Introduce PostUploadHook to replace UploadPackLogger

UploadPackLogger is incorrectly named--it can be used to trigger any
post upload action, such as GC/compaction. This change introduces
PostUploadHook/PostUploadHookChain to replace
UploadPackLogger/UploadPackLoggerChain and deprecates the latter.

It also introduces PackStatistics as a replacement for
PackWriter.Statistics, since the latter is not public API.
It changes PackWriter to use PackStatistics and reimplements
PackWriter.Statistics to delegate to PackStatistics.

Change-Id: Ic51df1613e471f568ffee25ae67e118425b38986
Signed-off-by: Terry Parker <tparker@google.com>

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

@@ -72,6 +72,7 @@ import org.eclipse.jgit.lib.ProgressMonitor;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.storage.pack.PackConfig;
+import org.eclipse.jgit.storage.pack.PackStatistics;
 import org.eclipse.jgit.util.io.CountingOutputStream;
 
 /** Repack and garbage collect a repository. */
@@ -84,7 +85,7 @@ public class DfsGarbageCollector {
 
 	private final List<DfsPackDescription> newPackDesc;
 
-	private final List<PackWriter.Statistics> newPackStats;
+	private final List<PackStatistics> newPackStats;
 
 	private final List<PackWriter.ObjectIdSet> newPackObj;
 
@@ -115,7 +116,7 @@ public class DfsGarbageCollector {
 		refdb = repo.getRefDatabase();
 		objdb = repo.getObjectDatabase();
 		newPackDesc = new ArrayList<DfsPackDescription>(4);
-		newPackStats = new ArrayList<PackWriter.Statistics>(4);
+		newPackStats = new ArrayList<PackStatistics>(4);
 		newPackObj = new ArrayList<PackWriter.ObjectIdSet>(4);
 
 		packConfig = new PackConfig(repo);
@@ -258,7 +259,7 @@ public class DfsGarbageCollector {
 	}
 
 	/** @return statistics corresponding to the {@link #getNewPacks()}. */
-	public List<PackWriter.Statistics> getNewPackStatistics() {
+	public List<PackStatistics> getNewPackStatistics() {
 		return newPackStats;
 	}
 
@@ -396,7 +397,7 @@ public class DfsGarbageCollector {
 			}
 		});
 
-		PackWriter.Statistics stats = pw.getStatistics();
+		PackStatistics stats = pw.getStatistics();
 		pack.setPackStats(stats);
 		newPackStats.add(stats);
 

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

@@ -67,6 +67,7 @@ import org.eclipse.jgit.revwalk.RevFlag;
 import org.eclipse.jgit.revwalk.RevObject;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.storage.pack.PackConfig;
+import org.eclipse.jgit.storage.pack.PackStatistics;
 import org.eclipse.jgit.util.BlockList;
 import org.eclipse.jgit.util.io.CountingOutputStream;
 
@@ -94,7 +95,7 @@ public class DfsPackCompactor {
 
 	private final List<DfsPackDescription> newPacks;
 
-	private final List<PackWriter.Statistics> newStats;
+	private final List<PackStatistics> newStats;
 
 	private int autoAddSize;
 
@@ -114,7 +115,7 @@ public class DfsPackCompactor {
 		srcPacks = new ArrayList<DfsPackFile>();
 		exclude = new ArrayList<PackWriter.ObjectIdSet>(4);
 		newPacks = new ArrayList<DfsPackDescription>(1);
-		newStats = new ArrayList<PackWriter.Statistics>(1);
+		newStats = new ArrayList<PackStatistics>(1);
 	}
 
 	/**
@@ -231,7 +232,7 @@ public class DfsPackCompactor {
 					writePack(objdb, pack, pw, pm);
 					writeIndex(objdb, pack, pw);
 
-					PackWriter.Statistics stats = pw.getStatistics();
+					PackStatistics stats = pw.getStatistics();
 					pw.close();
 					pw = null;
 
@@ -264,7 +265,7 @@ public class DfsPackCompactor {
 	}
 
 	/** @return statistics corresponding to the {@link #getNewPacks()}. */
-	public List<PackWriter.Statistics> getNewPackStatistics() {
+	public List<PackStatistics> getNewPackStatistics() {
 		return newStats;
 	}
 

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

@@ -50,7 +50,7 @@ import java.util.Map;
 
 import org.eclipse.jgit.internal.storage.dfs.DfsObjDatabase.PackSource;
 import org.eclipse.jgit.internal.storage.pack.PackExt;
-import org.eclipse.jgit.internal.storage.pack.PackWriter;
+import org.eclipse.jgit.storage.pack.PackStatistics;
 
 /**
  * Description of a DFS stored pack/index file.
@@ -75,7 +75,7 @@ public class DfsPackDescription implements Comparable<DfsPackDescription> {
 
 	private long deltaCount;
 
-	private PackWriter.Statistics stats;
+	private PackStatistics stats;
 
 	private int extensions;
 
@@ -225,11 +225,11 @@ public class DfsPackDescription implements Comparable<DfsPackDescription> {
 	 *         DfsGarbageCollector or DfsPackCompactor, and only when the pack
 	 *         is being committed to the repository.
 	 */
-	public PackWriter.Statistics getPackStats() {
+	public PackStatistics getPackStats() {
 		return stats;
 	}
 
