1 files changed, 61 insertions, 8 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackBitmapIndex.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackBitmapIndex.java
index beb51dc2eb..2334bd4851 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackBitmapIndex.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackBitmapIndex.java
@@ -14,6 +14,7 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.text.MessageFormat;
+import java.util.function.Supplier;
 
 import org.eclipse.jgit.errors.CorruptObjectException;
 import org.eclipse.jgit.internal.JGitText;
@@ -57,11 +58,10 @@ public abstract class PackBitmapIndex {
 	 * @throws CorruptObjectException
 	 *             the stream does not contain a valid pack bitmap index.
 	 */
-	public static PackBitmapIndex open(
-			File idxFile, PackIndex packIndex, PackReverseIndex reverseIndex)
+	public static PackBitmapIndex open(File idxFile, PackIndex packIndex,
+			PackReverseIndex reverseIndex)
 			throws IOException {
-		try (SilentFileInputStream fd = new SilentFileInputStream(
-				idxFile)) {
+		try (SilentFileInputStream fd = new SilentFileInputStream(idxFile)) {
 			try {
 				return read(fd, packIndex, reverseIndex);
 			} catch (IOException ioe) {
@@ -94,12 +94,44 @@ public abstract class PackBitmapIndex {
 	 * @throws CorruptObjectException
 	 *             the stream does not contain a valid pack bitmap index.
 	 */
-	public static PackBitmapIndex read(
-			InputStream fd, PackIndex packIndex, PackReverseIndex reverseIndex)
-			throws IOException {
+	public static PackBitmapIndex read(InputStream fd, PackIndex packIndex,
+			PackReverseIndex reverseIndex) throws IOException {
 		return new PackBitmapIndexV1(fd, packIndex, reverseIndex);
 	}
 
+	/**
+	 * Read an existing pack bitmap index file from a buffered stream.
+	 * <p>
+	 * The format of the file will be automatically detected and a proper access
+	 * implementation for that format will be constructed and returned to the
+	 * caller. The file may or may not be held open by the returned instance.
+	 *
+	 * @param fd
+	 *            stream to read the bitmap index file from. The stream must be
+	 *            buffered as some small IOs are performed against the stream.
+	 *            The caller is responsible for closing the stream.
+	 * @param packIndexSupplier
+	 *            the supplier for pack index for the corresponding pack file.
+	 * @param reverseIndexSupplier
+	 *            the supplier for pack reverse index for the corresponding pack
+	 *            file.
+	 * @param loadParallelRevIndex
+	 *            whether reverse index should be loaded in parallel
+	 * @return a copy of the index in-memory.
+	 * @throws java.io.IOException
+	 *             the stream cannot be read.
+	 * @throws CorruptObjectException
+	 *             the stream does not contain a valid pack bitmap index.
+	 */
+	public static PackBitmapIndex read(InputStream fd,
+			SupplierWithIOException<PackIndex> packIndexSupplier,
+			SupplierWithIOException<PackReverseIndex> reverseIndexSupplier,
+			boolean loadParallelRevIndex)
+			throws IOException {
+		return new PackBitmapIndexV1(fd, packIndexSupplier,
+				reverseIndexSupplier, loadParallelRevIndex);
+	}
+
 	/** Footer checksum applied on the bottom of the pack file. */
 	byte[] packChecksum;
 
@@ -121,7 +153,8 @@ public abstract class PackBitmapIndex {
 	 * @throws java.lang.IllegalArgumentException
 	 *             when the item is not found.
 	 */
-	public abstract ObjectId getObject(int position) throws IllegalArgumentException;
+	public abstract ObjectId getObject(int position)
+			throws IllegalArgumentException;
 
 	/**
 	 * Returns a bitmap containing positions for objects that have the given Git
@@ -161,4 +194,24 @@ public abstract class PackBitmapIndex {
 	 * @return the number of bitmaps in this bitmap index.
 	 */
 	public abstract int getBitmapCount();
+
+	/**
+	 * Supplier that propagates IOException.
+	 *
+	 * @param <T>
+	 *            the return type which is expected from {@link #get()}
+	 */
+	@FunctionalInterface
+	public interface SupplierWithIOException<T> {
+		/**
+		 * Get result.
+		 *
+		 * @see Supplier#get()
+		 *
+		 * @return result
+		 * @throws IOException
+		 *             if an IO error occurred
+		 */
+		T get() throws IOException;
+	}
 }