reftable: split off generic code from DFS code

This introduces ReftableBatchRefUpdate and ReftableDatabase, as
generic classes, with some code moved to DfsReftableBatchRefUpdate and
DfsReftableDatabase.

Clarify thread-safety requirements by asserting locked status in
accessors, and acquiring locks in callers. This does not fix threading
problems, because ReftableBatchRefUpdate already wraps the whole
transaction in a lock.

This also fixes a number of bugs in ReftableBatchRefUpdate:

* non-atomic updates should not bail on first failure

* isNameConflicting should also check for conflicts between names that
  are added and removed in the BatchRefUpdate.

Change-Id: I5ec91173ea9a0aa19da444c8c0b2e0f4e8f88798
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

1 files changed, 38 insertions, 3 deletions

diff --git a/org.eclipse.jgit.http.test/src/org/eclipse/jgit/http/test/RefsUnreadableInMemoryRepository.java b/org.eclipse.jgit.http.test/src/org/eclipse/jgit/http/test/RefsUnreadableInMemoryRepository.java
index 78f909eeac..6f85979785 100644
--- a/org.eclipse.jgit.http.test/src/org/eclipse/jgit/http/test/RefsUnreadableInMemoryRepository.java
+++ b/org.eclipse.jgit.http.test/src/org/eclipse/jgit/http/test/RefsUnreadableInMemoryRepository.java
@@ -43,10 +43,14 @@
 package org.eclipse.jgit.http.test;
 
 import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
 
 import org.eclipse.jgit.internal.storage.dfs.DfsRepositoryDescription;
 import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository;
-import org.eclipse.jgit.internal.storage.reftable.Reftable;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.RefDatabase;
 
 /**
@@ -82,12 +86,43 @@ class RefsUnreadableInMemoryRepository extends InMemoryRepository {
 	}
 
 	private class RefsUnreadableRefDatabase extends MemRefDatabase {
+
+		/** {@inheritDoc} */
+		@Override
+		public Ref exactRef(String name) throws IOException {
+			if (failing) {
+				throw new IOException("disk failed, no refs found");
+			}
+			return super.exactRef(name);
+		}
+
+		/** {@inheritDoc} */
+		@Override
+		public Map<String, Ref> getRefs(String prefix) throws IOException {
+			if (failing) {
+				throw new IOException("disk failed, no refs found");
+			}
+
+			return super.getRefs(prefix);
+		}
+
+		/** {@inheritDoc} */
+		@Override
+		public List<Ref> getRefsByPrefix(String prefix) throws IOException {
+			if (failing) {
+				throw new IOException("disk failed, no refs found");
+			}
+
+			return super.getRefsByPrefix(prefix);
+		}
+
+		/** {@inheritDoc} */
 		@Override
-		protected Reftable reader() throws IOException {
+		public Set<Ref> getTipsWithSha1(ObjectId id) throws IOException {
 			if (failing) {
 				throw new IOException("disk failed, no refs found");
 			}
-			return super.reader();
+			return super.getTipsWithSha1(id);
 		}
 	}
 }