Provide read and overwrite for Lisk counters

Summary:
Ref T6881. This is part 1 of my 35-step plan to support subscriptions that bill monthly.

Expanding the capabilities of counters will let me use them to create a logical clock on time-based event updates, build a daemon on top of that, and eventually get time-based triggers.

Test Plan: Added and executed unit tests.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: chad, epriestley

Maniphest Tasks: T6881

Differential Revision: https://secure.phabricator.com/D11395

src/__phutil_library_map__.php

@@ -2231,7 +2231,6 @@ phutil_register_library_map(array(
     'PhabricatorProjectUpdateController' => 'applications/project/controller/PhabricatorProjectUpdateController.php',
     'PhabricatorProjectViewController' => 'applications/project/controller/PhabricatorProjectViewController.php',
     'PhabricatorProjectWatchController' => 'applications/project/controller/PhabricatorProjectWatchController.php',
-    'PhabricatorProjectWikiExplainController' => 'applications/project/controller/PhabricatorProjectWikiExplainController.php',
     'PhabricatorProjectsPolicyRule' => 'applications/policy/rule/PhabricatorProjectsPolicyRule.php',
     'PhabricatorPygmentSetupCheck' => 'applications/config/check/PhabricatorPygmentSetupCheck.php',
     'PhabricatorQuery' => 'infrastructure/query/PhabricatorQuery.php',
@@ -5459,7 +5458,6 @@ phutil_register_library_map(array(
     'PhabricatorProjectUpdateController' => 'PhabricatorProjectController',
     'PhabricatorProjectViewController' => 'PhabricatorProjectController',
     'PhabricatorProjectWatchController' => 'PhabricatorProjectController',
-    'PhabricatorProjectWikiExplainController' => 'PhabricatorProjectController',
     'PhabricatorProjectsPolicyRule' => 'PhabricatorPolicyRule',
     'PhabricatorPygmentSetupCheck' => 'PhabricatorSetupCheck',
     'PhabricatorRecaptchaConfigOptions' => 'PhabricatorApplicationConfigOptions',

src/infrastructure/storage/lisk/LiskDAO.php

@@ -1173,7 +1173,7 @@ abstract class LiskDAO {
         $id_key = $this->getIDKeyForUse();
         if (empty($data[$id_key])) {
           $counter_name = $this->getTableName();
-          $id = self::loadNextCounterID($conn, $counter_name);
+          $id = self::loadNextCounterValue($conn, $counter_name);
           $this->setID($id);
           $data[$id_key] = $id;
         }
@@ -1688,6 +1688,7 @@ abstract class LiskDAO {
     $this->$name = $value;
   }
 
+
   /**
    * Increments a named counter and returns the next value.
    *
@@ -1697,7 +1698,7 @@ abstract class LiskDAO {
    *
    * @task util
    */
-  public static function loadNextCounterID(
+  public static function loadNextCounterValue(
     AphrontDatabaseConnection $conn_w,
     $counter_name) {
 
@@ -1721,6 +1722,58 @@ abstract class LiskDAO {
     return $conn_w->getInsertID();
   }
 
+
+  /**
+   * Returns the current value of a named counter.
+   *
+   * @param AphrontDatabaseConnection Database where the counter resides.
+   * @param string Counter name to read.
+   * @return int|null Current value, or `null` if the counter does not exist.
+   *
+   * @task util
+   */
+  public static function loadCurrentCounterValue(
+    AphrontDatabaseConnection $conn_r,
+    $counter_name) {
+
+    $row = queryfx_one(
+      $conn_r,
+      'SELECT counterValue FROM %T WHERE counterName = %s',
+      self::COUNTER_TABLE_NAME,
+      $counter_name);
+    if (!$row) {
+      return null;
+    }
+
+    return (int)$row['counterValue'];
+  }
+
+
+  /**
+   * Overwrite a named counter, forcing it to a specific value.
+   *
+   * If the counter does not exist, it is created.
+   *
+   * @param AphrontDatabaseConnection Database where the counter resides.
+   * @param string Counter name to create or overwrite.
+   * @return void
+   *
+   * @task util
+   */
+  public static function overwriteCounterValue(
+    AphrontDatabaseConnection $conn_w,
+    $counter_name,
+    $counter_value) {
+
+    queryfx(
+      $conn_w,
+      'INSERT INTO %T (counterName, counterValue) VALUES (%s, %d)
+        ON DUPLICATE KEY UPDATE counterValue = VALUES(counterValue)',
+      self::COUNTER_TABLE_NAME,
+      $counter_name,
+      $counter_value);
+  }
+
   private function getBinaryColumns() {
     return $this->getConfigOption(self::CONFIG_BINARY);
   }

