rdbms: normalize Database/LBFactory logging and add snapshot flushing warnings

[lhc/web/wiklou.git] / includes / libs / rdbms / database / DBConnRef.php

diff --git a/includes/libs/rdbms/database/DBConnRef.php b/includes/libs/rdbms/database/DBConnRef.php
index b216892..2cc2c90 100644 (file)
--- a/includes/libs/rdbms/database/DBConnRef.php
+++ b/includes/libs/rdbms/database/DBConnRef.php
@@ -5,8 +5,23 @@ namespace Wikimedia\Rdbms;
 use InvalidArgumentException;
 
 /**
- * Helper class to handle automatically marking connections as reusable (via RAII pattern)
- * as well handling deferring the actual network connection until the handle is used
+ * Helper class used for automatically marking an IDatabase connection as reusable (once it no
+ * longer matters which DB domain is selected) and for deferring the actual network connection
+ *
+ * This uses an RAII-style pattern where calling code is expected to keep the returned reference
+ * handle as a function variable that falls out of scope when no longer needed. This avoids the
+ * need for matching reuseConnection() calls for every "return" statement as well as the tedious
+ * use of try/finally.
+ *
+ * @par Example:
+ * @code
+ *     function getRowData() {
+ *         $conn = $this->lb->getConnectedRef( DB_REPLICA );
+ *         $row = $conn->select( ... );
+ *         return $row ? (array)$row : false;
+ *         // $conn falls out of scope and $this->lb->reuseConnection() gets called
+ *     }
+ * @endcode
  *
  * @ingroup Database
  * @since 1.22
@@ -28,14 +43,14 @@ class DBConnRef implements IDatabase {
 
        /**
         * @param ILoadBalancer $lb Connection manager for $conn
-        * @param Database|array $conn Database or (server index, query groups, domain, flags)
+        * @param IDatabase|array $conn Database or (server index, query groups, domain, flags)
         * @param int $role The type of connection asked for; one of DB_MASTER/DB_REPLICA
         * @internal This method should not be called outside of LoadBalancer
         */
        public function __construct( ILoadBalancer $lb, $conn, $role ) {
                $this->lb = $lb;
                $this->role = $role;
-               if ( $conn instanceof Database ) {
+               if ( $conn instanceof IDatabase && !( $conn instanceof DBConnRef ) ) {
                        $this->conn = $conn; // live handle
                } elseif ( is_array( $conn ) && count( $conn ) >= 4 && $conn[self::FLD_DOMAIN] !== false ) {
                        $this->params = $conn;
@@ -461,7 +476,7 @@ class DBConnRef implements IDatabase {
                return $this->__call( __FUNCTION__, func_get_args() );
        }
 
-       public function buildLike() {
+       public function buildLike( $param ) {
                return $this->__call( __FUNCTION__, func_get_args() );
        }
 
@@ -598,6 +613,10 @@ class DBConnRef implements IDatabase {
                return $this->__call( __FUNCTION__, func_get_args() );
        }
 
+       public function onAtomicSectionCancel( callable $callback, $fname = __METHOD__ ) {
+               return $this->__call( __FUNCTION__, func_get_args() );
+       }
+
        public function setTransactionListener( $name, callable $callback = null ) {
                return $this->__call( __FUNCTION__, func_get_args() );
        }
@@ -630,15 +649,15 @@ class DBConnRef implements IDatabase {
                return $this->__call( __FUNCTION__, func_get_args() );
        }
 
-       public function commit( $fname = __METHOD__, $flush = '' ) {
+       public function commit( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
                return $this->__call( __FUNCTION__, func_get_args() );
        }
 
-       public function rollback( $fname = __METHOD__, $flush = '' ) {
+       public function rollback( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
                return $this->__call( __FUNCTION__, func_get_args() );
        }
 
-       public function flushSnapshot( $fname = __METHOD__ ) {
+       public function flushSnapshot( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
                return $this->__call( __FUNCTION__, func_get_args() );
        }
 
@@ -740,6 +759,19 @@ class DBConnRef implements IDatabase {
                return $this->__call( __FUNCTION__, func_get_args() );
        }
 
+       public function __toString() {
+               if ( $this->conn === null ) {
+                       // spl_object_id is PHP >= 7.2
+                       $id = function_exists( 'spl_object_id' )
+                               ? spl_object_id( $this )
+                               : spl_object_hash( $this );
+
+                       return $this->getType() . ' object #' . $id;
+               }
+
+               return $this->__call( __FUNCTION__, func_get_args() );
+       }
+
        /**
         * Error out if the role is not DB_MASTER
         *