-	DfsPackDescription setPackStats(PackWriter.Statistics stats) {
+	DfsPackDescription setPackStats(PackStatistics stats) {
 		this.stats = stats;
 		setFileSize(PACK, stats.getTotalBytes());
 		setObjectCount(stats.getTotalObjects());

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

@@ -114,6 +114,7 @@ import org.eclipse.jgit.revwalk.RevSort;
 import org.eclipse.jgit.revwalk.RevTag;
 import org.eclipse.jgit.revwalk.RevTree;
 import org.eclipse.jgit.storage.pack.PackConfig;
+import org.eclipse.jgit.storage.pack.PackStatistics;
 import org.eclipse.jgit.transport.ObjectCountCallback;
 import org.eclipse.jgit.transport.WriteAbortedException;
 import org.eclipse.jgit.util.BlockList;
@@ -247,13 +248,13 @@ public class PackWriter implements AutoCloseable {
 
 	private final PackConfig config;
 
-	private final Statistics stats;
+	private final PackStatistics.Accumulator stats;
 
 	private final MutableState state;
 
 	private final WeakReference<PackWriter> selfRef;
 
-	private Statistics.ObjectType typeStats;
+	private PackStatistics.ObjectType.Accumulator typeStats;
 
 	private List<ObjectToPack> sortedByName;
 
@@ -356,7 +357,7 @@ public class PackWriter implements AutoCloseable {
 		deltaBaseAsOffset = config.isDeltaBaseAsOffset();
 		reuseDeltas = config.isReuseDeltas();
 		reuseValidate = true; // be paranoid by default
-		stats = new Statistics();
+		stats = new PackStatistics.Accumulator();
 		state = new MutableState();
 		selfRef = new WeakReference<PackWriter>(this);
 		instances.put(selfRef, Boolean.TRUE);
@@ -981,7 +982,7 @@ public class PackWriter implements AutoCloseable {
 
 			writeObjects(out);
 			if (!edgeObjects.isEmpty() || !cachedPacks.isEmpty()) {
-				for (Statistics.ObjectType typeStat : stats.objectTypes) {
+				for (PackStatistics.ObjectType.Accumulator typeStat : stats.objectTypes) {
 					if (typeStat == null)
 						continue;
 					stats.thinPackBytes += typeStat.bytes;
@@ -1002,7 +1003,7 @@ public class PackWriter implements AutoCloseable {
 			stats.timeWriting = System.currentTimeMillis() - writeStart;
 			stats.depth = depth;
 
-			for (Statistics.ObjectType typeStat : stats.objectTypes) {
+			for (PackStatistics.ObjectType.Accumulator typeStat : stats.objectTypes) {
 				if (typeStat == null)
 					continue;
 				typeStat.cntDeltas += typeStat.reusedDeltas;
@@ -1022,8 +1023,8 @@ public class PackWriter implements AutoCloseable {
 	 *         final pack stream. The object is only available to callers after
 	 *         {@link #writePack(ProgressMonitor, ProgressMonitor, OutputStream)}
 	 */
-	public Statistics getStatistics() {
-		return stats;
+	public PackStatistics getStatistics() {
+		return new PackStatistics(stats);
 	}
 
 	/** @return snapshot of the current state of this PackWriter. */
@@ -2028,28 +2029,36 @@ public class PackWriter implements AutoCloseable {
 		return true;
 	}
 
-	/** Summary of how PackWriter created the pack. */
+	/**
+	 * Summary of how PackWriter created the pack.
+	 *
+	 * @deprecated Use {@link PackStatistics} instead.
+	 */
+	@Deprecated
 	public static class Statistics {
 		/** Statistics about a single class of object. */
 		public static class ObjectType {
-			long cntObjects;
-
-			long cntDeltas;
+			// All requests are forwarded to this object.
+			private PackStatistics.ObjectType objectType;
 
-			long reusedObjects;
-
-			long reusedDeltas;
-
-			long bytes;
-
-			long deltaBytes;
+			/**
+			 * Wraps an
+			 * {@link org.eclipse.jgit.storage.pack.PackStatistics.ObjectType}
+			 * instance to maintain backwards compatibility with existing API.
+			 *
+			 * @param type
+			 *            the wrapped instance
+			 */
+			public ObjectType(PackStatistics.ObjectType type) {
+				objectType = type;
+			}
 
 			/**
 			 * @return total number of objects output. This total includes the
 			 *         value of {@link #getDeltas()}.
 			 */
 			public long getObjects() {
-				return cntObjects;
+				return objectType.getObjects();
 			}
 
 			/**
@@ -2057,7 +2066,7 @@ public class PackWriter implements AutoCloseable {
 			 *         actual number of deltas if a cached pack was reused.
 			 */
 			public long getDeltas() {
-				return cntDeltas;
+				return objectType.getDeltas();
 			}
 
 			/**
@@ -2066,7 +2075,7 @@ public class PackWriter implements AutoCloseable {
 			 *         {@link #getReusedDeltas()}.
 			 */
 			public long getReusedObjects() {
-				return reusedObjects;
+				return objectType.getReusedObjects();
 			}
 
