CircuitBreaker::getRetryTimeout() - Code Metrics - dzubchik/php-circuit-breaker - Measure and Improve Code Quality continuously with Scrutinizer

CircuitBreaker::getRetryTimeout() A
last analyzed 2017-03-09 21:35 UTC

↳ Parent: CircuitBreaker

Complexity

Conditions	1
Paths	1

Size

Total Lines	4
Code Lines	2

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	2
CRAP Score	1

Importance

Changes

Metric	Value
dl	0
loc	4
ccs	2
cts	2
cp	1
rs	10
c	0
b	0
f	0
cc	1
eloc	2
nc	1
nop	1
crap	1

<?php
declare(strict_types = 1);


namespace Paymaxi\Component\CircuitBreaker\Core;

use Paymaxi\Component\CircuitBreaker\CircuitBreakerInterface;
use Paymaxi\Component\CircuitBreaker\Storage\StorageInterface;

/**
 * Allows user code to track availability of any service by serviceName.
 *
 * @see \Paymaxi\Component\CircuitBreaker\CircuitBreakerInterface
 * @package Paymaxi\Component\CircuitBreaker\Components
 */
class CircuitBreaker implements CircuitBreakerInterface
{

    /**
     * @var CircuitBreakerInterface used to load/save availability statistics
     */
    protected $storageAdapter;

    /**
     * @var int default threshold, if service fails this many times will be disabled
     */
    protected $defaultMaxFailures;

    /**
     * @var int  how many seconds should we wait before retry
     */
    protected $defaultRetryTimeout;

    /**
     * Array with configuration per service name, format:
     *  array(
     *      "serviceName1" => array('maxFailures' => X, 'retryTimeout => Y),
     *      "serviceName2" => array('maxFailures' => X, 'retryTimeout => Y),
     *  )
     *
     * @var array[] settings per service name
     */
    protected $settings = array();

    /**
     * Configure instance with storage implementation and default threshold and retry timeout.
     *
     * @param StorageInterface $storage storage implementation
     * @param int $maxFailures default threshold, if service fails this many times will be disabled
     * @param int $retryTimeout how many seconds should we wait before retry
     */
    public function __construct(StorageInterface $storage, $maxFailures = 20, $retryTimeout = 60)
    {
        $this->storageAdapter = $storage;

        $this->defaultMaxFailures = $maxFailures;
        $this->defaultRetryTimeout = $retryTimeout;
    }

    /**
     * Use this method only if you want to add server specific threshold and retry timeout.
     *
     * @param $serviceName
     * @param int $maxFailures default threshold, if service fails this many times will be disabled
     * @param int $retryTimeout how many seconds should we wait before retry
     *
     * @return CircuitBreaker
     * @internal param StorageInterface $storage storage implementation
     */
    public function setServiceSettings($serviceName, $maxFailures, $retryTimeout)
    {
        $this->settings[$serviceName] = array(
            'maxFailures'  => $maxFailures ? $maxFailures : $this->defaultMaxFailures,
            'retryTimeout' => $retryTimeout ? $retryTimeout : $this->defaultRetryTimeout,
        );

        return $this;
    }

    // ---------------------- HELPERS -----------------

    public function isAvailable(string $serviceName): bool
    {
        $failures = $this->getFailures($serviceName);
        $maxFailures = $this->getMaxFailures($serviceName);
        if ($failures < $maxFailures) {
            // this is what happens most of the time so we evaluate first
            return true;
        } else {
            $lastTest = $this->getLastTest($serviceName);
            $retryTimeout = $this->getRetryTimeout($serviceName);
            if ($lastTest + $retryTimeout < time()) {
                // Once we wait $retryTimeout, we have to allow one
                // thread to try to connect again. To prevent all other threads
                // from flooding, the potentially dead db, we update the time first
                // and then try to connect. If db is dead only one thread will hang
                // waiting for the connection. Others will get updated timeout from stats.
                //
                // 'Race condition' is between first thread getting into this line and
                // time it takes to store the settings. In that time other threads will
                // also be entering this statement. Even on very busy servers it
                // wont allow more than a few requests to get through before stats are updated.
                //
                // updating lastTest
                $this->setFailures($serviceName, $failures);
                // allowing this thread to try to connect to the resource
                return true;
            } else {
                return false;
            }
        }
    }

    // ---------------------- Directly accessed by interface methods -----------------

