Improve uint8array serializing perf (#13)

Signed-off-by: Marcos Candeia <[email protected]>

src/actors/runtime.ts

@@ -11,6 +11,7 @@ import type { ActorStorage } from "./storage.ts";
 import { DenoKvActorStorage } from "./storage/denoKv.ts";
 import { S3ActorStorage } from "./storage/s3.ts";
 import { EVENT_STREAM_RESPONSE_HEADER } from "./stream.ts";
+import { serializeUint8Array } from "./util/buffers.ts";
 import { isUpgrade, makeWebSocket } from "./util/channels/channel.ts";
 import {
   type ServerSentEventMessage,
@@ -190,7 +191,7 @@ export class ActorRuntime {
               for await (const content of res) {
                 controller.enqueue({
                   data: encodeURIComponent(
-                    JSON.stringify(content),
+                    JSON.stringify(content, serializeUint8Array),
                   ),
                   id: Date.now().toString(),
                   event: "message",

src/actors/stream.ts

@@ -1,3 +1,5 @@
+import { deserializeUint8Array } from "./util/buffers.ts";
+
 export const EVENT_STREAM_RESPONSE_HEADER: string = "text/event-stream";
 export async function* readFromStream<T>(
   response: Response,
@@ -28,7 +30,7 @@ export async function* readFromStream<T>(
 
       try {
         const chunk = data.replace("data:", "");
-        yield JSON.parse(decodeURIComponent(chunk));
+        yield JSON.parse(decodeURIComponent(chunk), deserializeUint8Array);
       } catch (_err) {
         console.log("error parsing data", _err, data);
         continue;
@@ -41,6 +43,7 @@ export async function* readFromStream<T>(
     try {
       yield JSON.parse(
         decodeURIComponent(buffer.replace("data:", "")),
+        deserializeUint8Array,
       );
     } catch (_err) {
       console.log("error parsing data", _err, buffer);

src/actors/util/buffers.ts

@@ -0,0 +1,28 @@
+export interface SerializedUint8Array {
+  __uint8array: number[];
+}
+
+const isSerializedUint8Array = (
+  s: unknown | SerializedUint8Array,
+): s is SerializedUint8Array => {
+  return typeof s === "object" &&
+    (s as SerializedUint8Array)?.__uint8array instanceof Array;
+};
+export const serializeUint8Array = (_: string, value: unknown) => {
+  if (value instanceof Uint8Array) {
+    return {
+      __uint8array: Array.from(value), // Mark arrays that should be Uint8Array
+    };
+  }
+  return value;
+};
+
+export const deserializeUint8Array = (
+  _: string,
+  value: unknown | SerializedUint8Array,
+) => {
+  if (isSerializedUint8Array(value)) {
+    return new Uint8Array(value.__uint8array);
+  }
+  return value;
+};