src/infrastructure/storage/lisk/__tests__/LiskFixtureTestCase.php

@@ -99,14 +99,21 @@ final class LiskFixtureTestCase extends PhabricatorTestCase {
     $conn_w = $obj->establishConnection('w');
 
     // Test that the counter bascially behaves as expected.
-    $this->assertEqual(1, LiskDAO::loadNextCounterID($conn_w, 'a'));
-    $this->assertEqual(2, LiskDAO::loadNextCounterID($conn_w, 'a'));
-    $this->assertEqual(3, LiskDAO::loadNextCounterID($conn_w, 'a'));
+    $this->assertEqual(1, LiskDAO::loadNextCounterValue($conn_w, 'a'));
+    $this->assertEqual(2, LiskDAO::loadNextCounterValue($conn_w, 'a'));
+    $this->assertEqual(3, LiskDAO::loadNextCounterValue($conn_w, 'a'));
 
     // This first insert is primarily a test that the previous LAST_INSERT_ID()
     // value does not bleed into the creation of a new counter.
-    $this->assertEqual(1, LiskDAO::loadNextCounterID($conn_w, 'b'));
-    $this->assertEqual(2, LiskDAO::loadNextCounterID($conn_w, 'b'));
+    $this->assertEqual(1, LiskDAO::loadNextCounterValue($conn_w, 'b'));
+    $this->assertEqual(2, LiskDAO::loadNextCounterValue($conn_w, 'b'));
+
+    // Test alternate access/overwrite methods.
+    $this->assertEqual(3, LiskDAO::loadCurrentCounterValue($conn_w, 'a'));
+
+    LiskDAO::overwriteCounterValue($conn_w, 'a', 42);
+    $this->assertEqual(42, LiskDAO::loadCurrentCounterValue($conn_w, 'a'));
+    $this->assertEqual(43, LiskDAO::loadNextCounterValue($conn_w, 'a'));
 
     // These inserts alternate database connections. Since unit tests are
     // transactional by default, we need to break out of them or we'll deadlock
@@ -117,11 +124,11 @@ final class LiskFixtureTestCase extends PhabricatorTestCase {
       $conn_1 = $obj->establishConnection('w', $force_new = true);
       $conn_2 = $obj->establishConnection('w', $force_new = true);
 
-      $this->assertEqual(1, LiskDAO::loadNextCounterID($conn_1, 'z'));
-      $this->assertEqual(2, LiskDAO::loadNextCounterID($conn_2, 'z'));
-      $this->assertEqual(3, LiskDAO::loadNextCounterID($conn_1, 'z'));
-      $this->assertEqual(4, LiskDAO::loadNextCounterID($conn_2, 'z'));
-      $this->assertEqual(5, LiskDAO::loadNextCounterID($conn_1, 'z'));
+      $this->assertEqual(1, LiskDAO::loadNextCounterValue($conn_1, 'z'));
+      $this->assertEqual(2, LiskDAO::loadNextCounterValue($conn_2, 'z'));
+      $this->assertEqual(3, LiskDAO::loadNextCounterValue($conn_1, 'z'));
+      $this->assertEqual(4, LiskDAO::loadNextCounterValue($conn_2, 'z'));
+      $this->assertEqual(5, LiskDAO::loadNextCounterValue($conn_1, 'z'));
 
       LiskDAO::beginIsolateAllLiskEffectsToTransactions();
     } catch (Exception $ex) {