<?php
class DbaReader implements Iterator
{

protected $db = NULL;
private $key = false;
private $val = false;

/**
* Open database $file with $handler in read only mode.
*
* @param file Database file to open.
* @param handler Handler to use for database access.
*/
function __construct($file, $handler) {
if (!$this->db = dba_open($file, 'r', $handler)) {
throw new exception('Could not open file ' . $file);
}
}

/**
* Close database.
*/
function __destruct() {
dba_close($this->db);
}

/**
* Rewind to first element.
*/
function rewind() {
$this->key = dba_firstkey($this->db);
$this->fetch_data();
}

/**
* Move to next element.
*
* @return void
*/
function next() {
$this->key = dba_nextkey($this->db);
$this->fetch_data();
}

/**
* Fetches the current data if $key is valid
*/
private function fetch_data() {
if ($this->key !== false) {
$this->val = dba_fetch($this->key, $this->db);
}
}

/**
* @return Current data.
*/
function current() {
return $this->val;
}

/**
* @return Whether more elements are available.
*/
function valid() {
if ($this->db && $this->key !== false) {
return true;
} else {
return false;
}
}

/**
* @return Current key.
*/
function key() {
return $this->key;
}
}
?>

<?php
class DbaArray extends DbaReader implements ArrayAccess
{

/**
* Open database $file with $handler in read only mode.
*
* @param file Database file to open.
* @param handler Handler to use for database access.取值http://www.php.net/manual/en/dba.requirements.php
*/
function __construct($file, $handler)
{
$this->db = dba_popen($file, "c", $handler);
if (!$this->db) {
throw new exception("Databse could not be opened");
}
}

/**
* Close database.
*/
function __destruct()
{
parent::__destruct();
}

/**
* Read an entry.
*
* @param $name key to read from
* @return value associated with $name
*/
function offsetGet($name)
{
$data = dba_fetch($name, $this->db);
if($data) {
if (ini_get('magic_quotes_runtime')) {
$data = stripslashes($data);
}
//return unserialize($data);
return $data;
}
else
{
return NULL;
}
}

/**
* Set an entry.
*
* @param $name key to write