[JGIT PATCH 3/3] Rescan for packs and retry once if object lookup scan fails

From

Robin Rosenberg <robin.rosenberg@dewire.com>

Date

Apr 19, 2009, 18:30 UTC

Message-ID

<1240165809-16703-4-git-send-email-robin.rosenberg@dewire.com>

In-Reply-To

<1240165809-16703-3-git-send-email-robin.rosenberg@dewire.com>

At the same time we stop scanning for new packs regularly since we now
have another mechanism for finding them.
---
 .../src/org/spearce/jgit/lib/Repository.java       |   76 ++++++++++++++++----
 1 files changed, 63 insertions(+), 13 deletions(-)

diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/Repository.java b/org.spearce.jgit/src/org/spearce/jgit/lib/Repository.java
index cfd92b8..ec4226c 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/Repository.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/Repository.java
@@ -100,6 +100,8 @@
 	private GitIndex index;
 
 	private List<RepositoryListener> listeners = new Vector<RepositoryListener>(); // thread safe
+
+	private int packFileListGeneration;
 	static private List<RepositoryListener> allListeners = new Vector<RepositoryListener>(); // thread safe
 
 	/**
@@ -291,6 +293,40 @@ public ObjectLoader openObject(final AnyObjectId id)
 	 */
 	public ObjectLoader openObject(final WindowCursor curs, final AnyObjectId id)
 			throws IOException {
+		boolean scanned = false;
+		try {
+			ObjectLoader loader = openObjectInPacks(curs, id);
+			if (loader != null)
+				return loader;
+		} catch (FileNotFoundException fnfe) {
+			System.out.println(new java.util.Date().toString() + ": failed to load " + id + ", rescanning for new packs");
+			scanned = true;
+			if (scanForPacks()) {
+				ObjectLoader loader = openObjectInPacks(curs, id);
+				if (loader != null)
+					return loader;
+			}
+		}
+		try {
+			return new UnpackedObjectLoader(this, id);
+		} catch (FileNotFoundException fnfe) {
+			System.out.println(new java.util.Date().toString() + ": failed to load " + id + ", rescanning for new packs");
+			if (!scanned && scanForPacks()) {
+				ObjectLoader loader = openObjectInPacks(curs, id);
+				if (loader != null)
+					return loader;
+				try {
+					return new UnpackedObjectLoader(this, id);
+				} catch (FileNotFoundException fnfe2) {
+					return null;
+				}
+			}
+			return null;
+		}
+	}
+
+	private ObjectLoader openObjectInPacks(final WindowCursor curs, final AnyObjectId id)
+			throws IOException {
 		final PackFile[] packs = packs();
 		int k = packs.length;
 		while (k > 0) {
@@ -298,11 +334,7 @@ public ObjectLoader openObject(final WindowCursor curs, final AnyObjectId id)
 			if (ol != null)
 				return ol;
 		}
-		try {
-			return new UnpackedObjectLoader(this, id);
-		} catch (FileNotFoundException fnfe) {
-			return null;
-		}
+		return null;
 	}
 
 	/**
@@ -813,23 +845,39 @@ synchronized (this) {
 	}
 
 	/**
-	 * Scan the object dirs, including alternates for packs
-	 * to use.
+	 * Scan the object dirs, including alternates for packs to use.
+	 * 
+	 * @return true if new packs were found
 	 */
-	public void scanForPacks() {
+	public boolean scanForPacks() {
+		int oldPackFileListGeneration = packFileListGeneration;
 		final ArrayList<PackFile> p = new ArrayList<PackFile>();
-		p.addAll(Arrays.asList(packs()));
 		for (final File d : objectsDirs())
-			scanForPacks(new File(d, "pack"), p);
+			scanForPacks(new File(d, "pack"), p, packFileList);
 		final PackFile[] arr = new PackFile[p.size()];
 		p.toArray(arr);
 		Arrays.sort(arr, PackFile.SORT);
 		synchronized (this) {
+			if (!samePackfileArray(packFileList, arr))
+				packFileListGeneration++;
 			packFileList = arr;
 		}
+		return oldPackFileListGeneration != packFileListGeneration;
 	}
 
-	private void scanForPacks(final File packDir, Collection<PackFile> packList) {
+	private static<T> boolean samePackfileArray(PackFile[] oldList, PackFile[] newList) {
+		if (oldList == null)
+			return false;
+		if (oldList.length != newList.length)
+			return false;
+		for (int i = 0; i < oldList.length; ++i) {
+			if (!oldList[i].getPackFile().equals(newList[i].getPackFile()))
+				return false;
+		}
+		return true;
+	}
+	
+	private void scanForPacks(final File packDir, Collection<PackFile> packList, PackFile[] oldPackFileList) {
 		final String[] idxList = packDir.list(new FilenameFilter() {
 			public boolean accept(final File baseDir, final String n) {
 				// Must match "pack-[0-9a-f]{40}.idx" to be an index.
@@ -851,9 +899,11 @@ public boolean accept(final File baseDir, final String n) {
 					continue;
 				}
 
-				for (final PackFile p : packList) {
-					if (packFile.equals(p.getPackFile()))
+				for (final PackFile p : oldPackFileList) {
+					if (packFile.equals(p.getPackFile())) {
+						packList.add(p);
 						continue SCAN;
+					}
 				}
 
 				packList.add(new PackFile(idxFile, packFile));

-- 
1.6.2.2.446.gfbdc0