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Persistence Files

This reference documents the current eMuleBB runtime .met and .dat files found in the app source. It covers file roles, ownership, broad structure, and maintenance risk. It is not a replacement for the source readers and writers; use it as the map before touching a profile, writing migration code, or debugging profile corruption.

Most files live in the config/profile directory. Active download metadata lives beside the incomplete .part data in the configured temp directory.

Maintenance Rules

  • Close eMuleBB before hand-editing or replacing profile files.
  • Back up the full config directory and all temp directories before profile migration or recovery work.
  • Do not hand-edit binary profile files such as preferences.dat, known.met, known2_64.met, clients.met, .part.met, server.met, or nodes.dat.
  • Text policy files such as shareignore.dat, shareddir.dat, staticservers.dat, webservices.dat, and PreviewApps.dat are intended for controlled editing.
  • Cache files can usually be deleted to force rebuild, but identity, credits, known-file, part-file, and Kad preference files should be restored from backup instead of deleted during normal recovery.

Companion files such as .tmp, .new, .bak, .backup, and temp-* candidates are save, backup, download, or recovery artifacts. They are not separate profile authorities.

Format Families

  • Tag-vector .met
  • Files: known.met, .part.met, server.met

  • Shape: Binary header plus records carrying typed tags. Unknown tag IDs are usually skippable when the tag type is known.

  • Fixed binary state

  • Files: preferences.dat, preferencesKad.dat, nodes.dat, known2_64.met, Kad indexes

  • Shape: Versioned or fixed-field binary structures. Treat as implementation-owned.

  • Text lists

  • Files: shareddir.dat, shareignore.dat, addresses.dat, staticservers.dat, autocomplete .dat files

  • Shape: Line-oriented or simple text lists, normally editable through Tools or UI.

  • Derived caches

  • Files: sharedcache.dat, shareddups.dat, FakeFile.met, Kad indexes
  • Shape: Rebuildable acceleration or analysis state. Deletion can slow the next startup or scan.

Many legacy .met timestamps are stored as unsigned 32-bit Unix seconds. That does not have the signed-2038 storage limit, but the stored range still ends in 2106 and careless signed consumers can still mishandle values after 2038.

Identity And Peer State

  • preferences.dat: legacy binary preference and local identity state that complements preferences.ini. Preserve it and do not hand-edit it.
  • preferencesKad.dat: local Kad identity and Kad preference state. Current saves validate and promote prepared candidates; preserve it for Kad continuity.
  • cryptkey.dat: Base64 private key material for secure user identification and credit signing. Preserve it and keep it private.
  • collectioncryptkey.dat: Base64 key material for signed collection files. Preserve it if signed collections matter.
  • clients.met: peer credit database keyed by user hash. Preserve it for credit continuity and do not hand-edit it.
  • emfriends.met: friend list with hashes and last-known connection fields. Preserve it for friend list continuity.

Known, Shared, And Download State

  • known.met: canonical known-file database for shared files and remembered downloads. It stores file dates, MD4 hashsets, tags, AICH tags, last-shared time, and all-time transfer/request statistics. Current saves use a temporary file and atomic replacement.
  • known2_64.met: AICH recovery hashset store for known complete files. It is not general file metadata. The structure is uint8 version 0x02, then repeated AICH master hash, uint32 hash count, and 20-byte hashes.
  • known2.met: legacy AICH recovery hashset input converted to known2_64.met when needed. Do not add new metadata here.
  • cancelled.met: cancelled-download hash memory. It uses a binary header/version/seed/count plus hash records and tags, and is saved through the known metadata atomic path.
  • *.part.met: per-download resume metadata: file identity, hashes, name/size, priorities, categories, transfer stats, gaps, corrupted parts, and AICH state. It is critical for incomplete downloads and should not be hand-edited.
  • *.part.met.bak: previous .part.met snapshot kept for recovery. Keep it with its active download.
  • *.part.met.backup: additional recovered or imported part metadata backup. Keep it during recovery investigations.
  • sharedfiles.dat: single-file share list outside normal shared-directory roots. Preserve it if single-file shares are used.
  • sharedcache.dat: startup acceleration cache for large shared libraries. It reconnects directory snapshots to known.met metadata. It is disposable; deletion forces a slower rescan.
  • shareddups.dat: duplicate shared-path cache. It is disposable and can be rebuilt.

known.met and .part.met are tag-based and are the natural place for durable file statistics. known2_64.met is keyed by AICH hash and stores only recovery hashsets, so it should not be used for GUI statistics or request timestamps.

