adodb-compress-bzip2.php

php聊天源码

<?php

/*
V4.01 23 Oct 2003  (c) 2000-2004 John Lim ([e-mail]). All rights reserved.
         Contributed by Ross Smith ([e-mail]). 
  Released under both BSD license and Lesser GPL library license.
  Whenever there is any discrepancy between the two licenses,
  the BSD license will take precedence.
	  Set tabs to 4 for best viewing.

*/

if (!function_exists('bzcompress')) {
	trigger_error('bzip2 functions are not available', E_USER_ERROR);
	return 0;
}

/*
*/
class ADODB_Compress_Bzip2 {
	/**
	 */
	var $_block_size = null;

	/**
	 */
	var $_work_level = null;

	/**
	 */
	var $_min_length = 1;

	/**
	 */
	function getBlockSize() {
		return $this->_block_size;
	}

	/**
	 */
	function setBlockSize($block_size) {
		assert('$block_size >= 1');
		assert('$block_size <= 9');
		$this->_block_size = (int) $block_size;
	}

	/**
	 */
	function getWorkLevel() {
		return $this->_work_level;
	}

	/**
	 */
	function setWorkLevel($work_level) {
		assert('$work_level >= 0');
		assert('$work_level <= 250');
		$this->_work_level = (int) $work_level;
	}

	/**
	 */
	function getMinLength() {
		return $this->_min_length;
	}

	/**
	 */
	function setMinLength($min_length) {
		assert('$min_length >= 0');
		$this->_min_length = (int) $min_length;
	}

	/**
	 */
	function ADODB_Compress_Bzip2($block_size = null, $work_level = null, $min_length = null) {
		if (!is_null($block_size)) {
			$this->setBlockSize($block_size);
		}

		if (!is_null($work_level)) {
			$this->setWorkLevel($work_level);
		}

		if (!is_null($min_length)) {
			$this->setMinLength($min_length);
		}
	}

	/**
	 */
	function write($data, $key) {
		if (strlen($data) < $this->_min_length) {
			return $data;
		}

		if (!is_null($this->_block_size)) {
			if (!is_null($this->_work_level)) {
				return bzcompress($data, $this->_block_size, $this->_work_level);
			} else {
				return bzcompress($data, $this->_block_size);
			}
		}

		return bzcompress($data);
	}

	/**
	 */
	function read($data, $key) {
		return $data ? bzdecompress($data) : $data;
	}

}

return 1;

?>