refactor: simplify collection.toArray()

On recent VMs, collection.toArray(new T[0]) is faster than
collection.toArray(new T[collection.size()]). Since it is also more
readable, it should now be the preferred way of collection to array
conversion.

https://shipilev.net/blog/2016/arrays-wisdom-ancients/

Change-Id: I80388532fb4b2b0663ee1fe8baa94f5df55c8442
Signed-off-by: Michael Keppler <Michael.Keppler@gmx.de>

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

@@ -77,7 +77,7 @@ abstract class SmartServiceInfoRefs implements Filter {
 
 	SmartServiceInfoRefs(String service, List<Filter> filters) {
 		this.svc = service;
-		this.filters = filters.toArray(new Filter[filters.size()]);
+		this.filters = filters.toArray(new Filter[0]);
 	}
 
 	/** {@inheritDoc} */

org.eclipse.jgit.http.server/src/org/eclipse/jgit/http/server/glue/ServletBinderImpl.java

@@ -98,7 +98,7 @@ protected HttpServlet getServlet() {
 	 * @return the configured filters; zero-length array if none.
 	 */
 	protected Filter[] getFilters() {
-		return filters.toArray(new Filter[filters.size()]);
+		return filters.toArray(new Filter[0]);
 	}
 
 	/** @return the pipeline that matches and executes this chain. */

org.eclipse.jgit.junit.http/src/org/eclipse/jgit/junit/http/AppServer.java

@@ -349,7 +349,7 @@ private void auth(ServletContextHandler ctx, Authenticator authType,
 		sec.setAuthenticator(authType);
 		sec.setLoginService(users);
 		sec.setConstraintMappings(
-				mappings.toArray(new ConstraintMapping[mappings.size()]));
+				mappings.toArray(new ConstraintMapping[0]));
 		sec.setHandler(ctx);
 
 		contexts.removeHandler(ctx);

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

@@ -201,7 +201,7 @@ private String remote() {
 
 	private Map<String, LfsPointer> requestBatchUpload(HttpConnection api,
 			Set<LfsPointer> toPush) throws IOException {
-		LfsPointer[] res = toPush.toArray(new LfsPointer[toPush.size()]);
+		LfsPointer[] res = toPush.toArray(new LfsPointer[0]);
 		Map<String, LfsPointer> oidStr2ptr = new HashMap<>();
 		for (LfsPointer p : res) {
 			oidStr2ptr.put(p.getOid().name(), p);

org.eclipse.jgit.pgm.test/src/org/eclipse/jgit/pgm/CLIGitCommand.java

@@ -230,7 +230,7 @@ else if (r.length() > 0) {
 		}
 		if (r.length() > 0)
 			list.add(r.toString());
-		return list.toArray(new String[list.size()]);
+		return list.toArray(new String[0]);
 	}
 
 	public static class Result {

org.eclipse.jgit.pgm.test/tst/org/eclipse/jgit/pgm/ArchiveTest.java

@@ -544,7 +544,7 @@ public void testArchiveWithLongFilename() throws Exception {
 
 		byte[] result = CLIGitCommand.executeRaw(
 				"git archive --format=zip HEAD", db).outBytes();
-		assertArrayEquals(l.toArray(new String[l.size()]),
+		assertArrayEquals(l.toArray(new String[0]),
 				listZipEntries(result));
 	}
 
@@ -564,7 +564,7 @@ public void testTarWithLongFilename() throws Exception {
 
 		byte[] result = CLIGitCommand.executeRaw(
 				"git archive --format=tar HEAD", db).outBytes();
-		assertArrayEquals(l.toArray(new String[l.size()]),
+		assertArrayEquals(l.toArray(new String[0]),
 				listTarEntries(result));
 	}
 
@@ -697,7 +697,7 @@ private static String[] listZipEntries(byte[] zipData) throws IOException {
 			while ((e = in.getNextEntry()) != null)
 				l.add(e.getName());
 		}
-		return l.toArray(new String[l.size()]);
+		return l.toArray(new String[0]);
 	}
 
 	private static Future<Object> writeAsync(OutputStream stream, byte[] data) {
@@ -730,7 +730,7 @@ private String[] listTarEntries(byte[] tarData) throws Exception {
 				while ((line = reader.readLine()) != null)
 					l.add(line);
 
-				return l.toArray(new String[l.size()]);
+				return l.toArray(new String[0]);
 			} finally {
 				writing.get();
 				proc.destroy();
@@ -754,7 +754,7 @@ private static String[] zipEntryContent(byte[] zipData, String path)
 			String line;
 			while ((line = reader.readLine()) != null)
 				l.add(line);
-			return l.toArray(new String[l.size()]);
+			return l.toArray(new String[0]);
 		}
 
 		// not found
@@ -774,7 +774,7 @@ private String[] tarEntryContent(byte[] tarData, String path)
 				while ((line = reader.readLine()) != null)
 					l.add(line);
 
-				return l.toArray(new String[l.size()]);
+				return l.toArray(new String[0]);
 			} finally {
 				writing.get();
 				proc.destroy();

