Move all ApplicationTransaction publishing to daemons

Summary:
Ref T6367. Do all mail, feed, notification and search stuff from the daemons, in all editors.

There are four relatively-stateful editors (Audit, Differential, Phriction, PhortuneCart) which needed special care to move state into the daemons properly.

Beyond that, I moved mailTo/mailCC/feedRelated/feedNotify to be computed before we enter the worker:

  - This is simpler, since a lot of editors rely on being able to call `$object->getReviewers()` or similar to compute them.
  - This is more correct, since we want to freeze the lists at this moment in time.

Finally, I renamed `loadEdges` to `willPublish` and made it a slightly more general hook.

---

This is a bit fragile and I'm not //thrilled// about it.

It would probably be cleaner to have separate Editor and Publisher classes (something like @fabe's D11329 did). However, I think that's quite a lot of work, and I'd like to see stronger motivation for it (either in this actually being more fragile than I think, or there being other things we get out of it). Overall, I'm comfortable with this change, just definitely not a big fan of the "save" + "load" pattern since I think it's really fragile, nonobvious, hard to debug/predict, etc.

Test Plan:
Directly updated editors:

- Created a new Phriction page, saw "Document Content".
- Edited a Phriction page, saw "Document Diff".
- Edited a revision, got normal looking mail.
- Faked in `changedPriorToCommitURI` and verified it survived the state boundary.
- Sent Audit mail.
- Sent invoice mail.

Indirect editors - for these, I just made a change and made sure the mail generated:

- Updated a paste.
- Updated an event.
- Updated a thread.
- Updated a task.
- Updated a mock.
- Updated a question.
- Updated a project.
- Updated a file.
- Updated an initiative.
- Updated a Legalpad document.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley, fabe

Maniphest Tasks: T6367

Differential Revision: https://secure.phabricator.com/D13115

src/applications/audit/editor/PhabricatorAuditEditor.php

@@ -8,6 +8,7 @@ final class PhabricatorAuditEditor
   private $auditReasonMap = array();
   private $affectedFiles;
   private $rawPatch;
+  private $auditorPHIDs = array();
 
   private $didExpandInlineState;
 
@@ -342,6 +343,9 @@ final class PhabricatorAuditEditor
       $object->writeImportStatusFlag($import_status_flag);
     }
 
+    // Collect auditor PHIDs for building mail.
+    $this->auditorPHIDs = mpull($object->getAudits(), 'getAuditorPHID');
+
     return $xactions;
   }
 
@@ -689,10 +693,7 @@ final class PhabricatorAuditEditor
       $user_phids[$committer_phid][] = pht('Committer');
     }
 
-    // we loaded this in applyFinalEffects
-    $audit_requests = $object->getAudits();
-    $auditor_phids = mpull($audit_requests, 'getAuditorPHID');
-    foreach ($auditor_phids as $auditor_phid) {
+    foreach ($this->auditorPHIDs as $auditor_phid) {
       $user_phids[$auditor_phid][] = pht('Auditor');
     }
 
@@ -983,4 +984,19 @@ final class PhabricatorAuditEditor
     return $this->shouldPublishRepositoryActivity($object, $xactions);
   }
 
+  protected function getCustomWorkerState() {
+    return array(
+      'rawPatch' => $this->rawPatch,
+      'affectedFiles' => $this->affectedFiles,
+      'auditorPHIDs' => $this->auditorPHIDs,
+    );
+  }
+
+  protected function loadCustomWorkerState(array $state) {
+    $this->rawPatch = idx($state, 'rawPatch');
+    $this->affectedFiles = idx($state, 'affectedFiles');
+    $this->auditorPHIDs = idx($state, 'auditorPHIDs');
+    return $this;
+  }
+
 }

src/applications/differential/editor/DifferentialTransactionEditor.php

@@ -1902,4 +1902,15 @@ final class DifferentialTransactionEditor
     return $section;
   }
 
