Add negotiation statistics to PackStatistics

Add fetch statistics for the counts of advertised refs, wants and haves.
Also add the duration in milliseconds for the negotiation phase. For
non-bidirectional transports like HTTP, this is the time for the final
round that sends the pack back to the user.

Change-Id: I1af7ffd3cb7b62182340682e2a243691ea24ec2e
Signed-off-by: Terry Parker <tparker@google.com>

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

@@ -81,6 +81,7 @@ import java.util.zip.Deflater;
 import java.util.zip.DeflaterOutputStream;
 
 import org.eclipse.jgit.annotations.NonNull;
+import org.eclipse.jgit.annotations.Nullable;
 import org.eclipse.jgit.errors.CorruptObjectException;
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.LargeObjectException;
@@ -355,6 +356,24 @@ public class PackWriter implements AutoCloseable {
 	 *            reader to read from the repository with.
 	 */
 	public PackWriter(final PackConfig config, final ObjectReader reader) {
+		this(config, reader, null);
+	}
+
+	/**
+	 * Create writer with a specified configuration.
+	 * <p>
+	 * Objects for packing are specified in {@link #preparePack(Iterator)} or
+	 * {@link #preparePack(ProgressMonitor, Set, Set)}.
+	 *
+	 * @param config
+	 *            configuration for the pack writer.
+	 * @param reader
+	 *            reader to read from the repository with.
+	 * @param statsAccumulator
+	 *            accumulator for statics
+	 */
+	public PackWriter(PackConfig config, final ObjectReader reader,
+			@Nullable PackStatistics.Accumulator statsAccumulator) {
 		this.config = config;
 		this.reader = reader;
 		if (reader instanceof ObjectReuseAsIs)
@@ -365,7 +384,8 @@ public class PackWriter implements AutoCloseable {
 		deltaBaseAsOffset = config.isDeltaBaseAsOffset();
 		reuseDeltas = config.isReuseDeltas();
 		reuseValidate = true; // be paranoid by default
-		stats = new PackStatistics.Accumulator();
+		stats = statsAccumulator != null ? statsAccumulator
+				: new PackStatistics.Accumulator();
 		state = new MutableState();
 		selfRef = new WeakReference<>(this);
 		instances.put(selfRef, Boolean.TRUE);

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

@@ -166,6 +166,36 @@ public class PackStatistics {
 	 * POJO for accumulating the statistics.
 	 */
 	public static class Accumulator {
+		/**
+		 * The count of references in the ref advertisement.
+		 *
+		 * @since 4.11
+		 */
+		public long advertised;
+
+		/**
+		 * The count of client wants.
+		 *
+		 * @since 4.11
+		 */
+		public long wants;
+
+		/**
+		 * The count of client haves.
+		 *
+		 * @since 4.11
+		 */
+		public long haves;
+
+		/**
+		 * Time in ms spent in the negotiation phase. For non-bidirectional
+		 * transports (e.g., HTTP), this is only for the final request that
+		 * sends back the pack file.
+		 *
+		 * @since 4.11
+		 */
+		public long timeNegotiating;
+
 		/** The set of objects to be included in the pack. */
 		public Set<ObjectId> interestingObjects;
 
@@ -270,6 +300,48 @@ public class PackStatistics {
 		statistics = accumulator;
 	}
 
+	/**
+	 * Get the count of references in the ref advertisement.
+	 *
+	 * @return count of refs in the ref advertisement.
+	 * @since 4.11
+	 */
+	public long getAdvertised() {
+		return statistics.advertised;
+	}
+
+	/**
+	 * Get the count of client wants.
+	 *
+	 * @return count of client wants.
+	 * @since 4.11
+	 */
+	public long getWants() {
+		return statistics.wants;
+	}
+
+	/**
+	 * Get the count of client haves.
+	 *
+	 * @return count of client haves.
+	 * @since 4.11
+	 */
+	public long getHaves() {
+		return statistics.haves;
+	}
+
+	/**
+	 * Time in ms spent in the negotiation phase. For non-bidirectional
+	 * transports (e.g., HTTP), this is only for the final request that sends
+	 * back the pack file.
+	 *
+	 * @return time for ref advertisement in ms.
+	 * @since 4.11
+	 */
+	public long getTimeNegotiating() {
+		return statistics.timeNegotiating;
+	}
+
 	/**
 	 * Get unmodifiable collection of objects to be included in the pack.
 	 *

