FileMutex::acquireLock() - Code Metrics - Inspection of "Merge branch 'kidol-filemutex'" - yiisoft/yii2 - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 04281c...63ec8d )

by Dmitry

created 2017-09-13 19:47 UTC

FileMutex::acquireLock() C

↳ Parent: FileMutex

Complexity

Conditions	8
Paths	10

Size

Total Lines	51
Code Lines	23

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	14
CRAP Score	11.8345

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
c	1
b	0
f	0
dl	0
loc	51
ccs	14
cts	23
cp	0.6087
rs	6.5978
cc	8
eloc	23
nc	10
nop	2
crap	11.8345

How to fix Long Method

<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\mutex;

use Yii;
use yii\base\InvalidConfigException;
use yii\helpers\FileHelper;

/**
 * FileMutex implements mutex "lock" mechanism via local file system files.
 * This component relies on PHP `flock()` function.
 *
 * Application configuration example:
 *
 * ```php
 * [
 *     'components' => [
 *         'mutex' => [
 *             'class' => 'yii\mutex\FileMutex'
 *         ],
 *     ],
 * ]
 * ```
 *
 * Note: this component can maintain the locks only for the single web server,
 * it probably will not suffice to your in case you are using cloud server solution.
 *
 * Warning: due to `flock()` function nature this component is unreliable when
 * using a multithreaded server API like ISAPI.
 *
 * @see Mutex
 *
 * @author resurtm <[email protected]>
 * @since 2.0
 */
class FileMutex extends Mutex
{
    /**
     * @var string the directory to store mutex files. You may use [path alias](guide:concept-aliases) here.
     * Defaults to the "mutex" subdirectory under the application runtime path.
     */
    public $mutexPath = '@runtime/mutex';
    /**
     * @var int the permission to be set for newly created mutex files.
     * This value will be used by PHP chmod() function. No umask will be applied.
     * If not set, the permission will be determined by the current environment.
     */
    public $fileMode;
    /**
     * @var int the permission to be set for newly created directories.
     * This value will be used by PHP chmod() function. No umask will be applied.
     * Defaults to 0775, meaning the directory is read-writable by owner and group,
     * but read-only for other users.
     */
    public $dirMode = 0775;

    /**
     * @var resource[] stores all opened lock files. Keys are lock names and values are file handles.
     */
    private $_files = [];


    /**
     * Initializes mutex component implementation dedicated for UNIX, GNU/Linux, Mac OS X, and other UNIX-like
     * operating systems.
     * @throws InvalidConfigException
     */
    public function init()
    {
        parent::init();
        $this->mutexPath = Yii::getAlias($this->mutexPath);
class Id
{
    public $id;

    public function __construct($id)
    {
        $this->id = $id;
    }

}

class Account
{
    /** @var  Id $id */
    public $id;
}

$account_id = false;

if (starsAreRight()) {
    $account_id = new Id(42);
}

$account = new Account();
if ($account instanceof Id)
{
    $account->id = $account_id;
}
        if (!is_dir($this->mutexPath)) {
            FileHelper::createDirectory($this->mutexPath, $this->dirMode, true);
        }
    }

    /**
     * Acquires lock by given name.
     * @param string $name of the lock to be acquired.
     * @param int $timeout to wait for lock to become released.
     * @return bool acquiring result.
     */
    protected function acquireLock($name, $timeout = 0)
    {
        $filePath = $this->getLockFilePath($name);
        $waitTime = 0;

        while (true) {
            $file = fopen($filePath, 'w+');

            if ($file === false) {
                return false;
            }

            if ($this->fileMode !== null) {
                @chmod($filePath, $this->fileMode);
// For example instead of
@mkdir($dir);

// Better use
if (@mkdir($dir) === false) {
    throw new \RuntimeException('The directory '.$dir.' could not be created.');
}
            }

            if (!flock($file, LOCK_EX | LOCK_NB)) {
                fclose($file);

                if (++$waitTime > $timeout) {
                    return false;
                }

                sleep(1);
                continue;
            }

            // Under unix we delete the lock file before releasing the related handle. Thus it's possible that we've acquired a lock on
            // a non-existing file here (race condition). We must compare the inode of the lock file handle with the inode of the actual lock file.
            // If they do not match we simply continue the loop since we can assume the inodes will be equal on the next try.
            // Example of race condition without inode-comparison:
            // Script A: locks file
            // Script B: opens file
            // Script A: unlinks and unlocks file
            // Script B: locks handle of *unlinked* file
            // Script C: opens and locks *new* file
            // In this case we would have acquired two locks for the same file path.
            if (DIRECTORY_SEPARATOR !== '\\' && fstat($file)['ino'] !== @fileinode($filePath)) {
                clearstatcache(true, $filePath);
                flock($file, LOCK_UN);
                fclose($file);
                continue;
            }

