Use constants for git packet protocol line identifiers

Introduce named constants for packet line headers and use them instead
of direct string literals everywhere. This not only makes the code more
readable because we don't need NON-NLS markers, it also makes it more
robust since we can use the length of these constants instead of magic
numbers.

Change-Id: Ie4b7239e0b479a68a2dc23e6e05f25061d481a31
Signed-off-by: Thomas Wolf <twolf@apache.org>

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

@@ -12,6 +12,18 @@
 
 package org.eclipse.jgit.transport;
 
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DELIM;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DEEPEN;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DEEPEN_NOT;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DEEPEN_SINCE;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DONE;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_END;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_ERR;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_HAVE;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_SHALLOW;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_UNSHALLOW;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_WANT;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -483,7 +495,7 @@ private void doFetchV2(ProgressMonitor monitor, Collection<Ref> want,
 		clearState();
 		String line = pckIn.readString();
 		// If we sent a done, we may have an error reply here.
-		if (sentDone && line.startsWith("ERR ")) { //$NON-NLS-1$
+		if (sentDone && line.startsWith(PACKET_ERR)) {
 			throw new RemoteRepositoryException(uri, line.substring(4));
 		}
 
@@ -491,7 +503,8 @@ private void doFetchV2(ProgressMonitor monitor, Collection<Ref> want,
 			line = handleShallowUnshallow(shallowCommits, pckIn);
 			if (!PacketLineIn.isDelimiter(line)) {
 				throw new PackProtocolException(MessageFormat
-						.format(JGitText.get().expectedGot, "0001", line)); //$NON-NLS-1$
+						.format(JGitText.get().expectedGot, PACKET_DELIM,
+								line));
 			}
 			line = pckIn.readString();
 		}
@@ -532,7 +545,7 @@ private boolean sendNextHaveBatch(FetchStateV2 fetchState,
 			if (c == null) {
 				break;
 			}
-			output.writeString("have " + c.getId().name() + '\n'); //$NON-NLS-1$
+			output.writeString(PACKET_HAVE + c.getId().name() + '\n');
 			n++;
 			if (n % 10 == 0 && monitor.isCancelled()) {
 				throw new CancelledException();
@@ -543,7 +556,7 @@ private boolean sendNextHaveBatch(FetchStateV2 fetchState,
 				|| (fetchState.hadAcks
 						&& fetchState.havesWithoutAck > MAX_HAVES)
 				|| fetchState.havesTotal > maxHaves) {
-			output.writeString("done\n"); //$NON-NLS-1$
+			output.writeString(PACKET_DONE + '\n');
 			output.end();
 			return true;
 		}
@@ -610,11 +623,12 @@ private boolean readAcknowledgments(FetchStateV2 fetchState,
 		if (gotReady) {
 			if (!PacketLineIn.isDelimiter(line)) {
 				throw new PackProtocolException(MessageFormat
-						.format(JGitText.get().expectedGot, "0001", line)); //$NON-NLS-1$
+						.format(JGitText.get().expectedGot, PACKET_DELIM,
+								line));
 			}
 		} else if (!PacketLineIn.isEnd(line)) {
 			throw new PackProtocolException(MessageFormat
-					.format(JGitText.get().expectedGot, "0000", line)); //$NON-NLS-1$
+					.format(JGitText.get().expectedGot, PACKET_END, line));
 		}
 		return gotReady;
 	}
@@ -726,8 +740,7 @@ private boolean sendWants(Collection<Ref> want, PacketLineOut p)
 			}
 
 			final StringBuilder line = new StringBuilder(46);
-			line.append("want "); //$NON-NLS-1$
+			line.append(PACKET_WANT).append(objectId.name());
-			line.append(objectId.name());
 			if (first && TransferConfig.ProtocolVersion.V0
 					.equals(getProtocolVersion())) {
 				line.append(enableCapabilities());
@@ -836,7 +849,7 @@ private void negotiate(ProgressMonitor monitor, boolean mayHaveShallow, Set<Obje
 			}
 
 			ObjectId o = c.getId();
-			pckOut.writeString("have " + o.name() + "\n"); //$NON-NLS-1$ //$NON-NLS-2$
+			pckOut.writeString(PACKET_HAVE + o.name() + '\n');
 			havesSent++;
 			havesSinceLastContinue++;
 