 			/**
@@ -2077,7 +2086,7 @@ public class PackWriter implements AutoCloseable {
 			 *         was reused.
 			 */
 			public long getReusedDeltas() {
-				return reusedDeltas;
+				return objectType.getReusedDeltas();
 			}
 
 			/**
@@ -2086,7 +2095,7 @@ public class PackWriter implements AutoCloseable {
 			 *         also includes all of {@link #getDeltaBytes()}.
 			 */
 			public long getBytes() {
-				return bytes;
+				return objectType.getBytes();
 			}
 
 			/**
@@ -2094,54 +2103,22 @@ public class PackWriter implements AutoCloseable {
 			 *         object headers for the delta objects.
 			 */
 			public long getDeltaBytes() {
-				return deltaBytes;
+				return objectType.getDeltaBytes();
 			}
 		}
 
-		Set<ObjectId> interestingObjects;
-
-		Set<ObjectId> uninterestingObjects;
-
-		Collection<CachedPack> reusedPacks;
-
-		int depth;
-
-		int deltaSearchNonEdgeObjects;
-
-		int deltasFound;
-
-		long totalObjects;
+		// All requests are forwarded to this object.
+		private PackStatistics statistics;
 
-		long bitmapIndexMisses;
-
-		long totalDeltas;
-
-		long reusedObjects;
-
-		long reusedDeltas;
-
-		long totalBytes;
-
-		long thinPackBytes;
-
-		long timeCounting;
-
-		long timeSearchingForReuse;
-
-		long timeSearchingForSizes;
-
-		long timeCompressing;
-
-		long timeWriting;
-
-		ObjectType[] objectTypes;
-
-		{
-			objectTypes = new ObjectType[5];
-			objectTypes[OBJ_COMMIT] = new ObjectType();
-			objectTypes[OBJ_TREE] = new ObjectType();
-			objectTypes[OBJ_BLOB] = new ObjectType();
-			objectTypes[OBJ_TAG] = new ObjectType();
+		/**
+		 * Wraps a {@link PackStatistics} object to maintain backwards
+		 * compatibility with existing API.
+		 *
+		 * @param stats
+		 *            the wrapped PackStatitics object
+		 */
+		public Statistics(PackStatistics stats) {
+			statistics = stats;
 		}
 
 		/**
@@ -2150,7 +2127,7 @@ public class PackWriter implements AutoCloseable {
 		 *         test.
 		 */
 		public Set<ObjectId> getInterestingObjects() {
-			return interestingObjects;
+			return statistics.getInterestingObjects();
 		}
 
 		/**
@@ -2159,7 +2136,7 @@ public class PackWriter implements AutoCloseable {
 		 *         has these objects.
 		 */
 		public Set<ObjectId> getUninterestingObjects() {
-			return uninterestingObjects;
+			return statistics.getUninterestingObjects();
 		}
 
 		/**
@@ -2167,7 +2144,7 @@ public class PackWriter implements AutoCloseable {
 		 *         in the output, if any were selected for reuse.
 		 */
 		public Collection<CachedPack> getReusedPacks() {
-			return reusedPacks;
+			return statistics.getReusedPacks();
 		}
 
 		/**
@@ -2175,7 +2152,7 @@ public class PackWriter implements AutoCloseable {
 		 *         delta search process in order to find a potential delta base.
 		 */
 		public int getDeltaSearchNonEdgeObjects() {
-			return deltaSearchNonEdgeObjects;
+			return statistics.getDeltaSearchNonEdgeObjects();
 		}
 
 		/**
@@ -2184,7 +2161,7 @@ public class PackWriter implements AutoCloseable {
 		 *         {@link #getDeltaSearchNonEdgeObjects()}.
 		 */
 		public int getDeltasFound() {
-			return deltasFound;
+			return statistics.getDeltasFound();
 		}
 
 		/**
@@ -2192,7 +2169,7 @@ public class PackWriter implements AutoCloseable {
 		 *         of {@link #getTotalDeltas()}.
 		 */
 		public long getTotalObjects() {
-			return totalObjects;
+			return statistics.getTotalObjects();
 		}
 
 		/**
@@ -2203,7 +2180,7 @@ public class PackWriter implements AutoCloseable {
 		 * @since 4.0
 		 */
 		public long getBitmapIndexMisses() {
-			return bitmapIndexMisses;
+			return statistics.getBitmapIndexMisses();
 		}
 
 		/**
@@ -2211,7 +2188,7 @@ public class PackWriter implements AutoCloseable {
 		 *         actual number of deltas if a cached pack was reused.
 		 */
 		public long getTotalDeltas() {
-			return totalDeltas;
+			return statistics.getTotalDeltas();
 		}
 
 		/**
@@ -2219,7 +2196,7 @@ public class PackWriter implements AutoCloseable {
 		 *         the output. This count includes {@link #getReusedDeltas()}.
 		 */
 		public long getReusedObjects() {
-			return reusedObjects;
+			return statistics.getReusedObjects();
 		}
 
 		/**
@@ -2229,7 +2206,7 @@ public class PackWriter implements AutoCloseable {
 		 *         actual number of reused deltas if a cached pack was reused.
 		 */
 		public long getReusedDeltas() {
-			return reusedDeltas;
+			return statistics.getReusedDeltas();
 		}
 