+  protected function getCustomWorkerState() {
+    return array(
+      'changedPriorToCommitURI' => $this->changedPriorToCommitURI,
+    );
+  }
+
+  protected function loadCustomWorkerState(array $state) {
+    $this->changedPriorToCommitURI = idx($state, 'changedPriorToCommitURI');
+    return $this;
+  }
+
 }

src/applications/paste/editor/PhabricatorPasteEditor.php

@@ -184,8 +184,4 @@ final class PhabricatorPasteEditor
     return false;
   }
 
-  protected function supportsWorkers() {
-    return true;
-  }
-
 }

src/applications/phortune/editor/PhortuneCartEditor.php

@@ -189,7 +189,7 @@ final class PhortuneCartEditor
   protected function getMailTo(PhabricatorLiskDAO $object) {
     $phids = array();
 
-    // Relaod the cart to pull merchant and account information, in case we
+    // Reload the cart to pull merchant and account information, in case we
     // just created the object.
     $cart = id(new PhortuneCartQuery())
       ->setViewer($this->requireActor())
@@ -220,4 +220,24 @@ final class PhortuneCartEditor
       ->setMailReceiver($object);
   }
 
+  protected function willPublish(PhabricatorLiskDAO $object, array $xactions) {
+    // We need the purchases in order to build mail.
+    return id(new PhortuneCartQuery())
+      ->setViewer($this->getActor())
+      ->withIDs(array($object->getID()))
+      ->needPurchases(true)
+      ->executeOne();
+  }
+
+  protected function getCustomWorkerState() {
+    return array(
+      'invoiceIssues' => $this->invoiceIssues,
+    );
+  }
+
+  protected function loadCustomWorkerState(array $state) {
+    $this->invoiceIssues = idx($state, 'invoiceIssues');
+    return $this;
+  }
+
 }

src/applications/phriction/editor/PhrictionTransactionEditor.php

@@ -13,6 +13,7 @@ final class PhrictionTransactionEditor
   private $skipAncestorCheck;
   private $contentVersion;
   private $processContentVersionError = true;
+  private $contentDiffURI;
 
   public function setDescription($description) {
     $this->description = $description;
@@ -348,6 +349,20 @@ final class PhrictionTransactionEditor
         ->applyTransactions($this->moveAwayDocument, $move_away_xactions);
     }
 
+    // Compute the content diff URI for the publishing phase.
+    foreach ($xactions as $xaction) {
+      switch ($xaction->getTransactionType()) {
+        case PhrictionTransaction::TYPE_CONTENT:
+          $uri = id(new PhutilURI('/phriction/diff/'.$object->getID().'/'))
+            ->alter('l', $this->getOldContent()->getVersion())
+            ->alter('r', $this->getNewContent()->getVersion());
+          $this->contentDiffURI = (string)$uri;
+          break 2;
+        default:
+          break;
+      }
+    }
+
     return $xactions;
   }
 
@@ -403,24 +418,10 @@ final class PhrictionTransactionEditor
       $body->addTextSection(
         pht('DOCUMENT CONTENT'),
         $object->getContent()->getContent());
-    } else {
-
-      foreach ($xactions as $xaction) {
-        switch ($xaction->getTransactionType()) {
-          case PhrictionTransaction::TYPE_CONTENT:
-            $diff_uri = id(new PhutilURI(
-              '/phriction/diff/'.$object->getID().'/'))
-              ->alter('l', $this->getOldContent()->getVersion())
-              ->alter('r', $this->getNewContent()->getVersion());
-            $body->addLinkSection(
-              pht('DOCUMENT DIFF'),
-              PhabricatorEnv::getProductionURI($diff_uri));
-            break 2;
-          default:
-            break;
-        }
-      }
-
+    } else if ($this->contentDiffURI) {
+      $body->addLinkSection(
+        pht('DOCUMENT DIFF'),
+        PhabricatorEnv::getProductionURI($this->contentDiffURI));
     }
 
     $body->addLinkSection(
@@ -810,4 +811,15 @@ final class PhrictionTransactionEditor
     return $new_content;
   }
 