@@ -939,7 +952,7 @@ private void negotiate(ProgressMonitor monitor, boolean mayHaveShallow, Set<Obje
 			// loop above while in the middle of a request. This allows us
 			// to just write done immediately.
 			//
-			pckOut.writeString("done\n"); //$NON-NLS-1$
+			pckOut.writeString(PACKET_DONE + '\n');
 			pckOut.flush();
 		}
 
@@ -956,7 +969,7 @@ private void negotiate(ProgressMonitor monitor, boolean mayHaveShallow, Set<Obje
 			String line = handleShallowUnshallow(shallowCommits, pckIn);
 			if (!PacketLineIn.isEnd(line)) {
 				throw new PackProtocolException(MessageFormat
-						.format(JGitText.get().expectedGot, "0000", line)); //$NON-NLS-1$
+						.format(JGitText.get().expectedGot, PACKET_END, line));
 			}
 		}
 
@@ -1041,7 +1054,7 @@ private void markAdvertised(AnyObjectId id) {
 	private void markCommon(RevObject obj, AckNackResult anr, boolean useState)
 			throws IOException {
 		if (useState && anr == AckNackResult.ACK_COMMON && !obj.has(STATE)) {
-			pckState.writeString("have " + obj.name() + '\n'); //$NON-NLS-1$
+			pckState.writeString(PACKET_HAVE + obj.name() + '\n');
 			obj.add(STATE);
 		}
 		obj.add(COMMON);
@@ -1074,41 +1087,46 @@ private void receivePack(final ProgressMonitor monitor,
 		}
 	}
 
-	private void sendShallow(Set<ObjectId> shallowCommits, PacketLineOut output) throws IOException {
+	private void sendShallow(Set<ObjectId> shallowCommits, PacketLineOut output)
+			throws IOException {
 		for (ObjectId shallowCommit : shallowCommits) {
-			output.writeString("shallow " + shallowCommit.name()); //$NON-NLS-1$
+			output.writeString(PACKET_SHALLOW + shallowCommit.name());
 		}
 
 		if (depth != null) {
-			output.writeString("deepen " + depth); //$NON-NLS-1$
+			output.writeString(PACKET_DEEPEN + depth);
 		}
 
 		if (deepenSince != null) {
-			output.writeString("deepen-since " + deepenSince.getEpochSecond()); //$NON-NLS-1$
+			output.writeString(
+					PACKET_DEEPEN_SINCE + deepenSince.getEpochSecond());
 		}
 
 		if (deepenNots != null) {
 			for (String deepenNotRef : deepenNots) {
-				output.writeString("deepen-not " + deepenNotRef); //$NON-NLS-1$
+				output.writeString(PACKET_DEEPEN_NOT + deepenNotRef);
 			}
 		}
 	}
 
-	private String handleShallowUnshallow(Set<ObjectId> advertisedShallowCommits, PacketLineIn input)
+	private String handleShallowUnshallow(
+			Set<ObjectId> advertisedShallowCommits, PacketLineIn input)
 			throws IOException {
 		String line = input.readString();
 		ObjectDatabase objectDatabase = local.getObjectDatabase();
-		HashSet<ObjectId> newShallowCommits = new HashSet<>(advertisedShallowCommits);
+		HashSet<ObjectId> newShallowCommits = new HashSet<>(
+				advertisedShallowCommits);
 		while (!PacketLineIn.isDelimiter(line) && !PacketLineIn.isEnd(line)) {
-			if (line.startsWith("shallow ")) { //$NON-NLS-1$
+			if (line.startsWith(PACKET_SHALLOW)) {
 				newShallowCommits.add(ObjectId
-						.fromString(line.substring("shallow ".length()))); //$NON-NLS-1$
+						.fromString(line.substring(PACKET_SHALLOW.length())));
-			} else if (line.startsWith("unshallow ")) { //$NON-NLS-1$
+			} else if (line.startsWith(PACKET_UNSHALLOW)) {
 				ObjectId unshallow = ObjectId
-						.fromString(line.substring("unshallow ".length())); //$NON-NLS-1$
+						.fromString(line.substring(PACKET_UNSHALLOW.length()));
 				if (!advertisedShallowCommits.contains(unshallow)) {
-					throw new PackProtocolException(MessageFormat.format(JGitText.get()
+					throw new PackProtocolException(MessageFormat.format(
-							.notShallowedUnshallow, unshallow.name()));
+							JGitText.get().notShallowedUnshallow,
+							unshallow.name()));
 				}
 				newShallowCommits.remove(unshallow);
 			}

