1 files changed, 122 insertions, 0 deletions
diff --git a/www/wiki/includes/libs/rdbms/database/resultwrapper/ResultWrapper.php b/www/wiki/includes/libs/rdbms/database/resultwrapper/ResultWrapper.php
new file mode 100644
index 00000000..df354af8
--- /dev/null
+++ b/www/wiki/includes/libs/rdbms/database/resultwrapper/ResultWrapper.php
@@ -0,0 +1,122 @@
+<?php
+
+namespace Wikimedia\Rdbms;
+
+use stdClass;
+use RuntimeException;
+
+/**
+ * Result wrapper for grabbing data queried from an IDatabase object
+ *
+ * Note that using the Iterator methods in combination with the non-Iterator
+ * DB result iteration functions may cause rows to be skipped or repeated.
+ *
+ * By default, this will use the iteration methods of the IDatabase handle if provided.
+ * Subclasses can override methods to make it solely work on the result resource instead.
+ * If no database is provided, and the subclass does not override the DB iteration methods,
+ * then a RuntimeException will be thrown when iteration is attempted.
+ *
+ * The result resource field should not be accessed from non-Database related classes.
+ * It is database class specific and is stored here to associate iterators with queries.
+ *
+ * @ingroup Database
+ */
+class ResultWrapper implements IResultWrapper {
+	/** @var resource|array|null Optional underlying result handle for subclass usage */
+	public $result;
+
+	/** @var IDatabase|null */
+	protected $db;
+
+	/** @var int */
+	protected $pos = 0;
+	/** @var stdClass|null */
+	protected $currentRow = null;
+
+	/**
+	 * Create a row iterator from a result resource and an optional Database object
+	 *
+	 * Only Database-related classes should construct ResultWrapper. Other code may
+	 * use the FakeResultWrapper subclass for convenience or compatibility shims, however.
+	 *
+	 * @param IDatabase|null $db Optional database handle
+	 * @param ResultWrapper|array|resource $result Optional underlying result handle
+	 */
+	public function __construct( IDatabase $db = null, $result ) {
+		$this->db = $db;
+		if ( $result instanceof ResultWrapper ) {
+			$this->result = $result->result;
+		} else {
+			$this->result = $result;
+		}
+	}
+
+	public function numRows() {
+		return $this->getDB()->numRows( $this );
+	}
+
+	public function fetchObject() {
+		return $this->getDB()->fetchObject( $this );
+	}
+
+	public function fetchRow() {
+		return $this->getDB()->fetchRow( $this );
+	}
+
+	public function seek( $row ) {
+		$this->getDB()->dataSeek( $this, $row );
+	}
+
+	public function free() {
+		if ( $this->db ) {
+			$this->db->freeResult( $this );
+			$this->db = null;
+		}
+		$this->result = null;
+	}
+
+	/**
+	 * @return IDatabase
+	 * @throws RuntimeException
+	 */
+	private function getDB() {
+		if ( !$this->db ) {
+			throw new RuntimeException( static::class . ' needs a DB handle for iteration.' );
+		}
+
+		return $this->db;
+	}
+
+	function rewind() {
+		if ( $this->numRows() ) {
+			$this->getDB()->dataSeek( $this, 0 );
+		}
+		$this->pos = 0;
+		$this->currentRow = null;
+	}
+
+	function current() {
+		if ( is_null( $this->currentRow ) ) {
+			$this->next();
+		}
+
+		return $this->currentRow;
+	}
+
+	function key() {
+		return $this->pos;
+	}
+
+	function next() {
+		$this->pos++;
+		$this->currentRow = $this->fetchObject();
+
+		return $this->currentRow;
+	}
+
+	function valid() {
+		return $this->current() !== false;
+	}
+}
+
+class_alias( ResultWrapper::class, 'ResultWrapper' );