Add a cache purger for builtin files

Summary: Fixes T12859.

Test Plan:
- Loaded Diffusion builtin icons before recent updates, saw cached builtins.
- Ran `bin/cache purge --caches builtin-file`.
- Reloaded, saw new files.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T12859

Differential Revision: https://secure.phabricator.com/D18147

src/__phutil_library_map__.php

···
     'PhabricatorBoolEditField' => 'applications/transactions/editfield/PhabricatorBoolEditField.php',
     'PhabricatorBritishEnglishTranslation' => 'infrastructure/internationalization/translation/PhabricatorBritishEnglishTranslation.php',
     'PhabricatorBuiltinDraftEngine' => 'applications/transactions/draft/PhabricatorBuiltinDraftEngine.php',
+    'PhabricatorBuiltinFileCachePurger' => 'applications/cache/purger/PhabricatorBuiltinFileCachePurger.php',
     'PhabricatorBuiltinPatchList' => 'infrastructure/storage/patch/PhabricatorBuiltinPatchList.php',
     'PhabricatorBulkContentSource' => 'infrastructure/daemon/contentsource/PhabricatorBulkContentSource.php',
     'PhabricatorCacheDAO' => 'applications/cache/storage/PhabricatorCacheDAO.php',
···
     'PhabricatorBoolEditField' => 'PhabricatorEditField',
     'PhabricatorBritishEnglishTranslation' => 'PhutilTranslation',
     'PhabricatorBuiltinDraftEngine' => 'PhabricatorDraftEngine',
+    'PhabricatorBuiltinFileCachePurger' => 'PhabricatorCachePurger',
     'PhabricatorBuiltinPatchList' => 'PhabricatorSQLPatchList',
     'PhabricatorBulkContentSource' => 'PhabricatorContentSource',
     'PhabricatorCacheDAO' => 'PhabricatorLiskDAO',

src/applications/cache/management/PhabricatorCacheManagementPurgeWorkflow.php

···
       }
     }
 
+    $viewer = $this->getViewer();
+
     foreach ($purgers as $key => $purger) {
+      $purger->setViewer($viewer);
+
       echo tsprintf(
         "%s\n",
         pht(

src/applications/cache/purger/PhabricatorBuiltinFileCachePurger.php

···
+<?php
+
+final class PhabricatorBuiltinFileCachePurger
+  extends PhabricatorCachePurger {
+
+  const PURGERKEY = 'builtin-file';
+
+  public function purgeCache() {
+    $viewer = $this->getViewer();
+
+    $files = id(new PhabricatorFileQuery())
+      ->setViewer($viewer)
+      ->withIsBuiltin(true)
+      ->execute();
+
+    $engine = new PhabricatorDestructionEngine();
+    foreach ($files as $file) {
+      $engine->destroyObject($file);
+    }
+  }
+
+}

src/applications/files/query/PhabricatorFileQuery.php

···
   private $isDeleted;
   private $needTransforms;
   private $builtinKeys;
+  private $isBuiltin;
 
   public function withIDs(array $ids) {
     $this->ids = $ids;
···
 
   public function withBuiltinKeys(array $keys) {
     $this->builtinKeys = $keys;
+    return $this;
+  }
+
+  public function withIsBuiltin($is_builtin) {
+    $this->isBuiltin = $is_builtin;
     return $this;
   }
 
···
         $conn,
         'builtinKey IN (%Ls)',
         $this->builtinKeys);
+    }
+
+    if ($this->isBuiltin !== null) {
+      if ($this->isBuiltin) {
+        $where[] = qsprintf(
+          $conn,
+          'builtinKey IS NOT NULL');
+      } else {
+        $where[] = qsprintf(
+          $conn,
+          'builtinKey IS NULL');
+      }
     }
 
     return $where;