Sharing Policy Files

  • shareddir.dat: main configured shared-directory roots. It is a text path list and is user-editable while the app is closed or through Tools.
  • shareddir.monitored.dat: roots watched for automatic share changes. It is a text path list; edit with care.
  • shareddir.monitor-owned.dat: directories added and owned by monitored-share automation. Prefer app-managed edits.
  • shareddir.monitor-journal.dat: monitored-share journal state used to track observed root state. Preserve it for continuity, or rebuild by rescanning.
  • shareignore.dat: additive ignore rules for shared-file scanning. It is a commented text rule file; reload through the app after edits.
  • FakeFileFilter.dat: local fake-file signal rules. It is user-editable when maintaining fake-file detection inputs.
  • FakeFile.met: fake-file analyzer cache. It is disposable; deletion loses cached analysis only.

Network And Bootstrap Files

  • server.met: persisted eD2K server list and imported server-list payload format. It uses binary server records with typed tags. Current update paths validate candidates before promotion.
  • staticservers.dat: user-maintained static eD2K servers. It is a text list.
  • addresses.dat: server-list update URLs, seeded when missing or blank. It is user-editable text.
  • nodes.dat: Kad routing/bootstrap contact snapshot and downloaded bootstrap payload format. It stores binary Kad contacts and supports normal and bootstrap-only handling. Current import validates before replacement.
  • nodes.fastkad.dat: eMuleBB Fast Kad sidecar with contact health and response metadata. It improves bootstrap quality and can rebuild over time.
  • src_index.dat: Kad indexed source records. This is derived local DHT state.
  • key_index.dat: Kad keyword index records. This is derived local DHT state.
  • load_index.dat: Kad load-tracking index records. This is derived local DHT state.

Filters, Services, And Tools Files

  • ipfilter.dat: IP filter rules for peers, sources, Kad contacts, and servers. It is text ranges with level and optional description; see the IP Filters guide for syntax.
  • webservices.dat: external web-service command definitions used by UI actions. It is commented text configuration.
  • PreviewApps.dat: preview application command configuration. Keep command quoting narrow and explicit.
  • onlinesig.dat: small online-signature status output for external consumers. It is runtime output and is usually not edited.

UI History And Autocomplete Files

  • AC_BootstrapIPs.dat: Kad bootstrap IP autocomplete/history.
  • AC_IPFilterUpdateURLs.dat: IP filter update URL autocomplete/history.
  • AC_SearchStrings.dat: search string autocomplete/history.
  • AC_ServerMetURLs.dat: server-list URL autocomplete/history.
  • AC_VF_RegExpr.dat: view/filter regular-expression autocomplete/history.
  • SearchSpam.met: app-managed search spam filter state. It can be rebuilt from future search activity.
  • StoredSearches.met: stored search state. Preserve it if stored searches matter.

Autocomplete files are text lists. Deleting them is safe, but it loses local history.

Temporary And Backup Patterns

Pattern Role Maintenance
*.tmp, *.new Prepared save candidates used before replacement. Normally transient. Investigate only after failed saves.
*.bak, *.backup Prior snapshots or recovery backups. Keep until the corresponding live file is known good.
temp-*-server.met, temp-*-nodes.dat Downloaded update candidates before validation and promotion. Transient. Not authoritative profile state.
*.part.met.tmp Prepared part-file metadata save candidate. Transient. Live .part.met and backups are authoritative.

Recovery Priorities

If a profile is damaged, restore files in this order:

  1. Identity and trust: preferences.dat, preferencesKad.dat, cryptkey.dat, clients.met.
  2. Incomplete downloads: all .part, .part.met, .part.met.bak, and .part.met.backup companions from the temp directories.
  3. Known/shared metadata: known.met, known2_64.met, cancelled.met, share directory files, and monitored-share files.
  4. Network startup state: server.met, nodes.dat, nodes.fastkad.dat, addresses.dat, and staticservers.dat.
  5. Caches and histories: shared caches, Kad indexes, fake-file cache, autocomplete files, and online-signature output.

When in doubt, keep the file and let the app decide whether it is usable. The current code has validation and recovery paths for several critical files, but manual deletion can discard evidence that would otherwise be recoverable.