+  protected function getCustomWorkerState() {
+    return array(
+      'contentDiffURI' => $this->contentDiffURI,
+    );
+  }
+
+  protected function loadCustomWorkerState(array $state) {
+    $this->contentDiffURI = idx($state, 'contentDiffURI');
+    return $this;
+  }
+
 }

src/applications/project/editor/PhabricatorProjectTransactionEditor.php

@@ -397,14 +397,13 @@ final class PhabricatorProjectTransactionEditor
     return parent::requireCapabilities($object, $xaction);
   }
 
-  protected function loadEdges(
-    PhabricatorLiskDAO $object,
-    array $xactions) {
-
+  protected function willPublish(PhabricatorLiskDAO $object, array $xactions) {
     $member_phids = PhabricatorEdgeQuery::loadDestinationPHIDs(
       $object->getPHID(),
       PhabricatorProjectProjectHasMemberEdgeType::EDGECONST);
     $object->attachMemberPHIDs($member_phids);
+
+    return $object;
   }
 
   protected function shouldSendMail(

src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php

@@ -1,6 +1,36 @@
 <?php
 
 /**
+ *
+ * Publishing and Managing State
+ * ======
+ *
+ * After applying changes, the Editor queues a worker to publish mail, feed,
+ * and notifications, and to perform other background work like updating search
+ * indexes. This allows it to do this work without impacting performance for
+ * users.
+ *
+ * When work is moved to the daemons, the Editor state is serialized by
+ * @{method:getWorkerState}, then reloaded in a daemon process by
+ * @{method:loadWorkerState}. **This is fragile.**
+ *
+ * State is not persisted into the daemons by default, because we can not send
+ * arbitrary objects into the queue. This means the default behavior of any
+ * state properties is to reset to their defaults without warning prior to
+ * publishing.
+ *
+ * The easiest way to avoid this is to keep Editors stateless: the overwhelming
+ * majority of Editors can be written statelessly. If you need to maintain
+ * state, you can either:
+ *
+ *   - not require state to exist during publishing; or
+ *   - pass state to the daemons by implementing @{method:getCustomWorkerState}
+ *     and @{method:loadCustomWorkerState}.
+ *
+ * This architecture isn't ideal, and we may eventually split this class into
+ * "Editor" and "Publisher" parts to make it more robust. See T6367 for some
+ * discussion and context.
+ *
  * @task mail Sending Mail
  * @task feed Publishing Feed Stories
  * @task search Search Index
@@ -34,6 +64,10 @@ abstract class PhabricatorApplicationTransactionEditor
   private $heraldEmailPHIDs = array();
   private $heraldForcedEmailPHIDs = array();
   private $heraldHeader;
+  private $mailToPHIDs = array();
+  private $mailCCPHIDs = array();
+  private $feedNotifyPHIDs = array();
+  private $feedRelatedPHIDs = array();
 
   /**
    * Get the class name for the application this editor is a part of.
@@ -907,23 +941,43 @@ abstract class PhabricatorApplicationTransactionEditor
     }
     $this->heraldHeader = $herald_header;
 
-    if ($this->supportsWorkers()) {
-      PhabricatorWorker::scheduleTask(
-        'PhabricatorApplicationTransactionPublishWorker',
-        array(
-          'objectPHID' => $object->getPHID(),
-          'actorPHID' => $this->getActingAsPHID(),
-          'xactionPHIDs' => mpull($xactions, 'getPHID'),
-          'state' => $this->getWorkerState(),
-        ),
-        array(
-          'objectPHID' => $object->getPHID(),
-          'priority' => PhabricatorWorker::PRIORITY_ALERTS,
-        ));
-    } else {
-      $this->publishTransactions($object, $xactions);
+    // We're going to compute some of the data we'll use to publish these
+    // transactions here, before queueing a worker.
+    //
+    // Primarily, this is more correct: we want to publish the object as it
+    // exists right now. The worker may not execute for some time, and we want
+    // to use the current To/CC list, not respect any changes which may occur
+    // between now and when the worker executes.
+    //
+    // As a secondary benefit, this tends to reduce the amount of state that
+    // Editors need to pass into workers.
+    $object = $this->willPublish($object, $xactions);
+
+    if (!$this->getDisableEmail()) {
+      if ($this->shouldSendMail($object, $xactions)) {
+        $this->mailToPHIDs = $this->getMailTo($object);
+        $this->mailCCPHIDs = $this->getMailCC($object);
+      }
     }
 
