Delete deprecated ObjectWriter

ObjectWriter is a deprecated API that people shouldn't be using.
So get rid of it in favor of the ObjectInserter API.

Change-Id: I6218bcb26b6b9ffb64e3e470dba5dca2e0a62fd4
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

9 files changed, 124 insertions, 72 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/IndexDiffTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/IndexDiffTest.java
index c439baccf6..3d19576758 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/IndexDiffTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/IndexDiffTest.java
@@ -56,7 +56,7 @@ public class IndexDiffTest extends RepositoryTestCase {
 		writeTrashFile("file1", "file1");
 		writeTrashFile("dir/subfile", "dir/subfile");
 		Tree tree = new Tree(db);
-		tree.setId(new ObjectWriter(db).writeTree(tree));
+		tree.setId(insertTree(tree));
 
 		index.add(trash, new File(trash, "file1"));
 		index.add(trash, new File(trash, "dir/subfile"));
@@ -83,8 +83,8 @@ public class IndexDiffTest extends RepositoryTestCase {
 		tree.findBlobMember("file2").setId(ObjectId.fromString("30d67d4672d5c05833b7192cc77a79eaafb5c7ad"));
 		Tree tree2 = (Tree) tree.findTreeMember("dir");
 		tree2.findBlobMember("file3").setId(ObjectId.fromString("873fb8d667d05436d728c52b1d7a09528e6eb59b"));
-		tree2.setId(new ObjectWriter(db).writeTree(tree2));
-		tree.setId(new ObjectWriter(db).writeTree(tree));
+		tree2.setId(insertTree(tree2));
+		tree.setId(insertTree(tree));
 
 		FileTreeIterator iterator = new FileTreeIterator(db);
 		IndexDiff diff = new IndexDiff(db, tree.getId(), iterator);
@@ -113,8 +113,8 @@ public class IndexDiffTest extends RepositoryTestCase {
 		assertEquals(2, tree.memberCount());
 
 		Tree tree2 = (Tree) tree.findTreeMember("dir");
-		tree2.setId(new ObjectWriter(db).writeTree(tree2));
-		tree.setId(new ObjectWriter(db).writeTree(tree));
+		tree2.setId(insertTree(tree2));
+		tree.setId(insertTree(tree));
 		FileTreeIterator iterator = new FileTreeIterator(db);
 		IndexDiff diff = new IndexDiff(db, tree.getId(), iterator);
 		diff.diff();
@@ -144,7 +144,7 @@ public class IndexDiffTest extends RepositoryTestCase {
 		tree.addFile("a=c").setId(ObjectId.fromString("06022365ddbd7fb126761319633bf73517770714"));
 		tree.addFile("a=d").setId(ObjectId.fromString("fa6414df3da87840700e9eeb7fc261dd77ccd5c2"));
 
-		tree.setId(new ObjectWriter(db).writeTree(tree));
+		tree.setId(insertTree(tree));
 
 		FileTreeIterator iterator = new FileTreeIterator(db);
 		IndexDiff diff = new IndexDiff(db, tree.getId(), iterator);
@@ -185,10 +185,10 @@ public class IndexDiffTest extends RepositoryTestCase {
 		tree.addFile("a=d").setId(ObjectId.fromString("fa6414df3da87840700e9eeb7fc261dd77ccd5c2"));
 
 		Tree tree3 = (Tree) tree.findTreeMember("a/b.b");
-		tree3.setId(new ObjectWriter(db).writeTree(tree3));
+		tree3.setId(insertTree(tree3));
 		Tree tree2 = (Tree) tree.findTreeMember("a");
-		tree2.setId(new ObjectWriter(db).writeTree(tree2));
-		tree.setId(new ObjectWriter(db).writeTree(tree));
+		tree2.setId(insertTree(tree2));
+		tree.setId(insertTree(tree));
 
