reduced memory churn using fixed_xxx containers (#236)

* Added EASTL to help with eliminating memory allocations
* Applied EASTL to eliminate memory allocations, primarily by using `fixed_vector` et al to use stack allocations / inline struct allocations

Reduces memory events in traces by close to a factor of 10 in test scenario (starting editor for project F)

1 files changed, 18 insertions, 14 deletions

diff --git a/src/zenserver/projectstore/httpprojectstore.cpp b/src/zenserver/projectstore/httpprojectstore.cpp
index 0b8e5f13b..47748dd90 100644
--- a/src/zenserver/projectstore/httpprojectstore.cpp
+++ b/src/zenserver/projectstore/httpprojectstore.cpp
@@ -983,15 +983,19 @@ HttpProjectService::HandleOplogOpPrepRequest(HttpRouterRequest& Req)
 	IoBuffer Payload	   = HttpReq.ReadPayload();
 	CbObject RequestObject = LoadCompactBinaryObject(Payload);
 
-	std::vector<IoHash> ChunkList;
-	CbArrayView			HaveList = RequestObject["have"sv].AsArrayView();
-	ChunkList.reserve(HaveList.Num());
-	for (auto& Entry : HaveList)
+	std::vector<IoHash> NeedList;
+
 	{
-		ChunkList.push_back(Entry.AsHash());
-	}
+		eastl::fixed_vector<IoHash, 16> ChunkList;
+		CbArrayView						HaveList = RequestObject["have"sv].AsArrayView();
+		ChunkList.reserve(HaveList.Num());
+		for (auto& Entry : HaveList)
+		{
+			ChunkList.push_back(Entry.AsHash());
+		}
 
-	std::vector<IoHash> NeedList = FoundLog->CheckPendingChunkReferences(ChunkList, std::chrono::minutes(2));
+		NeedList = FoundLog->CheckPendingChunkReferences(std::span(begin(ChunkList), end(ChunkList)), std::chrono::minutes(2));
+	}
 
 	CbObjectWriter Cbo(1 + 1 + 5 + NeedList.size() * (1 + sizeof(IoHash::Hash)) + 1);
 	Cbo.BeginArray("need");
@@ -1151,7 +1155,7 @@ HttpProjectService::HandleOplogOpNewRequest(HttpRouterRequest& Req)
 		return HttpReq.WriteResponse(HttpResponseCode::BadRequest, HttpContentType::kText, "No oplog entry key specified");
 	}
 
-	std::vector<IoHash> ReferencedChunks;
+	eastl::fixed_vector<IoHash, 16> ReferencedChunks;
 	Core.IterateAttachments([&ReferencedChunks](CbFieldView View) { ReferencedChunks.push_back(View.AsAttachment()); });
 
 	// Write core to oplog
@@ -1169,7 +1173,7 @@ HttpProjectService::HandleOplogOpNewRequest(HttpRouterRequest& Req)
 	// Once we stored the op, we no longer need to retain any chunks this op references
 	if (!ReferencedChunks.empty())
 	{
-		FoundLog->RemovePendingChunkReferences(ReferencedChunks);
+		FoundLog->RemovePendingChunkReferences(std::span(begin(ReferencedChunks), end(ReferencedChunks)));
 	}
 
 	m_ProjectStats.OpWriteCount++;
@@ -1301,9 +1305,9 @@ HttpProjectService::HandleOpLogOpRequest(HttpRouterRequest& Req)
 
 	HttpServerRequest& HttpReq = Req.ServerRequest();
 
-	const std::string& ProjectId  = Req.GetCapture(1);
-	const std::string& OplogId	  = Req.GetCapture(2);
-	const std::string& OpIdString = Req.GetCapture(3);
+	const std::string_view ProjectId  = Req.GetCapture(1);
+	const std::string_view OplogId	  = Req.GetCapture(2);
+	const std::string_view OpIdString = Req.GetCapture(3);
 
 	Ref<ProjectStore::Project> Project = m_ProjectStore->OpenProject(ProjectId);
 	if (!Project)
@@ -1690,8 +1694,8 @@ HttpProjectService::HandleProjectRequest(HttpRouterRequest& Req)
 
 	using namespace std::literals;
 
-	HttpServerRequest& HttpReq	 = Req.ServerRequest();
-	const std::string  ProjectId = Req.GetCapture(1);
+	HttpServerRequest&	   HttpReq	 = Req.ServerRequest();
+	const std::string_view ProjectId = Req.GetCapture(1);
 
 	switch (HttpReq.RequestVerb())
 	{