Add Differential parse cache to the GC daemon

Summary:
Add the differential parse cache to the GC. This is the largest object in the
system by a wide margin, I think.

This table is potentially gigantic which is why the script truncates it before
doing a schema change.

Test Plan: Ran the GC daemon, it cleaned up some parse caches.
Reviewed By: jungejason
Reviewers: tuomaspelkonen, jungejason, aran
Commenters: tuomaspelkonen
CC: aran, jungejason, tuomaspelkonen, epriestley
Differential Revision: 620

conf/default.conf.php

@@ -413,7 +413,7 @@ return array(
 
   'gcdaemon.ttl.herald-transcripts'         => 30 * (24 * 60 * 60),
   'gcdaemon.ttl.daemon-logs'                =>  7 * (24 * 60 * 60),
-  'gcdaemon.ttl.differential-render-cache'  =>  7 * (24 * 60 * 60),
+  'gcdaemon.ttl.differential-parse-cache'   => 14 * (24 * 60 * 60),
 
 
 // -- Customization --------------------------------------------------------- //

resources/sql/patches/057.parsecache.sql

@@ -0,0 +1,7 @@
+TRUNCATE phabricator_differential.differential_changeset_parse_cache;
+
+ALTER TABLE phabricator_differential.differential_changeset_parse_cache
+  ADD dateCreated INT UNSIGNED NOT NULL;
+
+ALTER TABLE phabricator_differential.differential_changeset_parse_cache
+  ADD KEY (dateCreated);

src/applications/differential/parser/changeset/DifferentialChangesetParser.php

@@ -624,11 +624,12 @@ class DifferentialChangesetParser {
       $conn_w = $changeset->establishConnection('w');
       queryfx(
         $conn_w,
-        'INSERT INTO %T (id, cache) VALUES (%d, %s)
+        'INSERT INTO %T (id, cache, dateCreated) VALUES (%d, %s, %d)
           ON DUPLICATE KEY UPDATE cache = VALUES(cache)',
-        $changeset->getTableName().'_parse_cache',
+        DifferentialChangeset::TABLE_CACHE,
         $render_cache_key,
-        $cache);
+        $cache,
+        time());
     } catch (AphrontQueryException $ex) {
       // TODO: uhoh
     }

src/applications/differential/storage/changeset/DifferentialChangeset.php

@@ -33,6 +33,8 @@ class DifferentialChangeset extends DifferentialDAO {
   private $unsavedHunks = array();
   private $hunks;
 
+  const TABLE_CACHE = 'differential_changeset_parse_cache';
+
   protected function getConfiguration() {
     return array(
       self::CONFIG_SERIALIZATION => array(

src/infrastructure/daemon/garbagecollector/PhabricatorGarbageCollectorDaemon.php

@@ -62,12 +62,12 @@ class PhabricatorGarbageCollectorDaemon extends PhabricatorDaemon {
 
       $n_herald = $this->collectHeraldTranscripts();
       $n_daemon = $this->collectDaemonLogs();
-      $n_render = $this->collectRenderCaches();
+      $n_parse  = $this->collectParseCaches();
 
       $collected = array(
-        'Herald Transcript'  => $n_herald,
-        'Daemon Log'         => $n_daemon,
-        'Render Cache'       => $n_render,
+        'Herald Transcript'           => $n_herald,
+        'Daemon Log'                  => $n_daemon,
+        'Differential Parse Cache'    => $n_parse,
       );
       $collected = array_filter($collected);
 
@@ -131,9 +131,23 @@ class PhabricatorGarbageCollectorDaemon extends PhabricatorDaemon {
     return $conn_w->getAffectedRows();
   }
 
-  private function collectRenderCaches() {
-    // TODO: Implement this, no epoch column on the table right now.
-    return 0;
+  private function collectParseCaches() {
+    $key = 'gcdaemon.ttl.differential-parse-cache';
+    $ttl = PhabricatorEnv::getEnvConfig($key);
+    if ($ttl <= 0) {
+      return 0;
+    }
+
+    $table = new DifferentialChangeset();
+    $conn_w = $table->establishConnection('w');
+
+    queryfx(
+      $conn_w,
+      'DELETE FROM %T WHERE dateCreated < %d LIMIT 100',
+      DifferentialChangeset::TABLE_CACHE,
+      time() - $ttl);
+
+    return $conn_w->getAffectedRows();
   }
 
 }

src/infrastructure/daemon/garbagecollector/__init__.php

@@ -6,6 +6,7 @@
 
 
 
+phutil_require_module('phabricator', 'applications/differential/storage/changeset');
 phutil_require_module('phabricator', 'applications/herald/storage/transcript/base');
 phutil_require_module('phabricator', 'infrastructure/daemon/base');
 phutil_require_module('phabricator', 'infrastructure/daemon/storage/event');