            $this->_files[$name] = $file;
            return true;
        }

        // Should not be reached normally.
        return false;
    }

    /**
     * Releases lock by given name.
     * @param string $name of the lock to be released.
     * @return bool release result.
     */
    protected function releaseLock($name)
    {
        if (!isset($this->_files[$name])) {
            return false;
        }

        if (DIRECTORY_SEPARATOR === '\\') {
            // Under windows it's not possible to delete a file opened via fopen (either by own or other process).
            // That's why we must first unlock and close the handle and then *try* to delete the lock file.
            flock($this->_files[$name], LOCK_UN);
            fclose($this->_files[$name]);
            @unlink($this->getLockFilePath($name));
// For example instead of
@mkdir($dir);

// Better use
if (@mkdir($dir) === false) {
    throw new \RuntimeException('The directory '.$dir.' could not be created.');
}
        } else {
            // Under unix it's possible to delete a file opened via fopen (either by own or other process).
            // That's why we must unlink (the currently locked) lock file first and then unlock and close the handle.
            unlink($this->getLockFilePath($name));
            flock($this->_files[$name], LOCK_UN);
            fclose($this->_files[$name]);
        }

        unset($this->_files[$name]);
        return true;
    }

    /**
     * Generate path for lock file.
     * @param string $name
     * @return string
     * @since 2.0.10
     */
    protected function getLockFilePath($name)
    {
        return $this->mutexPath . DIRECTORY_SEPARATOR . md5($name) . '.lock';
    }
}


