Merge pull/4524: Add prefetchTimeout

defaults/config.js

@@ -160,6 +160,20 @@ module.exports = {
 	// This value is set to `50` kilobytes by default.
 	prefetchMaxSearchSize: 50,
 
+	// ### `prefetchTimeout`
+	//
+	// When `prefetch` is enabled, this value sets the number of milliseconds
+	// before The Lounge gives up attempting to fetch a link. This can be useful
+	// if you've increased the `prefetchMaxImageSize`.
+	//
+	// Take caution, however, that an inordinately large value may lead to
+	// performance issues or even a denial of service, since The Lounge will not
+	// be able to clean up outgoing connections as quickly. Usually the default
+	// value is appropriate, so only change it if necessary.
+	//
+	// This value is set to `5000` milliseconds by default.
+	prefetchTimeout: 5000,
+
 	// ### `fileUpload`
 	//
 	// Allow uploading files to the server hosting The Lounge.

src/plugins/irc-events/link.js

@@ -10,6 +10,7 @@ const storage = require("../storage");
 const currentFetchPromises = new Map();
 const imageTypeRegex = /^image\/.+/;
 const mediaTypeRegex = /^(audio|video)\/.+/;
+const log = require("../../log");
 
 module.exports = function (client, chan, msg, cleanText) {
 	if (!Helper.config.prefetch) {
@@ -381,6 +382,14 @@ function fetch(uri, headers) {
 		return promise;
 	}
 
+	const prefetchTimeout = Helper.config.prefetchTimeout;
+
+	if (!prefetchTimeout) {
+		log.warn(
+			"prefetchTimeout is missing from your The Lounge configuration, defaulting to 5000 ms"
+		);
+	}
+
 	promise = new Promise((resolve, reject) => {
 		let buffer = Buffer.from("");
 		let contentLength = 0;
@@ -390,7 +399,7 @@ function fetch(uri, headers) {
 		try {
 			const gotStream = got.stream(uri, {
 				retry: 0,
-				timeout: 5000,
+				timeout: prefetchTimeout || 5000, // milliseconds
 				headers: getRequestHeaders(headers),
 				https: {
 					rejectUnauthorized: false,