Remove unnecessary ObjectId.copy() calls

When RevObject overrode equals() to provide only reference equality
we used to need to convert a RevObject into an ObjectId by copy()
just to use standard Java tools like JUnit assertEquals(), or to
use contains() or get() on standard java.util collection types.

Now that we have removed this override and made ObjectId's equals()
final (preventing any of this mess in the future), some copy()
calls are unnecessary.  Anytime the value is being used as an input
to a lookup routine, or to an equals, we can avoid the copy().

However we still want to use copy() anytime we are given an ObjectId
that may exist long-term, where we don't want the high cost of the
additional storage from a RevCommit extension.  So we can't remove
all uses of copy(), just some of them.

Change-Id: Ief275dace435c0ddfa362ac8e5d93558bc7e9fc3
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

7 files changed, 10 insertions, 14 deletions

diff --git a/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/LocalDiskRepositoryTestCase.java b/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/LocalDiskRepositoryTestCase.java
index 47956e5127..d28c7edb50 100644
--- a/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/LocalDiskRepositoryTestCase.java
+++ b/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/LocalDiskRepositoryTestCase.java
@@ -409,10 +409,6 @@ public abstract class LocalDiskRepositoryTestCase extends TestCase {
 	}
 
 	protected static void assertEquals(AnyObjectId exp, AnyObjectId act) {
-		if (exp != null)
-			exp = exp.copy();
-		if (act != null)
-			act = act.copy();
 		Assert.assertEquals(exp, act);
 	}
 
diff --git a/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/TestRepository.java b/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/TestRepository.java
index afe1c0bc63..858fe64a6d 100644
--- a/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/TestRepository.java
+++ b/org.eclipse.jgit.junit/src/org/eclipse/jgit/junit/TestRepository.java
@@ -586,7 +586,7 @@ public class TestRepository<R extends Repository> {
 		md.update(Constants.encodeASCII(bin.length));
 		md.update((byte) 0);
 		md.update(bin);
-		Assert.assertEquals(id.copy(), ObjectId.fromRaw(md.digest()));
+		Assert.assertEquals(id, ObjectId.fromRaw(md.digest()));
 	}
 
 	/**
diff --git a/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Log.java b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Log.java
index fbc019fa24..d0ae22a216 100644
--- a/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Log.java
+++ b/org.eclipse.jgit.pgm/src/org/eclipse/jgit/pgm/Log.java
@@ -161,7 +161,7 @@ class Log extends RevWalkTextBuiltin {
 		out.print(" ");
 		c.getId().copyTo(outbuffer, out);
 		if (decorate) {
-			Collection<Ref> list = allRefsByPeeledObjectId.get(c.copy());
+			Collection<Ref> list = allRefsByPeeledObjectId.get(c);
 			if (list != null) {
 				out.print(" (");
 				for (Iterator<Ref> i = list.iterator(); i.hasNext(); ) {
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/RevObjectTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/RevObjectTest.java
index 2b24aa49ad..052d390033 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/RevObjectTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/RevObjectTest.java
@@ -60,8 +60,8 @@ public class RevObjectTest extends RevWalkTestCase {
 		assertTrue(a1.equals((Object) a1));
 		assertFalse(a1.equals(b1));
 
-		assertTrue(a1.equals(a1.copy()));
-		assertTrue(a1.equals((Object) a1.copy()));
+		assertTrue(a1.equals(a1));
+		assertTrue(a1.equals((Object) a1));
 		assertFalse(a1.equals(""));
 
 		final RevWalk rw2 = new RevWalk(db);
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/RefUpdateTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/RefUpdateTest.java
index 871700898f..a8a6d9d823 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/RefUpdateTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/RefUpdateTest.java
@@ -115,7 +115,7 @@ public class RefUpdateTest extends SampleDataRepositoryTestCase {
 		assertNotNull(r.getObjectId());
 		assertNotSame(newid, r.getObjectId());
 		assertSame(ObjectId.class, r.getObjectId().getClass());
-		assertEquals(newid.copy(), r.getObjectId());
+		assertEquals(newid, r.getObjectId());
 		List<org.eclipse.jgit.storage.file.ReflogReader.Entry> reverseEntries1 = db.getReflogReader("refs/heads/abc").getReverseEntries();
 		org.eclipse.jgit.storage.file.ReflogReader.Entry entry1 = reverseEntries1.get(0);
 		assertEquals(1, reverseEntries1.size());
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/ReceivePackRefFilterTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/ReceivePackRefFilterTest.java
index b331f9cf54..f89959c68c 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/ReceivePackRefFilterTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/ReceivePackRefFilterTest.java
@@ -102,7 +102,7 @@ public class ReceivePackRefFilterTest extends LocalDiskRepositoryTestCase {
 		Transport t = Transport.open(src, uriOf(dst));
 		try {
 			t.fetch(PM, Collections.singleton(new RefSpec("+refs/*:refs/*")));
-			assertEquals(B.copy(), src.resolve(R_MASTER));
+			assertEquals(B, src.resolve(R_MASTER));
 		} finally {
 			t.close();
 		}
@@ -154,7 +154,7 @@ public class ReceivePackRefFilterTest extends LocalDiskRepositoryTestCase {
 
 		Ref master = refs.get(R_MASTER);
 		assertNotNull("has master", master);
-		assertEquals(B.copy(), master.getObjectId());
+		assertEquals(B, master.getObjectId());
 	}
 
 	public void testSuccess() throws Exception {
@@ -219,7 +219,7 @@ public class ReceivePackRefFilterTest extends LocalDiskRepositoryTestCase {
 		assertNotNull("have result", r);
 		assertNull("private not advertised", r.getAdvertisedRef(R_PRIVATE));
 		assertSame("master updated", RemoteRefUpdate.Status.OK, u.getStatus());
-		assertEquals(N.copy(), dst.resolve(R_MASTER));
+		assertEquals(N, dst.resolve(R_MASTER));
 	}
 
 	public void testCreateBranchAtHiddenCommitFails() throws Exception {
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkFetchConnection.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkFetchConnection.java
index 237b4314c4..a669ac5cec 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkFetchConnection.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/WalkFetchConnection.java
@@ -317,7 +317,7 @@ class WalkFetchConnection extends BaseFetchConnection {
 		// If we had any prior errors fetching this object they are
 		// now resolved, as the object was parsed successfully.
 		//
-		fetchErrors.remove(id.copy());
+		fetchErrors.remove(id);
 	}
 
 	private void processBlob(final RevObject obj) throws TransportException {
@@ -461,7 +461,7 @@ class WalkFetchConnection extends BaseFetchConnection {
 
 			// We could not obtain the object. There may be reasons why.
 			//
-			List<Throwable> failures = fetchErrors.get(id.copy());
+			List<Throwable> failures = fetchErrors.get(id);
 			final TransportException te;
 
 			te = new TransportException(MessageFormat.format(JGitText.get().cannotGet, id.name()));