 		FileTreeIterator iterator = new FileTreeIterator(db);
 		IndexDiff diff = new IndexDiff(db, tree.getId(), iterator);
@@ -199,4 +199,15 @@ public class IndexDiffTest extends RepositoryTestCase {
 		assertEquals(0, diff.getMissing().size());
 		assertEquals(0, diff.getModified().size());
 	}
+
+	private ObjectId insertTree(Tree tree) throws IOException {
+		ObjectInserter oi = db.newObjectInserter();
+		try {
+			ObjectId id = oi.insert(Constants.OBJ_TREE, tree.format());
+			oi.flush();
+			return id;
+		} finally {
+			oi.release();
+		}
+	}
 }
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ReadTreeTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ReadTreeTest.java
index fe2d0b248c..f2bb66fd30 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ReadTreeTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ReadTreeTest.java
@@ -110,21 +110,25 @@ public abstract class ReadTreeTest extends RepositoryTestCase {
 
 	private Tree buildTree(HashMap<String, String> headEntries) throws IOException {
 		Tree tree = new Tree(db);
-		ObjectWriter ow = new ObjectWriter(db);
 		if (headEntries == null)
 			return tree;
 		FileTreeEntry fileEntry;
 		Tree parent;
-		for (java.util.Map.Entry<String, String> e : headEntries.entrySet()) {
-			fileEntry = tree.addFile(e.getKey());
-			fileEntry.setId(genSha1(e.getValue()));
-			parent = fileEntry.getParent();
-			while (parent != null) {
-				parent.setId(ow.writeTree(parent));
-				parent = parent.getParent();
+		ObjectInserter oi = db.newObjectInserter();
+		try {
+			for (java.util.Map.Entry<String, String> e : headEntries.entrySet()) {
+				fileEntry = tree.addFile(e.getKey());
+				fileEntry.setId(genSha1(e.getValue()));
+				parent = fileEntry.getParent();
+				while (parent != null) {
+					parent.setId(oi.insert(Constants.OBJ_TREE, parent.format()));
+					parent = parent.getParent();
+				}
 			}
+			oi.flush();
+		} finally {
+			oi.release();
 		}
-
 		return tree;
 	}
 
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ReflogConfigTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ReflogConfigTest.java
index ebe2db111d..92c4b9cc04 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ReflogConfigTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ReflogConfigTest.java
@@ -109,8 +109,13 @@ public class ReflogConfigTest extends RepositoryTestCase {
 		commit.setCommitter(committer);
 		commit.setMessage(commitMsg);
 		commit.setTreeId(t.getTreeId());
-		ObjectWriter writer = new ObjectWriter(db);
-		commit.setCommitId(writer.writeCommit(commit));
+		ObjectInserter inserter = db.newObjectInserter();
+		try {
+			inserter.insert(commit);
+			inserter.flush();
+		} finally {
+			inserter.release();
+		}
 
 		int nl = commitMsg.indexOf('\n');
 		final RefUpdate ru = db.updateRef(Constants.HEAD);
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/ObjectWalkTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/ObjectWalkTest.java
index 0ff4d512e8..840bee8466 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/ObjectWalkTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/ObjectWalkTest.java
@@ -43,9 +43,10 @@
 
 package org.eclipse.jgit.revwalk;
 
+import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.FileTreeEntry;
 import org.eclipse.jgit.lib.ObjectId;
-import org.eclipse.jgit.lib.ObjectWriter;
+import org.eclipse.jgit.lib.ObjectInserter;
 import org.eclipse.jgit.lib.Tree;
 
 public class ObjectWalkTest extends RevWalkTestCase {
@@ -214,11 +215,16 @@ public class ObjectWalkTest extends RevWalkTestCase {
 			Tree A_A = A.addTree("A");
 			Tree A_B = A.addTree("B");
 
-			final ObjectWriter ow = new ObjectWriter(db);
-			A_A.setId(ow.writeTree(A_A));
-			A_B.setId(ow.writeTree(A_B));
-			A.setId(ow.writeTree(A));
-			root.setId(ow.writeTree(root));
+			final ObjectInserter inserter = db.newObjectInserter();
+			try {
+				A_A.setId(inserter.insert(Constants.OBJ_TREE, A_A.format()));
+				A_B.setId(inserter.insert(Constants.OBJ_TREE, A_B.format()));
+				A.setId(inserter.insert(Constants.OBJ_TREE, A.format()));
+				root.setId(inserter.insert(Constants.OBJ_TREE, root.format()));
+				inserter.flush();
+			} finally {
+				inserter.release();
+			}
 
