用PHP解析巨大的XML文件

只有两个php API真正适合处理大文件。第一个是旧的expatapi，第二个是较新的XMLreader函数。这些api读取连续流，而不是将整个树加载到内存中（这是simplexml和DOM所做的）。

例如，您可能需要查看DMOZ目录的部分解析器：

<?phpclass SimpleDMOZParser{    protected $_stack = array();    protected $_file = "";    protected $_parser = null;    protected $_currentId = "";    protected $_current = "";    public function __construct($file)    {        $this->_file = $file;        $this->_parser = xml_parser_create("UTF-8");        xml_set_object($this->_parser, $this);        xml_set_element_handler($this->_parser, "startTag", "endTag");    }    public function startTag($parser, $name, $attribs)    {        array_push($this->_stack, $this->_current);        if ($name == "TOPIC" && count($attribs)) { $this->_currentId = $attribs["R:ID"];        }        if ($name == "link" && strpos($this->_currentId, "Top/Home/Consumer_Information/Electronics/") === 0) { echo $attribs["R:RESOURCE"] . "n";        }        $this->_current = $name;    }    public function endTag($parser, $name)    {        $this->_current = array_pop($this->_stack);    }    public function parse()    {        $fh = fopen($this->_file, "r");        if (!$fh) { die("Epic fail!n");        }        while (!feof($fh)) { $data = fread($fh, 4096); xml_parse($this->_parser, $data, feof($fh));        }    }}$parser = new SimpleDMOZParser("content.rdf.u8");$parser->parse();