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)

5 files changed, 70 insertions, 50 deletions

diff --git a/src/zenserver/objectstore/objectstore.cpp b/src/zenserver/objectstore/objectstore.cpp
index 5d96de225..e757ef84e 100644
--- a/src/zenserver/objectstore/objectstore.cpp
+++ b/src/zenserver/objectstore/objectstore.cpp
@@ -269,9 +269,9 @@ HttpObjectStoreService::Inititalize()
 	m_Router.RegisterRoute(
 		"bucket/{path}",
 		[this](zen::HttpRouterRequest& Request) {
-			const std::string Path	   = Request.GetCapture(1);
-			const auto		  Sep	   = Path.find_last_of('.');
-			const bool		  IsObject = Sep != std::string::npos && Path.size() - Sep > 0;
+			const std::string_view Path		= Request.GetCapture(1);
+			const auto			   Sep		= Path.find_last_of('.');
+			const bool			   IsObject = Sep != std::string::npos && Path.size() - Sep > 0;
 
 			if (IsObject)
 			{
@@ -337,18 +337,18 @@ HttpObjectStoreService::CreateBucket(zen::HttpRouterRequest& Request)
 }
 
 void
-HttpObjectStoreService::ListBucket(zen::HttpRouterRequest& Request, const std::string& Path)
+HttpObjectStoreService::ListBucket(zen::HttpRouterRequest& Request, const std::string_view Path)
 {
 	namespace fs = std::filesystem;
 
-	const auto		  Sep		 = Path.find_first_of('/');
-	const std::string BucketName = Sep == std::string::npos ? Path : Path.substr(0, Sep);
+	const auto		  Sep = Path.find_first_of('/');
+	const std::string BucketName{Sep == std::string::npos ? Path : Path.substr(0, Sep)};
 	if (BucketName.empty())
 	{
 		return Request.ServerRequest().WriteResponse(HttpResponseCode::BadRequest);
 	}
 
-	std::string BucketPrefix = Sep == std::string::npos || Sep == Path.size() - 1 ? std::string() : Path.substr(BucketName.size() + 1);
+	std::string BucketPrefix{Sep == std::string::npos || Sep == Path.size() - 1 ? std::string() : Path.substr(BucketName.size() + 1)};
 	if (BucketPrefix.empty())
 	{
 		const auto QueryParms = Request.ServerRequest().GetQueryParams();
@@ -450,14 +450,13 @@ HttpObjectStoreService::DeleteBucket(zen::HttpRouterRequest& Request)
 }
 
 void
-HttpObjectStoreService::GetObject(zen::HttpRouterRequest& Request, const std::string& Path)
+HttpObjectStoreService::GetObject(zen::HttpRouterRequest& Request, const std::string_view Path)
 {
 	namespace fs = std::filesystem;
 
-	const auto		  Sep		 = Path.find_first_of('/');
-	const std::string BucketName = Sep == std::string::npos ? Path : Path.substr(0, Sep);
-	const std::string BucketPrefix =
-		Sep == std::string::npos || Sep == Path.size() - 1 ? std::string() : Path.substr(BucketName.size() + 1);
+	const auto		  Sep = Path.find_first_of('/');
+	const std::string BucketName{Sep == std::string::npos ? Path : Path.substr(0, Sep)};
+	const std::string BucketPrefix{Sep == std::string::npos || Sep == Path.size() - 1 ? std::string() : Path.substr(BucketName.size() + 1)};
 
 	const fs::path BucketDir = GetBucketDirectory(BucketName);
 
@@ -554,8 +553,8 @@ HttpObjectStoreService::PutObject(zen::HttpRouterRequest& Request)
 {
 	namespace fs = std::filesystem;
 