 			tree_root = rw.parseTree(root.getId());
 			tree_A = rw.parseTree(A.getId());
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/ConcurrentRepackTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/ConcurrentRepackTest.java
index c8f2aad759..7608a51f22 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/ConcurrentRepackTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/ConcurrentRepackTest.java
@@ -57,8 +57,8 @@ import org.eclipse.jgit.lib.AnyObjectId;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.NullProgressMonitor;
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.ObjectInserter;
 import org.eclipse.jgit.lib.ObjectLoader;
-import org.eclipse.jgit.lib.ObjectWriter;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.lib.RepositoryTestCase;
 import org.eclipse.jgit.revwalk.RevObject;
@@ -265,8 +265,14 @@ public class ConcurrentRepackTest extends RepositoryTestCase {
 			throws IOException {
 		final RevWalk revWalk = new RevWalk(repo);
 		final byte[] bytes = Constants.encode(data);
-		final ObjectWriter ow = new ObjectWriter(repo);
-		final ObjectId id = ow.writeBlob(bytes);
+		final ObjectInserter inserter = repo.newObjectInserter();
+		final ObjectId id;
+		try {
+			id = inserter.insert(Constants.OBJ_BLOB, bytes);
+			inserter.flush();
+		} finally {
+			inserter.release();
+		}
 		try {
 			parse(id);
 			fail("Object " + id.name() + " should not exist in test repository");
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/T0003_Basic.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/T0003_Basic.java
index 0352a40bfd..baa35f274b 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/T0003_Basic.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/storage/file/T0003_Basic.java
@@ -46,7 +46,6 @@
 
 package org.eclipse.jgit.storage.file;
 
-import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileReader;
@@ -67,7 +66,6 @@ import org.eclipse.jgit.lib.FileTreeEntry;
 import org.eclipse.jgit.lib.ObjectDatabase;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectInserter;
-import org.eclipse.jgit.lib.ObjectWriter;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.RefUpdate;
 import org.eclipse.jgit.lib.Repository;
@@ -294,7 +292,7 @@ public class T0003_Basic extends SampleDataRepositoryTestCase {
 
 	public void test003_WriteShouldBeEmptyTree() throws IOException {
 		final Tree t = new Tree(db);
-		final ObjectId emptyId = new ObjectWriter(db).writeBlob(new byte[0]);
+		final ObjectId emptyId = insertEmptyBlob();
 		t.addFile("should-be-empty").setId(emptyId);
 		t.accept(new WriteTree(trash, db), TreeEntry.MODIFIED_ONLY);
 		assertEquals("7bb943559a305bdd6bdee2cef6e5df2413c3d30a", t.getId()
@@ -419,7 +417,7 @@ public class T0003_Basic extends SampleDataRepositoryTestCase {
 	}
 
 	public void test012_SubtreeExternalSorting() throws IOException {
-		final ObjectId emptyBlob = new ObjectWriter(db).writeBlob(new byte[0]);
+		final ObjectId emptyBlob = insertEmptyBlob();
 		final Tree t = new Tree(db);
 		final FileTreeEntry e0 = t.addFile("a-");
 		final FileTreeEntry e1 = t.addFile("a-b");
@@ -439,7 +437,7 @@ public class T0003_Basic extends SampleDataRepositoryTestCase {
 	}
 
 	public void test020_createBlobTag() throws IOException {
-		final ObjectId emptyId = new ObjectWriter(db).writeBlob(new byte[0]);
+		final ObjectId emptyId = insertEmptyBlob();
 		final TagBuilder t = new TagBuilder();
 		t.setObjectId(emptyId, Constants.OBJ_BLOB);
 		t.setTag("test020");
@@ -456,10 +454,10 @@ public class T0003_Basic extends SampleDataRepositoryTestCase {
 	}
 
 	public void test021_createTreeTag() throws IOException {
-		final ObjectId emptyId = new ObjectWriter(db).writeBlob(new byte[0]);
+		final ObjectId emptyId = insertEmptyBlob();
 		final Tree almostEmptyTree = new Tree(db);
 		almostEmptyTree.addEntry(new FileTreeEntry(almostEmptyTree, emptyId, "empty".getBytes(), false));
-		final ObjectId almostEmptyTreeId = new ObjectWriter(db).writeTree(almostEmptyTree);
+		final ObjectId almostEmptyTreeId = insertTree(almostEmptyTree);
 		final TagBuilder t = new TagBuilder();
 		t.setObjectId(almostEmptyTreeId, Constants.OBJ_TREE);
 		t.setTag("test021");
@@ -476,10 +474,10 @@ public class T0003_Basic extends SampleDataRepositoryTestCase {
 	}
 
