Optimize RPN execution to reduce FPS overhead via deduplication #33
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While multiple clients Add(MF.SimVars.Add.xxxxRPNcodexxx) the exact same SimVars to WASM,
From MSFS2020 perspective, it is unnecessary to execute the same RPNcode several times in each frame. This is an enhancement change to reduce FPS impact
WASM will smartly execute duplicated SimVars only once in each frame.
introduce new data structure:
//RPN code execution for reading values in every frame
struct ReadRPNCode {
std::string Code;
int RetType; //RetType: 0:float 1:integer 2:string
std::vector<SimVar> SimVars;
std::vector<StringSimVar> StringSimVars;
};
--
This patch is stable because we have 1000+ customers who have been using these changes over a year
cpuwolf
changed the title
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Description:
This PR introduces a performance enhancement for handling multiple clients subscribing to identical SimVars. Currently, if multiple clients add the same RPN code (e.g., via MF.SimVars.Add), the WASM module executes the code redundantly for every instance within a single frame.
Changes:
Implemented a "calculate once, distribute to many" logic. The WASM module will now detect duplicate RPN codes and execute them only once per frame.
Introduced a new ReadRPNCode structure to manage the mapping of single code executions to multiple SimVars/StringSimVars.
Stability:
This patch is highly stable and production-ready. It has been deployed to over 1,000 customers for more than a year with no reported issues.