 		/**
@@ -2237,7 +2214,7 @@ public class PackWriter implements AutoCloseable {
 		 *         header, trailer, thin pack, and reused cached pack(s).
 		 */
 		public long getTotalBytes() {
-			return totalBytes;
+			return statistics.getTotalBytes();
 		}
 
 		/**
@@ -2249,7 +2226,7 @@ public class PackWriter implements AutoCloseable {
 		 *         pack header or trailer.
 		 */
 		public long getThinPackBytes() {
-			return thinPackBytes;
+			return statistics.getThinPackBytes();
 		}
 
 		/**
@@ -2258,17 +2235,17 @@ public class PackWriter implements AutoCloseable {
 		 * @return information about this type of object in the pack.
 		 */
 		public ObjectType byObjectType(int typeCode) {
-			return objectTypes[typeCode];
+			return new ObjectType(statistics.byObjectType(typeCode));
 		}
 
 		/** @return true if the resulting pack file was a shallow pack. */
 		public boolean isShallow() {
-			return depth > 0;
+			return statistics.isShallow();
 		}
 
 		/** @return depth (in commits) the pack includes if shallow. */
 		public int getDepth() {
-			return depth;
+			return statistics.getDepth();
 		}
 
 		/**
@@ -2277,7 +2254,7 @@ public class PackWriter implements AutoCloseable {
 		 *         that occur when a cached pack is selected for reuse.
 		 */
 		public long getTimeCounting() {
-			return timeCounting;
+			return statistics.getTimeCounting();
 		}
 
 		/**
@@ -2286,7 +2263,7 @@ public class PackWriter implements AutoCloseable {
 		 *         can be assumed to already have.
 		 */
 		public long getTimeSearchingForReuse() {
-			return timeSearchingForReuse;
+			return statistics.getTimeSearchingForReuse();
 		}
 
 		/**
@@ -2296,7 +2273,7 @@ public class PackWriter implements AutoCloseable {
 		 *         together and improve delta compression ratios.
 		 */
 		public long getTimeSearchingForSizes() {
-			return timeSearchingForSizes;
+			return statistics.getTimeSearchingForSizes();
 		}
 
 		/**
@@ -2306,7 +2283,7 @@ public class PackWriter implements AutoCloseable {
 		 *         delta compression.
 		 */
 		public long getTimeCompressing() {
-			return timeCompressing;
+			return statistics.getTimeCompressing();
 		}
 
 		/**
@@ -2316,16 +2293,12 @@ public class PackWriter implements AutoCloseable {
 		 *         value.
 		 */
 		public long getTimeWriting() {
-			return timeWriting;
+			return statistics.getTimeWriting();
 		}
 
 		/** @return total time spent processing this pack. */
 		public long getTimeTotal() {
-			return timeCounting
-				+ timeSearchingForReuse
-				+ timeSearchingForSizes
-				+ timeCompressing
-				+ timeWriting;
+			return statistics.getTimeTotal();
 		}
 
 		/**
@@ -2333,14 +2306,12 @@ public class PackWriter implements AutoCloseable {
 		 *         {@code getTotalBytes() / (getTimeWriting() / 1000.0)}.
 		 */
 		public double getTransferRate() {
-			return getTotalBytes() / (getTimeWriting() / 1000.0);
+			return statistics.getTransferRate();
 		}
 
 		/** @return formatted message string for display to clients. */
 		public String getMessage() {
-			return MessageFormat.format(JGitText.get().packWriterStatistics, //
-					Long.valueOf(totalObjects), Long.valueOf(totalDeltas), //
-					Long.valueOf(reusedObjects), Long.valueOf(reusedDeltas));
+			return statistics.getMessage();
 		}
 	}
 

