Remove "dateTouched" from ConpherenceParticipant

Summary:
Pathway to D17685. This column is (mostly) a denormalization of `dateModified` on the thread.

Just use a JOIN instead.

This isn't //exactly// the same: we'll bump threads to the top now for non-message changes (e.g., a topic or title change). That seems fine, but we could put a `lastMessageDate` on Thread later if we want to refine it.

Also got rid of a lot of other unused stuff. There's a big garbage TODO here, I'll fix that in the next change.

Test Plan:
  - Grepped for `dateTouched`.
  - Grepped for `participantCursor`.
  - Grepped for `ConpherenceParticipantQuery::LIMIT`.
  - Looked for callsites to `setOrder()`, found none.
  - Added a message to an older thread, saw it bump up to the top.

Reviewers: chad

Reviewed By: chad

Differential Revision: https://secure.phabricator.com/D17731

resources/sql/autopatches/20170419.thread.03.touched.sql

@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_conpherence.conpherence_participant
+  DROP dateTouched;

src/applications/conpherence/editor/ConpherenceEditor.php

@@ -181,7 +181,6 @@ final class ConpherenceEditor extends PhabricatorApplicationTransactionEditor {
               id(new ConpherenceParticipant())
               ->setConpherencePHID($object->getPHID())
               ->setParticipantPHID($phid)
-              ->setDateTouched(time())
               ->setSeenMessageCount($message_count)
               ->save();
             $object->attachParticipants($participants);
@@ -248,7 +247,6 @@ final class ConpherenceEditor extends PhabricatorApplicationTransactionEditor {
             id(new ConpherenceParticipant())
             ->setConpherencePHID($object->getPHID())
             ->setParticipantPHID($phid)
-            ->setDateTouched(time())
             ->setSeenMessageCount($message_count)
             ->save();
         }
@@ -282,10 +280,8 @@ final class ConpherenceEditor extends PhabricatorApplicationTransactionEditor {
                 $participant->setSeenMessageCount(
                   $object->getMessageCount() - $message_count);
               }
-              $participant->setDateTouched($time);
             } else {
               $participant->setSeenMessageCount($object->getMessageCount());
-              $participant->setDateTouched($time);
             }
             $participant->save();
           }

src/applications/conpherence/query/ConpherenceParticipantQuery.php

@@ -1,128 +1,65 @@
 <?php
 
-/**
- * Query class that answers these questions:
- *
- * - Q: What are the conpherences to show when I land on /conpherence/ ?
- * - A:
- *
- *     id(new ConpherenceParticipantQuery())
- *     ->withParticipantPHIDs(array($my_phid))
- *     ->execute();
- *
- * - Q: What are the next set of conpherences as I scroll up (more recent) or
- *      down (less recent) this list of conpherences?
- * - A:
- *
- *     id(new ConpherenceParticipantQuery())
- *     ->withParticipantPHIDs(array($my_phid))
- *     ->withParticipantCursor($top_participant)
- *     ->setOrder(ConpherenceParticipantQuery::ORDER_NEWER)
- *     ->execute();
- *
- *     -or-
- *
- *     id(new ConpherenceParticipantQuery())
- *     ->withParticipantPHIDs(array($my_phid))
- *     ->withParticipantCursor($bottom_participant)
- *     ->setOrder(ConpherenceParticipantQuery::ORDER_OLDER)
- *     ->execute();
- *
- * For counts of read, un-read, or all conpherences by participant, see
- * @{class:ConpherenceParticipantCountQuery}.
- */
 final class ConpherenceParticipantQuery extends PhabricatorOffsetPagedQuery {
 
-  const LIMIT = 100;
-  const ORDER_NEWER = 'newer';
-  const ORDER_OLDER = 'older';
-
   private $participantPHIDs;
-  private $participantCursor;
-  private $order = self::ORDER_OLDER;
 
   public function withParticipantPHIDs(array $phids) {
     $this->participantPHIDs = $phids;
     return $this;
   }
 
-  public function withParticipantCursor(ConpherenceParticipant $participant) {
-    $this->participantCursor = $participant;
-    return $this;
-  }
-
-  public function setOrder($order) {
-    $this->order = $order;
-    return $this;
-  }
-
   public function execute() {
     $table = new ConpherenceParticipant();
-    $conn_r = $table->establishConnection('r');
+    $thread = new ConpherenceThread();
+
+    $conn = $table->establishConnection('r');
 
