-			processBlob(obj);
-
-		else if (obj instanceof RevTree)
+		switch (obj.getType()) {
+		case Constants.OBJ_BLOB:
+			processBlob(obj);	
+			break;
+		case Constants.OBJ_TREE:
 			processTree(obj);
-
-		else if (obj instanceof RevCommit)
+			break;
+		case Constants.OBJ_COMMIT:
 			processCommit(obj);
-
-		else if (obj instanceof RevTag)
+			break;
+		case Constants.OBJ_TAG:
 			processTag(obj);
-
-		else
+			break;
+		default:
 			throw new TransportException("Unknown object type " + obj.getId());
+		}
 
 		// If we had any prior errors fetching this object they are
 		// now resolved, as the object was parsed successfully.

@@ -632,19 +633,24 @@ class WalkFetchConnection extends FetchConnection {
 	}
 
 	private void markLocalObjComplete(RevObject obj) throws IOException {
-		while (obj instanceof RevTag) {
+		while (obj.getType() == Constants.OBJ_TAG) {
 			obj.add(COMPLETE);
 			obj.dispose();
 			obj = ((RevTag) obj).getObject();
 			revWalk.parse(obj);
 		}
 
-		if (obj instanceof RevBlob)
+		switch (obj.getType()) {
+		case Constants.OBJ_BLOB:
 			obj.add(COMPLETE);
-		else if (obj instanceof RevCommit)
+			break;
+		case Constants.OBJ_COMMIT:			
 			pushLocalCommit((RevCommit) obj);
-		else if (obj instanceof RevTree)
+			break;
+		case Constants.OBJ_TREE:
 			markTreeComplete((RevTree) obj);
+			break;
+		}
 	}
 
 	private void markLocalCommitsComplete(final int until)

@@ -107,6 +107,15 @@ public class ObjectIdSubclassMap<V extends ObjectId> {
 		size++;
 	}
 
+	/**
+	 * Returns number of objects in map.
+	 * 
+	 * @return number of objects in map
+	 */
+	public int size() {
+		return size;
+	}
+
 	private final int index(final AnyObjectId id) {
 		return (id.w1 >>> 1) % obj_hash.length;
 	}

@@ -46,6 +46,27 @@ import org.spearce.jgit.util.NB;
  */
 public class MutableObjectId extends AnyObjectId {
 	/**
+	 * Empty constructor. Initialize object with default (zeros) value.
+	 */
+	public MutableObjectId() {
+		super();
+	}
+
+	/**
+	 * Copying constructor.
+	 * 
+	 * @param src
+	 *            original entry, to copy id from
+	 */
+	MutableObjectId(MutableObjectId src) {
+		this.w1 = src.w1;
+		this.w2 = src.w2;
+		this.w3 = src.w3;
+		this.w4 = src.w4;
+		this.w5 = src.w5;
+	}
+
+	/**
 	 * Convert an ObjectId from raw binary representation.
 	 * 
 	 * @param bs

@@ -38,6 +38,7 @@
 package org.spearce.jgit.revwalk;
 
 import org.spearce.jgit.lib.AnyObjectId;
+import org.spearce.jgit.lib.Constants;
 
 /** A binary file, or a symbolic link. */
 public class RevBlob extends RevObject {

@@ -55,4 +56,9 @@ public class RevBlob extends RevObject {
 	void parse(final RevWalk walk) {
 		flags |= PARSED;
 	}
+	
+	@Override
+	public int getType() {
+		return Constants.OBJ_BLOB;
+	}
 }

@@ -135,6 +135,11 @@ public class RevCommit extends RevObject {
 		buffer = raw;
 		flags |= PARSED;
 	}
+	
+	@Override
+	public int getType() {
+		return Constants.OBJ_COMMIT;
+	}
 
 	static void carryFlags(RevCommit c, final int carry) {
 		for (;;) {

@@ -42,6 +42,7 @@ import java.io.IOException;
 import org.spearce.jgit.errors.IncorrectObjectTypeException;
 import org.spearce.jgit.errors.MissingObjectException;
 import org.spearce.jgit.lib.AnyObjectId;
+import org.spearce.jgit.lib.Constants;
 import org.spearce.jgit.lib.ObjectId;
 
 /** Base object type accessed during revision walking. */

@@ -56,6 +57,13 @@ public abstract class RevObject extends ObjectId {
 
 	abstract void parse(RevWalk walk) throws MissingObjectException,
 			IncorrectObjectTypeException, IOException;
+	
+	/**
+	 * Get Git object type. See {@link Constants}.
+	 * 
+	 * @return object type
+	 */
+	public abstract int getType();
 
 	/**
 	 * Get the name of this object.

