From cb90ed08526bd51f04e5d72e3ba3cf5bd30c11e4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sa=C5=A1a=20=C5=BDivkov?= <sasa.zivkov@sap.com>
Date: Fri, 21 Oct 2022 16:32:03 +0200
Subject: [PATCH] Allow to perform PackedBatchRefUpdate without locking loose
 refs

Add another newBatchUpdate method in the RefDirectory where we can
control if the created PackedBatchRefUpdate will lock the loose refs or
not.

This can be useful in cases when we run programs which have exclusive
access to a Git repository and we know that locking loose refs is
unnecessary and just a performance loss.

Change-Id: I7d0932eb1598a3871a2281b1a049021380234df9
---
 .../storage/file/PackedBatchRefUpdate.java        | 12 +++++++++---
 .../jgit/internal/storage/file/RefDirectory.java  | 15 +++++++++++++++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackedBatchRefUpdate.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackedBatchRefUpdate.java
index 9c1d33dc3..8b0ea4fcd 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackedBatchRefUpdate.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/PackedBatchRefUpdate.java
@@ -86,10 +86,16 @@
  */
 class PackedBatchRefUpdate extends BatchRefUpdate {
 	private RefDirectory refdb;
+	private boolean shouldLockLooseRefs;
 
 	PackedBatchRefUpdate(RefDirectory refdb) {
-		super(refdb);
-		this.refdb = refdb;
+		this(refdb, true);
+	}
+
+	PackedBatchRefUpdate(RefDirectory refdb, boolean shouldLockLooseRefs) {
+	  super(refdb);
+	  this.refdb = refdb;
+	  this.shouldLockLooseRefs = shouldLockLooseRefs;
 	}
 
 	/** {@inheritDoc} */
@@ -155,7 +161,7 @@ public void execute(RevWalk walk, ProgressMonitor monitor,
 		refdb.inProcessPackedRefsLock.lock();
 		try {
 			PackedRefList oldPackedList;
-			if (!refdb.isInClone()) {
+			if (!refdb.isInClone() && shouldLockLooseRefs) {
 				locks = lockLooseRefs(pending);
 				if (locks == null) {
 					return;
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/RefDirectory.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/RefDirectory.java
index 07e38147f..b46ffe367 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/RefDirectory.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/RefDirectory.java
@@ -587,6 +587,21 @@ public PackedBatchRefUpdate newBatchUpdate() {
 		return new PackedBatchRefUpdate(this);
 	}
 
+	/**
+	 * Create a new batch update to attempt on this database.
+	 *
+	 * @param shouldLockLooseRefs
+	 *            whether loose refs should be locked during the batch ref
+	 *            update. Note that this should only be set to {@code false} if
+	 *            the application using this ensures that no other ref updates
+	 *            run concurrently to avoid lost updates caused by a race. In
+	 *            such cases it can improve performance.
+	 * @return a new batch update object
+	 */
+	public PackedBatchRefUpdate newBatchUpdate(boolean shouldLockLooseRefs) {
+		return new PackedBatchRefUpdate(this, shouldLockLooseRefs);
+	}
+
 	/** {@inheritDoc} */
 	@Override
 	public boolean performsAtomicTransactions() {