snapshot of https://github.com/centrifugal/centrifugo.git (master, 2026-09-16; blobs > 131072B omitted)

internal/proxy/sub_refresh_handler.go

@@ -0,0 +1,153 @@
+package proxy
+
+import (
+	"encoding/base64"
+	"time"
+
+	"github.com/centrifugal/centrifugo/v6/internal/configtypes"
+	"github.com/centrifugal/centrifugo/v6/internal/metrics"
+	"github.com/centrifugal/centrifugo/v6/internal/proxyproto"
+
+	"github.com/centrifugal/centrifuge"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/rs/zerolog/log"
+)
+
+// SubRefreshHandlerConfig ...
+type SubRefreshHandlerConfig struct {
+	Proxies map[string]SubRefreshProxy
+}
+
+// SubRefreshHandler ...
+type SubRefreshHandler struct {
+	config    SubRefreshHandlerConfig
+	summary   map[string]prometheus.Observer
+	histogram map[string]prometheus.Observer
+	errors    map[string]prometheus.Counter
+	inflight  map[string]prometheus.Gauge
+}
+
+// NewSubRefreshHandler ...
+func NewSubRefreshHandler(c SubRefreshHandlerConfig) *SubRefreshHandler {
+	h := &SubRefreshHandler{
+		config: c,
+	}
+	summary := map[string]prometheus.Observer{}
+	histogram := map[string]prometheus.Observer{}
+	errors := map[string]prometheus.Counter{}
+	inflight := map[string]prometheus.Gauge{}
+	for name, p := range c.Proxies {
+		summary[name] = metrics.ProxyCallDurationSummary.WithLabelValues(p.Protocol(), "sub_refresh", name)
+		histogram[name] = metrics.ProxyCallDurationHistogram.WithLabelValues(p.Protocol(), "sub_refresh", name)
+		errors[name] = metrics.ProxyCallErrorCount.WithLabelValues(p.Protocol(), "sub_refresh", name)
+		inflight[name] = metrics.ProxyCallInflightRequests.WithLabelValues(p.Protocol(), "sub_refresh", name)
+	}
+	h.summary = summary
+	h.histogram = histogram
+	h.errors = errors
+	h.inflight = inflight
+	return h
+}
+
+type SubRefreshExtra struct {
+}
+
+// SubRefreshHandlerFunc ...
+type SubRefreshHandlerFunc func(Client, centrifuge.SubRefreshEvent, configtypes.ChannelOptions, PerCallData) (centrifuge.SubRefreshReply, SubRefreshExtra, error)
+
+// Handle refresh.
+func (h *SubRefreshHandler) Handle() SubRefreshHandlerFunc {
+	return func(client Client, e centrifuge.SubRefreshEvent, chOpts configtypes.ChannelOptions, pcd PerCallData) (centrifuge.SubRefreshReply, SubRefreshExtra, error) {
+		started := time.Now()
+
+		var p SubRefreshProxy
+		var summary prometheus.Observer
+		var histogram prometheus.Observer
+		var errors prometheus.Counter
+
+		proxyEnabled := chOpts.SubRefreshProxyEnabled
+		proxyName := chOpts.SubRefreshProxyName
+		if !proxyEnabled {
+			log.Info().Str("channel", e.Channel).Msg("sub refresh proxy not configured for a channel")
+			return centrifuge.SubRefreshReply{}, SubRefreshExtra{}, centrifuge.ErrorNotAvailable
+		}
+		p = h.config.Proxies[proxyName]
+		summary = h.summary[proxyName]
+		histogram = h.histogram[proxyName]
+		errors = h.errors[proxyName]
+		inflight := h.inflight[proxyName]
+		inflight.Inc()
+		defer inflight.Dec()
+
+		req := &proxyproto.SubRefreshRequest{
+			Client:    client.ID(),
+			Protocol:  string(client.Transport().Protocol()),
+			Transport: client.Transport().Name(),
+			Encoding:  getEncoding(p.UseBase64()),
+
+			User:    client.UserID(),
+			Channel: e.Channel,
+		}
+		if p.IncludeMeta() && pcd.Meta != nil {
+			req.Meta = proxyproto.Raw(pcd.Meta)
+		}
+		refreshRep, err := p.ProxySubRefresh(client.Context(), req)
+		duration := time.Since(started).Seconds()
+		if err != nil {
+			select {
+			case <-client.Context().Done():
+				// Client connection already closed.
+				return centrifuge.SubRefreshReply{}, SubRefreshExtra{}, centrifuge.DisconnectConnectionClosed
+			default:
+			}
+			summary.Observe(duration)
+			histogram.Observe(duration)
+			errors.Inc()
+			log.Error().Err(err).Str("client", client.ID()).Str("channel", e.Channel).Msg("error proxying sub refresh")
+			// In case of an error give connection one more minute to live and
+			// then try to check again. This way we gracefully handle temporary
+			// problems on application backend side.
+			// NOTE: this interval must be configurable maybe, but for now looks
+			// like a reasonable value.
+			return centrifuge.SubRefreshReply{
+				ExpireAt: time.Now().Unix() + 60,
+			}, SubRefreshExtra{}, nil
+		}
+		summary.Observe(duration)
+		histogram.Observe(duration)
+
+		result := refreshRep.Result
+		if result == nil {
+			// Subscription will be unsubscribed.
+			log.Error().Msg("no sub refresh result found")
+			return centrifuge.SubRefreshReply{
+				Expired: true,
+			}, SubRefreshExtra{}, nil
+		}
+
+		if result.Expired {
+			return centrifuge.SubRefreshReply{
+				Expired: true,
+			}, SubRefreshExtra{}, nil
+		}
+
+		var info []byte
+		if result.B64Info != "" {
+			decodedInfo, err := base64.StdEncoding.DecodeString(result.B64Info)
+			if err != nil {
+				log.Error().Err(err).Str("client", client.ID()).Msg("error decoding base64 info")
+				return centrifuge.SubRefreshReply{}, SubRefreshExtra{}, centrifuge.ErrorInternal
+			}
+			info = decodedInfo
+		} else {
+			info = result.Info
+		}
+
+		extra := SubRefreshExtra{}
+
+		return centrifuge.SubRefreshReply{
+			ExpireAt: result.ExpireAt,
+			Info:     info,
+		}, extra, nil
+	}
+}