From 2f34cfa5884cddde8aca37f57bedab56557ac45f Mon Sep 17 00:00:00 2001
From: Tony Garnock-Jones <tonyg@leastfixedpoint.com>
Date: Sun, 3 Dec 2023 23:05:49 +0100
Subject: [PATCH] suppressCycleWarning

---
 packages/core/src/runtime/dataflow.ts | 21 ++++++++++++++++++++-
 packages/ws-relay/src/index.ts        |  1 +
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/packages/core/src/runtime/dataflow.ts b/packages/core/src/runtime/dataflow.ts
index 5176bce..db2447d 100644
--- a/packages/core/src/runtime/dataflow.ts
+++ b/packages/core/src/runtime/dataflow.ts
@@ -10,6 +10,7 @@ import * as MapSet from './mapset.js';
 export interface ObservingGraph<ObjectId> {
     recordObservation(objectId: ObjectId): void;
     recordDamage(objectId: ObjectId): void;
+    suppressCycleWarning(objectId: ObjectId): void;
 }
 
 export class Graph<SubjectId, ObjectId> implements ObservingGraph<ObjectId> {
@@ -17,6 +18,7 @@ export class Graph<SubjectId, ObjectId> implements ObservingGraph<ObjectId> {
     readonly edgesReverse: FlexMap<SubjectId, FlexSet<ObjectId>>;
     damagedNodes: FlexSet<ObjectId>;
     currentSubjectId: SubjectId | undefined;
+    cyclicWarningSuppressed: FlexSet<ObjectId> | undefined;
 
     constructor(
         public readonly subjectIdCanonicalizer: Canonicalizer<SubjectId>,
@@ -65,13 +67,26 @@ export class Graph<SubjectId, ObjectId> implements ObservingGraph<ObjectId> {
         return Array.from(subjects);
     }
 
+    suppressCycleWarning(objectId: ObjectId): void {
+        if (this.cyclicWarningSuppressed === void 0) {
+            this.cyclicWarningSuppressed = new FlexSet(this.objectIdCanonicalizer);
+        }
+        this.cyclicWarningSuppressed.add(objectId);
+    }
+
     repairDamage(repairNode: (subjectId: SubjectId) => void) {
         let repairedThisRound = new FlexSet(this.objectIdCanonicalizer);
+        let suppressed = new FlexSet(this.objectIdCanonicalizer);
         while (true) {
+            if (this.cyclicWarningSuppressed !== void 0) {
+                suppressed = suppressed.union(this.cyclicWarningSuppressed);
+                this.cyclicWarningSuppressed = void 0;
+            }
+
             let workSet = this.damagedNodes;
             this.damagedNodes = new FlexSet(this.objectIdCanonicalizer);
 
-            const alreadyDamaged = workSet.intersect(repairedThisRound);
+            const alreadyDamaged = workSet.intersect(repairedThisRound).subtract(suppressed);
             if (alreadyDamaged.size > 0) {
                 console.warn('Cyclic dependencies involving', this.formatCycle(alreadyDamaged));
             }
@@ -105,6 +120,10 @@ export abstract class Cell {
         this.__value = initial;
     }
 
+    suppressCycleWarning() {
+        this.graph.suppressCycleWarning(this);
+    }
+
     observe(): unknown {
         this.graph.recordObservation(this);
         return this.__value;
diff --git a/packages/ws-relay/src/index.ts b/packages/ws-relay/src/index.ts
index 95b6b3f..420ad83 100644
--- a/packages/ws-relay/src/index.ts
+++ b/packages/ws-relay/src/index.ts
@@ -153,6 +153,7 @@ export function boot(ds = Dataspace.global, debug: boolean = false, WebSocketCon
                 field best: TransportState | null = null;
                 field rootPeer: Ref | null = null;
                 dataflow {
+                    best.suppressCycleWarning();
                     best.value = null;
                     for (const c of candidates.value) {
                         best.value = c;