1		<?php
2		/**
3		* @link http://www.yiiframework.com/
4		* @copyright Copyright (c) 2008 Yii Software LLC
5		* @license http://www.yiiframework.com/license/
6		*/
7
8		namespace yii\mutex;
9
10		use Yii;
11		use yii\base\InvalidConfigException;
12		use yii\helpers\FileHelper;
13
14		/**
15		* FileMutex implements mutex "lock" mechanism via local file system files.
16		* This component relies on PHP `flock()` function.
17		*
18		* Application configuration example:
19		*
20		* ```php
21		* [
22		* 'components' => [
23		* 'mutex' => [
24		* 'class' => 'yii\mutex\FileMutex'
25		* ],
26		* ],
27		* ]
28		* ```
29		*
30		* Note: this component can maintain the locks only for the single web server,
31		* it probably will not suffice to your in case you are using cloud server solution.
32		*
33		* Warning: due to `flock()` function nature this component is unreliable when
34		* using a multithreaded server API like ISAPI.
35		*
36		* @see Mutex
37		*
38		* @author resurtm <[email protected]>
39		* @since 2.0
40		*/
41		class FileMutex extends Mutex
42		{
43		/**
44		* @var string the directory to store mutex files. You may use [path alias](guide:concept-aliases) here.
45		* Defaults to the "mutex" subdirectory under the application runtime path.
46		*/
47		public $mutexPath = '@runtime/mutex';
48		/**
49		* @var int the permission to be set for newly created mutex files.
50		* This value will be used by PHP chmod() function. No umask will be applied.
51		* If not set, the permission will be determined by the current environment.
52		*/
53		public $fileMode;
54		/**
55		* @var int the permission to be set for newly created directories.
56		* This value will be used by PHP chmod() function. No umask will be applied.
57		* Defaults to 0775, meaning the directory is read-writable by owner and group,
58		* but read-only for other users.
59		*/
60		public $dirMode = 0775;
61
62		/**
63		* @var resource[] stores all opened lock files. Keys are lock names and values are file handles.
64		*/
65		private $_files = [];
66
67
68		/**
69		* Initializes mutex component implementation dedicated for UNIX, GNU/Linux, Mac OS X, and other UNIX-like
70		* operating systems.
71		* @throws InvalidConfigException
72		*/
73	3	public function init()
74		{
75	3	parent::init();
76	3	$this->mutexPath = Yii::getAlias($this->mutexPath);
		0 ignored issues – show Documentation Bug introduced 2015-11-20 21:52 UTC by Report Bug Copy Issue Report It seems like `\Yii::getAlias($this->mutexPath)` can also be of type `boolean`. However, the property `$mutexPath` is declared as type `string`. Maybe add an additional type check? Our type inference engine has found a suspicous assignment of a value to a property. This check raises an issue when a value that can be of a mixed type is assigned to a property that is type hinted more strictly. For example, imagine you have a variable `$accountId` that can either hold an Id object or false (if there is no account id yet). Your code now assigns that value to the `id` property of an instance of the `Account` class. This class holds a proper account, so the id value must no longer be false. Either this assignment is in error or a type check should be added for that assignment. class Id { public $id; public function __construct($id) { $this->id = $id; } } class Account { /** @var Id $id */ public $id; } $account_id = false; if (starsAreRight()) { $account_id = new Id(42); } $account = new Account(); if ($account instanceof Id) { $account->id = $account_id; } Loading history...
77	3	if (!is_dir($this->mutexPath)) {
78	1	FileHelper::createDirectory($this->mutexPath, $this->dirMode, true);
79		}
80	3	}
81
82		/**
83		* Acquires lock by given name.
84		* @param string $name of the lock to be acquired.
85		* @param int $timeout to wait for lock to become released.
86		* @return bool acquiring result.
87		*/
88	3	protected function acquireLock($name, $timeout = 0)
89		{
90	3	$filePath = $this->getLockFilePath($name);
91	3	$waitTime = 0;
92
93	3	while (true) {
94	3	$file = fopen($filePath, 'w+');
95
96	3	if ($file === false) {
97		return false;
98		}
99
100	3	if ($this->fileMode !== null) {
101		@chmod($filePath, $this->fileMode);
		0 ignored issues – show Security Best Practice introduced 2016-12-20 14:41 UTC by Report Bug Copy Issue Report It seems like you do not handle an error condition here. This can introduce security issues, and is generally not recommended. If you suppress an error, we recommend checking for the error condition explicitly: // For example instead of @mkdir($dir); // Better use if (@mkdir($dir) === false) { throw new \RuntimeException('The directory '.$dir.' could not be created.'); } Loading history...
102		}
103
104	3	if (!flock($file, LOCK_EX \| LOCK_NB)) {
105	1	fclose($file);
106
107	1	if (++$waitTime > $timeout) {
108	1	return false;
109		}
110
111		sleep(1);
112		continue;
113		}
114
115		// Under unix we delete the lock file before releasing the related handle. Thus it's possible that we've acquired a lock on
116		// a non-existing file here (race condition). We must compare the inode of the lock file handle with the inode of the actual lock file.
117		// If they do not match we simply continue the loop since we can assume the inodes will be equal on the next try.
118		// Example of race condition without inode-comparison:
119		// Script A: locks file
120		// Script B: opens file
121		// Script A: unlinks and unlocks file
122		// Script B: locks handle of unlinked file
123		// Script C: opens and locks new file
124		// In this case we would have acquired two locks for the same file path.
125	3	if (DIRECTORY_SEPARATOR !== '\\' && fstat($file)['ino'] !== @fileinode($filePath)) {
126		clearstatcache(true, $filePath);
127		flock($file, LOCK_UN);
128		fclose($file);
129		continue;
130		}
131
132	3	$this->_files[$name] = $file;
133	3	return true;
134		}
135
136		// Should not be reached normally.
137		return false;
138		}
139
140		/**
141		* Releases lock by given name.
142		* @param string $name of the lock to be released.
143		* @return bool release result.
144		*/
145	3	protected function releaseLock($name)
146		{
147	3	if (!isset($this->_files[$name])) {
148		return false;
149		}
150
151	3	if (DIRECTORY_SEPARATOR === '\\') {
152		// Under windows it's not possible to delete a file opened via fopen (either by own or other process).
153		// That's why we must first unlock and close the handle and then try to delete the lock file.
154		flock($this->_files[$name], LOCK_UN);
155		fclose($this->_files[$name]);
156		@unlink($this->getLockFilePath($name));
		0 ignored issues – show Security Best Practice introduced 2016-12-20 14:41 UTC by Report Bug Copy Issue Report It seems like you do not handle an error condition here. This can introduce security issues, and is generally not recommended. If you suppress an error, we recommend checking for the error condition explicitly: // For example instead of @mkdir($dir); // Better use if (@mkdir($dir) === false) { throw new \RuntimeException('The directory '.$dir.' could not be created.'); } Loading history...
157		} else {
158		// Under unix it's possible to delete a file opened via fopen (either by own or other process).
159		// That's why we must unlink (the currently locked) lock file first and then unlock and close the handle.
160	3	unlink($this->getLockFilePath($name));
161	3	flock($this->_files[$name], LOCK_UN);
162	3	fclose($this->_files[$name]);
163		}
164
165	3	unset($this->_files[$name]);
166	3	return true;
167		}
168
169		/**
170		* Generate path for lock file.
171		* @param string $name
172		* @return string
173		* @since 2.0.10
174		*/
175	3	protected function getLockFilePath($name)
176		{
177	3	return $this->mutexPath . DIRECTORY_SEPARATOR . md5($name) . '.lock';
178		}
179		}
180

yiisoft / yii2

Push — master ( 04281c...63ec8d )

FileMutex::acquireLock() C

Complexity

Size

Duplication

Code Coverage

Importance

How to fix Long Method

Long Method

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