 	public void test022_createCommitTag() throws IOException {
-		final ObjectId emptyId = new ObjectWriter(db).writeBlob(new byte[0]);
+		final ObjectId emptyId = insertEmptyBlob();
 		final Tree almostEmptyTree = new Tree(db);
 		almostEmptyTree.addEntry(new FileTreeEntry(almostEmptyTree, emptyId, "empty".getBytes(), false));
-		final ObjectId almostEmptyTreeId = new ObjectWriter(db).writeTree(almostEmptyTree);
+		final ObjectId almostEmptyTreeId = insertTree(almostEmptyTree);
 		final CommitBuilder almostEmptyCommit = new CommitBuilder();
 		almostEmptyCommit.setAuthor(new PersonIdent(author, 1154236443000L, -2 * 60)); // not exactly the same
 		almostEmptyCommit.setCommitter(new PersonIdent(author, 1154236443000L, -2 * 60));
@@ -502,10 +500,10 @@ public class T0003_Basic extends SampleDataRepositoryTestCase {
 	}
 
 	public void test023_createCommitNonAnullii() throws IOException {
-		final ObjectId emptyId = new ObjectWriter(db).writeBlob(new byte[0]);
+		final ObjectId emptyId = insertEmptyBlob();
 		final Tree almostEmptyTree = new Tree(db);
 		almostEmptyTree.addEntry(new FileTreeEntry(almostEmptyTree, emptyId, "empty".getBytes(), false));
-		final ObjectId almostEmptyTreeId = new ObjectWriter(db).writeTree(almostEmptyTree);
+		final ObjectId almostEmptyTreeId = insertTree(almostEmptyTree);
 		CommitBuilder commit = new CommitBuilder();
 		commit.setTreeId(almostEmptyTreeId);
 		commit.setAuthor(new PersonIdent("Joe H\u00e4cker","joe@example.com",4294967295000L,60));
@@ -520,10 +518,10 @@ public class T0003_Basic extends SampleDataRepositoryTestCase {
 	}
 
 	public void test024_createCommitNonAscii() throws IOException {
-		final ObjectId emptyId = new ObjectWriter(db).writeBlob(new byte[0]);
+		final ObjectId emptyId = insertEmptyBlob();
 		final Tree almostEmptyTree = new Tree(db);
 		almostEmptyTree.addEntry(new FileTreeEntry(almostEmptyTree, emptyId, "empty".getBytes(), false));
-		final ObjectId almostEmptyTreeId = new ObjectWriter(db).writeTree(almostEmptyTree);
+		final ObjectId almostEmptyTreeId = insertTree(almostEmptyTree);
 		CommitBuilder commit = new CommitBuilder();
 		commit.setTreeId(almostEmptyTreeId);
 		commit.setAuthor(new PersonIdent("Joe H\u00e4cker","joe@example.com",4294967295000L,60));
@@ -537,9 +535,8 @@ public class T0003_Basic extends SampleDataRepositoryTestCase {
 	public void test025_computeSha1NoStore() throws IOException {
 		byte[] data = "test025 some data, more than 16 bytes to get good coverage"
 				.getBytes("ISO-8859-1");
-		// TODO: but we do not test legacy header writing
-		final ObjectId id = new ObjectWriter(db).computeBlobSha1(data.length,
-				new ByteArrayInputStream(data));
+		final ObjectId id = new ObjectInserter.Formatter().idFor(
+				Constants.OBJ_BLOB, data);
 		assertEquals("4f561df5ecf0dfbd53a0dc0f37262fef075d9dde", id.name());
 	}
 
@@ -693,6 +690,29 @@ public class T0003_Basic extends SampleDataRepositoryTestCase {
 
