do not retrieve content if it's too large

src/ContentRetriever/FileSystemContentRetriever.php

@@ -3,6 +3,7 @@ declare(strict_types = 1);
 
 namespace LanguageServer\ContentRetriever;
 
+use LanguageServer\ContentTooLargeException;
 use Sabre\Event\Promise;
 use function LanguageServer\uriToPath;
 
@@ -19,6 +20,13 @@ class FileSystemContentRetriever implements ContentRetriever
      */
     public function retrieve(string $uri): Promise
     {
-        return Promise\resolve(file_get_contents(uriToPath($uri)));
+        $limit = 150000;
+
+        $path = uriToPath($uri);
+        $size = filesize($path);
+        if ($size > $limit) {
+            return Promise\reject(new ContentTooLargeException($uri, $size, $limit));
+        }
+        return Promise\resolve(file_get_contents($path));
     }
 }

src/PhpDocumentLoader.php

@@ -105,13 +105,7 @@ class PhpDocumentLoader
     public function load(string $uri): Promise
     {
         return coroutine(function () use ($uri) {
-
-            $limit = 150000;
             $content = yield $this->contentRetriever->retrieve($uri);
-            $size = strlen($content);
-            if ($size > $limit) {
-                throw new ContentTooLargeException($uri, $size, $limit);
-            }
 
             if (isset($this->documents[$uri])) {
                 $document = $this->documents[$uri];