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

@@ -0,0 +1,462 @@
+/*
+ * Copyright (C) 2015, Google Inc.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * 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 Eclipse Foundation, Inc. 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.eclipse.jgit.storage.pack;
+
+import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
+import static org.eclipse.jgit.lib.Constants.OBJ_COMMIT;
+import static org.eclipse.jgit.lib.Constants.OBJ_TAG;
+import static org.eclipse.jgit.lib.Constants.OBJ_TREE;
+
+import java.text.MessageFormat;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.eclipse.jgit.internal.JGitText;
+import org.eclipse.jgit.internal.storage.pack.CachedPack;
+import org.eclipse.jgit.lib.ObjectId;
+
+/**
+ * Statistics about {@link org.eclipse.jgit.internal.storage.pack.PackWriter}
+ * pack creation.
+ *
+ * @since 4.1
+ */
+public class PackStatistics {
+	/**
+	 * Statistics about a single type of object (commits, tags, trees and
+	 * blobs).
+	 */
+	public static class ObjectType {
+		/**
+		 * POJO for accumulating the ObjectType statistics.
+		 */
+		public static class Accumulator {
+			/** Count of objects of this type. */
+			public long cntObjects;
+
+			/** Count of deltas of this type. */
+			public long cntDeltas;
+
+			/** Count of reused objects of this type. */
+			public long reusedObjects;
+
+			/** Count of reused deltas of this type. */
+			public long reusedDeltas;
+
+			/** Count of bytes for all objects of this type. */
+			public long bytes;
+
+			/** Count of delta bytes for objects of this type. */
+			public long deltaBytes;
+		}
+
+		private ObjectType.Accumulator objectType;
+
+		/**
+		 * Creates a new {@link ObjectType} object from the accumulator.
+		 *
+		 * @param accumulator
+		 *            the accumulator of the statistics
+		 */
+		public ObjectType(ObjectType.Accumulator accumulator) {
+			objectType = accumulator;
+		}
+
+		/**
+		 * @return total number of objects output. This total includes the value
+		 *         of {@link #getDeltas()}.
+		 */
+		public long getObjects() {
+			return objectType.cntObjects;
+		}
+
+		/**
+		 * @return total number of deltas output. This may be lower than the
+		 *         actual number of deltas if a cached pack was reused.
+		 */
+		public long getDeltas() {
+			return objectType.cntDeltas;
+		}
+
+		/**
+		 * @return number of objects whose existing representation was reused in
+		 *         the output. This count includes {@link #getReusedDeltas()}.
+		 */
+		public long getReusedObjects() {
+			return objectType.reusedObjects;
+		}
+
+		/**
+		 * @return number of deltas whose existing representation was reused in
+		 *         the output, as their base object was also output or was
+		 *         assumed present for a thin pack. This may be lower than the
+		 *         actual number of reused deltas if a cached pack was reused.
+		 */
+		public long getReusedDeltas() {
+			return objectType.reusedDeltas;
+		}
+
+		/**
+		 * @return total number of bytes written. This size includes the object
+		 *         headers as well as the compressed data. This size also
+		 *         includes all of {@link #getDeltaBytes()}.
+		 */
+		public long getBytes() {
+			return objectType.bytes;
+		}
+
+		/**
+		 * @return number of delta bytes written. This size includes the object
+		 *         headers for the delta objects.
+		 */
+		public long getDeltaBytes() {
+			return objectType.deltaBytes;
+		}
+	}
+
+	/**
+	 * POJO for accumulating the statistics.
+	 */
+	public static class Accumulator {
+		/** The set of objects to be included in the pack. */
+		public Set<ObjectId> interestingObjects;
+
+		/** The set of objects to be excluded from the pack. */
+		public Set<ObjectId> uninterestingObjects;
+
+		/** The collection of reused packs in the upload. */
+		public List<CachedPack> reusedPacks;
+
+		/** If a shallow pack, the depth in commits. */
+		public int depth;
+
+		/**
+		 * The count of objects in the pack that went through the delta search
+		 * process in order to find a potential delta base.
+		 */
+		public int deltaSearchNonEdgeObjects;
+
+		/**
+		 * The count of objects in the pack that went through delta base search
+		 * and found a suitable base. This is a subset of
+		 * deltaSearchNonEdgeObjects.
+		 */
+		public int deltasFound;
+
+		/** The total count of objects in the pack. */
+		public long totalObjects;
+
+		/**
+		 * The count of objects that needed to be discovered through an object
+		 * walk because they were not found in bitmap indices.
+		 */
+		public long bitmapIndexMisses;
+
+		/** The total count of deltas output. */
+		public long totalDeltas;
+
+		/** The count of reused objects in the pack. */
+		public long reusedObjects;
+
+		/** The count of reused deltas in the pack. */
+		public long reusedDeltas;
+
+		/** The count of total bytes in the pack. */
+		public long totalBytes;
+
+		/** The size of the thin pack in bytes, if a thin pack was generated. */
+		public long thinPackBytes;
+
+		/** Time in ms spent counting the objects that will go into the pack. */
+		public long timeCounting;
+
+		/** Time in ms spent searching for objects to reuse. */
+		public long timeSearchingForReuse;
+
+		/** Time in ms spent searching for sizes of objects. */
+		public long timeSearchingForSizes;
+
+		/** Time in ms spent compressing the pack. */
+		public long timeCompressing;
+
+		/** Time in ms spent writing the pack. */
+		public long timeWriting;
+
+		/**
+		 * Statistics about each object type in the pack (commits, tags, trees
+		 * and blobs.)
+		 */
+		public ObjectType.Accumulator[] objectTypes;
+
+		{
+			objectTypes = new ObjectType.Accumulator[5];
+			objectTypes[OBJ_COMMIT] = new ObjectType.Accumulator();
+			objectTypes[OBJ_TREE] = new ObjectType.Accumulator();
+			objectTypes[OBJ_BLOB] = new ObjectType.Accumulator();
+			objectTypes[OBJ_TAG] = new ObjectType.Accumulator();
+		}
+	}
+
+	private Accumulator statistics;
+
+	/**
+	 * Creates a new {@link PackStatistics} object from the accumulator.
+	 *
+	 * @param accumulator
+	 *            the accumulator of the statistics
+	 */
+	public PackStatistics(Accumulator accumulator) {
+		// Note: PackStatistics directly serves up the collections in the
+		// accumulator.
+		statistics = accumulator;
+	}
+
+	/**
+	 * @return unmodifiable collection of objects to be included in the pack.
+	 *         May be {@code null} if the pack was hand-crafted in a unit test.
+	 */
+	public Set<ObjectId> getInterestingObjects() {
+		return statistics.interestingObjects;
+	}
+
+	/**