 	}
 
+	private ObjectId insertEmptyBlob() throws IOException {
+		final ObjectId emptyId;
+		ObjectInserter oi = db.newObjectInserter();
+		try {
+			emptyId = oi.insert(Constants.OBJ_BLOB, new byte[] {});
+			oi.flush();
+		} finally {
+			oi.release();
+		}
+		return emptyId;
+	}
+
+	private ObjectId insertTree(Tree tree) throws IOException {
+		ObjectInserter oi = db.newObjectInserter();
+		try {
+			ObjectId id = oi.insert(Constants.OBJ_TREE, tree.format());
+			oi.flush();
+			return id;
+		} finally {
+			oi.release();
+		}
+	}
+
 	private ObjectId insertCommit(final CommitBuilder builder) throws IOException,
 			UnsupportedEncodingException {
 		ObjectInserter oi = db.newObjectInserter();
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/NameConflictTreeWalkTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/NameConflictTreeWalkTest.java
index e59b7c18d3..7e3dea6714 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/NameConflictTreeWalkTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/NameConflictTreeWalkTest.java
@@ -43,15 +43,13 @@
 
 package org.eclipse.jgit.treewalk;
 
-import java.io.ByteArrayInputStream;
-
 import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheBuilder;
 import org.eclipse.jgit.dircache.DirCacheEntry;
 import org.eclipse.jgit.dircache.DirCacheIterator;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.FileMode;
-import org.eclipse.jgit.lib.ObjectWriter;
+import org.eclipse.jgit.lib.ObjectInserter;
 import org.eclipse.jgit.lib.RepositoryTestCase;
 
 public class NameConflictTreeWalkTest extends RepositoryTestCase {
@@ -248,11 +246,10 @@ public class NameConflictTreeWalkTest extends RepositoryTestCase {
 
 	private DirCacheEntry makeEntry(final String path, final FileMode mode)
 			throws Exception {
-		final byte[] pathBytes = Constants.encode(path);
 		final DirCacheEntry ent = new DirCacheEntry(path);
 		ent.setFileMode(mode);
-		ent.setObjectId(new ObjectWriter(db).computeBlobSha1(pathBytes.length,
-				new ByteArrayInputStream(pathBytes)));
+		ent.setObjectId(new ObjectInserter.Formatter().idFor(
+				Constants.OBJ_BLOB, Constants.encode(path)));
 		return ent;
 	}
 
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/PostOrderTreeWalkTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/PostOrderTreeWalkTest.java
index 274df5bec0..8f813a806b 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/PostOrderTreeWalkTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/PostOrderTreeWalkTest.java
@@ -43,7 +43,8 @@
 
 package org.eclipse.jgit.treewalk;
 
-import java.io.ByteArrayInputStream;
+import static org.eclipse.jgit.lib.FileMode.REGULAR_FILE;
+import static org.eclipse.jgit.lib.FileMode.TREE;
 
 import org.eclipse.jgit.dircache.DirCache;
 import org.eclipse.jgit.dircache.DirCacheBuilder;
@@ -51,12 +52,9 @@ import org.eclipse.jgit.dircache.DirCacheEntry;
 import org.eclipse.jgit.dircache.DirCacheIterator;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.FileMode;
-import org.eclipse.jgit.lib.ObjectWriter;
+import org.eclipse.jgit.lib.ObjectInserter;
 import org.eclipse.jgit.lib.RepositoryTestCase;
 
-import static org.eclipse.jgit.lib.FileMode.REGULAR_FILE;
-import static org.eclipse.jgit.lib.FileMode.TREE;
-
 public class PostOrderTreeWalkTest extends RepositoryTestCase {
 	public void testInitialize_NoPostOrder() throws Exception {
 		final TreeWalk tw = new TreeWalk(db);
@@ -178,11 +176,10 @@ public class PostOrderTreeWalkTest extends RepositoryTestCase {
 	}
 
 	private DirCacheEntry makeFile(final String path) throws Exception {
-		final byte[] pathBytes = Constants.encode(path);
 		final DirCacheEntry ent = new DirCacheEntry(path);
 		ent.setFileMode(REGULAR_FILE);
-		ent.setObjectId(new ObjectWriter(db).computeBlobSha1(pathBytes.length,
-				new ByteArrayInputStream(pathBytes)));
+		ent.setObjectId(new ObjectInserter.Formatter().idFor(
+				Constants.OBJ_BLOB, Constants.encode(path)));
 		return ent;
 	}
 
