fix: switch to conditionally constructed from conditionally executed

Author: jm-clius

packages/sds/src/message_channel/message_channel.ts

@@ -53,7 +53,12 @@ export interface MessageChannelOptions {
    */
   possibleAcksThreshold?: number;
   /**
-   * SDS-R repair configuration. If not provided, repair is enabled with default settings.
+   * Whether to enable SDS-R repair protocol.
+   * @default true
+   */
+  enableRepair?: boolean;
+  /**
+   * SDS-R repair configuration. Only used if enableRepair is true.
    */
   repairConfig?: RepairConfig;
 }
@@ -76,7 +81,7 @@ export class MessageChannel extends TypedEventEmitter<MessageChannelEvents> {
   private readonly causalHistorySize: number;
   private readonly possibleAcksThreshold: number;
   private readonly timeoutForLostMessagesMs?: number;
-  private readonly repairManager: RepairManager;
+  private readonly repairManager?: RepairManager;
 
   private tasks: Task[] = [];
   private handlers: Handlers = {
@@ -120,13 +125,17 @@ export class MessageChannel extends TypedEventEmitter<MessageChannelEvents> {
       options.possibleAcksThreshold ?? DEFAULT_POSSIBLE_ACKS_THRESHOLD;
     this.timeReceived = new Map();
     this.timeoutForLostMessagesMs = options.timeoutForLostMessagesMs;
-    this.repairManager = new RepairManager(
-      senderId,
-      options.repairConfig,
-      (event: string, detail: unknown) => {
-        this.safeSendEvent(event as MessageChannelEvent, { detail });
-      }
-    );
+
+    // Only construct RepairManager if repair is enabled (default: true)
+    if (options.enableRepair ?? true) {
+      this.repairManager = new RepairManager(
+        senderId,
+        options.repairConfig,
+        (event: string, detail: unknown) => {
+          this.safeSendEvent(event as MessageChannelEvent, { detail });
+        }
+      );
+    }
   }
 
   public static getMessageId(payload: Uint8Array): MessageId {
@@ -381,9 +390,8 @@ export class MessageChannel extends TypedEventEmitter<MessageChannelEvents> {
   public async sweepRepairIncomingBuffer(
     callback?: (message: Message) => Promise<boolean>
   ): Promise<Message[]> {
-    const repairsToSend = this.repairManager.sweepIncomingBuffer(
-      this.localHistory
-    );
+    const repairsToSend =
+      this.repairManager?.sweepIncomingBuffer(this.localHistory) ?? [];
 
     if (callback) {
       for (const message of repairsToSend) {
@@ -426,9 +434,9 @@ export class MessageChannel extends TypedEventEmitter<MessageChannelEvents> {
     this.lamportTimestamp = lamportTimestampIncrement(this.lamportTimestamp);
 
     // Get repair requests to include in sync message (SDS-R)
-    const repairRequests = this.repairManager.getRepairRequests(
-      MAX_REPAIR_REQUESTS_PER_MESSAGE
-    );
+    const repairRequests =
+      this.repairManager?.getRepairRequests(MAX_REPAIR_REQUESTS_PER_MESSAGE) ??
+      [];
 
     const message = new SyncMessage(
       // does not need to be secure randomness
@@ -542,7 +550,7 @@ export class MessageChannel extends TypedEventEmitter<MessageChannelEvents> {
     }
 
     // SDS-R: Handle received message in repair manager
-    this.repairManager.markMessageReceived(message.messageId);
+    this.repairManager?.markMessageReceived(message.messageId);
 
     // SDS-R: Process incoming repair requests
     if (message.repairRequest && message.repairRequest.length > 0) {
@@ -554,7 +562,7 @@ export class MessageChannel extends TypedEventEmitter<MessageChannelEvents> {
         }
       });
 