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/CommandCatalog.java

@@ -114,7 +114,7 @@ public static CommandRef[] common() {
 	}
 
 	private static CommandRef[] toSortedArray(Collection<CommandRef> c) {
-		final CommandRef[] r = c.toArray(new CommandRef[c.size()]);
+		final CommandRef[] r = c.toArray(new CommandRef[0]);
 		Arrays.sort(r, new Comparator<CommandRef>() {
 			@Override
 			public int compare(CommandRef o1, CommandRef o2) {

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Describe.java

@@ -73,7 +73,7 @@ protected void run() throws Exception {
 			if (tree != null)
 				cmd.setTarget(tree);
 			cmd.setLong(longDesc);
-			cmd.setMatch(patterns.toArray(new String[patterns.size()]));
+			cmd.setMatch(patterns.toArray(new String[0]));
 			String result = null;
 			try {
 				result = cmd.call();

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Main.java

@@ -285,7 +285,7 @@ private void execute(String[] argv) throws Exception {
 		final TextBuiltin cmd = subcommand;
 		init(cmd);
 		try {
-			cmd.execute(arguments.toArray(new String[arguments.size()]));
+			cmd.execute(arguments.toArray(new String[0]));
 		} finally {
 			if (cmd.outw != null) {
 				cmd.outw.flush();

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Remote.java

@@ -130,7 +130,7 @@ protected void run() throws Exception {
 					fetchArgs.add(name);
 				}
 
-				fetch.execute(fetchArgs.toArray(new String[fetchArgs.size()]));
+				fetch.execute(fetchArgs.toArray(new String[0]));
 
 				// flush the streams
 				fetch.outw.flush();

org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/opt/CmdLineParser.java

@@ -177,7 +177,7 @@ public void parseArgument(String... args) throws CmdLineException {
 		}
 
 		try {
-			super.parseArgument(tmp.toArray(new String[tmp.size()]));
+			super.parseArgument(tmp.toArray(new String[0]));
 		} catch (Die e) {
 			if (!seenHelp) {
 				throw e;

org.eclipse.jgit.test/src/org/eclipse/jgit/events/ChangeRecorder.java

@@ -74,11 +74,11 @@ public void onWorkingTreeModified(WorkingTreeModifiedEvent event) {
 	}
 
 	private String[] getModified() {
-		return modified.toArray(new String[modified.size()]);
+		return modified.toArray(new String[0]);
 	}
 
 	private String[] getDeleted() {
-		return deleted.toArray(new String[deleted.size()]);
+		return deleted.toArray(new String[0]);
 	}
 
 	private void reset() {

org.eclipse.jgit.test/tst/org/eclipse/jgit/api/ReflogCommandTest.java

@@ -89,7 +89,7 @@ public void testHeadReflog() throws Exception {
 		Collection<ReflogEntry> reflog = git.reflog().call();
 		assertNotNull(reflog);
 		assertEquals(3, reflog.size());
-		ReflogEntry[] reflogs = reflog.toArray(new ReflogEntry[reflog.size()]);
+		ReflogEntry[] reflogs = reflog.toArray(new ReflogEntry[0]);
 		assertEquals(reflogs[2].getComment(),
 				"commit (initial): Initial commit");
 		assertEquals(reflogs[2].getNewId(), commit1.getId());
@@ -114,7 +114,7 @@ public void testBranchReflog() throws Exception {
 				.setRef(Constants.R_HEADS + "b1").call();
 		assertNotNull(reflog);
 		assertEquals(2, reflog.size());
-		ReflogEntry[] reflogs = reflog.toArray(new ReflogEntry[reflog.size()]);
+		ReflogEntry[] reflogs = reflog.toArray(new ReflogEntry[0]);
 		assertEquals(reflogs[0].getComment(), "commit: Removed file");
 		assertEquals(reflogs[0].getNewId(), commit2.getId());
 		assertEquals(reflogs[0].getOldId(), commit1.getId());
@@ -136,7 +136,7 @@ public void testAmendReflog() throws Exception {
 		Collection<ReflogEntry> reflog = git.reflog().call();
 		assertNotNull(reflog);
 		assertEquals(4, reflog.size());
-		ReflogEntry[] reflogs = reflog.toArray(new ReflogEntry[reflog.size()]);
+		ReflogEntry[] reflogs = reflog.toArray(new ReflogEntry[0]);
 		assertEquals(reflogs[3].getComment(),
 				"commit (initial): Initial commit");
 		assertEquals(reflogs[3].getNewId(), commit1.getId());

org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/filter/PathFilterGroupTest.java

@@ -231,8 +231,8 @@ private void assertMatches(Set<String> expect, TreeWalk tw)
 			}
 		}
 
