CI_Session_redis_driver - Code Metrics - Inspection of "Merge pull request #142 from dev-ggallon/f/Update_..." - ci-bonfire/Sprint - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — develop ( 7d455c...f6fa23 )

by Lonnie

created 2015-12-15 19:11 UTC

CI_Session_redis_driver B

↳ Parent: Project

Complexity

Total Complexity

Size/Duplication

Total Lines	336
Duplicated Lines	27.08 %

Coupling/Cohesion

Components	1
Dependencies	1

Metric	Value
wmc	50
lcom	1
cbo	1
dl	91
loc	336
rs	8.6207

9 Methods

Rating	Name	Duplication	Size	Complexity
D	__construct()	4	31	10
C	open()	0	28	7
A	read()	14	14	3
D	write()	39	39	9
B	close()	0	25	6
A	destroy()	0	15	3
A	gc()	0	5	1
C	_get_lock()	18	42	7
A	_release_lock()	16	16	4

How to fix Duplicated Code Complexity

Duplicated Code

Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.

Common duplication problems, and corresponding solutions are:

If you have the same expression in different places: Extract expression to a method
If you have the same method in different sub-classes: Extract method, and pull up field to the parent class
If you have the same code in unrelated classes: Consider extracting the code to a new class, and injecting that class

Complex Class

Tip: Before tackling complexity, make sure that you eliminate any duplication first. This often can reduce the size of classes significantly.

Complex classes like CI_Session_redis_driver often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.

Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.

While breaking up the class, it is a good idea to analyze how other classes use CI_Session_redis_driver, and based on these observations, apply Extract Interface, too.

<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package	CodeIgniter
 * @author	EllisLab Dev Team
 * @copyright	Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
 * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
 * @license	http://opensource.org/licenses/MIT	MIT License
 * @link	http://codeigniter.com
 * @since	Version 3.0.0
 * @filesource
 */
defined('BASEPATH') OR exit('No direct script access allowed');

/**
 * CodeIgniter Session Redis Driver
 *
 * @package	CodeIgniter
 * @subpackage	Libraries
 * @category	Sessions
 * @author	Andrey Andreev
 * @link	http://codeigniter.com/user_guide/libraries/sessions.html
 */
class CI_Session_redis_driver extends CI_Session_driver implements SessionHandlerInterface {

	/**
	 * phpRedis instance
	 *
	 * @var	resource
	 */
	protected $_redis;

	/**
	 * Key prefix
	 *
	 * @var	string
	 */
	protected $_key_prefix = 'ci_session:';

	/**
	 * Lock key
	 *
	 * @var	string
	 */
	protected $_lock_key;

	// ------------------------------------------------------------------------

	/**
	 * Class constructor
	 *
	 * @param	array	$params	Configuration parameters
	 * @return	void
	 */
	public function __construct(&$params)
	{
		parent::__construct($params);

		if (empty($this->_config['save_path']))
		{
			log_message('error', 'Session: No Redis save path configured.');
		}
		elseif (preg_match('#(?:tcp://)?([^:?]+)(?:\:(\d+))?(\?.+)?#', $this->_config['save_path'], $matches))
		{
			isset($matches[3]) OR $matches[3] = ''; // Just to avoid undefined index notices below
			$this->_config['save_path'] = array(
				'host' => $matches[1],
				'port' => empty($matches[2]) ? NULL : $matches[2],
				'password' => preg_match('#auth=([^\s&]+)#', $matches[3], $match) ? $match[1] : NULL,
				'database' => preg_match('#database=(\d+)#', $matches[3], $match) ? (int) $match[1] : NULL,
				'timeout' => preg_match('#timeout=(\d+\.\d+)#', $matches[3], $match) ? (float) $match[1] : NULL
			);

			preg_match('#prefix=([^\s&]+)#', $matches[3], $match) && $this->_key_prefix = $match[1];
		}
		else
		{
			log_message('error', 'Session: Invalid Redis save path format: '.$this->_config['save_path']);
		}

		if ($this->_config['match_ip'] === TRUE)
		{
			$this->_key_prefix .= $_SERVER['REMOTE_ADDR'].':';
		}
	}

	// ------------------------------------------------------------------------

	/**
	 * Open
	 *
	 * Sanitizes save_path and initializes connection.
	 *
	 * @param	string	$save_path	Server path
	 * @param	string	$name		Session cookie name, unused
	 * @return	bool
	 */
	public function open($save_path, $name)
	{
		if (empty($this->_config['save_path']))
		{
			return $this->_failure;
		}

