3 * GZIP compression and decompression class
5 * @author Roland Haeder <webmaster@shipsimu.org>
7 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2013 Core Developer Team
8 * @license GNU GPL 3.0 or any newer version
9 * @link http://www.shipsimu.org
11 * This program is free software: you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation, either version 3 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program. If not, see <http://www.gnu.org/licenses/>.
24 class GzipCompressor extends BaseFrameworkSystem implements Compressor {
26 * Protected constructor
30 protected function __construct () {
31 // Call parent constructor!
32 parent::__construct(__CLASS__);
36 * Create a new compressor channel based a given compression handler or NULL if the required PHP functions are not found.
38 * @return $compressorInstance An instance of this class or NULL if the required PHP functions are not found.
40 public static final function createGzipCompressor () {
41 // Routines not found by default
42 $compressorInstance = NULL;
45 if ((function_exists('gzencode')) && (function_exists('gzdecode'))) {
46 // Compressor can maybe be used
47 $compressorInstance = new GzipCompressor();
50 // Return the compressor instance
51 return $compressorInstance;
55 * GZIP compression stream
57 * @param $streamData Mixed non-object stream data
58 * @return $streamData The compressed stream data
59 * @throws InvalidObjectException If the stream is an object
61 public function compressStream ($streamData) {
62 if (is_object($streamData)) {
64 throw new InvalidObjectException($streamData, self::EXCEPTION_UNEXPECTED_OBJECT);
67 // Return the compressed stream
68 return gzencode($streamData, 1);
72 * GZIP decompression stream
74 * @param $streamData Mixed non-object stream data
75 * @return $streamData The decompressed stream data
76 * @throws InvalidObjectException If the stream is an object
78 public function decompressStream ($streamData) {
79 if (is_object($streamData)) {
81 throw new InvalidObjectException($streamData, self::EXCEPTION_UNEXPECTED_OBJECT);
84 // Return the decompressed stream
85 return gzdecode($streamData);
89 * Getter for the file extension of this compressor
91 * @return $string Returns always 'gz'
93 public final function getCompressorExtension () {