    /**
     * @param string $serviceName
     *
     * @return int
     */
    protected function getFailures(string $serviceName)
    {
        //FIXME - catch exceptions and replace implementation if occur
        return (int) $this->storageAdapter->loadStatus($serviceName, 'failures');

    }

    /**
     * @param string $serviceName
     *
     * @return int
     */
    protected function getMaxFailures(string $serviceName)
    {
        return $this->getSetting($serviceName, 'maxFailures');
    }

    /**
     * Load setting or initialise service name with defaults for faster lookups
     *
     * @param string $serviceName what service to look for
     * @param string $variable what setting to look for
     *
     * @return int
     */
    private function getSetting(string $serviceName, string $variable)
    {
        // make sure there are settings for the service
        if (!isset($this->settings[$serviceName])) {
            $this->settings[$serviceName] = array(
                'maxFailures'  => $this->defaultMaxFailures,
                'retryTimeout' => $this->defaultRetryTimeout,
            );
        }
        return $this->settings[$serviceName][$variable];
    }

    /**
     * @param string $serviceName
     *
     * @return int
     */
    protected function getLastTest(string $serviceName)
    {
        //FIXME - catch exceptions and replace implementation if occur
        return (int) $this->storageAdapter->loadStatus($serviceName, 'lastTest');

    }

    /**
     * @param string $serviceName
     *
     * @return int
     */
    protected function getRetryTimeout(string $serviceName)
    {
        return $this->getSetting($serviceName, 'retryTimeout');
    }


    /**
     * @param string $serviceName
     * @param integer $newValue
     */
    protected function setFailures(string $serviceName, $newValue)
    {
        //FIXME - catch exceptions and replace implementation if occur
        $this->storageAdapter->saveStatus($serviceName, 'failures', $newValue, false);

        // make sure storage adapter flushes changes this time
        $this->storageAdapter->saveStatus($serviceName, 'lastTest', time(), true);

    }


    public function reportFailure(string $serviceName)
    {
        // there is no science here, we always increase failures count
        $this->setFailures($serviceName, $this->getFailures($serviceName) + 1);
    }


    public function reportSuccess(string $serviceName)
    {
        $failures = $this->getFailures($serviceName);
        $maxFailures = $this->getMaxFailures($serviceName);
        if ($failures > $maxFailures) {
            // there were more failures than max failures
            // we have to reset failures count to max-1
            $this->setFailures($serviceName, $maxFailures - 1);
        } elseif ($failures > 0) {
            // if we are between max and 0 we decrease by 1 on each
            // success so we will go down to 0 after some time
            // but we are still more sensitive to failures
            $this->setFailures($serviceName, $failures - 1);
        } else {
if (rand(1, 6) > 3) {
print "Check failed";
} else {
    //print "Check succeeded";
}
            // if there are no failures reported we do not
            // have to do anything on success (system operational)
        }
    }