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

@@ -343,6 +343,106 @@ public final class GitProtocolConstants {
 	 */
 	public static final String VERSION_2_REQUEST = "version=2"; //$NON-NLS-1$
 
+	/**
+	 * The flush packet.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_FLUSH = "0000"; //$NON-NLS-1$
+
+	/**
+	 * An alias for {@link #PACKET_FLUSH}. "Flush" is the name used in the C git
+	 * documentation; the Java implementation calls this "end" in several
+	 * places.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_END = PACKET_FLUSH;
+
+	/**
+	 * The delimiter packet in protocol V2.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_DELIM = "0001"; //$NON-NLS-1$
+
+	/**
+	 * A "deepen" packet beginning.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_DEEPEN = "deepen "; //$NON-NLS-1$
+
+	/**
+	 * A "deepen-not" packet beginning.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_DEEPEN_NOT = "deepen-not "; //$NON-NLS-1$
+
+	/**
+	 * A "deepen-since" packet beginning.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_DEEPEN_SINCE = "deepen-since "; //$NON-NLS-1$
+
+	/**
+	 * An "ACK" packet beginning.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_ACK = "ACK "; //$NON-NLS-1$
+
+	/**
+	 * A "done" packet beginning.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_DONE = "done"; //$NON-NLS-1$
+
+	/**
+	 * A "ERR" packet beginning.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_ERR = "ERR "; //$NON-NLS-1$
+
+	/**
+	 * A "have" packet beginning.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_HAVE = "have "; //$NON-NLS-1$
+
+	/**
+	 * A "shallow" packet beginning.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_SHALLOW = OPTION_SHALLOW + ' ';
+
+	/**
+	 * A "shallow" packet beginning.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_UNSHALLOW = "unshallow "; //$NON-NLS-1$
+
+	/**
+	 * A "want" packet beginning.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_WANT = "want "; //$NON-NLS-1$
+
+	/**
+	 * A "want-ref" packet beginning.
+	 *
+	 * @since 6.3
+	 */
+	public static final String PACKET_WANT_REF = OPTION_WANT_REF + ' ';
+
 	enum MultiAck {
 		OFF, CONTINUE, DETAILED;
 	}

org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV0Parser.java

@@ -10,6 +10,11 @@
 package org.eclipse.jgit.transport;
 
 import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_FILTER;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DEEPEN;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DEEPEN_NOT;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DEEPEN_SINCE;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_SHALLOW;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_WANT;
 
 import java.io.EOFException;
 import java.io.IOException;
@@ -70,8 +75,9 @@ FetchV0Request recvWants(PacketLineIn pckIn)
 				break;
 			}
 
-			if (line.startsWith("deepen ")) { //$NON-NLS-1$
+			if (line.startsWith(PACKET_DEEPEN)) {
-				int depth = Integer.parseInt(line.substring(7));
+				int depth = Integer
+						.parseInt(line.substring(PACKET_DEEPEN.length()));
 				if (depth <= 0) {
 					throw new PackProtocolException(
 							MessageFormat.format(JGitText.get().invalidDepth,
@@ -89,8 +95,9 @@ FetchV0Request recvWants(PacketLineIn pckIn)
 				continue;
 			}
 
-			if (line.startsWith("deepen-not ")) { //$NON-NLS-1$
+			if (line.startsWith(PACKET_DEEPEN_NOT)) {
-				reqBuilder.addDeepenNot(line.substring(11));
+				reqBuilder.addDeepenNot(
+						line.substring(PACKET_DEEPEN_NOT.length()));
 				if (reqBuilder.getDepth() != 0) {
 					throw new PackProtocolException(
 							JGitText.get().deepenNotWithDeepen);
@@ -98,9 +105,10 @@ FetchV0Request recvWants(PacketLineIn pckIn)
 				continue;
 			}
 
