Merge "ReftableCompactor should accept 0 for minUpdateIndex"
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/ReftableCompactorTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/ReftableCompactorTest.java
new file mode 100644
index 0000000..73b7999
--- /dev/null
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/ReftableCompactorTest.java
@@ -0,0 +1,326 @@
+/*
+ * Copyright (C) 2017, Google Inc.
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.eclipse.jgit.internal.storage.reftable;
+
+import static org.eclipse.jgit.lib.Constants.OBJECT_ID_LENGTH;
+import static org.eclipse.jgit.lib.Ref.Storage.NEW;
+import static org.eclipse.jgit.lib.Ref.Storage.PACKED;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.Arrays;
+
+import org.eclipse.jgit.internal.storage.io.BlockSource;
+import org.eclipse.jgit.internal.storage.reftable.ReftableWriter.Stats;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.ObjectIdRef;
+import org.eclipse.jgit.lib.Ref;
+import org.junit.Test;
+
+public class ReftableCompactorTest {
+	private static final String MASTER = "refs/heads/master";
+	private static final String NEXT = "refs/heads/next";
+
+	@Test
+	public void noTables() throws IOException {
+		ReftableCompactor compactor = new ReftableCompactor();
+		try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
+			compactor.compact(out);
+		}
+		Stats stats = compactor.getStats();
+		assertEquals(0, stats.minUpdateIndex());
+		assertEquals(0, stats.maxUpdateIndex());
+		assertEquals(0, stats.refCount());
+	}
+
+	@Test
+	public void oneTable() throws IOException {
+		byte[] inTab;
+		try (ByteArrayOutputStream inBuf = new ByteArrayOutputStream()) {
+			ReftableWriter writer = new ReftableWriter()
+				.setMinUpdateIndex(0)
+				.setMaxUpdateIndex(0)
+				.begin(inBuf);
+
+			writer.writeRef(ref(MASTER, 1));
+			writer.finish();
+			inTab = inBuf.toByteArray();
+		}
+
+		byte[] outTab;
+		ReftableCompactor compactor = new ReftableCompactor();
+		try (ByteArrayOutputStream outBuf = new ByteArrayOutputStream()) {
+			compactor.tryAddFirst(read(inTab));
+			compactor.compact(outBuf);
+			outTab = outBuf.toByteArray();
+		}
+		Stats stats = compactor.getStats();
+		assertEquals(0, stats.minUpdateIndex());
+		assertEquals(0, stats.maxUpdateIndex());
+		assertEquals(1, stats.refCount());
+
+		ReftableReader rr = read(outTab);
+		try (RefCursor rc = rr.allRefs()) {
+			assertTrue(rc.next());
+			assertEquals(MASTER, rc.getRef().getName());
+			assertEquals(id(1), rc.getRef().getObjectId());
+			assertEquals(0, rc.getUpdateIndex());
+		}
+	}
+
+	@Test
+	public void twoTablesOneRef() throws IOException {
+		byte[] inTab1;
+		try (ByteArrayOutputStream inBuf = new ByteArrayOutputStream()) {
+			ReftableWriter writer = new ReftableWriter()
+				.setMinUpdateIndex(0)
+				.setMaxUpdateIndex(0)
+				.begin(inBuf);
+
+			writer.writeRef(ref(MASTER, 1));
+			writer.finish();
+			inTab1 = inBuf.toByteArray();
+		}
+
+		byte[] inTab2;
+		try (ByteArrayOutputStream inBuf = new ByteArrayOutputStream()) {
+			ReftableWriter writer = new ReftableWriter()
+				.setMinUpdateIndex(1)
+				.setMaxUpdateIndex(1)
+				.begin(inBuf);
+
+			writer.writeRef(ref(MASTER, 2));
+			writer.finish();
+			inTab2 = inBuf.toByteArray();
+		}
+
+		byte[] outTab;
+		ReftableCompactor compactor = new ReftableCompactor();
+		try (ByteArrayOutputStream outBuf = new ByteArrayOutputStream()) {
