Use transactions in user status Conduit methods

Test Plan:
Add status, verify DB.
Remove status, verify DB.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Koolvin

Differential Revision: https://secure.phabricator.com/D2397

Author: vrana

src/applications/conduit/method/user/addstatus/ConduitAPI_user_addstatus_Method.php

@@ -58,14 +58,18 @@ protected function execute(ConduitAPIRequest $request) {
       throw new ConduitException('ERR-BAD-EPOCH');
     }
 
-    // TODO: This SELECT should have LOCK IN SHARE MODE and be in transaction
-    // with the next INSERT.
-    $overlap = id(new PhabricatorUserStatus())->loadAllWhere(
+    $table = new PhabricatorUserStatus();
+    $table->openTransaction();
+    $table->beginWriteLocking();
+
+    $overlap = $table->loadAllWhere(
       'userPHID = %s AND dateFrom < %d AND dateTo > %d',
       $user_phid,
       $to,
       $from);
     if ($overlap) {
+      $table->endWriteLocking();
+      $table->killTransaction();
       throw new ConduitException('ERR-OVERLAP');
     }
 
@@ -83,6 +87,9 @@ protected function execute(ConduitAPIRequest $request) {
       ->setDateTo($to)
       ->setStatus($status)
       ->save();
+
+    $table->endWriteLocking();
+    $table->saveTransaction();
   }
 
 }

src/applications/conduit/method/user/removestatus/ConduitAPI_user_removestatus_Method.php

@@ -55,7 +55,11 @@ protected function execute(ConduitAPIRequest $request) {
       throw new ConduitException('ERR-BAD-EPOCH');
     }
 
-    $overlap = id(new PhabricatorUserStatus())->loadAllWhere(
+    $table = new PhabricatorUserStatus();
+    $table->openTransaction();
+    $table->beginReadLocking();
+
+    $overlap = $table->loadAllWhere(
       'userPHID = %s AND dateFrom < %d AND dateTo > %d',
       $user_phid,
       $to,
@@ -80,6 +84,9 @@ protected function execute(ConduitAPIRequest $request) {
         $status->delete();
       }
     }
+
+    $table->endReadLocking();
+    $table->saveTransaction();
     return count($overlap);
   }