From df8b0a1fc599d94afc0038b564650aa3a8064fee Mon Sep 17 00:00:00 2001
From: Brown <github@muglug.com>
Date: Thu, 1 Nov 2018 17:42:48 -0400
Subject: [PATCH] =?UTF-8?q?Bust=20cache=20when=20config=20changes,=20don?=
 =?UTF-8?q?=E2=80=99t=20rely=20on=20>=20modified=20time?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/Psalm/Config.php                          |  6 +--
 .../ClassLikeStorageCacheProvider.php         |  2 +-
 .../Provider/FileReferenceCacheProvider.php   | 49 ++++++++++++++++++-
 .../Provider/FileStorageCacheProvider.php     |  2 +-
 4 files changed, 52 insertions(+), 7 deletions(-)

diff --git a/src/Psalm/Config.php b/src/Psalm/Config.php
index ff69e1b24..f2ec6d94a 100644
--- a/src/Psalm/Config.php
+++ b/src/Psalm/Config.php
@@ -297,9 +297,9 @@ class Config
     public $exit_functions = [];
 
     /**
-     * @var int
+     * @var string
      */
-    public $modified_time = 0;
+    public $hash = '';
 
     /** @var string|null */
     public $error_baseline = null;
@@ -388,7 +388,7 @@ class Config
 
         try {
             $config = self::loadFromXML($base_dir, $file_contents);
-            $config->modified_time = filemtime($file_path);
+            $config->hash = sha1($file_contents);
         } catch (ConfigException $e) {
             throw new ConfigException(
                 'Problem parsing ' . $file_path . ":\n" . '  ' . $e->getMessage()
diff --git a/src/Psalm/Provider/ClassLikeStorageCacheProvider.php b/src/Psalm/Provider/ClassLikeStorageCacheProvider.php
index 88cd5a4ed..acf8ebb1f 100644
--- a/src/Psalm/Provider/ClassLikeStorageCacheProvider.php
+++ b/src/Psalm/Provider/ClassLikeStorageCacheProvider.php
@@ -43,7 +43,7 @@ class ClassLikeStorageCacheProvider
             $this->modified_timestamps .= ' ' . filemtime($dependent_file_path);
         }
 
-        $this->modified_timestamps .= PSALM_VERSION . $this->config->modified_time;
+        $this->modified_timestamps .= PSALM_VERSION . $this->config->hash;
     }
 
     /**
diff --git a/src/Psalm/Provider/FileReferenceCacheProvider.php b/src/Psalm/Provider/FileReferenceCacheProvider.php
index 1f06f321e..b9f19d8e1 100644
--- a/src/Psalm/Provider/FileReferenceCacheProvider.php
+++ b/src/Psalm/Provider/FileReferenceCacheProvider.php
@@ -34,15 +34,23 @@ class FileReferenceCacheProvider
     const CLASS_METHOD_CACHE_NAME = 'class_method_references';
     const ISSUES_CACHE_NAME = 'issues';
     const FILE_MAPS_CACHE_NAME = 'file_maps';
+    const CONFIG_HASH_CACHE_NAME = 'config';
 
     /**
      * @var Config
      */
     private $config;
 
+    /**
+     * @var bool
+     */
+    public $config_changed;
+
     public function __construct(Config $config)
     {
         $this->config = $config;
+        $this->config_changed = $config->hash !== $this->getConfigHashCache();
+        $this->setConfigHashCache($config->hash);
     }
 
     /**
@@ -191,7 +199,7 @@ class FileReferenceCacheProvider
 
         if ($cache_directory
             && file_exists($correct_methods_cache_location)
-            && filemtime($correct_methods_cache_location) > $this->config->modified_time
+            && !$this->config_changed
         ) {
             /** @var array<string, array<string, int>> */
             return unserialize(file_get_contents($correct_methods_cache_location));
@@ -229,7 +237,7 @@ class FileReferenceCacheProvider
 
         if ($cache_directory
             && file_exists($file_maps_cache_location)
-            && filemtime($file_maps_cache_location) > $this->config->modified_time
+            && !$this->config_changed
         ) {
             /** @var array<string, array{0: TaggedCodeType, 1: TaggedCodeType}> */
             $file_maps_cache = unserialize(file_get_contents($file_maps_cache_location));
@@ -256,4 +264,41 @@ class FileReferenceCacheProvider
             );
         }
     }
+
+    /**
+     * @return string|false
+     */
+    public function getConfigHashCache()
+    {
+        $cache_directory = $this->config->getCacheDirectory();
+
+        $config_hash_cache_location = $cache_directory . DIRECTORY_SEPARATOR . self::CONFIG_HASH_CACHE_NAME;
+
+        if ($cache_directory
+            && file_exists($config_hash_cache_location)
+        ) {
+            /** @var string */
+            $file_maps_cache = unserialize(file_get_contents($config_hash_cache_location));
+            return $file_maps_cache;
+        }
+
+        return false;
+    }
+
+    /**
+     * @return void
+     */
+    public function setConfigHashCache(string $hash)
+    {
+        $cache_directory = Config::getInstance()->getCacheDirectory();
+
+        if ($cache_directory) {
+            $config_hash_cache_location = $cache_directory . DIRECTORY_SEPARATOR . self::CONFIG_HASH_CACHE_NAME;
+
+            file_put_contents(
+                $config_hash_cache_location,
+                serialize($hash)
+            );
+        }
+    }
 }
diff --git a/src/Psalm/Provider/FileStorageCacheProvider.php b/src/Psalm/Provider/FileStorageCacheProvider.php
index 50b69d469..0bca2e0b9 100644
--- a/src/Psalm/Provider/FileStorageCacheProvider.php
+++ b/src/Psalm/Provider/FileStorageCacheProvider.php
@@ -44,7 +44,7 @@ class FileStorageCacheProvider
             $this->modified_timestamps .= ' ' . filemtime($dependent_file_path);
         }
 
-        $this->modified_timestamps .= PSALM_VERSION . $this->config->modified_time;
+        $this->modified_timestamps .= PSALM_VERSION . $this->config->hash;
     }
 
     /**