QGIS » QGIS Application

Check file modified time when retrieving svg images from cache

If file has been modified since the cache, regenerate a new cache
image.

We don't want to check the file modified time too often though,
(e.g., we don't want to check for every point render in a 100k
point file), so use a hardcoded 30 second minimum time between
consecutive file modified checks.

This means that file modifications occuring more often than
every 30 seconds won't be picked up till 30 seconds has elapsed
since the last modification. But at the same time it means that
if the render takes < 30 seconds we'll only check each svg
at most once (and if a render takes > 30 seconds, adding a few
more milliseconds won't hurt!).

Fixes #13565