Constants for objects and info/{http-,}alternates

These are useful to avoid typos, and also for tab completion.

Change-Id: I0f2d267e46b36bc40297c9657c447f3fd8b9f831
Signed-off-by: David Turner <dturner@twosigma.com>

org.eclipse.jgit.http.server/src/org/eclipse/jgit/http/server/GitFilter.java

@@ -248,13 +248,13 @@ public class GitFilter extends MetaFilter {
 					.through(enabled)//
 					.with(new TextFileServlet(Constants.HEAD));
 
-			final String info_alternates = "objects/info/alternates";
+			final String info_alternates = Constants.OBJECTS + "/" + Constants.INFO_ALTERNATES;
 			serve("*/" + info_alternates)//
 					.through(mustBeLocal)//
 					.through(enabled)//
 					.with(new TextFileServlet(info_alternates));
 
-			final String http_alternates = "objects/info/http-alternates";
+			final String http_alternates = Constants.OBJECTS + "/" + Constants.INFO_HTTP_ALTERNATES;
 			serve("*/" + http_alternates)//
 					.through(mustBeLocal)//
 					.through(enabled)//

org.eclipse.jgit.lfs/src/org/eclipse/jgit/lfs/Lfs.java

@@ -42,6 +42,8 @@
  */
 package org.eclipse.jgit.lfs;
 
+import static org.eclipse.jgit.lib.Constants.OBJECTS;
+
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -104,7 +106,7 @@ public class Lfs {
 	 */
 	public Path getLfsObjDir() {
 		if (objDir == null) {
-			objDir = root.resolve("objects"); //$NON-NLS-1$
+			objDir = root.resolve(OBJECTS);
 		}
 		return objDir;
 	}

org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/AlternatesTest.java

@@ -42,6 +42,7 @@
  */
 package org.eclipse.jgit.internal.storage.file;
 
+import static org.eclipse.jgit.lib.Constants.INFO_ALTERNATES;
 import static org.junit.Assert.assertTrue;
 
 import java.io.File;
@@ -76,7 +77,7 @@ public class AlternatesTest extends SampleDataRepositoryTestCase {
 	private void setAlternate(FileRepository from, FileRepository to)
 			throws IOException {
 		File alt = new File(from.getObjectDatabase().getDirectory(),
-				"info/alternates");
+				INFO_ALTERNATES);
 		alt.getParentFile().mkdirs();
 		File fromDir = from.getObjectDatabase().getDirectory();
 		File toDir = to.getObjectDatabase().getDirectory();

org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/PackWriterTest.java

@@ -44,6 +44,7 @@
 package org.eclipse.jgit.internal.storage.file;
 
 import static org.eclipse.jgit.internal.storage.pack.PackWriter.NONE;
+import static org.eclipse.jgit.lib.Constants.INFO_ALTERNATES;
 import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -138,7 +139,7 @@ public class PackWriterTest extends SampleDataRepositoryTestCase {
 		config = new PackConfig(db);
 
 		dst = createBareRepository();
-		File alt = new File(dst.getObjectDatabase().getDirectory(), "info/alternates");
+		File alt = new File(dst.getObjectDatabase().getDirectory(), INFO_ALTERNATES);
 		alt.getParentFile().mkdirs();
 		write(alt, db.getObjectDatabase().getDirectory().getAbsolutePath() + "\n");
 	}

org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/T0003_BasicTest.java

@@ -96,7 +96,7 @@ public class T0003_BasicTest extends SampleDataRepositoryTestCase {
 	public void test001_Initalize() {
 		final File gitdir = new File(trash, Constants.DOT_GIT);
 		final File hooks = new File(gitdir, "hooks");
-		final File objects = new File(gitdir, "objects");
+		final File objects = new File(gitdir, Constants.OBJECTS);
 		final File objects_pack = new File(objects, "pack");
 		final File objects_info = new File(objects, "info");
 		final File refs = new File(gitdir, "refs");
@@ -148,7 +148,7 @@ public class T0003_BasicTest extends SampleDataRepositoryTestCase {
 		assertEqualsPath(theDir, r.getDirectory());
 		assertEqualsPath(repo1Parent, r.getWorkTree());
 		assertEqualsPath(new File(theDir, "index"), r.getIndexFile());
-		assertEqualsPath(new File(theDir, "objects"), r.getObjectDatabase()
+		assertEqualsPath(new File(theDir, Constants.OBJECTS), r.getObjectDatabase()
 				.getDirectory());
 	}
 