     $data = queryfx_all(
-      $conn_r,
+      $conn,
-      'SELECT * FROM %T participant %Q %Q %Q',
+      'SELECT * FROM %T participant JOIN %T thread
+        ON participant.conpherencePHID = thread.phid %Q %Q %Q',
       $table->getTableName(),
-      $this->buildWhereClause($conn_r),
+      $thread->getTableName(),
-      $this->buildOrderClause($conn_r),
+      $this->buildWhereClause($conn),
-      $this->buildLimitClause($conn_r));
+      $this->buildOrderClause($conn),
+      $this->buildLimitClause($conn));
 
     $participants = $table->loadAllFromArray($data);
 
+    // TODO: Fix this, it's bogus.
+    if ('garbage') {
+      if (count($this->participantPHIDs) !== 1) {
+        throw new Exception(
+          pht(
+            'This query only works when querying for exactly one participant '.
+            'PHID!'));
+      }
+      // This will throw results away if we aren't doing a query for exactly
+      // one participant PHID.
       $participants = mpull($participants, null, 'getConpherencePHID');
-
-    if ($this->order == self::ORDER_NEWER) {
-      $participants = array_reverse($participants);
     }
 
     return $participants;
   }
 
-  protected function buildWhereClause(AphrontDatabaseConnection $conn_r) {
+  protected function buildWhereClause(AphrontDatabaseConnection $conn) {
     $where = array();
 
-    if ($this->participantPHIDs) {
+    if ($this->participantPHIDs !== null) {
       $where[] = qsprintf(
-        $conn_r,
+        $conn,
         'participantPHID IN (%Ls)',
         $this->participantPHIDs);
     }
 
-    if ($this->participantCursor) {
-      $date_touched = $this->participantCursor->getDateTouched();
-      $id = $this->participantCursor->getID();
-      if ($this->order == self::ORDER_OLDER) {
-        $compare_date = '<';
-        $compare_id = '<=';
-      } else {
-        $compare_date = '>';
-        $compare_id = '>=';
-      }
-      $where[] = qsprintf(
-        $conn_r,
-        '(dateTouched %Q %d OR (dateTouched = %d AND id %Q %d))',
-        $compare_date,
-        $date_touched,
-        $date_touched,
-        $compare_id,
-        $id);
-    }
-
     return $this->formatWhereClause($where);
   }
 
-  private function buildOrderClause(AphrontDatabaseConnection $conn_r) {
+  private function buildOrderClause(AphrontDatabaseConnection $conn) {
-    $order_word = ($this->order == self::ORDER_OLDER) ? 'DESC' : 'ASC';
+    return qsprintf(
-    // if these are different direction we won't get as efficient a query
+      $conn,
-    // see http://dev.mysql.com/doc/refman/5.5/en/order-by-optimization.html
+      'ORDER BY thread.dateModified DESC, thread.id DESC, participant.id DESC');
-    $order = qsprintf(
-      $conn_r,
-      'ORDER BY dateTouched %Q, id %Q',
-      $order_word,
-      $order_word);
-
-    return $order;
   }
 
 }

src/applications/conpherence/storage/ConpherenceParticipant.php

@@ -5,7 +5,6 @@ final class ConpherenceParticipant extends ConpherenceDAO {
   protected $participantPHID;
   protected $conpherencePHID;
   protected $seenMessageCount;
-  protected $dateTouched;
   protected $settings = array();
 
   protected function getConfiguration() {
@@ -14,7 +13,6 @@ final class ConpherenceParticipant extends ConpherenceDAO {
         'settings' => self::SERIALIZATION_JSON,
       ),
       self::CONFIG_COLUMN_SCHEMA => array(
-        'dateTouched' => 'epoch',
         'seenMessageCount' => 'uint64',
       ),
       self::CONFIG_KEY_SCHEMA => array(
@@ -22,9 +20,6 @@ final class ConpherenceParticipant extends ConpherenceDAO {
           'columns' => array('conpherencePHID', 'participantPHID'),
           'unique' => true,
         ),
-        'participationIndex' => array(
-          'columns' => array('participantPHID', 'dateTouched', 'id'),
-        ),
         'key_thread' => array(
           'columns' => array('participantPHID', 'conpherencePHID'),
         ),