feat: adding fallback to other instances if rate limiting happens, PR from davidovski/librex.

Fallback to other librex instances

config.php.example

@@ -20,6 +20,9 @@
 
         "disable_hidden_service_search" => false,
 
+        // Fallback to another librex instance if google search fails
+        "instance_fallback" => true,
+
         /*
             Preset privacy friendly frontends for users, these can be overwritten by users in the settings
             e.g.: Preset the invidious instance URL: "instance_url" => "https://yewtu.be",

engines/google/text.php

@@ -71,6 +71,12 @@
             curl_multi_exec($mh, $running);
         } while ($running);
 
+        if (curl_getinfo($google_ch)['http_code'] != '200') 
+        {
+            require "engines/librex/text.php";
+            return get_librex_results($query, $page);
+        }
+
         if ($special_search != 0)
         {
             $special_result = null;

engines/librex/text.php

@@ -0,0 +1,51 @@
+<?php
+
+    function get_librex_results($query, $page) 
+    {
+        global $config;
+
+        if (!$config->instance_fallback) 
+            return array();
+
+        $instances_json = json_decode(file_get_contents("instances.json"), true);
+
+        if (empty($instances_json["instances"]))
+            return array();
+
+
+        $instances = array_map(fn($n) => $n['clearnet'], array_filter($instances_json['instances'], fn($n) => !is_null($n['clearnet'])));
+        shuffle($instances);
+
+        $query_encoded = urlencode($query);
+
+        $results = array();
+        $tries = 0;
+
+        do {
+            $tries++;
+
+            // after "too many" requests, give up
+            if ($tries > 5)
+                return array();
+
+            $instance = array_pop($instances);
+
+            if (parse_url($instance)["host"] == parse_url($_SERVER['HTTP_HOST'])["host"])
+                continue;
+
+            $url = $instance . "api.php?q=$query_encoded&p=$page&t=0";
+
+            $librex_ch = curl_init($url);
+            curl_setopt_array($librex_ch, $config->curl_settings);
+            copy_cookies($librex_ch);
+            $response = curl_exec($librex_ch);
+            curl_close($librex_ch);
+
+            $code = curl_getinfo($librex_ch)["http_code"];
+            $results = json_decode($response, true);
+
+        } while ( $results == null || count($results) <= 1);
+
+        return array_values($results);
+    }
+?>

misc/tools.php

@@ -230,4 +230,11 @@
         echo "<button type=\"submit\">$text</button>";
         echo "</form>";
     }
+
+    function copy_cookies($curl)
+    {
+        if (array_key_exists("HTTP_COOKIE", $_SERVER))
+            curl_setopt( $curl, CURLOPT_COOKIE, $_SERVER['HTTP_COOKIE'] );
+    }
+
 ?>

settings.php

@@ -1,7 +1,8 @@
 <?php
                 $config = require "config.php";
 
-                if (isset($_REQUEST["reset"]))
+                // Reset all cookies when resetting, or before saving new cookies
+                if (isset($_REQUEST["reset"]) || isset($_REQUEST["save"]))
                 {
                     if (isset($_SERVER["HTTP_COOKIE"]))
                     {