Added support for salt in oplog append operations, which can be used to avoid payload file conflicts when multiple operations end up producing the same large output chunks

1 files changed, 28 insertions, 3 deletions

diff --git a/zenserver/projectstore.cpp b/zenserver/projectstore.cpp
index eccaacff5..2aac5fe50 100644
--- a/zenserver/projectstore.cpp
+++ b/zenserver/projectstore.cpp
@@ -28,6 +28,7 @@
 #include <asio.hpp>
 #include <future>
 #include <latch>
+#include <string>
 
 namespace zen {
 
@@ -1070,6 +1071,18 @@ HttpProjectService::HttpProjectService(CasStore& Store, ProjectStore* Projects)
 			const auto& ProjectId = Req.GetCapture(1);
 			const auto& OplogId	  = Req.GetCapture(2);
 
+			HttpServerRequest::QueryParams Params = HttpReq.GetQueryParams();
+
+			bool   IsUsingSalt = false;
+			IoHash SaltHash	   = IoHash::Zero;
+
+			if (std::string_view SaltParam = Params.GetValue("salt"); SaltParam.empty() == false)
+			{
+				const uint32_t Salt = std::stoi(std::string(SaltParam));
+				SaltHash			= IoHash::HashMemory(&Salt, sizeof Salt);
+				IsUsingSalt			= true;
+			}
+
 			ProjectStore::Oplog* FoundLog = m_ProjectStore->OpenProjectOplog(ProjectId, OplogId);
 
 			if (FoundLog == nullptr)
@@ -1089,13 +1102,25 @@ HttpProjectService::HttpProjectService(CasStore& Store, ProjectStore* Projects)
 			std::vector<IoHash> MissingChunks;
 
 			CbPackage::AttachmentResolver Resolver = [&](const IoHash& Hash) -> SharedBuffer {
-				std::filesystem::path AttachmentPath = Log.TempPath() / Hash.ToHexString();
+				IoHash AttachmentId;
+
+				if (IsUsingSalt)
+				{
+					IoHash AttachmentSpec[]{SaltHash, Hash};
+					AttachmentId = IoHash::HashMemory(MakeMemoryView(AttachmentSpec));
+				}
+				else
+				{
+					AttachmentId = Hash;
+				}
+
+				std::filesystem::path AttachmentPath = Log.TempPath() / AttachmentId.ToHexString();
 
-				if (IoBuffer Data = IoBufferBuilder::MakeFromTemporaryFile(AttachmentPath.native().c_str()))
+				if (IoBuffer Data = m_CasStore.FindChunk(Hash))
 				{
 					return SharedBuffer(std::move(Data));
 				}
-				else if (Data = m_CasStore.FindChunk(Hash))
+				else if (Data = IoBufferBuilder::MakeFromTemporaryFile(AttachmentPath.native().c_str()))
 				{
 					return SharedBuffer(std::move(Data));
 				}