		$redis = new Redis();
		if ( ! $redis->connect($this->_config['save_path']['host'], $this->_config['save_path']['port'], $this->_config['save_path']['timeout']))
		{
			log_message('error', 'Session: Unable to connect to Redis with the configured settings.');
		}
		elseif (isset($this->_config['save_path']['password']) && ! $redis->auth($this->_config['save_path']['password']))
		{
			log_message('error', 'Session: Unable to authenticate to Redis instance.');
		}
		elseif (isset($this->_config['save_path']['database']) && ! $redis->select($this->_config['save_path']['database']))
		{
			log_message('error', 'Session: Unable to select Redis database with index '.$this->_config['save_path']['database']);
		}
		else
		{
			$this->_redis = $redis;
			return $this->_success;
		}

		return $this->_failure;
	}

	// ------------------------------------------------------------------------

	/**
	 * Read
	 *
	 * Reads session data and acquires a lock
	 *
	 * @param	string	$session_id	Session ID
	 * @return	string	Serialized session data
	 */
	public function read($session_id)
	{
		if (isset($this->_redis) && $this->_get_lock($session_id))
		{
			// Needed by write() to detect session_regenerate_id() calls
			$this->_session_id = $session_id;

			$session_data = (string) $this->_redis->get($this->_key_prefix.$session_id);
			$this->_fingerprint = md5($session_data);
			return $session_data;
		}

		return $this->_failure;
	}

	// ------------------------------------------------------------------------

	/**
	 * Write
	 *
	 * Writes (create / update) session data
	 *
	 * @param	string	$session_id	Session ID
	 * @param	string	$session_data	Serialized session data
	 * @return	bool
	 */
	public function write($session_id, $session_data)
	{
		if ( ! isset($this->_redis))
		{
			return $this->_failure;
		}
		// Was the ID regenerated?
		elseif ($session_id !== $this->_session_id)
		{
			if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id))
			{
				return $this->_failure;
			}

			$this->_fingerprint = md5('');
			$this->_session_id = $session_id;
		}

		if (isset($this->_lock_key))
		{
			$this->_redis->setTimeout($this->_lock_key, 300);
			if ($this->_fingerprint !== ($fingerprint = md5($session_data)))
			{
				if ($this->_redis->set($this->_key_prefix.$session_id, $session_data, $this->_config['expiration']))
				{
					$this->_fingerprint = $fingerprint;
					return $this->_success;
				}

				return $this->_failure;
			}

			return ($this->_redis->setTimeout($this->_key_prefix.$session_id, $this->_config['expiration']))
				? $this->_success
				: $this->_failure;
		}

		return $this->_failure;
	}

	// ------------------------------------------------------------------------

	/**
	 * Close
	 *
	 * Releases locks and closes connection.
	 *
	 * @return	bool
	 */
	public function close()
	{
		if (isset($this->_redis))
		{
			try {
				if ($this->_redis->ping() === '+PONG')
				{
					isset($this->_lock_key) && $this->_redis->delete($this->_lock_key);
					if ($this->_redis->close() === $this->_failure)

					{
						return $this->_failure;
					}
				}
			}
			catch (RedisException $e)
			{
				log_message('error', 'Session: Got RedisException on close(): '.$e->getMessage());
			}

			$this->_redis = NULL;
			return $this->_success;
		}

		return $this->_success;
	}

	// ------------------------------------------------------------------------

	/**
	 * Destroy
	 *
	 * Destroys the current session.
	 *
	 * @param	string	$session_id	Session ID
	 * @return	bool
	 */
	public function destroy($session_id)
	{
		if (isset($this->_redis, $this->_lock_key))
		{
			if (($result = $this->_redis->delete($this->_key_prefix.$session_id)) !== 1)
			{
				log_message('debug', 'Session: Redis::delete() expected to return 1, got '.var_export($result, TRUE).' instead.');
			}

			$this->_cookie_destroy();
			return $this->_success;
		}

		return $this->_failure;
	}

	// ------------------------------------------------------------------------

	/**
	 * Garbage Collector
	 *
	 * Deletes expired sessions
	 *
	 * @param	int 	$maxlifetime	Maximum lifetime of sessions
	 * @return	bool
	 */
	public function gc($maxlifetime)
	{
		// Not necessary, Redis takes care of that.
		return $this->_success;
	}