+	 * @return unmodifiable collection of objects that should be excluded from
+	 *         the pack, as the peer that will receive the pack already has
+	 *         these objects.
+	 */
+	public Set<ObjectId> getUninterestingObjects() {
+		return statistics.uninterestingObjects;
+	}
+
+	/**
+	 * @return unmodifiable list of the cached packs that were reused in the
+	 *         output, if any were selected for reuse.
+	 */
+	public List<CachedPack> getReusedPacks() {
+		return statistics.reusedPacks;
+	}
+
+	/**
+	 * @return number of objects in the output pack that went through the delta
+	 *         search process in order to find a potential delta base.
+	 */
+	public int getDeltaSearchNonEdgeObjects() {
+		return statistics.deltaSearchNonEdgeObjects;
+	}
+
+	/**
+	 * @return number of objects in the output pack that went through delta base
+	 *         search and found a suitable base. This is a subset of
+	 *         {@link #getDeltaSearchNonEdgeObjects()}.
+	 */
+	public int getDeltasFound() {
+		return statistics.deltasFound;
+	}
+
+	/**
+	 * @return total number of objects output. This total includes the value of
+	 *         {@link #getTotalDeltas()}.
+	 */
+	public long getTotalObjects() {
+		return statistics.totalObjects;
+	}
+
+	/**
+	 * @return the count of objects that needed to be discovered through an
+	 *         object walk because they were not found in bitmap indices.
+	 *         Returns -1 if no bitmap indices were found.
+	 */
+	public long getBitmapIndexMisses() {
+		return statistics.bitmapIndexMisses;
+	}
+
+	/**
+	 * @return total number of deltas output. This may be lower than the actual
+	 *         number of deltas if a cached pack was reused.
+	 */
+	public long getTotalDeltas() {
+		return statistics.totalDeltas;
+	}
+
+	/**
+	 * @return number of objects whose existing representation was reused in the
+	 *         output. This count includes {@link #getReusedDeltas()}.
+	 */
+	public long getReusedObjects() {
+		return statistics.reusedObjects;
+	}
+
+	/**
+	 * @return number of deltas whose existing representation was reused in the
+	 *         output, as their base object was also output or was assumed
+	 *         present for a thin pack. This may be lower than the actual number
+	 *         of reused deltas if a cached pack was reused.
+	 */
+	public long getReusedDeltas() {
+		return statistics.reusedDeltas;
+	}
+
+	/**
+	 * @return total number of bytes written. This size includes the pack
+	 *         header, trailer, thin pack, and reused cached pack(s).
+	 */
+	public long getTotalBytes() {
+		return statistics.totalBytes;
+	}
+
+	/**
+	 * @return size of the thin pack in bytes, if a thin pack was generated. A
+	 *         thin pack is created when the client already has objects and some
+	 *         deltas are created against those objects, or if a cached pack is
+	 *         being used and some deltas will reference objects in the cached
+	 *         pack. This size does not include the pack header or trailer.
+	 */
+	public long getThinPackBytes() {
+		return statistics.thinPackBytes;
+	}
+
+	/**
+	 * @param typeCode
+	 *            object type code, e.g. OBJ_COMMIT or OBJ_TREE.
+	 * @return information about this type of object in the pack.
+	 */
+	public ObjectType byObjectType(int typeCode) {
+		return new ObjectType(statistics.objectTypes[typeCode]);
+	}
+
+	/** @return true if the resulting pack file was a shallow pack. */
+	public boolean isShallow() {
+		return statistics.depth > 0;
+	}
+
+	/** @return depth (in commits) the pack includes if shallow. */
+	public int getDepth() {
+		return statistics.depth;
+	}
+
+	/**
+	 * @return time in milliseconds spent enumerating the objects that need to
+	 *         be included in the output. This time includes any restarts that
+	 *         occur when a cached pack is selected for reuse.
+	 */
+	public long getTimeCounting() {
+		return statistics.timeCounting;
+	}
+
+	/**
+	 * @return time in milliseconds spent matching existing representations
+	 *         against objects that will be transmitted, or that the client can
+	 *         be assumed to already have.
+	 */
+	public long getTimeSearchingForReuse() {
+		return statistics.timeSearchingForReuse;
+	}
+
+	/**
+	 * @return time in milliseconds spent finding the sizes of all objects that
+	 *         will enter the delta compression search window. The sizes need to
+	 *         be known to better match similar objects together and improve
+	 *         delta compression ratios.
+	 */
+	public long getTimeSearchingForSizes() {
+		return statistics.timeSearchingForSizes;
+	}
+
+	/**
+	 * @return time in milliseconds spent on delta compression. This is observed
+	 *         wall-clock time and does not accurately track CPU time used when
+	 *         multiple threads were used to perform the delta compression.
+	 */
+	public long getTimeCompressing() {
+		return statistics.timeCompressing;
+	}
+
+	/**
+	 * @return time in milliseconds spent writing the pack output, from start of
+	 *         header until end of trailer. The transfer speed can be
+	 *         approximated by dividing {@link #getTotalBytes()} by this value.
+	 */
+	public long getTimeWriting() {
+		return statistics.timeWriting;
+	}
+
+	/** @return total time spent processing this pack. */
+	public long getTimeTotal() {
+		return statistics.timeCounting + statistics.timeSearchingForReuse
+				+ statistics.timeSearchingForSizes + statistics.timeCompressing
+				+ statistics.timeWriting;
+	}
+
+	/**
+	 * @return get the average output speed in terms of bytes-per-second.
+	 *         {@code getTotalBytes() / (getTimeWriting() / 1000.0)}.
+	 */
+	public double getTransferRate() {
+		return getTotalBytes() / (getTimeWriting() / 1000.0);
+	}
+
+	/** @return formatted message string for display to clients. */
+	public String getMessage() {
+		return MessageFormat.format(JGitText.get().packWriterStatistics,
+				Long.valueOf(statistics.totalObjects),
+				Long.valueOf(statistics.totalDeltas),
+				Long.valueOf(statistics.reusedObjects),
+				Long.valueOf(statistics.reusedDeltas));
+	}
+
+	/** @return a map containing ObjectType statistics. */
+	public Map<Integer, ObjectType> getObjectTypes() {
+		HashMap<Integer, ObjectType> map = new HashMap<>();
+		map.put(Integer.valueOf(OBJ_BLOB), new ObjectType(
+				statistics.objectTypes[OBJ_BLOB]));
+		map.put(Integer.valueOf(OBJ_COMMIT), new ObjectType(
+				statistics.objectTypes[OBJ_COMMIT]));
+		map.put(Integer.valueOf(OBJ_TAG), new ObjectType(
+				statistics.objectTypes[OBJ_TAG]));
+		map.put(Integer.valueOf(OBJ_TREE), new ObjectType(
+				statistics.objectTypes[OBJ_TREE]));
+		return map;
+	}
+}

