check oplog op attachments when gathering references for GC (#363)

* Make sure to check oplog op attachments when gathering references for GC
* Add oplog op content to error result if attachment is missing when doing `oplog-export`

1 files changed, 15 insertions, 8 deletions

diff --git a/src/zenserver/projectstore/remoteprojectstore.cpp b/src/zenserver/projectstore/remoteprojectstore.cpp
index 20acdf159..1abd18a5c 100644
--- a/src/zenserver/projectstore/remoteprojectstore.cpp
+++ b/src/zenserver/projectstore/remoteprojectstore.cpp
@@ -220,21 +220,28 @@ BuildContainer(CidStore&																	ChunkStore,
 		size_t					  BlockSize = 0;
 		std::vector<SharedBuffer> ChunksInBlock;
 
-		std::unordered_set<IoHash, IoHash::Hasher> Attachments;
-		Oplog.IterateOplog([&Attachments, &SectionOpsWriter, &OpCount](CbObject Op) {
-			Op.IterateAttachments([&](CbFieldView FieldView) { Attachments.insert(FieldView.AsAttachment()); });
+		std::unordered_map<IoHash, int, IoHash::Hasher> Attachments;
+		Oplog.IterateOplogWithKey([&Attachments, &SectionOpsWriter, &OpCount](int LSN, const Oid&, CbObject Op) {
+			Op.IterateAttachments([&](CbFieldView FieldView) { Attachments.insert_or_assign(FieldView.AsAttachment(), LSN); });
 			(SectionOpsWriter) << Op;
 			OpCount++;
 		});
 
-		for (const IoHash& AttachmentHash : Attachments)
+		for (const auto& It : Attachments)
 		{
-			IoBuffer Payload = ChunkStore.FindChunkByCid(AttachmentHash);
+			const IoHash& AttachmentHash(It.first);
+			IoBuffer	  Payload = ChunkStore.FindChunkByCid(AttachmentHash);
 			if (!Payload)
 			{
-				RemoteResult.SetError(gsl::narrow<int>(HttpResponseCode::NotFound),
-									  fmt::format("Failed to find attachment {} for op", AttachmentHash),
-									  {});
+				std::optional<CbObject> Op = Oplog.GetOpByIndex(It.second);
+				ZEN_ASSERT(Op.has_value());
+				ExtendableStringBuilder<1024> Sb;
+				Sb.Append("Failed to find attachment '");
+				Sb.Append(AttachmentHash.ToHexString());
+				Sb.Append("' for op: \n");
+				Op.value().ToJson(Sb);
+
+				RemoteResult.SetError(gsl::narrow<int>(HttpResponseCode::NotFound), Sb.ToString(), {});
 				ZEN_ERROR("Failed to build container ({}). Reason: '{}'", RemoteResult.GetError(), RemoteResult.GetErrorReason());
 
 				BlockCreateLatch.CountDown();