php遍历CSV类实例

<?php
class csviterator implements iterator
{ 
  const row_size = 4096;
  private $filepointer;
  private $currentelement;
  private $rowcounter;
  private $delimiter;
  public function __construct( $file, $delimiter = ',' )
  {
    $this->filepointer = fopen( $file, 'r' );
    $this->delimiter  = $delimiter;
  }
  public function rewind()
  {
    $this->rowcounter = 0;
    rewind( $this->filepointer );
  }
  public function current()
  {
    $this->currentelement = fgetcsv($this->filepointer,self::row_size,$this->delimiter);
    $this->rowcounter++;
    return $this->currentelement;
  }
  public function key()
  {
    return $this->rowcounter;
  }
  public function next()
  {
    return !feof( $this->filepointer );
  }
  public function valid()
  {
    if( !$this->next() )
    {
      fclose( $this->filepointer );
      return false;
    }
    return true;
  }
} // end class
?>