Started to implement server

vendor/deno.land/std@0.178.0/streams/limited_transform_stream.ts

@@ -0,0 +1,32 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+
+/** A TransformStream that will only read & enqueue `size` amount of chunks.
+ *
+ * if options.error is set, then instead of terminating the stream,
+ * an error will be thrown.
+ *
+ * ```ts
+ * import { LimitedTransformStream } from "https://deno.land/std@$STD_VERSION/streams/limited_transform_stream.ts";
+ * const res = await fetch("https://example.com");
+ * const parts = res.body!.pipeThrough(new LimitedTransformStream(50));
+ * ```
+ */
+export class LimitedTransformStream<T> extends TransformStream<T, T> {
+  #read = 0;
+  constructor(size: number, options: { error?: boolean } = {}) {
+    super({
+      transform: (chunk, controller) => {
+        if ((this.#read + 1) > size) {
+          if (options.error) {
+            throw new RangeError(`Exceeded chunk limit of '${size}'`);
+          } else {
+            controller.terminate();
+          }
+        } else {
+          this.#read++;
+          controller.enqueue(chunk);
+        }
+      },
+    });
+  }
+}