-			if (line.startsWith("deepen-since ")) { //$NON-NLS-1$
+			if (line.startsWith(PACKET_DEEPEN_SINCE)) {
 				// TODO: timestamps should be long
-				int ts = Integer.parseInt(line.substring(13));
+				int ts = Integer
+						.parseInt(line.substring(PACKET_DEEPEN_SINCE.length()));
 				if (ts <= 0) {
 					throw new PackProtocolException(MessageFormat
 							.format(JGitText.get().invalidTimestamp, line));
@@ -113,9 +121,10 @@ FetchV0Request recvWants(PacketLineIn pckIn)
 				continue;
 			}
 
-			if (line.startsWith("shallow ")) { //$NON-NLS-1$
+			if (line.startsWith(PACKET_SHALLOW)) {
 				reqBuilder.addClientShallowCommit(
-						ObjectId.fromString(line.substring(8)));
+						ObjectId.fromString(
+								line.substring(PACKET_SHALLOW.length())));
 				continue;
 			}
 
@@ -133,7 +142,7 @@ FetchV0Request recvWants(PacketLineIn pckIn)
 				continue;
 			}
 
-			if (!line.startsWith("want ") || line.length() < 45) { //$NON-NLS-1$
+			if (!line.startsWith(PACKET_WANT) || line.length() < 45) {
 				throw new PackProtocolException(MessageFormat
 						.format(JGitText.get().expectedGot, "want", line)); //$NON-NLS-1$
 			}
@@ -147,7 +156,8 @@ FetchV0Request recvWants(PacketLineIn pckIn)
 				}
 			}
 
-			reqBuilder.addWantId(ObjectId.fromString(line.substring(5)));
+			reqBuilder.addWantId(
+					ObjectId.fromString(line.substring(PACKET_WANT.length())));
 			isFirst = false;
 		}
 

org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2Parser.java

@@ -20,7 +20,14 @@
 import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_SIDE_BAND_64K;
 import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_THIN_PACK;
 import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_WAIT_FOR_DONE;
-import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_WANT_REF;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DEEPEN;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DEEPEN_NOT;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DEEPEN_SINCE;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DONE;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_HAVE;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_SHALLOW;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_WANT;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_WANT_REF;
 
 import java.io.IOException;
 import java.text.MessageFormat;
@@ -115,15 +122,17 @@ FetchV2Request parseFetchRequest(PacketLineIn pckIn)
 
 		boolean filterReceived = false;
 		for (String line2 : pckIn.readStrings()) {
-			if (line2.startsWith("want ")) { //$NON-NLS-1$
+			if (line2.startsWith(PACKET_WANT)) {
-				reqBuilder.addWantId(ObjectId.fromString(line2.substring(5)));
+				reqBuilder.addWantId(ObjectId
+						.fromString(line2.substring(PACKET_WANT.length())));
 			} else if (transferConfig.isAllowRefInWant()
-					&& line2.startsWith(OPTION_WANT_REF + " ")) { //$NON-NLS-1$
+					&& line2.startsWith(PACKET_WANT_REF)) {
 				reqBuilder.addWantedRef(
-						line2.substring(OPTION_WANT_REF.length() + 1));
+						line2.substring(PACKET_WANT_REF.length()));
-			} else if (line2.startsWith("have ")) { //$NON-NLS-1$
+			} else if (line2.startsWith(PACKET_HAVE)) {
-				reqBuilder.addPeerHas(ObjectId.fromString(line2.substring(5)));
+				reqBuilder.addPeerHas(ObjectId
-			} else if (line2.equals("done")) { //$NON-NLS-1$
+						.fromString(line2.substring(PACKET_HAVE.length())));
+			} else if (line2.equals(PACKET_DONE)) {
 				reqBuilder.setDoneReceived();
 			} else if (line2.equals(OPTION_WAIT_FOR_DONE)) {
 				reqBuilder.setWaitForDone();
@@ -135,11 +144,13 @@ FetchV2Request parseFetchRequest(PacketLineIn pckIn)
 				reqBuilder.addClientCapability(OPTION_INCLUDE_TAG);
 			} else if (line2.equals(OPTION_OFS_DELTA)) {
 				reqBuilder.addClientCapability(OPTION_OFS_DELTA);
-			} else if (line2.startsWith("shallow ")) { //$NON-NLS-1$
+			} else if (line2.startsWith(PACKET_SHALLOW)) {
 				reqBuilder.addClientShallowCommit(
-						ObjectId.fromString(line2.substring(8)));
+						ObjectId.fromString(
-			} else if (line2.startsWith("deepen ")) { //$NON-NLS-1$
+								line2.substring(PACKET_SHALLOW.length())));
-				int parsedDepth = Integer.parseInt(line2.substring(7));
+			} else if (line2.startsWith(PACKET_DEEPEN)) {
+				int parsedDepth = Integer
+						.parseInt(line2.substring(PACKET_DEEPEN.length()));
 				if (parsedDepth <= 0) {
 					throw new PackProtocolException(
 							MessageFormat.format(JGitText.get().invalidDepth,
@@ -154,16 +165,18 @@ FetchV2Request parseFetchRequest(PacketLineIn pckIn)
 							JGitText.get().deepenNotWithDeepen);
 				}
 				reqBuilder.setDepth(parsedDepth);
-			} else if (line2.startsWith("deepen-not ")) { //$NON-NLS-1$
+			} else if (line2.startsWith(PACKET_DEEPEN_NOT)) {
-				reqBuilder.addDeepenNot(line2.substring(11));
+				reqBuilder.addDeepenNot(
+						line2.substring(PACKET_DEEPEN_NOT.length()));
 				if (reqBuilder.getDepth() != 0) {
 					throw new PackProtocolException(
 							JGitText.get().deepenNotWithDeepen);
 				}
 			} else if (line2.equals(OPTION_DEEPEN_RELATIVE)) {
 				reqBuilder.addClientCapability(OPTION_DEEPEN_RELATIVE);
-			} else if (line2.startsWith("deepen-since ")) { //$NON-NLS-1$
+			} else if (line2.startsWith(PACKET_DEEPEN_SINCE)) {
-				int ts = Integer.parseInt(line2.substring(13));
+				int ts = Integer.parseInt(
+						line2.substring(PACKET_DEEPEN_SINCE.length()));
 				if (ts <= 0) {
 					throw new PackProtocolException(MessageFormat
 							.format(JGitText.get().invalidTimestamp, line2));

