Claude
b57dbd0fa0
Implements a PostgreSQL logical replication module that streams WAL changes, buffers them per XID for transaction atomicity, and publishes CacheKey invalidation events to the existing framework broadcast channel. Key design choices: - Transaction atomicity: changes are buffered until COMMIT so the fanout always receives a consistent view. A 1000-row bulk-insert emits one table-level CacheKey, not 1000 row events. - Native protocol: uses a self-contained raw TCP + postgres-protocol implementation for the replication connection (tokio-postgres 0.7 does not expose copy_both_simple publicly). - Corrected pgoutput v1 parser: original maybe_sql_integration code incorrectly read XID from DML messages; DML messages carry no XID in proto v1 — only Begin does. - Clean integration: publishes CacheKey::Channel events to store.events so the existing fanout task picks them up with zero changes to the fanout loop. - New cx.subscribe(key) API on RenderContext for manually registering subscription keys (needed when queries go through PgPool, not cx.run). New files: src/pg_replication/mod.rs — PgReplicationListener, key helpers src/pg_replication/wal_parser.rs — pgoutput v1 binary protocol parser src/pg_replication/emitter.rs — WalEmitter (tx-buffering + CacheKey emit) src/pg_replication/proto.rs — raw TCP PG wire-protocol connection examples/pg_replication/main.rs — live message board example docker-compose.yml — PG 16 container with wal_level=logical Run the example: docker compose up -d cargo run --example pg_replication --features pg_replication https://claude.ai/code/session_01SLGgXeqKV2o7KTmCaQZZPg