dfs: optionally store blockSize in DfsPackDescription

Allow a DFS implementation to report blockSize to DfsPackFile,
bypassing alignment errors and corrections in the DfsBlockCache when
the blockSize of a specific file differs from the cache's configured
blockSize.

Change-Id: Ic376314d4a86a0bd528c033e169d93eef035b233

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsGarbageCollector.java

@@ -563,22 +563,25 @@ public class DfsGarbageCollector {
 		try (DfsOutputStream out = objdb.writeFile(pack, PACK)) {
 			pw.writePack(pm, pm, out);
 			pack.addFileExt(PACK);
+			pack.setBlockSize(PACK, out.blockSize());
 		}
 
-		try (CountingOutputStream cnt =
-				new CountingOutputStream(objdb.writeFile(pack, INDEX))) {
+		try (DfsOutputStream out = objdb.writeFile(pack, INDEX)) {
+			CountingOutputStream cnt = new CountingOutputStream(out);
 			pw.writeIndex(cnt);
 			pack.addFileExt(INDEX);
 			pack.setFileSize(INDEX, cnt.getCount());
+			pack.setBlockSize(INDEX, out.blockSize());
 			pack.setIndexVersion(pw.getIndexVersion());
 		}
 
 		if (pw.prepareBitmapIndex(pm)) {
-			try (CountingOutputStream cnt = new CountingOutputStream(
-					objdb.writeFile(pack, BITMAP_INDEX))) {
+			try (DfsOutputStream out = objdb.writeFile(pack, BITMAP_INDEX)) {
+				CountingOutputStream cnt = new CountingOutputStream(out);
 				pw.writeBitmapIndex(cnt);
 				pack.addFileExt(BITMAP_INDEX);
 				pack.setFileSize(BITMAP_INDEX, cnt.getCount());
+				pack.setBlockSize(BITMAP_INDEX, out.blockSize());
 			}
 		}
 

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsInserter.java

@@ -281,7 +281,9 @@ public class DfsInserter extends ObjectInserter {
 
 		rollback = true;
 		packDsc = db.newPack(DfsObjDatabase.PackSource.INSERT);
-		packOut = new PackStream(db.writeFile(packDsc, PACK));
+		DfsOutputStream dfsOut = db.writeFile(packDsc, PACK);
+		packDsc.setBlockSize(PACK, dfsOut.blockSize());
+		packOut = new PackStream(dfsOut);
 		packKey = packDsc.getStreamKey(PACK);
 
 		// Write the header as though it were a single object pack.
@@ -312,13 +314,14 @@ public class DfsInserter extends ObjectInserter {
 			packIndex = PackIndex.read(buf.openInputStream());
 		}
 
-		DfsOutputStream os = db.writeFile(pack, INDEX);
-		try (CountingOutputStream cnt = new CountingOutputStream(os)) {
+		try (DfsOutputStream os = db.writeFile(pack, INDEX)) {
+			CountingOutputStream cnt = new CountingOutputStream(os);
 			if (buf != null)
 				buf.writeTo(cnt, null);
 			else
 				index(cnt, packHash, list);
 			pack.addFileExt(INDEX);
+			pack.setBlockSize(INDEX, os.blockSize());
 			pack.setFileSize(INDEX, cnt.getCount());
 		} finally {
 			if (buf != null) {

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsPackCompactor.java

@@ -370,27 +370,23 @@ public class DfsPackCompactor {
 	private static void writePack(DfsObjDatabase objdb,
 			DfsPackDescription pack,
 			PackWriter pw, ProgressMonitor pm) throws IOException {
-		DfsOutputStream out = objdb.writeFile(pack, PACK);
-		try {
+		try (DfsOutputStream out = objdb.writeFile(pack, PACK)) {
 			pw.writePack(pm, pm, out);
 			pack.addFileExt(PACK);
-		} finally {
-			out.close();
+			pack.setBlockSize(PACK, out.blockSize());
 		}
 	}
 