@@ -174,7 +174,7 @@ public class T0003_BasicTest extends SampleDataRepositoryTestCase {
 		assertEqualsPath(theDir, r.getDirectory());
 		assertEqualsPath(repo1Parent.getParentFile(), r.getWorkTree());
 		assertEqualsPath(new File(theDir, "index"), r.getIndexFile());
-		assertEqualsPath(new File(theDir, "objects"), r.getObjectDatabase()
+		assertEqualsPath(new File(theDir, Constants.OBJECTS), r.getObjectDatabase()
 				.getDirectory());
 	}
 
@@ -198,7 +198,7 @@ public class T0003_BasicTest extends SampleDataRepositoryTestCase {
 		assertEqualsPath(theDir, r.getDirectory());
 		assertEqualsPath(repo1Parent, r.getWorkTree());
 		assertEqualsPath(new File(theDir, "index"), r.getIndexFile());
-		assertEqualsPath(new File(theDir, "objects"), r.getObjectDatabase()
+		assertEqualsPath(new File(theDir, Constants.OBJECTS), r.getObjectDatabase()
 				.getDirectory());
 	}
 
@@ -227,7 +227,7 @@ public class T0003_BasicTest extends SampleDataRepositoryTestCase {
 		assertEqualsPath(theDir, r.getDirectory());
 		assertEqualsPath(workdir, r.getWorkTree());
 		assertEqualsPath(new File(theDir, "index"), r.getIndexFile());
-		assertEqualsPath(new File(theDir, "objects"), r.getObjectDatabase()
+		assertEqualsPath(new File(theDir, Constants.OBJECTS), r.getObjectDatabase()
 				.getDirectory());
 	}
 
@@ -256,7 +256,7 @@ public class T0003_BasicTest extends SampleDataRepositoryTestCase {
 		assertEqualsPath(theDir, r.getDirectory());
 		assertEqualsPath(workdir, r.getWorkTree());
 		assertEqualsPath(new File(theDir, "index"), r.getIndexFile());
-		assertEqualsPath(new File(theDir, "objects"), r.getObjectDatabase()
+		assertEqualsPath(new File(theDir, Constants.OBJECTS), r.getObjectDatabase()
 				.getDirectory());
 	}
 
@@ -312,7 +312,7 @@ public class T0003_BasicTest extends SampleDataRepositoryTestCase {
 		}
 
 		final File o = new File(new File(new File(newdb.getDirectory(),
-				"objects"), "4b"), "825dc642cb6eb9a060e54bf8d69288fbee4904");
+				Constants.OBJECTS), "4b"), "825dc642cb6eb9a060e54bf8d69288fbee4904");
 		assertTrue("Exists " + o, o.isFile());
 		assertTrue("Read-only " + o, !o.canWrite());
 	}
@@ -324,7 +324,7 @@ public class T0003_BasicTest extends SampleDataRepositoryTestCase {
 		final ObjectId treeId = insertTree(new TreeFormatter());
 		assertEquals("4b825dc642cb6eb9a060e54bf8d69288fbee4904", treeId.name());
 		final File o = new File(new File(
-				new File(db.getDirectory(), "objects"), "4b"),
+				new File(db.getDirectory(), Constants.OBJECTS), "4b"),
 				"825dc642cb6eb9a060e54bf8d69288fbee4904");
 		assertFalse("Exists " + o, o.isFile());
 	}

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/ObjectDirectory.java

@@ -171,7 +171,7 @@ public class ObjectDirectory extends FileObjectDatabase {
 		infoDirectory = new File(objects, "info"); //$NON-NLS-1$
 		packDirectory = new File(objects, "pack"); //$NON-NLS-1$
 		preservedDirectory = new File(packDirectory, "preserved"); //$NON-NLS-1$
-		alternatesFile = new File(infoDirectory, "alternates"); //$NON-NLS-1$
+		alternatesFile = new File(objects, Constants.INFO_ALTERNATES);
 		packList = new AtomicReference<>(NO_PACKS);
 		unpackedObjectCache = new UnpackedObjectCache();
 		this.fs = fs;

org.eclipse.jgit/src/org/eclipse/jgit/lib/BaseRepositoryBuilder.java

@@ -681,7 +681,7 @@ public class BaseRepositoryBuilder<B extends BaseRepositoryBuilder, R extends Re
 	 */
 	protected void setupInternals() throws IOException {
 		if (getObjectDirectory() == null && getGitDir() != null)
-			setObjectDirectory(safeFS().resolve(getGitDir(), "objects")); //$NON-NLS-1$
+			setObjectDirectory(safeFS().resolve(getGitDir(), Constants.OBJECTS));
 	}
 