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

@@ -20,6 +20,8 @@
 import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_REPORT_STATUS;
 import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_SIDE_BAND_64K;
 import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_AGENT;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_ERR;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_SHALLOW;
 import static org.eclipse.jgit.transport.SideBandOutputStream.CH_DATA;
 import static org.eclipse.jgit.transport.SideBandOutputStream.CH_ERROR;
 import static org.eclipse.jgit.transport.SideBandOutputStream.CH_PROGRESS;
@@ -1247,7 +1249,7 @@ private void unlockPack() throws IOException {
 	public void sendAdvertisedRefs(RefAdvertiser adv)
 			throws IOException, ServiceMayNotContinueException {
 		if (advertiseError != null) {
-			adv.writeOne("ERR " + advertiseError); //$NON-NLS-1$
+			adv.writeOne(PACKET_ERR + advertiseError);
 			return;
 		}
 
@@ -1255,7 +1257,7 @@ public void sendAdvertisedRefs(RefAdvertiser adv)
 			advertiseRefsHook.advertiseRefs(this);
 		} catch (ServiceMayNotContinueException fail) {
 			if (fail.getMessage() != null) {
-				adv.writeOne("ERR " + fail.getMessage()); //$NON-NLS-1$
+				adv.writeOne(PACKET_ERR + fail.getMessage());
 				fail.setOutput();
 			}
 			throw fail;
@@ -1339,8 +1341,9 @@ private void recvCommands() throws IOException {
 					break;
 				}
 
-				if (line.length() >= 48 && line.startsWith("shallow ")) { //$NON-NLS-1$
+				int len = PACKET_SHALLOW.length() + 40;
-					parseShallow(line.substring(8, 48));
+				if (line.length() >= len && line.startsWith(PACKET_SHALLOW)) {
+					parseShallow(line.substring(PACKET_SHALLOW.length(), len));
 					continue;
 				}
 
@@ -1795,9 +1798,9 @@ private void sendStatusReport(Throwable unpackError) throws IOException {
 			@Override
 			void sendString(String s) throws IOException {
 				if (reportStatus) {
-					pckOut.writeString(s + "\n"); //$NON-NLS-1$
+					pckOut.writeString(s + '\n');
 				} else if (msgOut != null) {
-					msgOut.write(Constants.encode(s + "\n")); //$NON-NLS-1$
+					msgOut.write(Constants.encode(s + '\n'));
 				}
 			}
 		};

