.
*/
require_once 'phing/filters/BaseParamFilterReader.php';
/**
* Reads the last n lines of a stream. (Default is last10 lines.)
*
* Example:
*
*
*
* Or:
*
*
*
*
*
* @author Yannick Lecaillez
* @author hans lellelid, hans@velum.net
* @copyright © 2003 seasonfive. All rights reserved
* @version $Revision: 1.7 $
* @see BaseParamFilterReader
* @package phing.filters
*/
class TailFilter extends BaseParamFilterReader implements ChainableReader {
/**
* Parameter name for the number of lines to be returned.
* @var string
*/
const LINES_KEY = "lines";
/**
* Number of lines to be returned in the filtered stream.
* @var integer
*/
private $_lines = 10;
/**
* Array to hold lines.
* @var array
*/
private $_lineBuffer = array();
/**
* Returns the last n lines of a file.
* @param int $len Num chars to read.
* @return mixed The filtered buffer or -1 if EOF.
*/
function read($len = null) {
while ( ($buffer = $this->in->read($len)) !== -1 ) {
// Remove the last "\n" from buffer for
// prevent explode to add an empty cell at
// the end of array
$buffer= trim($buffer, "\n");
$lines = explode("\n", $buffer);
if ( count($lines) >= $this->_lines ) {
// Buffer have more (or same) number of lines than needed.
// Fill lineBuffer with the last "$this->_lines" lasts ones.
$off = count($lines)-$this->_lines;
$this->_lineBuffer = array_slice($lines, $off);
} else {
// Some new lines ...
// Prepare space for insert these new ones
$this->_lineBuffer = array_slice($this->_lineBuffer, count($lines)-1);
$this->_lineBuffer = array_merge($this->_lineBuffer, $lines);
}
}
if ( empty($this->_lineBuffer) )
$ret = -1;
else {
$ret = implode("\n", $this->_lineBuffer);
$this->_lineBuffer = array();
}
return $ret;
}
/**
* Sets the number of lines to be returned in the filtered stream.
*
* @param integer $lines the number of lines to be returned in the filtered stream.
*/
function setLines($lines) {
$this->_lines = (int) $lines;
}
/**
* Returns the number of lines to be returned in the filtered stream.
*
* @return integer The number of lines to be returned in the filtered stream.
*/
function getLines() {
return $this->_lines;
}
/**
* Creates a new TailFilter using the passed in
* Reader for instantiation.
*
* @param object A Reader object providing the underlying stream.
* Must not be null.
*
* @return object A new filter based on this configuration, but filtering
* the specified reader.
*/
function chain(Reader $reader) {
$newFilter = new TailFilter($reader);
$newFilter->setLines($this->getLines());
$newFilter->setInitialized(true);
$newFilter->setProject($this->getProject());
return $newFilter;
}
/**
* Scans the parameters list for the "lines" parameter and uses
* it to set the number of lines to be returned in the filtered stream.
*/
private function _initialize() {
$params = $this->getParameters();
if ( $params !== null ) {
for($i=0, $_i=count($params); $i < $_i; $i++) {
if ( self::LINES_KEY == $params[$i]->getName() ) {
$this->_lines = (int) $params[$i]->getValue();
break;
}
}
}
}
}
?>