Struct PGPubsub

coderd/database/pubsub/pubsub.go:211–238

PGPubsub is a pubsub implementation using PostgreSQL.

// PGPubsub is a pubsub implementation using PostgreSQL.
type PGPubsub struct {
	logger     slog.Logger
	listenDone chan struct{}
	pgListener pqListener
	db         *sql.DB

	qMu    sync.Mutex
	queues map[string]*queueSet

	// making the close state its own mutex domain simplifies closing logic so
	// that we don't have to hold the qMu --- which could block processing
	// notifications while the pqListener is closing.
	closeMu          sync.Mutex
	closedListener   bool
	closeListenerErr error

	publishesTotal      *prometheus.CounterVec
	subscribesTotal     *prometheus.CounterVec
	messagesTotal       *prometheus.CounterVec
	publishedBytesTotal prometheus.Counter
	receivedBytesTotal  prometheus.Counter
	disconnectionsTotal prometheus.Counter
	connected           prometheus.Gauge

	latencyMeasurer       *LatencyMeasurer
	latencyMeasureCounter atomic.Int64
	latencyErrCounter     atomic.Int64
}

// BufferSize is the maximum number of unhandled messages we will buffer
// for a subscriber before dropping messages.