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/TreeWalkBasicDiffTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/TreeWalkBasicDiffTest.java
index 581683e34f..e0957401c5 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/TreeWalkBasicDiffTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/treewalk/TreeWalkBasicDiffTest.java
@@ -43,9 +43,13 @@
 
 package org.eclipse.jgit.treewalk;
 
+import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
+import static org.eclipse.jgit.lib.Constants.OBJ_TREE;
+import static org.eclipse.jgit.lib.Constants.encode;
+
 import org.eclipse.jgit.lib.FileMode;
 import org.eclipse.jgit.lib.ObjectId;
-import org.eclipse.jgit.lib.ObjectWriter;
+import org.eclipse.jgit.lib.ObjectInserter;
 import org.eclipse.jgit.lib.RepositoryTestCase;
 import org.eclipse.jgit.lib.Tree;
 import org.eclipse.jgit.treewalk.filter.TreeFilter;
@@ -53,11 +57,11 @@ import org.eclipse.jgit.treewalk.filter.TreeFilter;
 public class TreeWalkBasicDiffTest extends RepositoryTestCase {
 	public void testMissingSubtree_DetectFileAdded_FileModified()
 			throws Exception {
-		final ObjectWriter ow = new ObjectWriter(db);
-		final ObjectId aFileId = ow.writeBlob("a".getBytes());
-		final ObjectId bFileId = ow.writeBlob("b".getBytes());
-		final ObjectId cFileId1 = ow.writeBlob("c-1".getBytes());
-		final ObjectId cFileId2 = ow.writeBlob("c-2".getBytes());
+		final ObjectInserter inserter = db.newObjectInserter();
+		final ObjectId aFileId = inserter.insert(OBJ_BLOB, encode("a"));
+		final ObjectId bFileId = inserter.insert(OBJ_BLOB, encode("b"));
+		final ObjectId cFileId1 = inserter.insert(OBJ_BLOB, encode("c-1"));
+		final ObjectId cFileId2 = inserter.insert(OBJ_BLOB, encode("c-2"));
 
 		// Create sub-a/empty, sub-c/empty = hello.
 		final ObjectId oldTree;
@@ -66,14 +70,14 @@ public class TreeWalkBasicDiffTest extends RepositoryTestCase {
 			{
 				final Tree subA = root.addTree("sub-a");
 				subA.addFile("empty").setId(aFileId);
-				subA.setId(ow.writeTree(subA));
+				subA.setId(inserter.insert(OBJ_TREE, subA.format()));
 			}
 			{
 				final Tree subC = root.addTree("sub-c");
 				subC.addFile("empty").setId(cFileId1);
-				subC.setId(ow.writeTree(subC));
+				subC.setId(inserter.insert(OBJ_TREE, subC.format()));
 			}
-			oldTree = ow.writeTree(root);
+			oldTree = inserter.insert(OBJ_TREE, root.format());
 		}
 
 		// Create sub-a/empty, sub-b/empty, sub-c/empty.
@@ -83,20 +87,22 @@ public class TreeWalkBasicDiffTest extends RepositoryTestCase {
 			{
 				final Tree subA = root.addTree("sub-a");
 				subA.addFile("empty").setId(aFileId);
-				subA.setId(ow.writeTree(subA));
+				subA.setId(inserter.insert(OBJ_TREE, subA.format()));
 			}
 			{
 				final Tree subB = root.addTree("sub-b");
 				subB.addFile("empty").setId(bFileId);
-				subB.setId(ow.writeTree(subB));
+				subB.setId(inserter.insert(OBJ_TREE, subB.format()));
 			}
 			{
 				final Tree subC = root.addTree("sub-c");
 				subC.addFile("empty").setId(cFileId2);
-				subC.setId(ow.writeTree(subC));
+				subC.setId(inserter.insert(OBJ_TREE, subC.format()));
 			}
-			newTree = ow.writeTree(root);
+			newTree = inserter.insert(OBJ_TREE, root.format());
 		}
+		inserter.flush();
+		inserter.release();
 
 		final TreeWalk tw = new TreeWalk(db);
 		tw.reset(new ObjectId[] { oldTree, newTree });