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, 31 insertions, 14 deletions

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())
 	{