	// ------------------------------------------------------------------------

	/**
	 * Get lock
	 *
	 * Acquires an (emulated) lock.
	 *
	 * @param	string	$session_id	Session ID
	 * @return	bool
	 */
	protected function _get_lock($session_id)
	{
		if (isset($this->_lock_key))
		{
			return $this->_redis->setTimeout($this->_lock_key, 300);
		}

		// 30 attempts to obtain a lock, in case another request already has it
		$lock_key = $this->_key_prefix.$session_id.':lock';
		$attempt = 0;
		do
		{
			if (($ttl = $this->_redis->ttl($lock_key)) > 0)
			{
				sleep(1);
				continue;
			}

			if ( ! $this->_redis->setex($lock_key, 300, time()))
			{
				log_message('error', 'Session: Error while trying to obtain lock for '.$this->_key_prefix.$session_id);
				return FALSE;
			}

			$this->_lock_key = $lock_key;
			break;
		}
		while (++$attempt < 30);

		if ($attempt === 30)
		{
			log_message('error', 'Session: Unable to obtain lock for '.$this->_key_prefix.$session_id.' after 30 attempts, aborting.');
			return FALSE;
		}
		elseif ($ttl === -1)
		{
			log_message('debug', 'Session: Lock for '.$this->_key_prefix.$session_id.' had no TTL, overriding.');
		}

		$this->_lock = TRUE;
		return TRUE;
	}

	// ------------------------------------------------------------------------

	/**
	 * Release lock
	 *
	 * Releases a previously acquired lock
	 *
	 * @return	bool
	 */
	protected function _release_lock()
	{
		if (isset($this->_redis, $this->_lock_key) && $this->_lock)
		{
			if ( ! $this->_redis->delete($this->_lock_key))
			{
				log_message('error', 'Session: Error while trying to free lock for '.$this->_lock_key);
				return FALSE;
			}

