axiom-storage-management-ref

iOS purge priority follows file location, clearing temporary data first, then caches, while preserving documents. Selecting appropriate storage locations ensures critical data survives storage pressure while purgeable content gets cleaned automatically.

Apply backup exclusion attributes via URLResourceValues to mark large cache or retrievable content, preventing it from inflating iOS backups. This keeps locally stored retrievable data available on-device without consuming backup storage capacity.

Query URLResourceValues for available and total volume capacity to determine if sufficient disk space exists before writing files. This informs write decisions by distinguishing important storage usage from opportunistic data allocation under limited disk space.

Mark app data as purgeable by storing retrievable content in caches directories and applying purgeable attributes via URLResourceValues. This allows the system to automatically clean up non-critical data during background storage pressure events.

Detect low storage pressure by monitoring volume capacity APIs and trigger proactive cleanup of purgeable cache data. Responding to limited disk space with automatic cleanup of non-critical content maintains app reliability and preserves user experience.

Purgeable data is retrievable content the system can automatically delete during storage pressure, while non-purgeable data includes important user documents. Location-based purge priorities across temporary, caches, and documents directories determine automatic deletion behavior.