org.eclipse.jgit/src/org/eclipse/jgit/transport/PostUploadHook.java

@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2015, Google Inc.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * 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 Eclipse Foundation, Inc. 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.eclipse.jgit.transport;
+
+import org.eclipse.jgit.internal.storage.pack.PackWriter;
+import org.eclipse.jgit.storage.pack.PackStatistics;
+
+/**
+ * Hook invoked by {@link UploadPack} after the pack has been uploaded.
+ * <p>
+ * Implementors of the interface are responsible for associating the current
+ * thread to a particular connection, if they need to also include connection
+ * information. One method is to use a {@link java.lang.ThreadLocal} to remember
+ * the connection information before invoking UploadPack.
+ *
+ * @since 4.1
+ */
+public interface PostUploadHook {
+	/** A simple no-op hook. */
+	public static final PostUploadHook NULL = new PostUploadHook() {
+		public void onPostUpload(PackStatistics stats) {
+			// Do nothing.
+		}
+	};
+
+	/**
+	 * Notifies the hook that a pack has been sent.
+	 *
+	 * @param stats
+	 *            the statistics gathered by {@link PackWriter} for the uploaded
+	 *            pack
+	 */
+	public void onPostUpload(PackStatistics stats);
+}

org.eclipse.jgit/src/org/eclipse/jgit/transport/PostUploadHookChain.java

@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2015, Google Inc.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * 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 Eclipse Foundation, Inc. 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.eclipse.jgit.transport;
+
+import java.util.List;
+
+import org.eclipse.jgit.storage.pack.PackStatistics;
+
+/**
+ * {@link PostUploadHook} that delegates to a list of other hooks.
+ * <p>
+ * Hooks are run in the order passed to the constructor.
+ *
+ * @since 4.1
+ */
+public class PostUploadHookChain implements PostUploadHook {
+	private final PostUploadHook[] hooks;
+	private final int count;
+
+	/**
+	 * Create a new hook chaining the given hooks together.
+	 *
+	 * @param hooks
+	 *            hooks to execute, in order.
+	 * @return a new chain of the given hooks.
+	 */
+	public static PostUploadHook newChain(List<? extends PostUploadHook> hooks) {
+		PostUploadHook[] newHooks = new PostUploadHook[hooks.size()];
+		int i = 0;
+		for (PostUploadHook hook : hooks)
+			if (hook != PostUploadHook.NULL)
+				newHooks[i++] = hook;
+		if (i == 0)
+			return PostUploadHook.NULL;
+		else if (i == 1)
+			return newHooks[0];
+		else
+			return new PostUploadHookChain(newHooks, i);
+	}
+
+	public void onPostUpload(PackStatistics stats) {
+		for (int i = 0; i < count; i++)
+			hooks[i].onPostUpload(stats);
+	}
+
+	private PostUploadHookChain(PostUploadHook[] hooks, int count) {
+		this.hooks = hooks;
+		this.count = count;
+	}
+}

org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPack.java

@@ -94,6 +94,7 @@ import org.eclipse.jgit.revwalk.RevTag;
 import org.eclipse.jgit.revwalk.RevWalk;
 import org.eclipse.jgit.revwalk.filter.CommitTimeRevFilter;
 import org.eclipse.jgit.storage.pack.PackConfig;
+import org.eclipse.jgit.storage.pack.PackStatistics;
 import org.eclipse.jgit.transport.GitProtocolConstants.MultiAck;
 import org.eclipse.jgit.transport.RefAdvertiser.PacketLineOutRefAdvertiser;
 import org.eclipse.jgit.util.io.InterruptTimer;
@@ -253,6 +254,9 @@ public class UploadPack {
 	/** Hook handling the various upload phases. */
 	private PreUploadHook preUploadHook = PreUploadHook.NULL;
 
