folder-purger

folder-purger is a small service for keeping one or more directories under configured size limits.

It is used on-device by hivemapper-folder-purger.service to prevent recording directories from growing without bound.

Usage

Pass one or more path max-size pairs:

folder-purger /data/recording/unprocessed_framekm 8000000000 /data/video 6500000000

Each max-size is interpreted as bytes by default. A value ending in % is interpreted as a percentage of the filesystem size at startup.

Behavior

On startup, and then every five minutes, the purger:

1. Computes the total size of each configured directory.
2. Includes files in subdirectories when calculating size.
3. If the directory is over its configured limit, removes 80% of its top-level items, oldest mtime first.

Top-level items can be files or directories. For directories, the directory's own mtime is used for ordering, and the directory is removed as a whole.

Limitation:

The service does not currently delete just enough items to land exactly on the configured limit.