 	/**

org.eclipse.jgit/src/org/eclipse/jgit/lib/Constants.java

@@ -275,9 +275,27 @@ public final class Constants {
 	/** Logs folder name */
 	public static final String LOGS = "logs";
 
+	/**
+	 * Objects folder name
+	 * @since 5.5
+	 */
+	public static final String OBJECTS = "objects";
+
 	/** Info refs folder */
 	public static final String INFO_REFS = "info/refs";
 
+	/**
+	 * Info alternates file (goes under OBJECTS)
+	 * @since 5.5
+	 */
+	public static final String INFO_ALTERNATES = "info/alternates";
+
+	/**
+	 * HTTP alternates file (goes under OBJECTS)
+	 * @since 5.5
+	 */
+	public static final String INFO_HTTP_ALTERNATES = "info/http-alternates";
+
 	/** Packed refs file */
 	public static final String PACKED_REFS = "packed-refs";
 

org.eclipse.jgit/src/org/eclipse/jgit/lib/RepositoryCache.java

@@ -474,7 +474,7 @@ public class RepositoryCache {
 		 *         Git directory.
 		 */
 		public static boolean isGitRepository(File dir, FS fs) {
-			return fs.resolve(dir, "objects").exists() //$NON-NLS-1$
+			return fs.resolve(dir, Constants.OBJECTS).exists()
 					&& fs.resolve(dir, "refs").exists() //$NON-NLS-1$
 					&& isValidHead(new File(dir, Constants.HEAD));
 		}

org.eclipse.jgit/src/org/eclipse/jgit/transport/TransportAmazonS3.java

@@ -259,7 +259,7 @@ public class TransportAmazonS3 extends HttpTransport implements WalkTransport {
 		@Override
 		Collection<WalkRemoteObjectDatabase> getAlternates() throws IOException {
 			try {
-				return readAlternates(INFO_ALTERNATES);
+				return readAlternates(Constants.INFO_ALTERNATES);
 			} catch (FileNotFoundException err) {
 				// Fall through.
 			}

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

@@ -48,6 +48,8 @@ package org.eclipse.jgit.transport;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.eclipse.jgit.lib.Constants.HEAD;
+import static org.eclipse.jgit.lib.Constants.INFO_ALTERNATES;
+import static org.eclipse.jgit.lib.Constants.INFO_HTTP_ALTERNATES;
 import static org.eclipse.jgit.util.HttpSupport.ENCODING_GZIP;
 import static org.eclipse.jgit.util.HttpSupport.ENCODING_X_GZIP;
 import static org.eclipse.jgit.util.HttpSupport.HDR_ACCEPT;

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

@@ -43,7 +43,9 @@
 
 package org.eclipse.jgit.transport;
 
+import static org.eclipse.jgit.lib.Constants.INFO_ALTERNATES;
 import static org.eclipse.jgit.lib.Constants.LOCK_SUFFIX;
+import static org.eclipse.jgit.lib.Constants.OBJECTS;
 
 import java.io.BufferedReader;
 import java.io.FileNotFoundException;
@@ -172,7 +174,7 @@ public class TransportSftp extends SshTransport implements WalkTransport {
 			try {
 				ftp = newSftp();
 				ftp.cd(path);
-				ftp.cd("objects"); //$NON-NLS-1$
+				ftp.cd(OBJECTS);
 				objectsPath = ftp.pwd();
 			} catch (FtpChannel.FtpException f) {
 				throw new TransportException(MessageFormat.format(

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

@@ -82,10 +82,6 @@ abstract class WalkRemoteObjectDatabase {
 
 	static final String INFO_PACKS = "info/packs"; //$NON-NLS-1$
 
-	static final String INFO_ALTERNATES = "info/alternates"; //$NON-NLS-1$
-
-	static final String INFO_HTTP_ALTERNATES = "info/http-alternates"; //$NON-NLS-1$
-
 	static final String INFO_REFS = ROOT_DIR + Constants.INFO_REFS;
 
 	abstract URIish getURI();
@@ -107,8 +103,10 @@ abstract class WalkRemoteObjectDatabase {
 	/**
 	 * Obtain alternate connections to alternate object databases (if any).
 	 * <p>
-	 * Alternates are typically read from the file {@link #INFO_ALTERNATES} or
-	 * {@link #INFO_HTTP_ALTERNATES}. The content of each line must be resolved
+         * Alternates are typically read from the file
+         * {@link org.eclipse.jgit.lib.Constants#INFO_ALTERNATES} or
+         * {@link org.eclipse.jgit.lib.Constants#INFO_HTTP_ALTERNATES}.
+         * The content of each line must be resolved
 	 * by the implementation and a new database reference should be returned to
 	 * represent the additional location.
 	 * <p>