Started to implement server

vendor/deno.land/std@0.189.0/streams/reader_from_iterable.ts

@@ -0,0 +1,56 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// This module is browser compatible.
+
+import { Buffer } from "../io/buffer.ts";
+import { writeAll } from "./write_all.ts";
+import { Reader } from "../types.d.ts";
+
+/** Create a `Reader` from an iterable of `Uint8Array`s.
+ *
+ * ```ts
+ *      import { readerFromIterable } from "https://deno.land/std@$STD_VERSION/streams/reader_from_iterable.ts";
+ *      import { copy } from "https://deno.land/std@$STD_VERSION/streams/copy.ts";
+ *
+ *      const file = await Deno.open("metrics.txt", { write: true });
+ *      const reader = readerFromIterable((async function* () {
+ *        while (true) {
+ *          await new Promise((r) => setTimeout(r, 1000));
+ *          const message = `data: ${JSON.stringify(Deno.metrics())}\n\n`;
+ *          yield new TextEncoder().encode(message);
+ *        }
+ *      })());
+ *      await copy(reader, file);
+ * ```
+ */
+export function readerFromIterable(
+  iterable: Iterable<Uint8Array> | AsyncIterable<Uint8Array>,
+): Reader {
+  const iterator: Iterator<Uint8Array> | AsyncIterator<Uint8Array> =
+    (iterable as AsyncIterable<Uint8Array>)[Symbol.asyncIterator]?.() ??
+      (iterable as Iterable<Uint8Array>)[Symbol.iterator]?.();
+  const buffer = new Buffer();
+  return {
+    async read(p: Uint8Array): Promise<number | null> {
+      if (buffer.length == 0) {
+        const result = await iterator.next();
+        if (result.done) {
+          return null;
+        } else {
+          if (result.value.byteLength <= p.byteLength) {
+            p.set(result.value);
+            return result.value.byteLength;
+          }
+          p.set(result.value.subarray(0, p.byteLength));
+          await writeAll(buffer, result.value.subarray(p.byteLength));
+          return p.byteLength;
+        }
+      } else {
+        const n = await buffer.read(p);
+        if (n == null) {
+          return this.read(p);
+        }
+        return n;
+      }
+    },
+  };
+}