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

@@ -36,6 +36,12 @@
 import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_SIDE_BAND_64K;
 import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_THIN_PACK;
 import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_WAIT_FOR_DONE;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_ACK;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_DONE;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_ERR;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_HAVE;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_SHALLOW;
+import static org.eclipse.jgit.transport.GitProtocolConstants.PACKET_UNSHALLOW;
 import static org.eclipse.jgit.transport.GitProtocolConstants.VERSION_2_REQUEST;
 import static org.eclipse.jgit.util.RefMap.toRefMap;
 
@@ -1076,9 +1082,10 @@ else if (requestValidator instanceof AnyRequestValidator)
 			deepenNots = parseDeepenNots(req.getDeepenNots());
 			if (req.getDepth() != 0 || req.getDeepenSince() != 0 || !req.getDeepenNots().isEmpty()) {
 				computeShallowsAndUnshallows(req, shallow -> {
-					pckOut.writeString("shallow " + shallow.name() + '\n'); //$NON-NLS-1$
+					pckOut.writeString(PACKET_SHALLOW + shallow.name() + '\n');
 				}, unshallow -> {
-					pckOut.writeString("unshallow " + unshallow.name() + '\n'); //$NON-NLS-1$
+					pckOut.writeString(
+							PACKET_UNSHALLOW + unshallow.name() + '\n');
 					unshallowCommits.add(unshallow);
 				}, deepenNots);
 				pckOut.end();
@@ -1227,7 +1234,7 @@ private void fetchV2(PacketLineOut pckOut) throws IOException {
 					GitProtocolConstants.SECTION_ACKNOWLEDGMENTS + '\n');
 			for (ObjectId id : req.getPeerHas()) {
 				if (walk.getObjectReader().has(id)) {
-					pckOut.writeString("ACK " + id.getName() + "\n"); //$NON-NLS-1$ //$NON-NLS-2$
+					pckOut.writeString(PACKET_ACK + id.getName() + '\n');
 				}
 			}
 			processHaveLines(req.getPeerHas(), ObjectId.zeroId(),
@@ -1245,12 +1252,13 @@ private void fetchV2(PacketLineOut pckOut) throws IOException {
 			if (mayHaveShallow) {
 				if (sectionSent)
 					pckOut.writeDelim();
-				pckOut.writeString("shallow-info\n"); //$NON-NLS-1$
+				pckOut.writeString(
+						GitProtocolConstants.SECTION_SHALLOW_INFO + '\n');
 				for (ObjectId o : shallowCommits) {
-					pckOut.writeString("shallow " + o.getName() + '\n'); //$NON-NLS-1$
+					pckOut.writeString(PACKET_SHALLOW + o.getName() + '\n');
 				}
 				for (ObjectId o : unshallowCommits) {
-					pckOut.writeString("unshallow " + o.getName() + '\n'); //$NON-NLS-1$
+					pckOut.writeString(PACKET_UNSHALLOW + o.getName() + '\n');
 				}
 				sectionSent = true;
 			}
@@ -1314,7 +1322,7 @@ private void objectInfo(PacketLineOut pckOut) throws IOException {
 						.format(JGitText.get().missingObject, oid.name()), e);
 			}
 
-			pckOut.writeString(oid.getName() + " " + size); //$NON-NLS-1$
+			pckOut.writeString(oid.getName() + ' ' + size);
 		}
 
 		pckOut.end();
@@ -1386,7 +1394,7 @@ private void serviceV2(PacketLineOut pckOut) throws IOException {
 			protocolV2Hook
 					.onCapabilities(CapabilitiesV2Request.builder().build());
 			for (String s : getV2CapabilityAdvertisement()) {
-				pckOut.writeString(s + "\n"); //$NON-NLS-1$
+				pckOut.writeString(s + '\n');
 			}
 			pckOut.end();
 