+    if ($this->shouldPublishFeedStory($object, $xactions)) {
+      $this->feedRelatedPHIDs = $this->getFeedRelatedPHIDs($object, $xactions);
+      $this->feedNotifyPHIDs = $this->getFeedNotifyPHIDs($object, $xactions);
+    }
+
+    PhabricatorWorker::scheduleTask(
+      'PhabricatorApplicationTransactionPublishWorker',
+      array(
+        'objectPHID' => $object->getPHID(),
+        'actorPHID' => $this->getActingAsPHID(),
+        'xactionPHIDs' => mpull($xactions, 'getPHID'),
+        'state' => $this->getWorkerState(),
+      ),
+      array(
+        'objectPHID' => $object->getPHID(),
+        'priority' => PhabricatorWorker::PRIORITY_ALERTS,
+      ));
+
     return $xactions;
   }
 
@@ -936,7 +990,7 @@ abstract class PhabricatorApplicationTransactionEditor
     // in various transaction phases).
     $this->loadSubscribers($object);
     // Hook for other edges that may need (re-)loading
-    $this->loadEdges($object, $xactions);
+    $object = $this->willPublish($object, $xactions);
 
     $this->loadHandles($xactions);
 
@@ -1042,12 +1096,6 @@ abstract class PhabricatorApplicationTransactionEditor
     }
   }
 
-  protected function loadEdges(
-    PhabricatorLiskDAO $object,
-    array $xactions) {
-    return;
-  }
-
   private function validateEditParameters(
     PhabricatorLiskDAO $object,
     array $xactions) {
@@ -2084,8 +2132,8 @@ abstract class PhabricatorApplicationTransactionEditor
     }
 
     $email_force = array();
-    $email_to = $this->getMailTo($object);
-    $email_cc = $this->getMailCC($object);
+    $email_to = $this->mailToPHIDs;
+    $email_cc = $this->mailCCPHIDs;
 
     $email_cc = array_merge($email_cc, $this->heraldEmailPHIDs);
     $email_force = $this->heraldForcedEmailPHIDs;
@@ -2511,8 +2559,8 @@ abstract class PhabricatorApplicationTransactionEditor
       return;
     }
 
-    $related_phids = $this->getFeedRelatedPHIDs($object, $xactions);
-    $subscribed_phids = $this->getFeedNotifyPHIDs($object, $xactions);
+    $related_phids = $this->feedRelatedPHIDs;
+    $subscribed_phids = $this->feedNotifyPHIDs;
 
     $story_type = $this->getFeedStoryType();
     $story_data = $this->getFeedStoryData($object, $xactions);
@@ -2800,11 +2848,17 @@ abstract class PhabricatorApplicationTransactionEditor
 
 
   /**
+   * Load any object state which is required to publish transactions.
+   *
+   * This hook is invoked in the main process before we compute data related
+   * to publishing transactions (like email "To" and "CC" lists), and again in
+   * the worker before publishing occurs.
+   *
+   * @return object Publishable object.
    * @task workers
    */
-  protected function supportsWorkers() {
-    // TODO: Remove this method once everything supports workers.
-    return false;
+  protected function willPublish(PhabricatorLiskDAO $object, array $xactions) {
+    return $object;
   }
 
 
@@ -2825,11 +2879,10 @@ abstract class PhabricatorApplicationTransactionEditor
 
     $state += array(
       'excludeMailRecipientPHIDs' => $this->getExcludeMailRecipientPHIDs(),
-    );
-
-    return $state + array(
       'custom' => $this->getCustomWorkerState(),
     );
+
+    return $state;
   }
 
 
@@ -2900,6 +2953,10 @@ abstract class PhabricatorApplicationTransactionEditor
       'heraldEmailPHIDs',
       'heraldForcedEmailPHIDs',
       'heraldHeader',
+      'mailToPHIDs',
+      'mailCCPHIDs',
+      'feedNotifyPHIDs',
+      'feedRelatedPHIDs',
     );
   }