Stored data
- Post meta on each attachment:
_lh_disk_usage_bytes (original plus variants) and _lh_disk_usage_original_bytes, rewritten whenever the attachment’s metadata is saved. Both keys are filterable.
- Option
lh_disk_usage_backfill_done on each site, set (to a GMT time) once every attachment has been measured.
- Network table
{base_prefix}lh_disk_usage_snapshots on the main site: one row per install scan with its root, depth, driver, completeness, total and a JSON payload of the tree and large files. The newest 20 are kept. Its schema is tracked by the network option lh_disk_usage_snapshots_schema_version.
- Network options
lh_disk_usage_site_storage (each site’s latest measurement) and lh_disk_usage_measure_cursor (where an unfinished pass resumes), and the network transient lh_disk_usage_legacy_meta_count.
- Site totals are cached in the object cache group
lh_disk_usage for an hour and cleared whenever an attachment is measured or deleted.
Cron
lh_disk_usage_backfill: single events on each site, scheduled from admin_init until the backfill is done, measuring 100 unmeasured attachments every 30 seconds.lh_disk_usage_measure_sites: daily on the main site, measuring sites until the 20-second budget has passed between sites; an unfinished pass reschedules itself a minute later with the argument continue.
Filters
lh_disk_usage_init_plugin: return false to stop the plugin loading.lh_disk_usage_return_capability (default manage_options) and lh_disk_usage_return_network_capability (default install_plugins).lh_disk_usage_calculate: the measurement of one attachment, with the attachment ID and metadata.lh_disk_usage_return_total_meta_key, lh_disk_usage_return_original_meta_key, lh_disk_usage_return_backfill_batch_size (100).lh_disk_usage_use_shell (true): return false to always use the PHP driver.lh_disk_usage_return_shell_time_budget (240 seconds per du or find command, always held 30 seconds under PHP’s max_execution_time) and lh_disk_usage_return_time_budget (20 seconds, for the PHP walk and between sites).lh_disk_usage_return_max_depth (4), lh_disk_usage_return_max_children (30 per directory), lh_disk_usage_return_large_file_bytes (10 MB), lh_disk_usage_return_large_file_limit (50).lh_disk_usage_return_allowed_roots: the directories a scan can start from, as key => path. Every path is still checked to be inside the install.lh_disk_usage_return_snapshots_keep (20) and lh_disk_usage_return_legacy_meta_keys (SS88MLFS, SS88MLFSV).