@@ -96,6 +96,11 @@ public class RevTag extends RevObject {
 		flags |= PARSED;
 	}
 
+	@Override
+	public int getType() {
+		return Constants.OBJ_TAG;
+	}
+	
 	/**
 	 * Parse this tag buffer for display.
 	 * 

@@ -38,6 +38,7 @@
 package org.spearce.jgit.revwalk;
 
 import org.spearce.jgit.lib.AnyObjectId;
+import org.spearce.jgit.lib.Constants;
 
 /** A reference to a tree of subtrees/files. */
 public class RevTree extends RevObject {

@@ -55,4 +56,9 @@ public class RevTree extends RevObject {
 	void parse(final RevWalk walk) {
 		flags |= PARSED;
 	}
+	
+	@Override
+	public int getType() {
+		return Constants.OBJ_TREE;
+	}
 }

@@ -40,6 +40,7 @@ package org.spearce.jgit.lib;
 
 import java.io.File;
 import java.io.IOException;
+import java.util.Iterator;
 import java.util.zip.DataFormatException;
 
 import org.spearce.jgit.util.NB;

@@ -49,7 +50,7 @@ import org.spearce.jgit.util.NB;
  * delta packed format yielding high compression of lots of object where some
  * objects are similar.
  */
-public class PackFile {
+public class PackFile implements Iterable<PackIndex.MutableEntry> {
 	private final WindowedFile pack;
 
 	private final PackIndex idx;

@@ -146,6 +147,22 @@ public class PackFile {
 	}
 
 	/**
+	 * Provide iterator over entries in associated pack index, that should also
+	 * exist in this pack file. Objects returned by such iterator are mutable
+	 * during iteration.
+	 * <p>
+	 * Iterator returns objects in SHA-1 lexicographical order.
+	 * </p>
+	 * 
+	 * @return iterator over entries of associated pack index
+	 * 
+	 * @see PackIndex#iterator()
+	 */
+	public Iterator<PackIndex.MutableEntry> iterator() {
+		return idx.iterator();
+	}
+
+	/**
 	 * Obtain the total number of objects available in this pack. This method
 	 * relies on pack index, giving number of effectively available objects.
 	 * 

@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
+ * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
  *
  * All rights reserved.
  *

@@ -41,6 +42,7 @@ import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.util.Iterator;
 
 import org.spearce.jgit.util.NB;
 

@@ -53,7 +55,7 @@ import org.spearce.jgit.util.NB;
  * by ObjectId.
  * </p>
  */
-public abstract class PackIndex {
+public abstract class PackIndex implements Iterable<PackIndex.MutableEntry> {
 	/**
 	 * Open an existing pack <code>.idx</code> file for reading.
 	 * <p>

@@ -117,6 +119,19 @@ public abstract class PackIndex {
 	}
 
 	/**
+	 * Provide iterator that gives access to index entries. Note, that iterator
+	 * returns reference to mutable object, the same reference in each call -
+	 * for performance reason. If client needs immutable objects, it must copy
+	 * returned object on its own.
+	 * <p>
+	 * Iterator returns objects in SHA-1 lexicographical order.
+	 * </p>
+	 * 
+	 * @return iterator over pack index entries
+	 */
+	public abstract Iterator<MutableEntry> iterator();
+
+	/**
 	 * Obtain the total number of objects described by this index.
 	 * 
 	 * @return number of objects in this index, and likewise in the associated