-	const std::string& BucketName = Request.GetCapture(1);
-	const fs::path	   BucketDir  = GetBucketDirectory(BucketName);
+	const std::string_view BucketName = Request.GetCapture(1);
+	const fs::path		   BucketDir  = GetBucketDirectory(BucketName);
 
 	if (BucketDir.empty())
 	{
diff --git a/src/zenserver/objectstore/objectstore.h b/src/zenserver/objectstore/objectstore.h
index c905ceab3..dae979c4c 100644
--- a/src/zenserver/objectstore/objectstore.h
+++ b/src/zenserver/objectstore/objectstore.h
@@ -36,9 +36,9 @@ private:
 	void				  Inititalize();
 	std::filesystem::path GetBucketDirectory(std::string_view BucketName);
 	void				  CreateBucket(zen::HttpRouterRequest& Request);
-	void				  ListBucket(zen::HttpRouterRequest& Request, const std::string& Path);
+	void				  ListBucket(zen::HttpRouterRequest& Request, const std::string_view Path);
 	void				  DeleteBucket(zen::HttpRouterRequest& Request);
-	void				  GetObject(zen::HttpRouterRequest& Request, const std::string& Path);
+	void				  GetObject(zen::HttpRouterRequest& Request, const std::string_view Path);
 	void				  PutObject(zen::HttpRouterRequest& Request);
 
 	ObjectStoreConfig	 m_Cfg;
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())
 	{
diff --git a/src/zenserver/projectstore/projectstore.cpp b/src/zenserver/projectstore/projectstore.cpp
index 53df12b14..86791e29a 100644
--- a/src/zenserver/projectstore/projectstore.cpp
+++ b/src/zenserver/projectstore/projectstore.cpp
@@ -423,9 +423,13 @@ ComputeOpKey(const CbObjectView& Op)
 {
 	using namespace std::literals;
 
-	BinaryWriter KeyStream;
+	eastl::fixed_vector<uint8_t, 256> KeyData;
 
-	Op["key"sv].WriteToStream([&](const void* Data, size_t Size) { KeyStream.Write(Data, Size); });
+	Op["key"sv].WriteToStream([&](const void* Data, size_t Size) {
+		auto Begin = reinterpret_cast<const uint8_t*>(Data);
+		auto End   = Begin + Size;
+		KeyData.insert(KeyData.end(), Begin, End);
+	});
 
 	XXH3_128 KeyHash128;
 
@@ -434,15 +438,15 @@ ComputeOpKey(const CbObjectView& Op)
 	// path but longer paths are evaluated properly. In the future all key lengths
 	// should be evaluated using the proper path, this is a temporary workaround to
 	// maintain compatibility with existing disk state.
-	if (KeyStream.GetSize() < 240)
+	if (KeyData.size() < 240)
 	{
 		XXH3_128Stream_deprecated KeyHasher;
-		KeyHasher.Append(KeyStream.Data(), KeyStream.Size());
+		KeyHasher.Append(KeyData.data(), KeyData.size());
 		KeyHash128 = KeyHasher.GetHash();
 	}
 	else
 	{
-		KeyHash128 = XXH3_128::HashMemory(KeyStream.GetView());
+		KeyHash128 = XXH3_128::HashMemory(KeyData.data(), KeyData.size());
 	}
 
 	Oid KeyHash;
@@ -2735,7 +2739,7 @@ ProjectStore::Oplog::CheckPendingChunkReferences(std::span<const IoHash> ChunkHa
 	MissingChunks.reserve(ChunkHashes.size());
 	for (const IoHash& FileHash : ChunkHashes)
 	{
-		if (IoBuffer Payload = m_CidStore.FindChunkByCid(FileHash); !Payload)
+		if (!m_CidStore.ContainsChunk(FileHash))
 		{
 			MissingChunks.push_back(FileHash);
 		}
@@ -3359,7 +3363,6 @@ ProjectStore::Project::OpenOplog(std::string_view OplogId, bool AllowCompact, bo
 	ZEN_MEMSCOPE(GetProjectstoreTag());
 	ZEN_TRACE_CPU("Store::OpenOplog");
 
-	std::filesystem::path OplogBasePath = BasePathForOplog(OplogId);
 	{
 		RwLock::SharedLockScope ProjectLock(m_ProjectLock);
 
@@ -3367,21 +3370,35 @@ ProjectStore::Project::OpenOplog(std::string_view OplogId, bool AllowCompact, bo
 
 		if (OplogIt != m_Oplogs.end())
 		{
-			if (!VerifyPathOnDisk || Oplog::ExistsAt(OplogBasePath))
+			bool ReOpen = false;
+
+			if (VerifyPathOnDisk)
 			{
-				return OplogIt->second.get();
+				std::filesystem::path OplogBasePath = BasePathForOplog(OplogId);
+
+				if (!Oplog::ExistsAt(OplogBasePath))
+				{
+					// Somebody deleted the oplog on disk behind our back
+					ProjectLock.ReleaseNow();
+					std::filesystem::path DeletePath;
+					if (!RemoveOplog(OplogId, DeletePath))
+					{
+						ZEN_WARN("Failed to clean up deleted oplog {}/{}", Identifier, OplogId, OplogBasePath);
+					}
+
+					ReOpen = true;
+				}
 			}
 
