Method clientFromIDs

engine/server/session.go:761–806

(sessID, clientID string)

}

func (srv *Server) clientFromIDs(sessID, clientID string) (*daggerClient, error) {
	if sessID == "" {
		return nil, fmt.Errorf("missing session ID")
	}
	if clientID == "" {
		return nil, fmt.Errorf("missing client ID")
	}
	srv.daggerSessionsMu.RLock()
	sess, ok := srv.daggerSessions[sessID]
	srv.daggerSessionsMu.RUnlock()
	if !ok {
		// This error can happen due to per-LLB-vertex deduplication in the buildkit solver,
		// where for instance the first client cancels and closes its session while others
		// are waiting on the result. In this case its safe to retry the operation again with
		// the still connected client metadata.
		err := flightcontrol.RetryableError{Err: fmt.Errorf("session %q not found", sessID)}
		return nil, err
	}

	// The session pointer is published before initializeDaggerSession populates
	// its fields, so gate on state under stateMu before reading them. stateMu is
	// taken only after releasing daggerSessionsMu to avoid inverting
	// removeDaggerSession's stateMu->daggerSessionsMu lock order.
	sess.stateMu.RLock()
	defer sess.stateMu.RUnlock()
	switch sess.state {
	case sessionStateInitialized:
		// continue
	case sessionStateRemoved:
		err := flightcontrol.RetryableError{Err: fmt.Errorf("session %q not found", sessID)}
		return nil, err
	case sessionStateUninitialized:
		return nil, fmt.Errorf("session %q not initialized", sessID)
	default:
		return nil, fmt.Errorf("session %q has unknown state %q", sessID, sess.state)
	}

	sess.clientMu.RLock()
	defer sess.clientMu.RUnlock()
	client, ok := sess.clients[clientID]
	if !ok {
		return nil, fmt.Errorf("client %q not found", clientID)
	}

	return client, nil
}

// initialize session+client if needed, return:
// * the initialized client