Add insert(TreeFormatter) to ObjectInserter

This makes usage of a TreeFormatter more similar to a CommitBuilder or
a TagBuilder: populate the formatter and pass to the ObjectInserter.

Change-Id: I5a45ef3a35cc73f4905a34bc6f6228510df8eb2c
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Reviewed-by: Chris Aniszczyk <caniszczyk@gmail.com>

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

@@ -338,7 +338,7 @@ ObjectId writeTree(final DirCacheEntry[] cache, int cIdx,
 				entryIdx++;
 			}
 
-			id = fmt.insert(ow);
+			id = ow.insert(fmt);
 		}
 		return id;
 	}

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

@@ -176,6 +176,22 @@ public ObjectId idFor(int objectType, long length, InputStream in)
 		return ObjectId.fromRaw(md.digest());
 	}
 
+	/**
+	 * Insert a single tree into the store, returning its unique name.
+	 *
+	 * @param formatter
+	 *            the formatter containing the proposed tree's data.
+	 * @return the name of the tree object.
+	 * @throws IOException
+	 *             the object could not be stored.
+	 */
+	public final ObjectId insert(TreeFormatter formatter) throws IOException {
+		// Delegate to the formatter, as then it can pass the raw internal
+		// buffer back to this inserter, avoiding unnecessary data copying.
+		//
+		return formatter.insertTo(this);
+	}
+
 	/**
 	 * Insert a single commit into the store, returning its unique name.
 	 *

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

@@ -279,7 +279,7 @@ private void fmtOverflowBuffer(byte[] nameBuf, int namePos, int nameLen,
 	 * @throws IOException
 	 *             the tree could not be stored.
 	 */
-	public ObjectId insert(ObjectInserter ins) throws IOException {
+	public ObjectId insertTo(ObjectInserter ins) throws IOException {
 		if (buf != null)
 			return ins.insert(OBJ_TREE, buf, 0, ptr);
 
@@ -293,7 +293,7 @@ public ObjectId insert(ObjectInserter ins) throws IOException {
 	 * This method is not efficient, as it needs to create a copy of the
 	 * internal buffer in order to supply an array of the correct size to the
 	 * caller. If the buffer is just to pass to an ObjectInserter, consider
-	 * using {@link #insert(ObjectInserter)} instead.
+	 * using {@link ObjectInserter#insert(TreeFormatter)} instead.
 	 *
 	 * @return a copy of this formatter's buffer.
 	 */

org.eclipse.jgit/src/org/eclipse/jgit/notes/FanoutBucket.java

@@ -254,7 +254,7 @@ ObjectId writeTree(ObjectInserter inserter) throws IOException {
 
 		for (; e != null; e = e.next)
 			e.format(fmt);
-		return fmt.insert(inserter);
+		return inserter.insert(fmt);
 	}
 
 	private int treeSize() {

org.eclipse.jgit/src/org/eclipse/jgit/notes/LeafBucket.java

@@ -190,7 +190,7 @@ ObjectId writeTree(ObjectInserter inserter) throws IOException {
 
 		for (; e != null; e = e.next)
 			e.format(fmt);
-		return fmt.insert(inserter);
+		return inserter.insert(fmt);
 	}
 
 	private int treeSize(final int nameLen) {