Started to implement server

vendor/deno.land/std@0.178.0/io/string_writer.ts

@@ -0,0 +1,73 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+// This module is browser compatible.
+
+import type { Writer, WriterSync } from "../types.d.ts";
+
+const decoder = new TextDecoder();
+
+/**
+ * Writer utility for buffering string chunks.
+ *
+ * @example
+ * ```ts
+ * import {
+ *   copyN,
+ *   StringReader,
+ *   StringWriter,
+ * } from "https://deno.land/std@$STD_VERSION/io/mod.ts";
+ * import { copy } from "https://deno.land/std@$STD_VERSION/streams/copy.ts";
+ *
+ * const w = new StringWriter("base");
+ * const r = new StringReader("0123456789");
+ * await copyN(r, w, 4); // copy 4 bytes
+ *
+ * // Number of bytes read
+ * console.log(w.toString()); //base0123
+ *
+ * await copy(r, w); // copy all
+ * console.log(w.toString()); // base0123456789
+ * ```
+ *
+ * **Output:**
+ *
+ * ```text
+ * base0123
+ * base0123456789
+ * ```
+ */
+export class StringWriter implements Writer, WriterSync {
+  #chunks: Uint8Array[] = [];
+  #byteLength = 0;
+  #cache: string | undefined;
+
+  constructor(private base: string = "") {
+    const c = new TextEncoder().encode(base);
+    this.#chunks.push(c);
+    this.#byteLength += c.byteLength;
+  }
+
+  write(p: Uint8Array): Promise<number> {
+    return Promise.resolve(this.writeSync(p));
+  }
+
+  writeSync(p: Uint8Array): number {
+    this.#chunks.push(new Uint8Array(p));
+    this.#byteLength += p.byteLength;
+    this.#cache = undefined;
+    return p.byteLength;
+  }
+
+  toString(): string {
+    if (this.#cache) {
+      return this.#cache;
+    }
+    const buf = new Uint8Array(this.#byteLength);
+    let offs = 0;
+    for (const chunk of this.#chunks) {
+      buf.set(chunk, offs);
+      offs += chunk.byteLength;
+    }
+    this.#cache = decoder.decode(buf);
+    return this.#cache;
+  }
+}