-		String[] e = expect.toArray(new String[expect.size()]);
+		String[] e = expect.toArray(new String[0]);
-		String[] a = actual.toArray(new String[actual.size()]);
+		String[] a = actual.toArray(new String[0]);
 		Arrays.sort(e);
 		Arrays.sort(a);
 		assertArrayEquals(e, a);

org.eclipse.jgit/src/org/eclipse/jgit/dircache/DirCacheCheckout.java

@@ -513,7 +513,7 @@ private boolean doCheckout() throws CorruptObjectException, IOException,
 
 			if (!conflicts.isEmpty()) {
 				if (failOnConflict)
-					throw new CheckoutConflictException(conflicts.toArray(new String[conflicts.size()]));
+					throw new CheckoutConflictException(conflicts.toArray(new String[0]));
 				else
 					cleanUpConflicts();
 			}

org.eclipse.jgit/src/org/eclipse/jgit/internal/ketch/KetchLeader.java

@@ -274,8 +274,8 @@ public void setReplicas(Collection<KetchReplica> replicas) {
 
 		lock.lock();
 		try {
-			voters = v.toArray(new KetchReplica[v.size()]);
+			voters = v.toArray(new KetchReplica[0]);
-			followers = f.toArray(new KetchReplica[f.size()]);
+			followers = f.toArray(new KetchReplica[0]);
 			self = me;
 		} finally {
 			lock.unlock();

org.eclipse.jgit/src/org/eclipse/jgit/internal/ketch/LocalReplica.java

@@ -209,7 +209,7 @@ private void update(Repository git, ReplicaPushRequest req,
 		checkFailed(failed, accepted);
 		checkFailed(failed, committed);
 		if (!failed.isEmpty()) {
-			String[] arr = failed.toArray(new String[failed.size()]);
+			String[] arr = failed.toArray(new String[0]);
 			req.setRefs(refdb.exactRef(arr));
 		}
 	}

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

@@ -62,13 +62,13 @@ class LocalCachedPack extends CachedPack {
 
 	LocalCachedPack(ObjectDirectory odb, List<String> packNames) {
 		this.odb = odb;
-		this.packNames = packNames.toArray(new String[packNames.size()]);
+		this.packNames = packNames.toArray(new String[0]);
 	}
 
 	LocalCachedPack(List<PackFile> packs) {
 		odb = null;
 		packNames = null;
-		this.packs = packs.toArray(new PackFile[packs.size()]);
+		this.packs = packs.toArray(new PackFile[0]);
 	}
 
 	/** {@inheritDoc} */

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

@@ -938,7 +938,7 @@ private PackList scanPacksImpl(PackList old) {
 		if (list.isEmpty())
 			return new PackList(snapshot, NO_PACKS.packs);
 
-		final PackFile[] r = list.toArray(new PackFile[list.size()]);
+		final PackFile[] r = list.toArray(new PackFile[0]);
 		Arrays.sort(r, PackFile.SORT);
 		return new PackList(snapshot, r);
 	}
@@ -1030,7 +1030,7 @@ private AlternateHandle[] loadAlternates() throws IOException {
 				l.add(openAlternate(line));
 			}
 		}
-		return l.toArray(new AlternateHandle[l.size()]);
+		return l.toArray(new AlternateHandle[0]);
 	}
 
 	private static BufferedReader open(File f)

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

@@ -91,7 +91,7 @@ class BaseSearch {
 			List<ObjectToPack> edges, ObjectReader or) {
 		progress = countingMonitor;
 		reader = or;
-		baseTrees = bases.toArray(new ObjectId[bases.size()]);
+		baseTrees = bases.toArray(new ObjectId[0]);
 		objectsMap = objects;
 		edgeObjects = edges;
 

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

@@ -283,7 +283,7 @@ public File[] getAlternateObjectDirectories() {
 		final List<File> alts = alternateObjectDirectories;
 		if (alts == null)
 			return null;
-		return alts.toArray(new File[alts.size()]);
+		return alts.toArray(new File[0]);
 	}
 
 	/**

org.eclipse.jgit/src/org/eclipse/jgit/revplot/PlotWalk.java

@@ -177,7 +177,7 @@ private Ref[] getRefs(AnyObjectId commitId) {
 		if (list == null) {
 			return PlotCommit.NO_REFS;
 		} else {
-			Ref[] tags = list.toArray(new Ref[list.size()]);
+			Ref[] tags = list.toArray(new Ref[0]);
 			Arrays.sort(tags, new PlotRefComparator());
 			return tags;
 		}

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

@@ -155,7 +155,7 @@ public abstract boolean get(URIish uri, CredentialItem... items)
 	 */
 	public boolean get(URIish uri, List<CredentialItem> items)
 			throws UnsupportedCredentialItem {
-		return get(uri, items.toArray(new CredentialItem[items.size()]));
+		return get(uri, items.toArray(new CredentialItem[0]));
 	}
 
 	/**

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

@@ -524,7 +524,7 @@ public String[] getValues(String key) {
 			if (values == null || values.isEmpty()) {
 				return new String[0];
 			}
-			return values.toArray(new String[values.size()]);
+			return values.toArray(new String[0]);
 		}
 
 		public void setValue(String key, String value) {

org.eclipse.jgit/src/org/eclipse/jgit/util/FS_Win32.java

@@ -169,7 +169,7 @@ public FileVisitResult visitFileFailed(Path file,
 		if (result.isEmpty()) {
 			return NO_ENTRIES;
 		}
-		return result.toArray(new Entry[result.size()]);
+		return result.toArray(new Entry[0]);
 	}
 
 	/** {@inheritDoc} */