fix(reddit): cache tweak for 403 forbidden (#3830)

actions/DisplayAction.php

@@ -19,6 +19,7 @@ class DisplayAction implements ActionInterface
                 'message'   => 'RSS-Bridge is down for maintenance.',
             ]), 503);
         }
+
         $cacheKey = 'http_' . json_encode($request);
         /** @var Response $cachedResponse */
         $cachedResponse = $this->cache->get($cacheKey);
@@ -80,16 +81,19 @@ class DisplayAction implements ActionInterface
             $this->cache->set($cacheKey, $response, $ttl);
         }
 
-        if (in_array($response->getCode(), [429, 503])) {
+        if (in_array($response->getCode(), [403, 429, 503])) {
-            $this->cache->set($cacheKey, $response, 60 * 15 + rand(1, 60 * 10)); // average 20m
+            // Cache these responses for about ~20 mins on average
+            $this->cache->set($cacheKey, $response, 60 * 15 + rand(1, 60 * 10));
         }
 
         if ($response->getCode() === 500) {
             $this->cache->set($cacheKey, $response, 60 * 15);
         }
+
         if (rand(1, 100) === 2) {
             $this->cache->prune();
         }
+
         return $response;
     }
 
@@ -187,6 +191,7 @@ class DisplayAction implements ActionInterface
 
     private function logBridgeError($bridgeName, $code)
     {
+        // todo: it's not really necessary to json encode $report
         $cacheKey = 'error_reporting_' . $bridgeName . '_' . $code;
         $report = $this->cache->get($cacheKey);
         if ($report) {

bridges/RedditBridge.php

@@ -85,6 +85,11 @@ class RedditBridge extends BridgeAbstract
             if ($e->getCode() === 429) {
                 $this->cache->set($cacheKey, true, 60 * 16);
             }
+            if ($e->getCode() === 403) {
+                // 403 Forbidden
+                // This can possibly mean that reddit has permanently blocked this server's ip address
+                $this->cache->set($cacheKey, true, 60 * 61);
+            }
             throw $e;
         }
     }

lib/contents.php

@@ -71,6 +71,7 @@ function getContents(
                 // Ignore invalid 'Last-Modified' HTTP header value
             }
         }
+        // todo: to be nice nice citizen we should also check for Etag
     }
 
     $response = $httpClient->request($url, $config);

lib/http.php

@@ -2,6 +2,7 @@
 
 class HttpException extends \Exception
 {
+    // todo: should include the failing http response (if present)
 }
 
 final class CloudFlareException extends HttpException