Merge changes Ie949f321,I403de522

* changes:
  Implement wasDeltaAttempted() in DfsObjectRepresentation.
  Do not delta compress objects that have already tried to compress.

org.eclipse.jgit/src/org/eclipse/jgit/storage/dfs/DfsObjectRepresentation.java

@@ -43,7 +43,11 @@
 
 package org.eclipse.jgit.storage.dfs;
 
+import static org.eclipse.jgit.storage.dfs.DfsObjDatabase.PackSource.GC;
+import static org.eclipse.jgit.storage.dfs.DfsObjDatabase.PackSource.UNREACHABLE_GARBAGE;
+
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.storage.dfs.DfsObjDatabase.PackSource;
 import org.eclipse.jgit.storage.pack.ObjectToPack;
 import org.eclipse.jgit.storage.pack.StoredObjectRepresentation;
 
@@ -87,4 +91,13 @@ class DfsObjectRepresentation extends StoredObjectRepresentation {
 	public ObjectId getDeltaBase() {
 		return baseId;
 	}
+
+	@Override
+	public boolean wasDeltaAttempted() {
+		if (pack != null) {
+			PackSource source = pack.getPackDescription().getPackSource();
+			return source == GC || source == UNREACHABLE_GARBAGE;
+		}
+		return false;
+	}
 }

org.eclipse.jgit/src/org/eclipse/jgit/storage/dfs/DfsPackDescription.java

@@ -46,6 +46,7 @@ package org.eclipse.jgit.storage.dfs;
 import java.util.Set;
 
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.storage.dfs.DfsObjDatabase.PackSource;
 import org.eclipse.jgit.storage.pack.PackWriter;
 
 /**
@@ -61,6 +62,8 @@ public class DfsPackDescription implements Comparable<DfsPackDescription> {
 
 	private final String packName;
 
+	private PackSource packSource;
+
 	private long lastModified;
 
 	private long packSize;
@@ -114,6 +117,21 @@ public class DfsPackDescription implements Comparable<DfsPackDescription> {
 		return name.substring(0, dot) + ".idx";
 	}
 
+	/** @return the source of the pack. */
+	public PackSource getPackSource() {
+		return packSource;
+	}
+
+	/**
+	 * @param source
+	 *            the source of the pack.
+	 * @return {@code this}
+	 */
+	public DfsPackDescription setPackSource(PackSource source) {
+		packSource = source;
+		return this;
+	}
+
 	/** @return time the pack was created, in milliseconds. */
 	public long getLastModified() {
 		return lastModified;

org.eclipse.jgit/src/org/eclipse/jgit/storage/dfs/InMemoryRepository.java

@@ -76,8 +76,10 @@ public class InMemoryRepository extends DfsRepository {
 		@Override
 		protected DfsPackDescription newPack(PackSource source) {
 			int id = packId.incrementAndGet();
-			return new MemPack("pack-" + id + "-" + source.name(),
+			DfsPackDescription desc = new MemPack(
+					"pack-" + id + "-" + source.name(),
 					getRepository().getDescription());
+			return desc.setPackSource(source);
 		}
 
 		@Override

org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/DeltaWindow.java

@@ -141,7 +141,7 @@ class DeltaWindow {
 				}
 				res.set(toSearch[off]);
 
-				if (res.object.isEdge()) {
+				if (res.object.isEdge() || res.object.doNotAttemptDelta()) {
 					// We don't actually want to make a delta for
 					// them, just need to push them into the window
 					// so they can be read by other objects.

org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/ObjectToPack.java

@@ -66,6 +66,10 @@ public class ObjectToPack extends PackedObjectInfo {
 
 	private static final int EDGE = 1 << 3;
 
+	private static final int DELTA_ATTEMPTED = 1 << 4;
+
+	private static final int ATTEMPT_DELTA_MASK = REUSE_AS_IS | DELTA_ATTEMPTED;
+
 	private static final int TYPE_SHIFT = 5;
 
 	private static final int EXT_SHIFT = 8;
@@ -88,7 +92,7 @@ public class ObjectToPack extends PackedObjectInfo {
 	 * <li>1 bit: canReuseAsIs</li>
 	 * <li>1 bit: doNotDelta</li>
 	 * <li>1 bit: edgeObject</li>
-	 * <li>1 bit: unused</li>
+	 * <li>1 bit: deltaAttempted</li>
 	 * <li>3 bits: type</li>
 	 * <li>4 bits: subclass flags (if any)</li>
 	 * <li>--</li>
@@ -265,6 +269,22 @@ public class ObjectToPack extends PackedObjectInfo {
 		flags |= EDGE;
 	}
 
+	boolean doNotAttemptDelta() {
+		// Do not attempt if delta attempted and object reuse.
+		return (flags & ATTEMPT_DELTA_MASK) == ATTEMPT_DELTA_MASK;
+	}
+
+	boolean isDeltaAttempted() {
+		return (flags & DELTA_ATTEMPTED) != 0;
+	}
+
+	void setDeltaAttempted(boolean deltaAttempted) {
+		if (deltaAttempted)
+			flags |= DELTA_ATTEMPTED;
+		else
+			flags &= ~DELTA_ATTEMPTED;
+	}
+
 	/** @return the extended flags on this object, in the range [0x0, 0xf]. */
 	protected int getExtendedFlags() {
 		return (flags >>> EXT_SHIFT) & EXT_MASK;

org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/PackWriter.java

@@ -1870,6 +1870,7 @@ public class PackWriter {
 			otp.clearReuseAsIs();
 		}
 
+		otp.setDeltaAttempted(next.wasDeltaAttempted());
 		otp.select(next);
 	}
 

org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/StoredObjectRepresentation.java

@@ -72,8 +72,9 @@ public class StoredObjectRepresentation {
 	}
 
 	/**
-	 * @return true if this is a delta against another object and this is stored
+	 * @return the storage format type, which must be one of
-	 *         in pack delta format.
+	 *         {@link #PACK_DELTA}, {@link #PACK_WHOLE}, or
+	 *         {@link #FORMAT_OTHER}.
 	 */
 	public int getFormat() {
 		return FORMAT_OTHER;
@@ -87,4 +88,13 @@ public class StoredObjectRepresentation {
 	public ObjectId getDeltaBase() {
 		return null;
 	}
+
+	/**
+	 * @return whether the current representation of the object has had delta
+	 *         compression attempted on it.
+	 */
+	public boolean wasDeltaAttempted() {
+		int fmt = getFormat();
+		return fmt == PACK_DELTA || fmt == PACK_WHOLE;
+	}
 }