}


1		<?php
2		declare(strict_types = 1);
3
4
5		namespace Paymaxi\Component\CircuitBreaker\Core;
6
7		use Paymaxi\Component\CircuitBreaker\CircuitBreakerInterface;
8		use Paymaxi\Component\CircuitBreaker\Storage\StorageInterface;
9
10		/**
11		* Allows user code to track availability of any service by serviceName.
12		*
13		* @see \Paymaxi\Component\CircuitBreaker\CircuitBreakerInterface
14		* @package Paymaxi\Component\CircuitBreaker\Components
15		*/
16		class CircuitBreaker implements CircuitBreakerInterface
17		{
18
19		/**
20		* @var CircuitBreakerInterface used to load/save availability statistics
21		*/
22		protected $storageAdapter;
23
24		/**
25		* @var int default threshold, if service fails this many times will be disabled
26		*/
27		protected $defaultMaxFailures;
28
29		/**
30		* @var int how many seconds should we wait before retry
31		*/
32		protected $defaultRetryTimeout;
33
34		/**
35		* Array with configuration per service name, format:
36		* array(
37		* "serviceName1" => array('maxFailures' => X, 'retryTimeout => Y),
38		* "serviceName2" => array('maxFailures' => X, 'retryTimeout => Y),
39		* )
40		*
41		* @var array[] settings per service name
42		*/
43		protected $settings = array();
44
45		/**
46		* Configure instance with storage implementation and default threshold and retry timeout.
47		*
48		* @param StorageInterface $storage storage implementation
49		* @param int $maxFailures default threshold, if service fails this many times will be disabled
50		* @param int $retryTimeout how many seconds should we wait before retry
51		*/
52	11	public function __construct(StorageInterface $storage, $maxFailures = 20, $retryTimeout = 60)
53		{
54	11	$this->storageAdapter = $storage;
		0 ignored issues – show Documentation Bug introduced 2017-03-09 20:54 UTC by Report Bug Copy Issue Report It seems like `$storage` of type `object<Paymaxi\Component...orage\StorageInterface>` is incompatible with the declared type `object<Paymaxi\Component...ircuitBreakerInterface>` of property `$storageAdapter`. Our type inference engine has found an assignment to a property that is incompatible with the declared type of that property. Either this assignment is in error or the assigned type should be added to the documentation/type hint for that property.. Loading history...
55	11	$this->defaultMaxFailures = $maxFailures;
56	11	$this->defaultRetryTimeout = $retryTimeout;
57	11	}
58
59		/**
60		* Use this method only if you want to add server specific threshold and retry timeout.
61		*
62		* @param $serviceName
63		* @param int $maxFailures default threshold, if service fails this many times will be disabled
64		* @param int $retryTimeout how many seconds should we wait before retry
65		*
66		* @return CircuitBreaker
67		* @internal param StorageInterface $storage storage implementation
68		*/
69	11	public function setServiceSettings($serviceName, $maxFailures, $retryTimeout)
70		{
71	11	$this->settings[$serviceName] = array(
72	11	'maxFailures' => $maxFailures ? $maxFailures : $this->defaultMaxFailures,
73	11	'retryTimeout' => $retryTimeout ? $retryTimeout : $this->defaultRetryTimeout,
74		);
75
76	11	return $this;
77		}
78
79		// ---------------------- HELPERS -----------------
80
81	8	public function isAvailable(string $serviceName): bool
82		{
83	8	$failures = $this->getFailures($serviceName);
84	8	$maxFailures = $this->getMaxFailures($serviceName);
85	8	if ($failures < $maxFailures) {
86		// this is what happens most of the time so we evaluate first
87	5	return true;
88		} else {
89	7	$lastTest = $this->getLastTest($serviceName);
90	7	$retryTimeout = $this->getRetryTimeout($serviceName);
91	7	if ($lastTest + $retryTimeout < time()) {
92		// Once we wait $retryTimeout, we have to allow one
93		// thread to try to connect again. To prevent all other threads
94		// from flooding, the potentially dead db, we update the time first
95		// and then try to connect. If db is dead only one thread will hang
96		// waiting for the connection. Others will get updated timeout from stats.
97		//
98		// 'Race condition' is between first thread getting into this line and
99		// time it takes to store the settings. In that time other threads will
100		// also be entering this statement. Even on very busy servers it
101		// wont allow more than a few requests to get through before stats are updated.
102		//
103		// updating lastTest
104	1	$this->setFailures($serviceName, $failures);
105		// allowing this thread to try to connect to the resource
106	1	return true;
107		} else {
108	7	return false;
109		}
110		}
111		}
112
113		// ---------------------- Directly accessed by interface methods -----------------
114
115		/**
116		* @param string $serviceName
117		*
118		* @return int
119		*/
120	11	protected function getFailures(string $serviceName)
121		{
122		//FIXME - catch exceptions and replace implementation if occur
123	11	return (int) $this->storageAdapter->loadStatus($serviceName, 'failures');
		0 ignored issues – show Bug introduced 2017-03-09 20:54 UTC by Report Bug Copy Issue Report The method `loadStatus()` does not seem to exist on `object<Paymaxi\Component...ircuitBreakerInterface>`. This check looks for calls to methods that do not seem to exist on a given type. It looks for the method on the type itself as well as in inherited classes or implemented interfaces. This is most likely a typographical error or the method has been renamed. Loading history...