@@ -134,4 +149,67 @@ public abstract class PackIndex {
 	 *         associated pack.
 	 */
 	abstract long findOffset(AnyObjectId objId);
+
+	/**
+	 * Represent mutable entry of pack index consisting of object id and offset
+	 * in pack (both mutable).
+	 * 
+	 */
+	public static class MutableEntry extends MutableObjectId {
+		private long offset;
+
+		/**
+		 * Empty constructor. Object fields should be filled in later.
+		 */
+		public MutableEntry() {
+			super();
+		}
+
+		/**
+		 * Returns offset for this index object entry
+		 * 
+		 * @return offset of this object in a pack file
+		 */
+		public long getOffset() {
+			return offset;
+		}
+
+		void setOffset(long offset) {
+			this.offset = offset;
+		}
+
+		private MutableEntry(MutableEntry src) {
+			super(src);
+			this.offset = src.offset;
+		}
+
+		/**
+		 * Returns mutable copy of this mutable entry.
+		 * 
+		 * @return copy of this mutable entry
+		 */
+		public MutableEntry cloneEntry() {
+			return new MutableEntry(this);
+		}
+	}
+
+	protected abstract class EntriesIterator implements Iterator<MutableEntry> {
+		protected MutableEntry objectId = new MutableEntry();
+
+		protected long returnedNumber = 0;
+
+		public boolean hasNext() {
+			return returnedNumber < getObjectCount();
+		}
+
+		/**
+		 * Implementation must update {@link #returnedNumber} before returning
+		 * element.
+		 */
+		public abstract MutableEntry next();
+
+		public void remove() {
+			throw new UnsupportedOperationException();
+		}
+	}
 }

@@ -40,6 +40,8 @@ package org.spearce.jgit.lib;
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
 
 import org.spearce.jgit.errors.CorruptObjectException;
 import org.spearce.jgit.util.NB;

@@ -104,4 +106,33 @@ class PackIndexV1 extends PackIndex {
 		} while (low < high);
 		return -1;
 	}
+
+	public Iterator<MutableEntry> iterator() {
+		return new IndexV1Iterator();
+	}
+
+	private class IndexV1Iterator extends EntriesIterator {
+		private int levelOne;
+
+		private int levelTwo;
+
+		public MutableEntry next() {
+			for (; levelOne < idxdata.length; levelOne++) {
+				if (idxdata[levelOne] == null)
+					continue;
+
+				if (levelTwo < idxdata[levelOne].length) {
+					long offset = NB.decodeUInt32(idxdata[levelOne], levelTwo);
+					objectId.setOffset(offset);
+					objectId.fromRaw(idxdata[levelOne], levelTwo + 4);
+					levelTwo += Constants.OBJECT_ID_LENGTH + 4;
+					returnedNumber++;
+					return objectId;
+				} else {
+					levelTwo = 0;
+				}
+			}
+			throw new NoSuchElementException();
+		}
+	}
 }

@@ -40,6 +40,8 @@ package org.spearce.jgit.lib;
 import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
 
 import org.spearce.jgit.util.NB;
 

@@ -174,4 +176,38 @@ class PackIndexV2 extends PackIndex {
 		} while (low < high);
 		return -1;
 	}
+
+	public Iterator<MutableEntry> iterator() {
+		return new EntriesIteratorV2();
+	}
+
+	private class EntriesIteratorV2 extends EntriesIterator {
+		private int levelOne;
+
+		private int levelTWo;
+
+		public MutableEntry next() {
+			for (; levelOne < names.length; levelOne++) {
+				if (levelTWo < names[levelOne].length) {
+					objectId.fromRaw(names[levelOne], levelTWo);
+					int arrayIdx = levelTWo / (Constants.OBJECT_ID_LENGTH / 4)
+							* 4;
+					long offset = NB.decodeUInt32(offset32[levelOne], arrayIdx);
+					if ((offset & IS_O64) != 0) {
+						arrayIdx = (8 * (int) (offset & ~IS_O64));
+						offset = NB.decodeUInt64(offset64, arrayIdx);
+					}
+					objectId.setOffset(offset);
+
+					levelTWo += Constants.OBJECT_ID_LENGTH / 4;
+					returnedNumber++;
+					return objectId;
+				} else {
+					levelTWo = 0;
+				}
+			}
+			throw new NoSuchElementException();
+		}
+	}
+
 }

