objectcache: Never use CACHE_NONE for CACHE_ANYTHING

If $wgMainCacheType = CACHE_ACCEL, but there is no APC, then its
possible that CACHE_ANYTHING will default to CACHE_NONE because
that's what CACHE_ACCEL would do.

Possibly also T147161

Bug: T160519
Change-Id: I9ac2d071437b35a0f9cd3678e2279628f7b1931e

diff --git a/includes/objectcache/ObjectCache.php b/includes/objectcache/ObjectCache.php
index cf9033b..3370e5b 100644 (file)
--- a/includes/objectcache/ObjectCache.php
+++ b/includes/objectcache/ObjectCache.php
@@ -246,8 +246,14 @@ class ObjectCache {
                global $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType;
                $candidates = [ $wgMainCacheType, $wgMessageCacheType, $wgParserCacheType ];
                foreach ( $candidates as $candidate ) {
+                       $cache = false;
                        if ( $candidate !== CACHE_NONE && $candidate !== CACHE_ANYTHING ) {
-                               return self::getInstance( $candidate );
+                               $cache = self::getInstance( $candidate );
+                               // CACHE_ACCEL might default to nothing if no APCu
+                               // See includes/ServiceWiring.php
+                               if ( !( $cache instanceof EmptyBagOStuff ) ) {
+                                       return $cache;
+                               }
                        }
                }
 

diff --git a/tests/phpunit/includes/objectcache/ObjectCacheTest.php b/tests/phpunit/includes/objectcache/ObjectCacheTest.php
new file mode 100644 (file)
index 0000000..d132183
--- /dev/null
+++ b/tests/phpunit/includes/objectcache/ObjectCacheTest.php
@@ -0,0 +1,82 @@
+<?php
+
+class ObjectCacheTest extends MediaWikiTestCase {
+
+       protected function setUp() {
+               // Parent calls ObjectCache::clear() among other things
+               parent::setUp();
+
+               $this->setCacheConfig();
+               $this->setMwGlobals( [
+                       'wgMainCacheType' => CACHE_NONE,
+                       'wgMessageCacheType' => CACHE_NONE,
+                       'wgParserCacheType' => CACHE_NONE,
+               ] );
+       }
+
+       private function setCacheConfig( $arr = [] ) {
+               $defaults = [
+                       CACHE_NONE => [ 'class' => 'EmptyBagOStuff' ],
+                       CACHE_DB => [ 'class' => 'SqlBagOStuff' ],
+                       CACHE_ANYTHING => [ 'factory' => 'ObjectCache::newAnything' ],
+                       // Mock ACCEL with 'hash' as being installed.
+                       // This makes tests deterministic regardless of APC.
+                       CACHE_ACCEL => [ 'class' => 'HashBagOStuff' ],
+                       'hash' => [ 'class' => 'HashBagOStuff' ],
+               ];
+               $this->setMwGlobals( 'wgObjectCaches', $arr + $defaults );
+       }
+
+       /** @covers ObjectCache::newAnything */
+       public function testNewAnythingNothing() {
+               $this->assertInstanceOf(
+                       SqlBagOStuff::class,
+                       ObjectCache::newAnything( [] ),
+                       'No available types. Fallback to DB'
+               );
+       }
+
+       /** @covers ObjectCache::newAnything */
+       public function testNewAnythingHash() {
+               $this->setMwGlobals( [
+                       'wgMainCacheType' => 'hash'
+               ] );
+
+               $this->assertInstanceOf(
+                       HashBagOStuff::class,
+                       ObjectCache::newAnything( [] ),
+                       'Use an available type (hash)'
+               );
+       }
+
+       /** @covers ObjectCache::newAnything */
+       public function testNewAnythingAccel() {
+               $this->setMwGlobals( [
+                       'wgMainCacheType' => CACHE_ACCEL
+               ] );
+
+               $this->assertInstanceOf(
+                       HashBagOStuff::class,
+                       ObjectCache::newAnything( [] ),
+                       'Use an available type (CACHE_ACCEL)'
+               );
+       }
+
+       /** @covers ObjectCache::newAnything */
+       public function txestNewAnythingNoAccel() {
+               $this->setMwGlobals( [
+                       'wgMainCacheType' => CACHE_ACCEL
+               ] );
+
+               $this->setCacheConfig( [
+                       // Mock APC not being installed (T160519, T147161)
+                       CACHE_ACCEL => [ 'class' => 'EmptyBagOStuff' ]
+               ] );
+
+               $this->assertInstanceOf(
+                       SqlBagOStuff::class,
+                       ObjectCache::newAnything( [] ),
+                       'Fallback to DB if available types fall back to Empty'
+               );
+       }
+}