124		}
125
126		/**
127		* @param string $serviceName
128		*
129		* @return int
130		*/
131	11	protected function getMaxFailures(string $serviceName)
132		{
133	11	return $this->getSetting($serviceName, 'maxFailures');
134		}
135
136		/**
137		* Load setting or initialise service name with defaults for faster lookups
138		*
139		* @param string $serviceName what service to look for
140		* @param string $variable what setting to look for
141		*
142		* @return int
143		*/
144	11	private function getSetting(string $serviceName, string $variable)
145		{
146		// make sure there are settings for the service
147	11	if (!isset($this->settings[$serviceName])) {
148	2	$this->settings[$serviceName] = array(
149	2	'maxFailures' => $this->defaultMaxFailures,
150	2	'retryTimeout' => $this->defaultRetryTimeout,
151		);
152		}
153	11	return $this->settings[$serviceName][$variable];
154		}
155
156		/**
157		* @param string $serviceName
158		*
159		* @return int
160		*/
161	7	protected function getLastTest(string $serviceName)
162		{
163		//FIXME - catch exceptions and replace implementation if occur
164	7	return (int) $this->storageAdapter->loadStatus($serviceName, 'lastTest');
		0 ignored issues – show Bug introduced 2017-03-09 20:54 UTC by Report Bug Copy Issue Report The method `loadStatus()` does not seem to exist on `object<Paymaxi\Component...ircuitBreakerInterface>`. This check looks for calls to methods that do not seem to exist on a given type. It looks for the method on the type itself as well as in inherited classes or implemented interfaces. This is most likely a typographical error or the method has been renamed. Loading history...
165		}
166
167		/**
168		* @param string $serviceName
169		*
170		* @return int
171		*/
172	7	protected function getRetryTimeout(string $serviceName)
173		{
174	7	return $this->getSetting($serviceName, 'retryTimeout');
175		}
176
177
178		/**
179		* @param string $serviceName
180		* @param integer $newValue
181		*/
182	8	protected function setFailures(string $serviceName, $newValue)
183		{
184		//FIXME - catch exceptions and replace implementation if occur
185	8	$this->storageAdapter->saveStatus($serviceName, 'failures', $newValue, false);
		0 ignored issues – show Bug introduced 2017-03-09 20:54 UTC by Report Bug Copy Issue Report The method `saveStatus()` does not seem to exist on `object<Paymaxi\Component...ircuitBreakerInterface>`. This check looks for calls to methods that do not seem to exist on a given type. It looks for the method on the type itself as well as in inherited classes or implemented interfaces. This is most likely a typographical error or the method has been renamed. Loading history...
186		// make sure storage adapter flushes changes this time
187	8	$this->storageAdapter->saveStatus($serviceName, 'lastTest', time(), true);
		0 ignored issues – show Bug introduced 2017-03-09 20:54 UTC by Report Bug Copy Issue Report The method `saveStatus()` does not seem to exist on `object<Paymaxi\Component...ircuitBreakerInterface>`. This check looks for calls to methods that do not seem to exist on a given type. It looks for the method on the type itself as well as in inherited classes or implemented interfaces. This is most likely a typographical error or the method has been renamed. Loading history...
188	8	}
189
190
191	8	public function reportFailure(string $serviceName)
192		{
193		// there is no science here, we always increase failures count
194	8	$this->setFailures($serviceName, $this->getFailures($serviceName) + 1);
195	8	}
196
197
198	5	public function reportSuccess(string $serviceName)
199		{
200	5	$failures = $this->getFailures($serviceName);
201	5	$maxFailures = $this->getMaxFailures($serviceName);
202	5	if ($failures > $maxFailures) {
203		// there were more failures than max failures
204		// we have to reset failures count to max-1
205	1	$this->setFailures($serviceName, $maxFailures - 1);
206	5	} elseif ($failures > 0) {
207		// if we are between max and 0 we decrease by 1 on each
208		// success so we will go down to 0 after some time
209		// but we are still more sensitive to failures
210	3	$this->setFailures($serviceName, $failures - 1);
211		} else {
		0 ignored issues – show Unused Code introduced 2017-03-09 20:54 UTC by Report Bug Copy Issue Report This `else` statement is empty and can be removed. This check looks for the `else` branches of `if` statements that have no statements or where all statements have been commented out. This may be the result of changes for debugging or the code may simply be obsolete. These `else` branches can be removed. if (rand(1, 6) > 3) { print "Check failed"; } else { //print "Check succeeded"; } could be turned into if (rand(1, 6) > 3) { print "Check failed"; } This is much more concise to read. Loading history...
212		// if there are no failures reported we do not
213		// have to do anything on success (system operational)
214		}
215	5	}
216
217		}
218

dzubchik / php-circuit-breaker

CircuitBreaker::getRetryTimeout() A last analyzed 2017-03-09 21:35 UTC

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CircuitBreaker::getRetryTimeout() A
last analyzed 2017-03-09 21:35 UTC