-      this.repairManager.processIncomingRepairRequests(
+      this.repairManager?.processIncomingRepairRequests(
         message.repairRequest,
         this.localHistory
       );
@@ -582,7 +590,7 @@ export class MessageChannel extends TypedEventEmitter<MessageChannelEvents> {
       );
 
       // SDS-R: Track missing dependencies in repair manager
-      this.repairManager.markDependenciesMissing(missingDependencies);
+      this.repairManager?.markDependenciesMissing(missingDependencies);
 
       this.safeSendEvent(MessageChannelEvent.InMessageMissing, {
         detail: Array.from(missingDependencies)
@@ -648,9 +656,10 @@ export class MessageChannel extends TypedEventEmitter<MessageChannelEvents> {
       log.info(this.senderId, "sending new message", messageId);
 
       // Get repair requests to include in the message (SDS-R)
-      const repairRequests = this.repairManager.getRepairRequests(
-        MAX_REPAIR_REQUESTS_PER_MESSAGE
-      );
+      const repairRequests =
+        this.repairManager?.getRepairRequests(
+          MAX_REPAIR_REQUESTS_PER_MESSAGE
+        ) ?? [];
 
       message = new ContentMessage(
         messageId,

packages/sds/src/message_channel/repair/repair.ts

@@ -37,8 +37,6 @@ export interface RepairConfig {
   numResponseGroups?: number;
   /** Maximum buffer size for repair requests */
   bufferSize?: number;
-  /** Whether repair is enabled */
-  enabled?: boolean;
 }
 
 /**
@@ -48,8 +46,7 @@ export const DEFAULT_REPAIR_CONFIG: Required<RepairConfig> = {
   tMin: 30000, // 30 seconds
   tMax: 120000, // 120 seconds
   numResponseGroups: 1, // Recommendation is 1 group per PARTICIPANTS_PER_RESPONSE_GROUP participants
-  bufferSize: 1000,
-  enabled: true
+  bufferSize: 1000
 };
 
 /**
@@ -141,10 +138,6 @@ export class RepairManager {
     missingEntries: HistoryEntry[],
     currentTime = Date.now()
   ): void {
-    if (!this.config.enabled) {
-      return;
-    }
-
     for (const entry of missingEntries) {
       // Calculate when to request this repair
       const tReq = this.calculateTReq(entry.messageId, currentTime);
@@ -198,10 +191,6 @@ export class RepairManager {
     maxRequests = 3,
     currentTime = Date.now()
   ): HistoryEntry[] {
-    if (!this.config.enabled) {
-      return [];
-    }
-
     return this.outgoingBuffer.getEligible(currentTime, maxRequests);
   }
 
@@ -214,10 +203,6 @@ export class RepairManager {
     localHistory: ILocalHistory,
     currentTime = Date.now()
   ): void {
-    if (!this.config.enabled) {
-      return;
-    }
-
     for (const request of requests) {
       // Remove from our own outgoing buffer (someone else is requesting it)
       this.outgoingBuffer.remove(request.messageId);
@@ -278,10 +263,6 @@ export class RepairManager {
     maxRequests = 3,
     currentTime = Date.now()
   ): HistoryEntry[] {
-    if (!this.config.enabled) {
-      return [];
-    }
-
     return this.getRepairRequests(maxRequests, currentTime);
   }
 
@@ -293,10 +274,6 @@ export class RepairManager {
     localHistory: ILocalHistory,
     currentTime = Date.now()
   ): Message[] {
-    if (!this.config.enabled) {
-      return [];
-    }
-
     const ready = this.incomingBuffer.getReady(currentTime);
     const messages: Message[] = [];
 
@@ -321,13 +298,6 @@ export class RepairManager {
     this.incomingBuffer.clear();
   }
 
-  /**
-   * Check if repair is enabled
-   */
-  public get isEnabled(): boolean {
-    return this.config.enabled;
-  }
-
   /**
    * Update number of response groups (e.g., when participants change)
    */