 	private static void writeIndex(DfsObjDatabase objdb,
 			DfsPackDescription pack,
 			PackWriter pw) throws IOException {
-		DfsOutputStream out = objdb.writeFile(pack, INDEX);
-		try {
+		try (DfsOutputStream out = objdb.writeFile(pack, INDEX)) {
 			CountingOutputStream cnt = new CountingOutputStream(out);
 			pw.writeIndex(cnt);
 			pack.addFileExt(INDEX);
 			pack.setFileSize(INDEX, cnt.getCount());
+			pack.setBlockSize(INDEX, out.blockSize());
 			pack.setIndexVersion(pw.getIndexVersion());
-		} finally {
-			out.close();
 		}
 	}
 

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsPackDescription.java

@@ -65,6 +65,7 @@ public class DfsPackDescription implements Comparable<DfsPackDescription> {
 	private PackSource packSource;
 	private long lastModified;
 	private long[] sizeMap;
+	private int[] blockSizeMap;
 	private long objectCount;
 	private long deltaCount;
 	private PackStatistics stats;
@@ -91,7 +92,10 @@ public class DfsPackDescription implements Comparable<DfsPackDescription> {
 		this.repoDesc = repoDesc;
 		int dot = name.lastIndexOf('.');
 		this.packName = (dot < 0) ? name : name.substring(0, dot);
-		this.sizeMap = new long[PackExt.values().length];
+
+		int extCnt = PackExt.values().length;
+		sizeMap = new long[extCnt];
+		blockSizeMap = new int[extCnt];
 	}
 
 	/** @return description of the repository. */
@@ -193,6 +197,34 @@ public class DfsPackDescription implements Comparable<DfsPackDescription> {
 		return i < sizeMap.length ? sizeMap[i] : 0;
 	}
 
+	/**
+	 * @param ext
+	 *            the file extension.
+	 * @return blockSize of the file, in bytes. If 0 the blockSize size is not
+	 *         yet known and may be discovered when opening the file.
+	 */
+	public int getBlockSize(PackExt ext) {
+		int i = ext.getPosition();
+		return i < blockSizeMap.length ? blockSizeMap[i] : 0;
+	}
+
+	/**
+	 * @param ext
+	 *            the file extension.
+	 * @param blockSize
+	 *            blockSize of the file, in bytes. If 0 the blockSize is not
+	 *            known and will be determined on first read.
+	 * @return {@code this}
+	 */
+	public DfsPackDescription setBlockSize(PackExt ext, int blockSize) {
+		int i = ext.getPosition();
+		if (i >= blockSizeMap.length) {
+			blockSizeMap = Arrays.copyOf(blockSizeMap, i + 1);
+		}
+		blockSizeMap[i] = Math.max(0, blockSize);
+		return this;
+	}
+
 	/**
 	 * @param estimatedPackSize
 	 *            estimated size of the .pack file in bytes. If 0 the pack file

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsPackFile.java

@@ -123,9 +123,14 @@ public final class DfsPackFile extends BlockBasedFile {
 	 */
 	DfsPackFile(DfsBlockCache cache, DfsPackDescription desc) {
 		super(cache, desc, PACK);
-		length = desc.getFileSize(PACK);
-		if (length <= 0)
-			length = -1;
+
+		int bs = desc.getBlockSize(PACK);
+		if (bs > 0) {
+			setBlockSize(bs);
+		}
+
+		long sz = desc.getFileSize(PACK);
+		length = sz > 0 ? sz : -1;
 	}
 
 	/** @return description that was originally used to configure this pack file. */

org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsPackParser.java

@@ -150,6 +150,7 @@ public class DfsPackParser extends PackParser {
 			readBlock = null;
 			packDsc.addFileExt(PACK);
 			packDsc.setFileSize(PACK, packEnd);
+			packDsc.setBlockSize(PACK, blockSize);
 
 			writePackIndex();
 			objdb.commitPack(Collections.singletonList(packDsc), null);