Merge "PackReverseIndexWriter: write out version 1 reverse index file"

2 files changed, 165 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/PackReverseIndexWriterTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/PackReverseIndexWriterTest.java
new file mode 100644
index 0000000000..220976471f
--- /dev/null
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/PackReverseIndexWriterTest.java
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2023, Google LLC and others
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Distribution License v. 1.0 which is available at
+ * https://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+package org.eclipse.jgit.internal.storage.file;
+
+import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
+
+import java.io.ByteArrayOutputStream;
+
+import org.junit.Test;
+
+public class PackReverseIndexWriterTest {
+
+	@Test
+	public void createWriter_defaultVersion() {
+		PackReverseIndexWriter version1 = PackReverseIndexWriter
+				.createWriter(new ByteArrayOutputStream());
+
+		assertTrue(version1 instanceof PackReverseIndexWriterV1);
+	}
+
+	@Test
+	public void createWriter_version1() {
+		PackReverseIndexWriter version1 = PackReverseIndexWriter
+				.createWriter(new ByteArrayOutputStream(), 1);
+
+		assertTrue(version1 instanceof PackReverseIndexWriterV1);
+	}
+
+	@Test
+	public void createWriter_unsupportedVersion() {
+		assertThrows(IllegalArgumentException.class,
+				() -> PackReverseIndexWriter
+						.createWriter(new ByteArrayOutputStream(), 2));
+	}
+}
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/PackReverseIndexWriterV1Test.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/PackReverseIndexWriterV1Test.java
new file mode 100644
index 0000000000..0124887af1
--- /dev/null
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/file/PackReverseIndexWriterV1Test.java
@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) 2023, Google LLC and others
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Distribution License v. 1.0 which is available at
+ * https://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+package org.eclipse.jgit.internal.storage.file;
+
+import static org.eclipse.jgit.lib.Constants.OBJECT_ID_STRING_LENGTH;
+import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
+import static org.eclipse.jgit.lib.Constants.OBJ_COMMIT;
+import static org.eclipse.jgit.lib.Constants.OBJ_TREE;
+import static org.junit.Assert.assertArrayEquals;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.transport.PackedObjectInfo;
+import org.junit.Test;
+
+public class PackReverseIndexWriterV1Test {
+
+	private static byte[] PACK_CHECKSUM = new byte[] { 'P', 'A', 'C', 'K', 'C',
+			'H', 'E', 'C', 'K', 'S', 'U', 'M', '3', '4', '5', '6', '7', '8',
+			'9', '0', };
+
+	@Test
+	public void write_noObjects() throws IOException {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		PackReverseIndexWriter writer = PackReverseIndexWriter.createWriter(out,
+				1);
+		List<PackedObjectInfo> objectsSortedByName = new ArrayList<>();
+
+		writer.write(objectsSortedByName, PACK_CHECKSUM);
+
+		byte[] expected = new byte[] { 'R', 'I', 'D', 'X', // magic
+				0x00, 0x00, 0x00, 0x01, // file version
+				0x00, 0x00, 0x00, 0x01, // oid version
+				// pack checksum to copy into at byte 12
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				// checksum
+				(byte) 0xd1, 0x1d, 0x17, (byte) 0xd5, (byte) 0xa1, 0x5c,
+				(byte) 0x8f, 0x45, 0x7e, 0x06, (byte) 0x91, (byte) 0xf2, 0x7e,
+				0x20, 0x35, 0x2c, (byte) 0xdc, 0x4c, 0x46, (byte) 0xe4, };
+		System.arraycopy(PACK_CHECKSUM, 0, expected, 12, PACK_CHECKSUM.length);
+		assertArrayEquals(expected, out.toByteArray());
+	}
+
+	@Test
+	public void write_oneObject() throws IOException {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		PackReverseIndexWriter writer = PackReverseIndexWriter.createWriter(out,
+				1);
+		PackedObjectInfo a = objectInfo("a", OBJ_COMMIT, 0);
+		List<PackedObjectInfo> objectsSortedByName = List.of(a);
+
+		writer.write(objectsSortedByName, PACK_CHECKSUM);
+
+		byte[] expected = new byte[] { 'R', 'I', 'D', 'X', // magic
+				0x00, 0x00, 0x00, 0x01, // file version
+				0x00, 0x00, 0x00, 0x01, // oid version
+				0x00, 0x00, 0x00, 0x00, // 0: "a" -> 0
+				// pack checksum to copy into at byte 16
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				// checksum
+				0x48, 0x04, 0x29, 0x69, 0x2f, (byte) 0xf3, (byte) 0x80,
+				(byte) 0xa1, (byte) 0xf5, (byte) 0x92, (byte) 0xc2, 0x21, 0x46,
+				(byte) 0xd5, 0x08, 0x44, (byte) 0xa4, (byte) 0xf4, (byte) 0xc0,
+				(byte) 0xec, };
+		System.arraycopy(PACK_CHECKSUM, 0, expected, 16, PACK_CHECKSUM.length);
+		assertArrayEquals(expected, out.toByteArray());
+	}
+
+	@Test
+	public void write_multipleObjects() throws IOException {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		PackReverseIndexWriter writer = PackReverseIndexWriter.createWriter(out,
+				1);
+		PackedObjectInfo a = objectInfo("a", OBJ_BLOB, 20);
+		PackedObjectInfo b = objectInfo("b", OBJ_COMMIT, 0);
+		PackedObjectInfo c = objectInfo("c", OBJ_COMMIT, 52);
+		PackedObjectInfo d = objectInfo("d", OBJ_TREE, 7);
+		PackedObjectInfo e = objectInfo("e", OBJ_COMMIT, 38);
+		List<PackedObjectInfo> objectsSortedByName = List.of(a, b, c, d, e);
+
+		writer.write(objectsSortedByName, PACK_CHECKSUM);
+
+		byte[] expected = new byte[] { 'R', 'I', 'D', 'X', // magic
+				0x00, 0x00, 0x00, 0x01, // file version
+				0x00, 0x00, 0x00, 0x01, // oid version
+				0x00, 0x00, 0x00, 0x01, // offset 0: "b" -> index @ 1
+				0x00, 0x00, 0x00, 0x03, // offset 7: "d" -> index @ 3
+				0x00, 0x00, 0x00, 0x00, // offset 20: "a" -> index @ 0
+				0x00, 0x00, 0x00, 0x04, // offset 38: "e" -> index @ 4
+				0x00, 0x00, 0x00, 0x02, // offset 52: "c" -> index @ 2
+				// pack checksum to copy into at byte 32
+				0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+				// checksum
+				(byte) 0xe3, 0x1c, (byte) 0xd3, (byte) 0xeb, (byte) 0x83, 0x47,
+				(byte) 0x80, (byte) 0xb1, (byte) 0xe0, 0x3c, 0x2b, 0x25,
+				(byte) 0xd6, 0x3e, (byte) 0xdc, (byte) 0xde, (byte) 0xbe, 0x4b,
+				0x0a, (byte) 0xe2, };
+		System.arraycopy(PACK_CHECKSUM, 0, expected, 32, PACK_CHECKSUM.length);
+		assertArrayEquals(expected, out.toByteArray());
+	}
+
+	private static PackedObjectInfo objectInfo(String objectId, int type,
+			long offset) {
+		assert (objectId.length() == 1);
+		PackedObjectInfo objectInfo = new PackedObjectInfo(
+				ObjectId.fromString(objectId.repeat(OBJECT_ID_STRING_LENGTH)));
+		objectInfo.setType(type);
+		objectInfo.setOffset(offset);
+		return objectInfo;
+	}
+}