@@ -0,0 +1,152 @@
+/*
+ * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
+ *
+ * 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 Git Development Community 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.spearce.jgit.lib;
+
+import java.io.File;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+import org.spearce.jgit.lib.PackIndex.MutableEntry;
+
+public abstract class PackIndexTest extends RepositoryTestCase {
+
+	PackIndex smallIdx;
+
+	PackIndex denseIdx;
+
+	public void setUp() throws Exception {
+		super.setUp();
+		smallIdx = PackIndex.open(getFileForPack34be9032());
+		denseIdx = PackIndex.open(getFileForPackdf2982f28());
+	}
+
+	/**
+	 * Return file with appropriate index version for prepared pack.
+	 * 
+	 * @return file with index
+	 */
+	public abstract File getFileForPack34be9032();
+
+	/**
+	 * Return file with appropriate index version for prepared pack.
+	 * 
+	 * @return file with index
+	 */
+	public abstract File getFileForPackdf2982f28();
+
+	/**
+	 * Test contracts of Iterator methods and this implementation remove()
+	 * limitations.
+	 */
+	public void testIteratorMethodsContract() {
+		Iterator<PackIndex.MutableEntry> iter = smallIdx.iterator();
+		while (iter.hasNext()) {
+			iter.next();
+		}
+
+		try {
+			iter.next();
+			fail("next() unexpectedly returned element");
+		} catch (NoSuchElementException x) {
+			// expected
+		}
+
+		try {
+			iter.remove();
+			fail("remove() shouldn't be implemented");
+		} catch (UnsupportedOperationException x) {
+			// expected
+		}
+	}
+
+	/**
+	 * Test results of iterator comparing to content of well-known (prepared)
+	 * small index.
+	 */
+	public void testIteratorReturnedValues1() {
+		Iterator<PackIndex.MutableEntry> iter = smallIdx.iterator();
+		assertEquals("4b825dc642cb6eb9a060e54bf8d69288fbee4904", iter.next()
+				.toString());
+		assertEquals("540a36d136cf413e4b064c2b0e0a4db60f77feab", iter.next()
+				.toString());
+		assertEquals("5b6e7c66c276e7610d4a73c70ec1a1f7c1003259", iter.next()
+				.toString());
+		assertEquals("6ff87c4664981e4397625791c8ea3bbb5f2279a3", iter.next()
+				.toString());
+		assertEquals("82c6b885ff600be425b4ea96dee75dca255b69e7", iter.next()
+				.toString());
+		assertEquals("902d5476fa249b7abc9d84c611577a81381f0327", iter.next()
+				.toString());
+		assertEquals("aabf2ffaec9b497f0950352b3e582d73035c2035", iter.next()
+				.toString());
+		assertEquals("c59759f143fb1fe21c197981df75a7ee00290799", iter.next()
+				.toString());
+		assertFalse(iter.hasNext());
+	}
+
+	/**
+	 * Compare offset from iterator entries with output of findOffset() method.
+	 */
+	public void testCompareEntriesOffsetsWithFindOffsets() {
+		for (MutableEntry me : smallIdx) {
+			assertEquals(smallIdx.findOffset(me), me.getOffset());
+		}
+		for (MutableEntry me : denseIdx) {
+			assertEquals(denseIdx.findOffset(me), me.getOffset());
+		}
+	}
+
+	/**
+	 * Test partial results of iterator comparing to content of well-known
+	 * (prepared) dense index, that may need multi-level indexing.
+	 */
+	public void testIteratorReturnedValues2() {
+		Iterator<PackIndex.MutableEntry> iter = denseIdx.iterator();
+		while (!iter.next().toString().equals(
+				"0a3d7772488b6b106fb62813c4d6d627918d9181")) {
+			// just iterating
+		}
+		assertEquals("1004d0d7ac26fbf63050a234c9b88a46075719d3", iter.next()
+				.toString()); // same level-1
+		assertEquals("10da5895682013006950e7da534b705252b03be6", iter.next()
+				.toString()); // same level-1
+		assertEquals("1203b03dc816ccbb67773f28b3c19318654b0bc8", iter.next()
+				.toString());
+	}
+
+}

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
+ *
+ * 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 Git Development Community 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.spearce.jgit.lib;
+
+import java.io.File;
+
+public class PackIndexV1Test extends PackIndexTest {
+	@Override
+	public File getFileForPack34be9032() {
+		return new File(new File("tst"),
+				"pack-34be9032ac282b11fa9babdc2b2a93ca996c9c2f.idx");
+	}
+
+	@Override
+	public File getFileForPackdf2982f28() {
+		return new File(new File("tst"),
+				"pack-df2982f284bbabb6bdb59ee3fcc6eb0983e20371.idx");
+	}
+}