-			// Somebody deleted the oplog on disk behind our back
-			ProjectLock.ReleaseNow();
-			std::filesystem::path DeletePath;
-			if (!RemoveOplog(OplogId, DeletePath))
+			if (!ReOpen)
 			{
-				ZEN_WARN("Failed to clean up deleted oplog {}/{}", Identifier, OplogId, OplogBasePath);
+				return OplogIt->second.get();
 			}
 		}
 	}
 
+	std::filesystem::path OplogBasePath = BasePathForOplog(OplogId);
+
 	RwLock::ExclusiveLockScope Lock(m_ProjectLock);
 	if (auto It = m_Oplogs.find(std::string{OplogId}); It != m_Oplogs.end())
 	{
diff --git a/src/zenserver/workspaces/httpworkspaces.cpp b/src/zenserver/workspaces/httpworkspaces.cpp
index 905ba5ab2..8a4b977ad 100644
--- a/src/zenserver/workspaces/httpworkspaces.cpp
+++ b/src/zenserver/workspaces/httpworkspaces.cpp
@@ -589,7 +589,7 @@ void
 HttpWorkspacesService::ShareAliasFilesRequest(HttpRouterRequest& Req)
 {
 	HttpServerRequest& ServerRequest = Req.ServerRequest();
-	std::string		   Alias		 = Req.GetCapture(1);
+	std::string_view   Alias		 = Req.GetCapture(1);
 	if (Alias.empty())
 	{
 		return ServerRequest.WriteResponse(HttpResponseCode::BadRequest,
@@ -608,7 +608,7 @@ void
 HttpWorkspacesService::ShareAliasChunkInfoRequest(HttpRouterRequest& Req)
 {
 	HttpServerRequest& ServerRequest = Req.ServerRequest();
-	std::string		   Alias		 = Req.GetCapture(1);
+	std::string_view   Alias		 = Req.GetCapture(1);
 	if (Alias.empty())
 	{
 		return ServerRequest.WriteResponse(HttpResponseCode::BadRequest,
@@ -635,7 +635,7 @@ void
 HttpWorkspacesService::ShareAliasBatchRequest(HttpRouterRequest& Req)
 {
 	HttpServerRequest& ServerRequest = Req.ServerRequest();
-	std::string		   Alias		 = Req.GetCapture(1);
+	std::string_view   Alias		 = Req.GetCapture(1);
 	if (Alias.empty())
 	{
 		return ServerRequest.WriteResponse(HttpResponseCode::BadRequest,
@@ -654,7 +654,7 @@ void
 HttpWorkspacesService::ShareAliasEntriesRequest(HttpRouterRequest& Req)
 {
 	HttpServerRequest& ServerRequest = Req.ServerRequest();
-	std::string		   Alias		 = Req.GetCapture(1);
+	std::string_view   Alias		 = Req.GetCapture(1);
 	if (Alias.empty())
 	{
 		return ServerRequest.WriteResponse(HttpResponseCode::BadRequest,
@@ -673,7 +673,7 @@ void
 HttpWorkspacesService::ShareAliasChunkRequest(HttpRouterRequest& Req)
 {
 	HttpServerRequest& ServerRequest = Req.ServerRequest();
-	std::string		   Alias		 = Req.GetCapture(1);
+	std::string_view   Alias		 = Req.GetCapture(1);
 	if (Alias.empty())
 	{
 		return ServerRequest.WriteResponse(HttpResponseCode::BadRequest,
@@ -700,7 +700,7 @@ void
 HttpWorkspacesService::ShareAliasRequest(HttpRouterRequest& Req)
 {
 	HttpServerRequest& ServerRequest = Req.ServerRequest();
-	std::string		   Alias		 = Req.GetCapture(1);
+	std::string_view   Alias		 = Req.GetCapture(1);
 	if (Alias.empty())
 	{
 		return ServerRequest.WriteResponse(HttpResponseCode::BadRequest,