Initial Commit

packages/networking/drive/drive-webrtc/src/peer-manager/topology/full-mesh.ts

@@ -0,0 +1,50 @@
+/**
+ * Full-mesh topology — every peer connects to every other peer, up
+ * to `maxPeers`. When capacity is reached, the lowest-scoring
+ * existing peer is evicted to make room for the new arrival.
+ */
+
+import type { PeerInfo } from "../../types/peer.types.js";
+import {
+    type AdmitDecision,
+    pickLowestScore,
+    type TopologySelectOptions,
+    type TopologyStrategy,
+} from "./topology-strategy.js";
+
+export class FullMeshStrategy implements TopologyStrategy {
+    public readonly name = "full-mesh" as const;
+
+    public selectConnections(
+        currentPeers: readonly PeerInfo[],
+        newPeer: PeerInfo,
+        options: TopologySelectOptions
+    ): readonly PeerInfo[] {
+        if (newPeer.id === options.selfPeerId) return [];
+        if (currentPeers.length >= options.maxPeers) return [];
+        return [newPeer];
+    }
+
+    public admitOrEvict(
+        currentPeers: readonly PeerInfo[],
+        newPeer: PeerInfo,
+        options: TopologySelectOptions
+    ): AdmitDecision {
+        if (currentPeers.some((p) => p.id === newPeer.id)) {
+            return { admit: false };
+        }
+        if (currentPeers.length < options.maxPeers) {
+            return { admit: true };
+        }
+        const newScore = options.metricsFor?.(newPeer.id)?.score ?? 1;
+        const evictCandidate = pickLowestScore(
+            currentPeers,
+            options.metricsFor
+        );
+        if (evictCandidate === undefined) return { admit: false };
+        const evictScore =
+            options.metricsFor?.(evictCandidate.id)?.score ?? 0.5;
+        if (newScore <= evictScore) return { admit: false };
+        return { admit: true, evict: evictCandidate };
+    }
+}