+			compactor.addAll(Arrays.asList(read(inTab1), read(inTab2)));
+			compactor.compact(outBuf);
+			outTab = outBuf.toByteArray();
+		}
+		Stats stats = compactor.getStats();
+		assertEquals(0, stats.minUpdateIndex());
+		assertEquals(1, stats.maxUpdateIndex());
+		assertEquals(1, stats.refCount());
+
+		ReftableReader rr = read(outTab);
+		try (RefCursor rc = rr.allRefs()) {
+			assertTrue(rc.next());
+			assertEquals(MASTER, rc.getRef().getName());
+			assertEquals(id(2), rc.getRef().getObjectId());
+			assertEquals(1, rc.getUpdateIndex());
+		}
+	}
+
+	@Test
+	public void twoTablesTwoRefs() throws IOException {
+		byte[] inTab1;
+		try (ByteArrayOutputStream inBuf = new ByteArrayOutputStream()) {
+			ReftableWriter writer = new ReftableWriter()
+				.setMinUpdateIndex(0)
+				.setMaxUpdateIndex(0)
+				.begin(inBuf);
+
+			writer.writeRef(ref(MASTER, 1));
+			writer.writeRef(ref(NEXT, 2));
+			writer.finish();
+			inTab1 = inBuf.toByteArray();
+		}
+
+		byte[] inTab2;
+		try (ByteArrayOutputStream inBuf = new ByteArrayOutputStream()) {
+			ReftableWriter writer = new ReftableWriter()
+				.setMinUpdateIndex(1)
+				.setMaxUpdateIndex(1)
+				.begin(inBuf);
+
+			writer.writeRef(ref(MASTER, 3));
+			writer.finish();
+			inTab2 = inBuf.toByteArray();
+		}
+
+		byte[] outTab;
+		ReftableCompactor compactor = new ReftableCompactor();
+		try (ByteArrayOutputStream outBuf = new ByteArrayOutputStream()) {
+			compactor.addAll(Arrays.asList(read(inTab1), read(inTab2)));
+			compactor.compact(outBuf);
+			outTab = outBuf.toByteArray();
+		}
+		Stats stats = compactor.getStats();
+		assertEquals(0, stats.minUpdateIndex());
+		assertEquals(1, stats.maxUpdateIndex());
+		assertEquals(2, stats.refCount());
+
+		ReftableReader rr = read(outTab);
+		try (RefCursor rc = rr.allRefs()) {
+			assertTrue(rc.next());
+			assertEquals(MASTER, rc.getRef().getName());
+			assertEquals(id(3), rc.getRef().getObjectId());
+			assertEquals(1, rc.getUpdateIndex());
+
+			assertTrue(rc.next());
+			assertEquals(NEXT, rc.getRef().getName());
+			assertEquals(id(2), rc.getRef().getObjectId());
+			assertEquals(0, rc.getUpdateIndex());
+		}
+	}
+
+	@Test
+	public void twoTablesIncludeOneDelete() throws IOException {
+		byte[] inTab1;
+		try (ByteArrayOutputStream inBuf = new ByteArrayOutputStream()) {
+			ReftableWriter writer = new ReftableWriter()
+				.setMinUpdateIndex(0)
+				.setMaxUpdateIndex(0)
+				.begin(inBuf);
+
+			writer.writeRef(ref(MASTER, 1));
+			writer.finish();
+			inTab1 = inBuf.toByteArray();
+		}
+
+		byte[] inTab2;
+		try (ByteArrayOutputStream inBuf = new ByteArrayOutputStream()) {
+			ReftableWriter writer = new ReftableWriter()
+				.setMinUpdateIndex(1)
+				.setMaxUpdateIndex(1)
+				.begin(inBuf);
+
+			writer.writeRef(tombstone(MASTER));
+			writer.finish();
+			inTab2 = inBuf.toByteArray();
+		}
+
+		byte[] outTab;
+		ReftableCompactor compactor = new ReftableCompactor();
+		try (ByteArrayOutputStream outBuf = new ByteArrayOutputStream()) {
+			compactor.setIncludeDeletes(true);
+			compactor.addAll(Arrays.asList(read(inTab1), read(inTab2)));
+			compactor.compact(outBuf);
+			outTab = outBuf.toByteArray();
+		}
+		Stats stats = compactor.getStats();
+		assertEquals(0, stats.minUpdateIndex());
+		assertEquals(1, stats.maxUpdateIndex());
+		assertEquals(1, stats.refCount());
+
+		ReftableReader rr = read(outTab);
