Lucene.Net.Index.TestPersistentSnapshotDeletionPolicy.TestExistingSnapshots C# (CSharp) Method

        public virtual void TestExistingSnapshots()
        {
            int numSnapshots = 3;
            MockDirectoryWrapper dir = NewMockDirectory();
            IndexWriter writer = new IndexWriter(dir, GetConfig(Random(), GetDeletionPolicy(dir)));
            PersistentSnapshotDeletionPolicy psdp = (PersistentSnapshotDeletionPolicy)writer.Config.DelPolicy;
            Assert.IsNull(psdp.LastSaveFile);
            PrepareIndexAndSnapshots(psdp, writer, numSnapshots);
            Assert.IsNotNull(psdp.LastSaveFile);
            writer.Dispose();

            // Make sure only 1 save file exists:
            int count = 0;
            foreach (string file in dir.ListAll())
            {
                if (file.StartsWith(PersistentSnapshotDeletionPolicy.SNAPSHOTS_PREFIX))
                {
                    count++;
                }
            }
            Assert.AreEqual(1, count);

            // Make sure we fsync:
            dir.Crash();
            dir.ClearCrash();

            // Re-initialize and verify snapshots were persisted
            psdp = new PersistentSnapshotDeletionPolicy(new KeepOnlyLastCommitDeletionPolicy(), dir, OpenMode_e.APPEND);

            writer = new IndexWriter(dir, GetConfig(Random(), psdp));
            psdp = (PersistentSnapshotDeletionPolicy)writer.Config.DelPolicy;

            Assert.AreEqual(numSnapshots, psdp.Snapshots.Count);
            Assert.AreEqual(numSnapshots, psdp.SnapshotCount);
            AssertSnapshotExists(dir, psdp, numSnapshots, false);

            writer.AddDocument(new Document());
            writer.Commit();
            Snapshots.Add(psdp.Snapshot());
            Assert.AreEqual(numSnapshots + 1, psdp.Snapshots.Count);
            Assert.AreEqual(numSnapshots + 1, psdp.SnapshotCount);
            AssertSnapshotExists(dir, psdp, numSnapshots + 1, false);

            writer.Dispose();
            dir.Dispose();
        }