+	/** Hook for taking post upload actions. */
+	private PostUploadHook postUploadHook = PostUploadHook.NULL;
+
 	/** Capabilities requested by the client. */
 	private Set<String> options;
 	String userAgent;
@@ -306,7 +310,7 @@ public class UploadPack {
 
 	private boolean noDone;
 
-	private PackWriter.Statistics statistics;
+	private PackStatistics statistics;
 
 	private UploadPackLogger logger = UploadPackLogger.NULL;
 
@@ -519,7 +523,7 @@ public class UploadPack {
 		this.refFilter = refFilter != null ? refFilter : RefFilter.DEFAULT;
 	}
 
-	/** @return the configured upload hook. */
+	/** @return the configured pre upload hook. */
 	public PreUploadHook getPreUploadHook() {
 		return preUploadHook;
 	}
@@ -534,6 +538,25 @@ public class UploadPack {
 		preUploadHook = hook != null ? hook : PreUploadHook.NULL;
 	}
 
+	/**
+	 * @return the configured post upload hook.
+	 * @since 4.1
+	 */
+	public PostUploadHook getPostUploadHook() {
+		return postUploadHook;
+	}
+
+	/**
+	 * Set the hook for post upload actions (logging, repacking).
+	 *
+	 * @param hook
+	 *            the hook; if null no special actions are taken.
+	 * @since 4.1
+	 */
+	public void setPostUploadHook(PostUploadHook hook) {
+		postUploadHook = hook != null ? hook : PostUploadHook.NULL;
+	}
+
 	/**
 	 * Set the configuration used by the pack generator.
 	 *
@@ -562,7 +585,12 @@ public class UploadPack {
 		}
 	}
 
-	/** @return the configured logger. */
+	/**
+	 * @return the configured logger.
+	 *
+	 * @deprecated Use {@link #getPreUploadHook()}.
+	 */
+	@Deprecated
 	public UploadPackLogger getLogger() {
 		return logger;
 	}
@@ -572,7 +600,9 @@ public class UploadPack {
 	 *
 	 * @param logger
 	 *            the logger instance. If null, no logging occurs.
+	 * @deprecated Use {@link #setPreUploadHook(PreUploadHook)}.
 	 */
+	@Deprecated
 	public void setLogger(UploadPackLogger logger) {
 		this.logger = logger;
 	}
@@ -654,8 +684,23 @@ public class UploadPack {
 	 *         was sent, such as during the negotation phase of a smart HTTP
 	 *         connection, or if the client was already up-to-date.
 	 * @since 3.0
+	 * @deprecated Use {@link #getStatistics()}.
 	 */
+	@Deprecated
 	public PackWriter.Statistics getPackStatistics() {
+		return statistics == null ? null
+				: new PackWriter.Statistics(statistics);
+	}
+
+	/**
+	 * Get the PackWriter's statistics if a pack was sent to the client.
+	 *
+	 * @return statistics about pack output, if a pack was sent. Null if no pack
+	 *         was sent, such as during the negotation phase of a smart HTTP
+	 *         connection, or if the client was already up-to-date.
+	 * @since 4.1
+	 */
+	public PackStatistics getStatistics() {
 		return statistics;
 	}
 
@@ -1468,8 +1513,10 @@ public class UploadPack {
 
 		} finally {
 			statistics = pw.getStatistics();
-			if (statistics != null)
-				logger.onPackStatistics(statistics);
+			if (statistics != null) {
+				postUploadHook.onPostUpload(statistics);
+				logger.onPackStatistics(new PackWriter.Statistics(statistics));
+			}
 			pw.close();
 		}
 

org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPackLogger.java

@@ -52,7 +52,10 @@ import org.eclipse.jgit.internal.storage.pack.PackWriter;
  * thread to a particular connection, if they need to also include connection
  * information. One method is to use a {@link java.lang.ThreadLocal} to remember
  * the connection information before invoking UploadPack.
+ *
+ * @deprecated use {@link PostUploadHook} instead
  */
+@Deprecated
 public interface UploadPackLogger {
 	/** A simple no-op logger. */
 	public static final UploadPackLogger NULL = new UploadPackLogger() {

org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPackLoggerChain.java

@@ -48,10 +48,13 @@ import java.util.List;
 import org.eclipse.jgit.internal.storage.pack.PackWriter;
 
 /**
- * {@link UploadPackLogger} that delegates to a list of other loggers.
+ * UploadPackLogger that delegates to a list of other loggers.
  * <p>
  * loggers are run in the order passed to the constructor.
+ *
+ * @deprecated Use {@link PostUploadHookChain} instead.
  */
+@Deprecated
 public class UploadPackLoggerChain implements UploadPackLogger {
 	private final UploadPackLogger[] loggers;
 	private final int count;