@@ -1613,7 +1621,7 @@ public void sendAdvertisedRefs(RefAdvertiser adv,
 	 */
 	public void sendMessage(String what) {
 		try {
-			msgOut.write(Constants.encode(what + "\n")); //$NON-NLS-1$
+			msgOut.write(Constants.encode(what + '\n'));
 		} catch (IOException e) {
 			// Ignore write failures.
 		}
@@ -1720,24 +1728,26 @@ private boolean negotiate(FetchRequest req,
 				if (commonBase.isEmpty() || multiAck != MultiAck.OFF)
 					pckOut.writeString("NAK\n"); //$NON-NLS-1$
 				if (noDone && sentReady) {
-					pckOut.writeString("ACK " + last.name() + "\n"); //$NON-NLS-1$ //$NON-NLS-2$
+					pckOut.writeString(PACKET_ACK + last.name() + '\n');
 					return true;
 				}
 				if (!biDirectionalPipe)
 					return false;
 				pckOut.flush();
 
-			} else if (line.startsWith("have ") && line.length() == 45) { //$NON-NLS-1$
+			} else if (line.startsWith(PACKET_HAVE)
-				peerHas.add(ObjectId.fromString(line.substring(5)));
+					&& line.length() == PACKET_HAVE.length() + 40) {
+				peerHas.add(ObjectId
+						.fromString(line.substring(PACKET_HAVE.length())));
 				accumulator.haves++;
-			} else if (line.equals("done")) { //$NON-NLS-1$
+			} else if (line.equals(PACKET_DONE)) {
 				last = processHaveLines(peerHas, last, pckOut, accumulator, Option.NONE);
 
 				if (commonBase.isEmpty())
 					pckOut.writeString("NAK\n"); //$NON-NLS-1$
 
 				else if (multiAck != MultiAck.OFF)
-					pckOut.writeString("ACK " + last.name() + "\n"); //$NON-NLS-1$ //$NON-NLS-2$
+					pckOut.writeString(PACKET_ACK + last.name() + '\n');
 
 				return true;
 
@@ -1798,14 +1808,15 @@ private ObjectId processHaveLines(List<ObjectId> peerHas, ObjectId last,
 				//
 				switch (multiAck) {
 				case OFF:
-					if (commonBase.size() == 1)
+					if (commonBase.size() == 1) {
-						out.writeString("ACK " + obj.name() + "\n"); //$NON-NLS-1$ //$NON-NLS-2$
+						out.writeString(PACKET_ACK + obj.name() + '\n');
+					}
 					break;
 				case CONTINUE:
-					out.writeString("ACK " + obj.name() + " continue\n"); //$NON-NLS-1$ //$NON-NLS-2$
+					out.writeString(PACKET_ACK + obj.name() + " continue\n"); //$NON-NLS-1$
 					break;
 				case DETAILED:
-					out.writeString("ACK " + obj.name() + " common\n"); //$NON-NLS-1$ //$NON-NLS-2$
+					out.writeString(PACKET_ACK + obj.name() + " common\n"); //$NON-NLS-1$
 					break;
 				}
 			}
@@ -1844,11 +1855,11 @@ private boolean shouldGiveUp(List<ObjectId> peerHas, PacketLineOut out, int miss
 							break;
 						case CONTINUE:
 							out.writeString(
-									"ACK " + id.name() + " continue\n"); //$NON-NLS-1$ //$NON-NLS-2$
+									PACKET_ACK + id.name() + " continue\n"); //$NON-NLS-1$
 							break;
 						case DETAILED:
 							out.writeString(
-									"ACK " + id.name() + " ready\n"); //$NON-NLS-1$ //$NON-NLS-2$
+									PACKET_ACK + id.name() + " ready\n"); //$NON-NLS-1$
 							readySent = true;
 							break;
 						}
@@ -1861,7 +1872,7 @@ private boolean shouldGiveUp(List<ObjectId> peerHas, PacketLineOut out, int miss
 		if (multiAck == MultiAck.DETAILED && !didOkToGiveUp
 				&& okToGiveUp()) {
 			ObjectId id = peerHas.get(peerHas.size() - 1);
-			out.writeString("ACK " + id.name() + " ready\n"); //$NON-NLS-1$ //$NON-NLS-2$
+			out.writeString(PACKET_ACK + id.name() + " ready\n"); //$NON-NLS-1$
 			readySent = true;
 		}
 
@@ -2552,7 +2563,7 @@ private class PackProtocolErrorWriter implements ErrorWriter {
 		@Override
 		public void writeError(String message) throws IOException {
 			new PacketLineOut(requireNonNull(rawOut))
-					.writeString("ERR " + message + '\n'); //$NON-NLS-1$
+					.writeString(PACKET_ERR + message + '\n');
 		}
 	}
 }