// SPDX-License-Identifier: MPL-2.0

// Copyright (c) 2023 RethinkDNS and its authors

import * as cfg from "../base/cfg.js";

import * as modres from "../base/res.js";

import * as log from "../base/log.js";

/**

* Sends a preset str to socket, writing the output to a Response.

* @param {TransformStream} socket

* @returns {Response}

*/

export async function echo(socket) {

try {

const enc = new TextEncoder();

const u8 = enc.encode("GET-IPADDR\r\n");

const writer = socket.writable.getWriter();

await writer.ready;

await writer.write(u8);

log.d("echo: write done");

return new Response(socket.readable, { headers: cfg.h2header });

} catch (ex) {

log.e("fixed: err", ex);

return modres.r500;

}

}

/**

* Stream req.body to egress, writing the output into res.body.

* @param {Request} req

* @param {TransformStream} egress

* @param {function(Promise)} waiter

* @returns {Promise<Response>}

*/

export async function pipe(req, egress, waiter = (p) => p) {

// ingress is null when request is GET or HEAD

const ingress = req.body;

if (ingress == null) {

log.d("ingress missing");

return modres.r400;

}

try {

// 1. pipe without await

// 2. do not close egress on completion

// 3. always use waiter, regardless of cfg.useWaiter

waiter(ingress.pipeTo(egress.writable, { preventClose: true }));

// stream the response out

// blog.cloudflare.com/workers-optimization-reduces-your-bill

return new Response(egress.readable, { headers: cfg.h2header });

} catch (ex) {

log.e("pipe: err", ex);

return modres.r500;

}

}