includes/libs/rdbms/database/resultwrapper/ResultWrapper.php

   1 <?php
   2 /**
   3  * Result wrapper for grabbing data queried by someone else
   4  * @ingroup Database
   5  */
   6 class ResultWrapper implements Iterator {
   7         /** @var resource */
   8         public $result;
   9
  10         /** @var IDatabase */
  11         protected $db;
  12
  13         /** @var int */
  14         protected $pos = 0;
  15
  16         /** @var object|null */
  17         protected $currentRow = null;
  18
  19         /**
  20          * Create a new result object from a result resource and a Database object
  21          *
  22          * @param IDatabase $database
  23          * @param resource|ResultWrapper $result
  24          */
  25         function __construct( $database, $result ) {
  26                 $this->db = $database;
  27
  28                 if ( $result instanceof ResultWrapper ) {
  29                         $this->result = $result->result;
  30                 } else {
  31                         $this->result = $result;
  32                 }
  33         }
  34
  35         /**
  36          * Get the number of rows in a result object
  37          *
  38          * @return int
  39          */
  40         function numRows() {
  41                 return $this->db->numRows( $this );
  42         }
  43
  44         /**
  45          * Fetch the next row from the given result object, in object form. Fields can be retrieved with
  46          * $row->fieldname, with fields acting like member variables. If no more rows are available,
  47          * false is returned.
  48          *
  49          * @return stdClass|bool
  50          * @throws DBUnexpectedError Thrown if the database returns an error
  51          */
  52         function fetchObject() {
  53                 return $this->db->fetchObject( $this );
  54         }
  55
  56         /**
  57          * Fetch the next row from the given result object, in associative array form. Fields are
  58          * retrieved with $row['fieldname']. If no more rows are available, false is returned.
  59          *
  60          * @return array|bool
  61          * @throws DBUnexpectedError Thrown if the database returns an error
  62          */
  63         function fetchRow() {
  64                 return $this->db->fetchRow( $this );
  65         }
  66
  67         /**
  68          * Free a result object
  69          */
  70         function free() {
  71                 $this->db->freeResult( $this );
  72                 unset( $this->result );
  73                 unset( $this->db );
  74         }
  75
  76         /**
  77          * Change the position of the cursor in a result object.
  78          * See mysql_data_seek()
  79          *
  80          * @param int $row
  81          */
  82         function seek( $row ) {
  83                 $this->db->dataSeek( $this, $row );
  84         }
  85
  86         /*
  87          * ======= Iterator functions =======
  88          * Note that using these in combination with the non-iterator functions
  89          * above may cause rows to be skipped or repeated.
  90          */
  91
  92         function rewind() {
  93                 if ( $this->numRows() ) {
  94                         $this->db->dataSeek( $this, 0 );
  95                 }
  96                 $this->pos = 0;
  97                 $this->currentRow = null;
  98         }
  99
 100         /**
 101          * @return stdClass|array|bool
 102          */
 103         function current() {
 104                 if ( is_null( $this->currentRow ) ) {
 105                         $this->next();
 106                 }
 107
 108                 return $this->currentRow;
 109         }
 110
 111         /**
 112          * @return int
 113          */
 114         function key() {
 115                 return $this->pos;
 116         }
 117
 118         /**
 119          * @return stdClass
 120          */
 121         function next() {
 122                 $this->pos++;
 123                 $this->currentRow = $this->fetchObject();
 124
 125                 return $this->currentRow;
 126         }
 127
 128         /**
 129          * @return bool
 130          */
 131         function valid() {
 132                 return $this->current() !== false;
 133         }
 134 }