Raven.Database.Prefetching.PrefetchingBehavior.GetDocumentsBatchFrom C# (CSharp) Method

		public List<JsonDocument> GetDocumentsBatchFrom(Etag etag)
		{
			var results = GetDocsFromBatchWithPossibleDuplicates(etag);
			// a single doc may appear multiple times, if it was updated while we were fetching things, 
			// so we have several versions of the same doc loaded, this will make sure that we will only  
			// take one of them.
			var ids = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
			for (int i = results.Count - 1; i >= 0; i--)
			{
				if(CanBeConsideredAsDuplicate(results[i]) && ids.Add(results[i].Key) == false)
				{
					results.RemoveAt(i);
				}
			}
			return results;
		}

        private List<JsonDocument> GetDocsToReplicate(IStorageActionsAccessor actions, PrefetchingBehavior prefetchingBehavior, JsonDocumentsToReplicate result, int? maxNumberOfItemsToReceiveInSingleBatch)
        {
            var docsToReplicate = prefetchingBehavior.GetDocumentsBatchFrom(result.LastEtag, maxNumberOfItemsToReceiveInSingleBatch);
            Etag lastEtag = null;
            if (docsToReplicate.Count > 0)
                lastEtag = docsToReplicate[docsToReplicate.Count - 1].Etag;

            var maxNumberOfTombstones = Math.Max(1024, docsToReplicate.Count);
            var tombstones = actions
                .Lists
                .Read(Constants.RavenReplicationDocsTombstones, result.LastEtag, lastEtag, maxNumberOfTombstones + 1)
                .Select(x => new JsonDocument
                {
                    Etag = x.Etag,
                    Key = x.Key,
                    Metadata = x.Data,
                    DataAsJson = new RavenJObject()
                })
                .ToList();

            var results = docsToReplicate.Concat(tombstones);

            if (tombstones.Count >= maxNumberOfTombstones + 1)
            {
                var lastTombstoneEtag = tombstones[tombstones.Count - 1].Etag;
                log.Info("Replication batch trimmed. Found more than '{0}' document tombstones. Last etag from prefetcher: '{1}'. Last tombstone etag: '{2}'.", maxNumberOfTombstones, lastEtag, lastTombstoneEtag);

                results = results.Where(x => EtagUtil.IsGreaterThan(x.Etag, lastTombstoneEtag) == false);
            }

            results = results.OrderBy(x => x.Etag);

            // can't return earlier, because we need to know if there are tombstones that need to be send
            if (maxNumberOfItemsToReceiveInSingleBatch.HasValue)
                results = results.Take(maxNumberOfItemsToReceiveInSingleBatch.Value);

            return results.ToList();
        }