Amap Tech

Mar 23, 2020 · Fundamentals

Performance Optimization of bsdiff for In‑Car Navigation OTA Updates

To enable fast, low‑memory OTA updates on resource‑constrained car head units, Amap’s team reengineered bsdiff by adopting a divsufsort‑based variant, adding a sliding‑window buffer, and swapping Bzip2 for lightweight RLE with secondary compression, reducing patch time to 3‑5 seconds and memory usage to about 2 MB.