			$this->_lock_key = NULL;
			$this->_lock = FALSE;
		}

		return TRUE;
	}

}


1		<?php
2		/**
3		* CodeIgniter
4		*
5		* An open source application development framework for PHP
6		*
7		* This content is released under the MIT License (MIT)
8		*
9		* Copyright (c) 2014 - 2015, British Columbia Institute of Technology
10		*
11		* Permission is hereby granted, free of charge, to any person obtaining a copy
12		* of this software and associated documentation files (the "Software"), to deal
13		* in the Software without restriction, including without limitation the rights
14		* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
15		* copies of the Software, and to permit persons to whom the Software is
16		* furnished to do so, subject to the following conditions:
17		*
18		* The above copyright notice and this permission notice shall be included in
19		* all copies or substantial portions of the Software.
20		*
21		* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22		* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23		* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
24		* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
25		* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
26		* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
27		* THE SOFTWARE.
28		*
29		* @package CodeIgniter
30		* @author EllisLab Dev Team
31		* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (http://ellislab.com/)
32		* @copyright Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
33		* @license http://opensource.org/licenses/MIT MIT License
34		* @link http://codeigniter.com
35		* @since Version 3.0.0
36		* @filesource
37		*/
38		defined('BASEPATH') OR exit('No direct script access allowed');
39
40		/**
41		* CodeIgniter Session Redis Driver
42		*
43		* @package CodeIgniter
44		* @subpackage Libraries
45		* @category Sessions
46		* @author Andrey Andreev
47		* @link http://codeigniter.com/user_guide/libraries/sessions.html
48		*/
49		class CI_Session_redis_driver extends CI_Session_driver implements SessionHandlerInterface {
50
51		/**
52		* phpRedis instance
53		*
54		* @var resource
55		*/
56		protected $_redis;
57
58		/**
59		* Key prefix
60		*
61		* @var string
62		*/
63		protected $_key_prefix = 'ci_session:';
64
65		/**
66		* Lock key
67		*
68		* @var string
69		*/
70		protected $_lock_key;
71
72		// ------------------------------------------------------------------------
73
74		/**
75		* Class constructor
76		*
77		* @param array $params Configuration parameters
78		* @return void
79		*/
80		public function __construct(&$params)
81		{
82		parent::__construct($params);
83
84		if (empty($this->_config['save_path']))
85		{
86		log_message('error', 'Session: No Redis save path configured.');
87		}
88		elseif (preg_match('#(?:tcp://)?([^:?]+)(?:\:(\d+))?(\?.+)?#', $this->_config['save_path'], $matches))
89		{
90		isset($matches[3]) OR $matches[3] = ''; // Just to avoid undefined index notices below
91		$this->_config['save_path'] = array(
92		'host' => $matches[1],
93		'port' => empty($matches[2]) ? NULL : $matches[2],
94		'password' => preg_match('#auth=([^\s&]+)#', $matches[3], $match) ? $match[1] : NULL,
95		'database' => preg_match('#database=(\d+)#', $matches[3], $match) ? (int) $match[1] : NULL,
96		'timeout' => preg_match('#timeout=(\d+\.\d+)#', $matches[3], $match) ? (float) $match[1] : NULL
97		);
98
99		preg_match('#prefix=([^\s&]+)#', $matches[3], $match) && $this->_key_prefix = $match[1];
100		}
101		else
102		{
103		log_message('error', 'Session: Invalid Redis save path format: '.$this->_config['save_path']);
104		}
105
106	View Code Duplication	if ($this->_config['match_ip'] === TRUE)
107		{
108		$this->_key_prefix .= $_SERVER['REMOTE_ADDR'].':';
109		}
110		}
111
112		// ------------------------------------------------------------------------
113
114		/**
115		* Open
116		*
117		* Sanitizes save_path and initializes connection.
118		*
119		* @param string $save_path Server path
120		* @param string $name Session cookie name, unused
121		* @return bool
122		*/
123		public function open($save_path, $name)
124		{
125		if (empty($this->_config['save_path']))
126		{
127		return $this->_failure;
128		}
129
130		$redis = new Redis();
131		if ( ! $redis->connect($this->_config['save_path']['host'], $this->_config['save_path']['port'], $this->_config['save_path']['timeout']))
132		{
133		log_message('error', 'Session: Unable to connect to Redis with the configured settings.');
134		}
135		elseif (isset($this->_config['save_path']['password']) && ! $redis->auth($this->_config['save_path']['password']))
136		{
137		log_message('error', 'Session: Unable to authenticate to Redis instance.');
138		}
139		elseif (isset($this->_config['save_path']['database']) && ! $redis->select($this->_config['save_path']['database']))
140		{
141		log_message('error', 'Session: Unable to select Redis database with index '.$this->_config['save_path']['database']);
142		}
143		else
144		{
145		$this->_redis = $redis;
146		return $this->_success;
147		}
148
149		return $this->_failure;
150		}
151
152		// ------------------------------------------------------------------------
153
154		/**
155		* Read
156		*
157		* Reads session data and acquires a lock
158		*
159		* @param string $session_id Session ID
160		* @return string Serialized session data
161		*/
162	View Code Duplication	public function read($session_id)
163		{
164		if (isset($this->_redis) && $this->_get_lock($session_id))
165		{
166		// Needed by write() to detect session_regenerate_id() calls
167		$this->_session_id = $session_id;
168
169		$session_data = (string) $this->_redis->get($this->_key_prefix.$session_id);
