update interface naming and add comments

src/event-log/event-stream.ts

@@ -1,6 +1,6 @@
 import type { MessageStore } from '../types/message-store.js';
 import type { EventsSubscribeMessage, EventsSubscription } from '../types/events-types.js';
-import type { EventStream, Subscription } from '../types/subscriptions.js';
+import type { EventStream, SubscriptionHandler } from '../types/subscriptions.js';
 import type { Filter, KeyValues } from '../types/query-types.js';
 import type { GenericMessage, GenericMessageSubscription } from '../types/message-types.js';
 import type { RecordsSubscribeMessage, RecordsSubscription } from '../types/records-types.js';
@@ -25,7 +25,7 @@ export class EventStreamEmitter implements EventStream {
   private reauthorizationTTL: number;
 
   private isOpen: boolean = false;
-  private subscriptions: Map<string, Subscription> = new Map();
+  private subscriptions: Map<string, SubscriptionHandler> = new Map();
 
   constructor(config?: EventStreamConfig) {
     this.reauthorizationTTL = config?.reauthorizationTTL || 0; // if set to zero it does not reauthorize

src/event-log/subscription.ts

@@ -1,13 +1,18 @@
 import type { DwnError } from '../core/dwn-error.js';
 import type { EventEmitter } from 'events';
 import type { MessageStore } from '../types/message-store.js';
-import type { EmitFunction, Subscription } from '../types/subscriptions.js';
+import type { EmitFunction, SubscriptionHandler } from '../types/subscriptions.js';
 import type { Filter, KeyValues } from '../types/query-types.js';
 import type { GenericMessage, GenericMessageHandler } from '../types/message-types.js';
 
 import { FilterUtility } from '../utils/filter.js';
 
-export class SubscriptionBase implements Subscription {
+/**
+ * Base class to extend default subscription behavior.
+ *
+ * ie. `RecordsSubscriptionHandler` has different rules for authorization and only matches specific message types.
+ */
+export class SubscriptionHandlerBase implements SubscriptionHandler {
   protected eventEmitter: EventEmitter;
   protected messageStore: MessageStore;
   protected filters: Filter[];

src/handlers/events-subscribe.ts

@@ -10,7 +10,7 @@ import { Events } from '../utils/events.js';
 import { EventsSubscribe } from '../interfaces/events-subscribe.js';
 import { Message } from '../core/message.js';
 import { messageReplyFromError } from '../core/message-reply.js';
-import { SubscriptionBase } from '../event-log/subscription.js';
+import { SubscriptionHandlerBase } from '../event-log/subscription.js';
 import { authenticate, authorizeOwner } from '../core/auth.js';
 
 export class EventsSubscribeHandler implements MethodHandler {
@@ -57,7 +57,7 @@ export class EventsSubscribeHandler implements MethodHandler {
   }
 }
 
-export class EventsSubscriptionHandler extends SubscriptionBase {
+export class EventsSubscriptionHandler extends SubscriptionHandlerBase {
   public static async create(input: {
     tenant: string,
     message: EventsSubscribeMessage,

src/handlers/records-subscribe.ts

@@ -14,7 +14,7 @@ import { Records } from '../utils/records.js';
 import { RecordsDelete } from '../interfaces/records-delete.js';
 import { RecordsSubscribe } from '../interfaces/records-subscribe.js';
 import { RecordsWrite } from '../interfaces/records-write.js';
-import { SubscriptionBase } from '../event-log/subscription.js';
+import { SubscriptionHandlerBase } from '../event-log/subscription.js';
 import { Time } from '../utils/time.js';
 import { DwnError, DwnErrorCode } from '../core/dwn-error.js';
 import { DwnInterfaceName, DwnMethodName } from '../enums/dwn-interface-method.js';
@@ -231,7 +231,7 @@ export class RecordsSubscribeHandler implements MethodHandler {
   }
 }
 
-export class RecordsSubscriptionHandler extends SubscriptionBase {
+export class RecordsSubscriptionHandler extends SubscriptionHandlerBase {
   private recordsSubscribe: RecordsSubscribe;
 
   private reauthorizationTTL: number;

src/types/subscriptions.ts

@@ -8,6 +8,9 @@ import type { RecordsSubscribeMessage, RecordsSubscription } from './records-typ
 
 export type EmitFunction = (tenant: string, message: GenericMessage, indexes: KeyValues) => void;
 
+/**
+ * The EventStream interface implements a pub/sub system based on Message filters.
+ */
 export interface EventStream {
   subscribe(tenant: string, message: EventsSubscribeMessage, filters: Filter[], messageStore: MessageStore): Promise<EventsSubscription>;
   subscribe(tenant: string, message: RecordsSubscribeMessage, filters: Filter[], messageStore: MessageStore): Promise<RecordsSubscription>;
@@ -17,7 +20,12 @@ export interface EventStream {
   close(): Promise<void>;
 }
 
-export interface Subscription {
+/**
+ * The SubscriptionHandler interface is implemented by specific types of Subscription Handlers.
+ *
+ * ie. `RecordsSubscriptionHandler` has behavior to re-authorize subscriptions.
+ */
+export interface SubscriptionHandler {
   id: string;
   listener: EmitFunction;
   on: (handler: GenericMessageHandler) => { off: () => void };