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

@@ -773,6 +773,7 @@ public class UploadPack {
 		boolean sendPack = false;
 		// If it's a non-bidi request, we need to read the entire request before
 		// writing a response. Buffer the response until then.
+		PackStatistics.Accumulator accumulator = new PackStatistics.Accumulator();
 		try {
 			if (biDirectionalPipe)
 				sendAdvertisedRefs(new PacketLineOutRefAdvertiser(pckOut));
@@ -781,12 +782,15 @@ public class UploadPack {
 			else
 				advertised = refIdSet(getAdvertisedOrDefaultRefs().values());
 
+			long negotiateStart = System.currentTimeMillis();
+			accumulator.advertised = advertised.size();
 			recvWants();
 			if (wantIds.isEmpty()) {
 				preUploadHook.onBeginNegotiateRound(this, wantIds, 0);
 				preUploadHook.onEndNegotiateRound(this, wantIds, 0, 0, false);
 				return;
 			}
+			accumulator.wants = wantIds.size();
 
 			if (options.contains(OPTION_MULTI_ACK_DETAILED)) {
 				multiAck = MultiAck.DETAILED;
@@ -802,7 +806,10 @@ public class UploadPack {
 				processShallow();
 			if (!clientShallowCommits.isEmpty())
 				walk.assumeShallow(clientShallowCommits);
-			sendPack = negotiate();
+			sendPack = negotiate(accumulator);
+			accumulator.timeNegotiating += System.currentTimeMillis()
+					- negotiateStart;
+
 			if (sendPack && !biDirectionalPipe) {
 				// Ensure the request was fully consumed. Any remaining input must
 				// be a protocol error. If we aren't at EOF the implementation is broken.
@@ -849,7 +856,7 @@ public class UploadPack {
 		}
 
 		if (sendPack)
-			sendPack();
+			sendPack(accumulator);
 	}
 
 	private static Set<ObjectId> refIdSet(Collection<Ref> refs) {
@@ -1093,7 +1100,8 @@ public class UploadPack {
 		return UserAgent.getAgent(options, userAgent);
 	}
 
-	private boolean negotiate() throws IOException {
+	private boolean negotiate(PackStatistics.Accumulator accumulator)
+			throws IOException {
 		okToGiveUp = Boolean.FALSE;
 
 		ObjectId last = ObjectId.zeroId();
@@ -1127,7 +1135,7 @@ public class UploadPack {
 
 			} else if (line.startsWith("have ") && line.length() == 45) { //$NON-NLS-1$
 				peerHas.add(ObjectId.fromString(line.substring(5)));
-
+				accumulator.haves++;
 			} else if (line.equals("done")) { //$NON-NLS-1$
 				last = processHaveLines(peerHas, last);
 
@@ -1485,12 +1493,13 @@ public class UploadPack {
 		return false;
 	}
 
-	private void sendPack() throws IOException {
+	private void sendPack(PackStatistics.Accumulator accumulator)
+			throws IOException {
 		final boolean sideband = options.contains(OPTION_SIDE_BAND)
 				|| options.contains(OPTION_SIDE_BAND_64K);
 		if (sideband) {
 			try {
-				sendPack(true);
+				sendPack(true, accumulator);
 			} catch (ServiceMayNotContinueException noPack) {
 				// This was already reported on (below).
 				throw noPack;
@@ -1511,7 +1520,7 @@ public class UploadPack {
 					throw err;
 			}
 		} else {
-			sendPack(false);
+			sendPack(false, accumulator);
 		}
 	}
 
@@ -1532,7 +1541,8 @@ public class UploadPack {
 	}
 
 	@SuppressWarnings("deprecation")
-	private void sendPack(final boolean sideband) throws IOException {
+	private void sendPack(final boolean sideband,
+			PackStatistics.Accumulator accumulator) throws IOException {
 		ProgressMonitor pm = NullProgressMonitor.INSTANCE;
 		OutputStream packOut = rawOut;
 
@@ -1573,7 +1583,8 @@ public class UploadPack {
 		PackConfig cfg = packConfig;
 		if (cfg == null)
 			cfg = new PackConfig(db);
-		final PackWriter pw = new PackWriter(cfg, walk.getObjectReader());
+		final PackWriter pw = new PackWriter(cfg, walk.getObjectReader(),
+				accumulator);
 		try {
 			pw.setIndexDisabled(true);
 			pw.setUseCachedPacks(true);