170		$this->_fingerprint = md5($session_data);
171		return $session_data;
172		}
173
174		return $this->_failure;
175		}
176
177		// ------------------------------------------------------------------------
178
179		/**
180		* Write
181		*
182		* Writes (create / update) session data
183		*
184		* @param string $session_id Session ID
185		* @param string $session_data Serialized session data
186		* @return bool
187		*/
188	View Code Duplication	public function write($session_id, $session_data)
189		{
190		if ( ! isset($this->_redis))
191		{
192		return $this->_failure;
193		}
194		// Was the ID regenerated?
195		elseif ($session_id !== $this->_session_id)
196		{
197		if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id))
198		{
199		return $this->_failure;
200		}
201
202		$this->_fingerprint = md5('');
203		$this->_session_id = $session_id;
204		}
205
206		if (isset($this->_lock_key))
207		{
208		$this->_redis->setTimeout($this->_lock_key, 300);
209		if ($this->_fingerprint !== ($fingerprint = md5($session_data)))
210		{
211		if ($this->_redis->set($this->_key_prefix.$session_id, $session_data, $this->_config['expiration']))
212		{
213		$this->_fingerprint = $fingerprint;
214		return $this->_success;
215		}
216
217		return $this->_failure;
218		}
219
220		return ($this->_redis->setTimeout($this->_key_prefix.$session_id, $this->_config['expiration']))
221		? $this->_success
222		: $this->_failure;
223		}
224
225		return $this->_failure;
226		}
227
228		// ------------------------------------------------------------------------
229
230		/**
231		* Close
232		*
233		* Releases locks and closes connection.
234		*
235		* @return bool
236		*/
237		public function close()
238		{
239		if (isset($this->_redis))
240		{
241		try {
242		if ($this->_redis->ping() === '+PONG')
243		{
244		isset($this->_lock_key) && $this->_redis->delete($this->_lock_key);
245		if ($this->_redis->close() === $this->_failure)
		0 ignored issues – show Bug introduced 2015-12-15 18:41 UTC by Report Bug Copy Issue Report The method `close` cannot be called on `$this->_redis` (of type `resource`). Methods can only be called on objects. This check looks for methods being called on variables that have been inferred to never be objects. Loading history...
246		{
247		return $this->_failure;
248		}
249		}
250		}
251		catch (RedisException $e)
252		{
253		log_message('error', 'Session: Got RedisException on close(): '.$e->getMessage());
254		}
255
256		$this->_redis = NULL;
257		return $this->_success;
258		}
259
260		return $this->_success;
261		}
262
263		// ------------------------------------------------------------------------
264
265		/**
266		* Destroy
267		*
268		* Destroys the current session.
269		*
270		* @param string $session_id Session ID
271		* @return bool
272		*/
273		public function destroy($session_id)
274		{
275		if (isset($this->_redis, $this->_lock_key))
276		{
277		if (($result = $this->_redis->delete($this->_key_prefix.$session_id)) !== 1)
278		{
279		log_message('debug', 'Session: Redis::delete() expected to return 1, got '.var_export($result, TRUE).' instead.');
280		}
281
282		$this->_cookie_destroy();
283		return $this->_success;
284		}
285
286		return $this->_failure;
287		}
288
289		// ------------------------------------------------------------------------
290
291		/**
292		* Garbage Collector
293		*
294		* Deletes expired sessions
295		*
296		* @param int $maxlifetime Maximum lifetime of sessions
297		* @return bool
298		*/
299		public function gc($maxlifetime)
300		{
301		// Not necessary, Redis takes care of that.
302		return $this->_success;
303		}
304
305		// ------------------------------------------------------------------------
306
307		/**
308		* Get lock
309		*
310		* Acquires an (emulated) lock.
311		*
312		* @param string $session_id Session ID
313		* @return bool
314		*/
315		protected function _get_lock($session_id)
316		{
317		if (isset($this->_lock_key))
318		{
319		return $this->_redis->setTimeout($this->_lock_key, 300);
320		}
321
322		// 30 attempts to obtain a lock, in case another request already has it
323		$lock_key = $this->_key_prefix.$session_id.':lock';
324		$attempt = 0;
325	View Code Duplication	do
326		{
327		if (($ttl = $this->_redis->ttl($lock_key)) > 0)
328		{
329		sleep(1);
330		continue;
331		}
332
333		if ( ! $this->_redis->setex($lock_key, 300, time()))
334		{
335		log_message('error', 'Session: Error while trying to obtain lock for '.$this->_key_prefix.$session_id);
336		return FALSE;
337		}
338
339		$this->_lock_key = $lock_key;
340		break;
341		}
342		while (++$attempt < 30);
343
344		if ($attempt === 30)
345		{
346		log_message('error', 'Session: Unable to obtain lock for '.$this->_key_prefix.$session_id.' after 30 attempts, aborting.');
347		return FALSE;
348		}
349		elseif ($ttl === -1)
350		{
351		log_message('debug', 'Session: Lock for '.$this->_key_prefix.$session_id.' had no TTL, overriding.');
352		}
353
354		$this->_lock = TRUE;
355		return TRUE;
356		}
357
358		// ------------------------------------------------------------------------
359
360		/**
361		* Release lock
362		*
363		* Releases a previously acquired lock
364		*
365		* @return bool
366		*/
367	View Code Duplication	protected function _release_lock()
368		{
369		if (isset($this->_redis, $this->_lock_key) && $this->_lock)
370		{
371		if ( ! $this->_redis->delete($this->_lock_key))
372		{
373		log_message('error', 'Session: Error while trying to free lock for '.$this->_lock_key);
374		return FALSE;
375		}
376
377		$this->_lock_key = NULL;
378		$this->_lock = FALSE;
379		}
380
381		return TRUE;
382		}
383
384		}
385

ci-bonfire / Sprint

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