Refactor logString method for efficiency#88
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Refactor logString to use snprintf for better performance and avoid heap fragmentation.
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Pull request overview
This PR refactors UDPLogger::logString to reduce heap allocations by avoiding String concatenation and instead formatting into a fixed-size buffer (intended to reduce heap fragmentation on frequent logging, e.g., during periodic NTP updates).
Changes:
- Changed
logStringto takeconst String&instead of takingStringby value. - Replaced
Stringconcatenation +toCharArraywithsnprintfinto_packetBufferand reused that buffer for UDP output. - Adjusted Serial logging to print the formatted buffer (now also subject to truncation).
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This was referenced Jul 11, 2026
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Integrate PR #88: Refactor logString method for efficiency
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Refactor logString to use snprintf for better performance and avoid heap fragmentation. The problem:
logString()takes the String by copy (notconst String&), AND internally builds yet another new string on top of that. So every single log call causes multiple heap allocations/deallocations instead of just one.(Internal concatenation → snprintf into existing fixed buffer)
The fatal part: this logger gets triggered automatically every 30 seconds – on every NTP update: