Add bundler for Yjs adaptor

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@ucla-irl/ndnts-aux",
-  "version": "1.1.0",
+  "version": "1.1.1",
   "description": "NDNts Auxiliary Package for Web and Deno",
   "scripts": {
     "test": "deno test --no-check",

src/adaptors/bundler.test.ts

@@ -0,0 +1,76 @@
+import { assert as assertMod, sleep } from '../dep.ts';
+import { Bundler } from './bundler.ts';
+
+const { assertEquals } = assertMod;
+
+export const b = ([value]: TemplateStringsArray) => new TextEncoder().encode(value);
+
+const joinMerger = (updates: Uint8Array[]) => {
+  const totLength = updates.reduce((acc, cur) => acc + cur.length, 0);
+  const ret = new Uint8Array(totLength);
+  updates.reduce((offset, cur) => {
+    ret.set(cur, offset);
+    return offset + cur.length;
+  }, 0);
+  return ret;
+};
+
+Deno.test('Bundler.1', async () => {
+  const result: Array<Uint8Array> = [];
+  const bundler = new Bundler(
+    joinMerger,
+    (update) => {
+      result.push(update);
+      return Promise.resolve();
+    },
+    {
+      thresholdSize: 100,
+      delayMs: 100,
+    },
+  );
+
+  await bundler.produce(b`Hello `);
+  await bundler.produce(b`World.`);
+  await sleep(0.1);
+  assertEquals(result, [b`Hello World.`]);
+});
+
+Deno.test('Bundler.2', async () => {
+  const result: Array<Uint8Array> = [];
+  const bundler = new Bundler(
+    joinMerger,
+    (update) => {
+      result.push(update);
+      return Promise.resolve();
+    },
+    {
+      thresholdSize: 3,
+      delayMs: 100,
+    },
+  );
+
+  await bundler.produce(b`Hello `);
+  await bundler.produce(b`World.`);
+  assertEquals(result, [b`Hello `, b`World.`]);
+});
+
+Deno.test('Bundler.3', async () => {
+  const result: Array<Uint8Array> = [];
+  const bundler = new Bundler(
+    joinMerger,
+    (update) => {
+      result.push(update);
+      return Promise.resolve();
+    },
+    {
+      thresholdSize: 10,
+      delayMs: 100,
+    },
+  );
+
+  await bundler.produce(b`Hello `);
+  await bundler.produce(b`World,`);
+  await bundler.produce(b`Hello `);
+  await bundler.produce(b`World.`);
+  assertEquals(result, [b`Hello World,`, b`Hello World.`]);
+});

src/adaptors/bundler.ts

@@ -0,0 +1,49 @@
+export type BundlerOpts = {
+  thresholdSize?: number;
+  delayMs?: number;
+};
+
+export class Bundler {
+  protected _bundle: Array<Uint8Array> = [];
+  protected _timerId: number | undefined;
+  protected _cumulativeSize = 0;
+  protected _opts: Required<BundlerOpts>;
+
+  constructor(
+    public readonly merge: (updates: Array<Uint8Array>) => Uint8Array,
+    public readonly emit: (update: Uint8Array) => Promise<void>,
+    opts: {
+      thresholdSize?: number;
+      delayMs?: number;
+    } = {},
+  ) {
+    this._opts = {
+      thresholdSize: 3000,
+      delayMs: 200,
+      ...opts,
+    };
+  }
+
+  public async produce(update: Uint8Array) {
+    this._bundle.push(update);
+    this._cumulativeSize += update.byteLength;
+    if (this._cumulativeSize > this._opts.thresholdSize) {
+      // Emit immediately
+      await this.issue();
+    } else if (!this._timerId) {
+      // Schedule emit
+      this._timerId = setTimeout(() => this.issue(), this._opts.delayMs);
+    }
+  }
+
+  public async issue() {
+    if (this._timerId) {
+      clearTimeout(this._timerId);
+    }
+    this._timerId = undefined;
+    const output = this._bundle.length === 1 ? this._bundle[0] : this.merge(this._bundle);
+    this._bundle = [];
+    this._cumulativeSize = 0;
+    await this.emit(output);
+  }
+}

src/adaptors/yjs-ndn-adaptor.ts

@@ -1,6 +1,7 @@
 import { SyncAgent } from '../sync-agent/mod.ts';
 import * as Y from 'yjs';
 import { Awareness } from 'y-protocols/awareness.js';
+import { Bundler } from './bundler.ts';
 
 /**
  * NDN SVS Provider for Yjs. Wraps update into `SyncAgent`'s `update` channel.
@@ -23,13 +24,26 @@ export class NdnSvsAdaptor {
     return this.#awareness;
   }
 
+  #bundler: Bundler | undefined;
+
   constructor(
     public syncAgent: SyncAgent,
     public readonly doc: Y.Doc,
     public readonly topic: string,
+    useBundler: boolean = false,
   ) {
     syncAgent.register('update', topic, (content) => this.handleSyncUpdate(content));
     doc.on('update', this.callback);
+    if (useBundler) {
+      this.#bundler = new Bundler(
+        Y.mergeUpdates,
+        (content) => this.syncAgent.publishUpdate(this.topic, content),
+        {
+          thresholdSize: 3000,
+          delayMs: 200,
+        },
+      );
+    }
   }
 
   public bindAwareness(subDoc: Y.Doc, docId: string) {
@@ -78,7 +92,11 @@ export class NdnSvsAdaptor {
   }
 
   private async produce(content: Uint8Array) {
-    await this.syncAgent.publishUpdate(this.topic, content);
+    if (this.#bundler) {
+      await this.#bundler.produce(content);
+    } else {
+      await this.syncAgent.publishUpdate(this.topic, content);
+    }
   }
 
   public handleSyncUpdate(content: Uint8Array) {

src/dep.ts

@@ -5,3 +5,4 @@
  */
 export * as assert from 'https://deno.land/[email protected]/assert/mod.ts';
 export * as hex from 'https://deno.land/[email protected]/encoding/hex.ts';
+export { sleep } from 'https://deno.land/x/[email protected]/mod.ts';