Compute load latency given a query-start timestamp and the current
timestamp. Returns 0 when the start is falsy (undefined or 0). The
truthy check matches the original startTime || Date.now() fallback
pattern in the spatial-index loader, so a missing start yields a
latency of 0 rather than a huge nonsense value.
Compute load latency given a query-start timestamp and the current timestamp. Returns 0 when the start is falsy (undefined or 0). The truthy check matches the original
startTime || Date.now()fallback pattern in the spatial-index loader, so a missing start yields a latency of 0 rather than a huge nonsense value.