Save object path hash codes during packing

We need to remember these so we can later cluster objects that
have similar file paths near each other as we search for deltas
between them.

Change-Id: I52cb1e4ca15c9c267a2dbf51dd0d795f885f4cf8
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/ObjectToPack.java b/org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/ObjectToPack.java
index 773ce44fd5abde38155051a57b3c49de02af94c6..cad3aaeec7129cf2a0c0b8abd3fe0e98aab593d4 100644 (file)
--- a/org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/ObjectToPack.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/ObjectToPack.java
@@ -83,6 +83,9 @@ public class ObjectToPack extends PackedObjectInfo {
         */
        private int flags;
 
+       /** Hash of the object's tree path. */
+       private int pathHash;
+
        /**
         * Construct for the specified object id.
         *
@@ -222,6 +225,14 @@ public class ObjectToPack extends PackedObjectInfo {
                setCRC(weight);
        }
 
+       int getPathHash() {
+               return pathHash;
+       }
+
+       void setPathHash(int hc) {
+               pathHash = hc;
+       }
+
        /**
         * Remember a specific representation for reuse at a later time.
         * <p>

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/PackWriter.java b/org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/PackWriter.java
index 2fecc6875832ab895fcb0e7c9b3f9c7d10dd2b94..5ecef832a97a046ca651498380b3b4f38359f849 100644 (file)
--- a/org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/PackWriter.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/storage/pack/PackWriter.java
@@ -181,7 +181,7 @@ public class PackWriter {
        private final ObjectIdSubclassMap<ObjectToPack> objectsMap = new ObjectIdSubclassMap<ObjectToPack>();
 
        // edge objects for thin packs
-       private final ObjectIdSubclassMap<ObjectId> edgeObjects = new ObjectIdSubclassMap<ObjectId>();
+       private final ObjectIdSubclassMap<ObjectToPack> edgeObjects = new ObjectIdSubclassMap<ObjectToPack>();
 
        private int compressionLevel;
 
@@ -813,11 +813,11 @@ public class PackWriter {
                RevObject o;
 
                while ((o = walker.next()) != null) {
-                       addObject(o);
+                       addObject(o, 0);
                        countingMonitor.update(1);
                }
                while ((o = walker.nextObject()) != null) {
-                       addObject(o);
+                       addObject(o, walker.getPathHashCode());
                        countingMonitor.update(1);
                }
                countingMonitor.endTask();
@@ -837,9 +837,21 @@ public class PackWriter {
         */
        public void addObject(final RevObject object)
                        throws IncorrectObjectTypeException {
+               addObject(object, 0);
+       }
+
+       private void addObject(final RevObject object, final int pathHashCode)
+                       throws IncorrectObjectTypeException {
                if (object.has(RevFlag.UNINTERESTING)) {
-                       edgeObjects.add(object);
-                       thin = true;
+                       switch (object.getType()) {
+                       case Constants.OBJ_TREE:
+                       case Constants.OBJ_BLOB:
+                               ObjectToPack otp = new ObjectToPack(object);
+                               otp.setPathHash(pathHashCode);
+                               edgeObjects.add(otp);
+                               thin = true;
+                               break;
+                       }
                        return;
                }
 
@@ -848,6 +860,8 @@ public class PackWriter {
                        otp = reuseSupport.newObjectToPack(object);
                else
                        otp = new ObjectToPack(object);
+               otp.setPathHash(pathHashCode);
+
                try {
                        objectsLists[object.getType()].add(otp);
                } catch (ArrayIndexOutOfBoundsException x) {