P0 — level rework + redaction:
- info now carries only lifecycle, per-post business results (sent /
forwarded / copied / template applied), admin actions and anomalies
(upload fallback, retry enqueue; dead-letter stays error).
- Per-request detail moved to debug: message/command logging, URL
extraction, fetching/fetched, link-cache hits, media-group batch sends,
queue processing (enqueue/processing/completed/rescheduled), photo
processing (downscale/transcode), inline queries, sensitive-tweet note.
- Full user-submitted URLs and message text now appear only at debug; at
info and above links are printed via the normalized cache key.
P1 — request correlation:
- handlers::log_key() maps a URL to its normalized post key
(twitter:<id> / pixiv:<id> / bsky:<handle>/<rkey>). The whole lifecycle
of one link (fetch -> send -> cache -> fallback) now logs [key=...], so
multi-worker logs can be correlated by grepping the key.
Convention documented in AGENTS.md.
Every DB operation (queue lease/enqueue, chat_state get/set, link_cache
read/write) used to open a fresh connection — including the busy timeout
and WAL pragma — then close it, on every message, URL job and callback.
Replace with DbPool: a tiny pool (4 connections max, semaphore-bounded
concurrency for backpressure) whose with_conn() method runs the closure on
a pooled connection inside spawn_blocking. Steady-state cost of an
operation is a list pop + semaphore acquire instead of a connection open.
The lease/earliest_run_after queries full-scanned tasks, and the
rollback journal blocked readers behind worker writes. journal_mode=WAL
(persistent, idempotent) plus idx_tasks_pending(status, run_after)
covers both without a schema migration.
A lease error (e.g. persistent SQLITE_BUSY) while rows are due made the
worker spin with sleep(0), hammering SQLite and flooding the log.
lease_next now returns the error and the loop sleeps 1s before retrying.
notify_waiters drops the notification when every worker is between its
DB reads and registering notified(); a task enqueued in that window sat
until a stale timer fired. notify_one stores a permit, so the next
worker to wait wakes immediately and re-leases. stop() still wakes all
workers with notify_waiters.
Every network retry hard-coded retry_delay_seconds(0), so backoff was
flat at 1.2-1.8s regardless of attempt; a multi-minute outage dead-
lettered after three rapid tries. The queue now scales the handler's
delay by 2^attempts (cap 300s) before rescheduling.
Rows left in_progress by a panicked/crashed worker were only recovered at
start(); a runtime sweep (30s interval, woken by the same notify) now
re-queues them once the 120s lock TTL expires. Workers run under a
supervisor that respawns a panicked loop instead of silently shrinking
the pool of 4.
Converge the duplicated open_db (open + busy_timeout) and the
spawn_blocking + expect ceremony that every table access repeated
into one db.rs module. ChatStore no longer creates the tasks table
(schema ownership: queue.rs owns tasks, state.rs chat_state,
link_cache.rs link_cache). No schema or behavior change - all
CREATE TABLE statements are byte-identical, IF NOT EXISTS stays
idempotent, so existing data/task_queue.db files need no migration.