Created DatabaseBase::trxTimestamp method and added usage in ActiveUsers query

[lhc/web/wiklou.git] / includes / db / Database.php

diff --git a/includes/db/Database.php b/includes/db/Database.php
index 9b783a9..29642d0 100644 (file)
--- a/includes/db/Database.php
+++ b/includes/db/Database.php
@@ -272,9 +272,20 @@ abstract class DatabaseBase implements IDatabase, DatabaseType {
         * Either a short hexidecimal string if a transaction is active or ""
         *
         * @var string
+        * @see DatabaseBase::mTrxLevel
         */
        protected $mTrxShortId = '';
 
+       /**
+        * The UNIX time that the transaction started. Callers can assume that if
+        * snapshot isolation is used, then the data is *at least* up to date to that
+        * point (possibly more up-to-date since the first SELECT defines the snapshot).
+        *
+        * @var float|null
+        * @see DatabaseBase::mTrxLevel
+        */
+       private $mTrxTimestamp = null;
+
        /**
         * Remembers the function name given for starting the most recent transaction via begin().
         * Used to provide additional context for error reporting.
@@ -419,6 +430,19 @@ abstract class DatabaseBase implements IDatabase, DatabaseType {
                return $this->mTrxLevel;
        }
 
+       /**
+        * Get the UNIX timestamp of the time that the transaction was established
+        *
+        * This can be used to reason about the staleness of SELECT data
+        * in REPEATABLE-READ transaction isolation level.
+        *
+        * @return float|null Returns null if there is not active transaction
+        * @since 1.25
+        */
+       public function trxTimestamp() {
+               return $this->mTrxLevel ? $this->mTrxTimestamp : null;
+       }
+
        /**
         * Get/set the number of errors logged. Only useful when errors are ignored
         * @param int $count The count to set, or omitted to leave it unchanged.
@@ -3512,6 +3536,7 @@ abstract class DatabaseBase implements IDatabase, DatabaseType {
                }
 
                $this->doBegin( $fname );
+               $this->mTrxTimestamp = microtime( true );
                $this->mTrxFname = $fname;
                $this->mTrxDoneWrites = false;
                $this->mTrxAutomatic = false;