+		try (RefCursor rc = rr.allRefs()) {
+			assertFalse(rc.next());
+		}
+	}
+
+	@Test
+	public void twoTablesNotIncludeOneDelete() throws IOException {
+		byte[] inTab1;
+		try (ByteArrayOutputStream inBuf = new ByteArrayOutputStream()) {
+			ReftableWriter writer = new ReftableWriter()
+				.setMinUpdateIndex(0)
+				.setMaxUpdateIndex(0)
+				.begin(inBuf);
+
+			writer.writeRef(ref(MASTER, 1));
+			writer.finish();
+			inTab1 = inBuf.toByteArray();
+		}
+
+		byte[] inTab2;
+		try (ByteArrayOutputStream inBuf = new ByteArrayOutputStream()) {
+			ReftableWriter writer = new ReftableWriter()
+				.setMinUpdateIndex(1)
+				.setMaxUpdateIndex(1)
+				.begin(inBuf);
+
+			writer.writeRef(tombstone(MASTER));
+			writer.finish();
+			inTab2 = inBuf.toByteArray();
+		}
+
+		byte[] outTab;
+		ReftableCompactor compactor = new ReftableCompactor();
+		try (ByteArrayOutputStream outBuf = new ByteArrayOutputStream()) {
+			compactor.setIncludeDeletes(false);
+			compactor.addAll(Arrays.asList(read(inTab1), read(inTab2)));
+			compactor.compact(outBuf);
+			outTab = outBuf.toByteArray();
+		}
+		Stats stats = compactor.getStats();
+		assertEquals(0, stats.minUpdateIndex());
+		assertEquals(1, stats.maxUpdateIndex());
+		assertEquals(0, stats.refCount());
+
+		ReftableReader rr = read(outTab);
+		try (RefCursor rc = rr.allRefs()) {
+			assertFalse(rc.next());
+		}
+	}
+
+	private static Ref ref(String name, int id) {
+		return new ObjectIdRef.PeeledNonTag(PACKED, name, id(id));
+	}
+
+	private static Ref tombstone(String name) {
+		return new ObjectIdRef.Unpeeled(NEW, name, null);
+	}
+
+	private static ObjectId id(int i) {
+		byte[] buf = new byte[OBJECT_ID_LENGTH];
+		buf[0] = (byte) (i & 0xff);
+		buf[1] = (byte) ((i >>> 8) & 0xff);
+		buf[2] = (byte) ((i >>> 16) & 0xff);
+		buf[3] = (byte) (i >>> 24);
+		return ObjectId.fromRaw(buf);
+	}
+
+	private static ReftableReader read(byte[] table) {
+		return new ReftableReader(BlockSource.from(table));
+	}
+}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftable/ReftableCompactor.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftable/ReftableCompactor.java
index c221577..6b53d41 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftable/ReftableCompactor.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftable/ReftableCompactor.java
@@ -74,7 +74,7 @@ public class ReftableCompactor {
 	private long compactBytesLimit;
 	private long bytesToCompact;
 	private boolean includeDeletes;
-	private long minUpdateIndex;
+	private long minUpdateIndex = -1;
 	private long maxUpdateIndex;
 	private long oldestReflogTimeMillis;
 	private Stats stats;
@@ -199,7 +199,7 @@ public boolean tryAddFirst(ReftableReader reader) throws IOException {
 	}
 
 	private void adjustUpdateIndexes(ReftableReader reader) throws IOException {
-		if (minUpdateIndex == 0) {
+		if (minUpdateIndex == -1) {
 			minUpdateIndex = reader.minUpdateIndex();
 		} else {
 			minUpdateIndex = Math.min(minUpdateIndex, reader.minUpdateIndex());
@@ -220,7 +220,7 @@ public void compact(OutputStream out) throws IOException {
 		MergedReftable mr = new MergedReftable(new ArrayList<>(tables));
 		mr.setIncludeDeletes(includeDeletes);
 
-		writer.setMinUpdateIndex(minUpdateIndex);
+		writer.setMinUpdateIndex(Math.max(minUpdateIndex, 0));
 		writer.setMaxUpdateIndex(maxUpdateIndex);
 		writer.begin(out);
 		mergeRefs(mr);