Changeset 253 in code for trunk/upstream.go

Timestamp:

Apr 10, 2020, 5:22:47 PM (5 years ago)

Author:

contact

Message:

Per-entity ring buffers

Instead of having one ring buffer per network, each network has one ring
buffer per entity (channel or nick). This allows history to be more
fair: if there's a lot of activity in a channel, it won't prune activity
in other channels.

We now track history sequence numbers per client and per network in
networkHistory. The overall list of offline clients is still tracked in
network.offlineClients.

When all clients have received history, the ring buffer can be released.

In the future, we should get rid of too-old offline clients to avoid
having to maintain history for them forever. We should also add a
per-user limit on the number of ring buffers.

File:

• trunk/upstream.go (modified) (4 diffs)

trunk/upstream.go

@@ -557 +557 @@
                                 ch.Members[newNick] = membership
                                 uc.appendLog(ch.Name, msg)
+                                uc.appendHistory(ch.Name, msg)
                         }
                 }
 
                 if !me {
-                        uc.network.ring.Produce(msg)
                         uc.forEachDownstream(func(dc *downstreamConn) {
                                 dc.SendMessage(dc.marshalMessage(msg, uc))
@@ -663 +663 @@
 
                                 uc.appendLog(ch.Name, msg)
+                                uc.appendHistory(ch.Name, msg)
                         }
                 }
 
                 if msg.Prefix.Name != uc.nick {
-                        uc.network.ring.Produce(msg)
                         uc.forEachDownstream(func(dc *downstreamConn) {
                                 dc.SendMessage(dc.marshalMessage(msg, uc))
@@ -1295 +1295 @@
 }
 
+// appendHistory appends a message to the history. entity can be empty.
+func (uc *upstreamConn) appendHistory(entity string, msg *irc.Message) {
+        // If no client is offline, no need to append the message to the buffer
+        if len(uc.network.offlineClients) == 0 {
+                return
+        }
+
+        history, ok := uc.network.history[entity]
+        if !ok {
+                history = &networkHistory{
+                        offlineClients: make(map[string]uint64),
+                        ring:           NewRing(uc.srv.RingCap),
+                }
+                uc.network.history[entity] = history
+
+                for clientName, _ := range uc.network.offlineClients {
+                        history.offlineClients[clientName] = 0
+                }
+        }
+
+        history.ring.Produce(msg)
+}
+
 // produce appends a message to the logs, adds it to the history and forwards
 // it to connected downstream connections.
@@ -1305 +1328 @@
         }
 
-        uc.network.ring.Produce(msg)
+        uc.appendHistory(target, msg)
 
         uc.forEachDownstream(func(dc *downstreamConn) {