Choking Strategy And Super-Seeding Configuration

• Status: Accepted
• Date: 2025-12-14
• Context:
  • TORRENT_GAPS requires configurable choke/unchoke strategy and super-seeding defaults.
  • We must keep config/runtime/FFI/native paths aligned while preserving safe defaults.
  • API and persistence need to surface new knobs without regressing existing behaviour.
• Decision:
  • Added engine profile fields for choking (choking_algorithm, seed_choking_algorithm, strict_super_seeding, optimistic_unchoke_slots, max_queued_disk_bytes) and super_seeding.
  • Normalise/validate values with guard-rail warnings; persist via a single stored-proc update path and migration 0006_choking_and_super_seeding.sql (consolidated into 0007_rebaseline.sql per ADR 030).
  • Thread new options through runtime config, FFI structs, and native session (settings_pack + per-torrent flags). Per-torrent super_seeding overrides are stored with metadata.
  • Updated API models/OpenAPI and added tests covering canonicalisation, clamping, and FFI planning.
• Consequences:
  • Engine config now exposes advanced choke/seeding controls; defaults remain safe (fixed_slots, round_robin, super-seeding off).
  • Metadata format and DB schema gain new fields; migration is required before runtime use.
  • Native session applies and can reset choking settings; add-path respects per-torrent super-seeding.
• Follow-up:
  • Expand native coverage for strict super-seeding and queue byte limits when integration harness is available.
  • Monitor telemetry for churn when users toggle new fields; add UX help text where appropriate.