RetryStrategy::changeServer() - Code Metrics - Inspection of "[WIP] avoid having nested Doctrine\DBAL\Connection..." - ezweb/dblinker - Measure and Improve Code Quality continuously with Scrutinizer

Failed Conditions

Pull Request — master (#32)

by Mathieu

created 2015-12-01 15:45 UTC

RetryStrategy::changeServer() B

↳ Parent: RetryStrategy

Complexity

Conditions	5
Paths	4

Size

Total Lines	15
Code Lines	10

Duplication

Lines	0
Ratio	0 %

Importance

Changes	2
Bugs	0	Features	1

Metric	Value
c	2
b	0
f	1
dl	0
loc	15
rs	8.8571
cc	5
eloc	10
nc	4
nop	2

<?php

namespace Ez\DbLinker\RetryStrategy;

use Exception;
use stdClass;
use Doctrine\DBAL\Driver\Connection;
use Ez\DbLinker\Driver\Connection\MasterSlavesConnection;
use Ez\DbLinker\Driver\Connection\RetryConnection;

trait RetryStrategy
{
    private $retryLimit;
    private $nestingLimit;

    public function __construct($retryLimit = INF, $nestingLimit = 1)
    {
        $this->retryLimit = $retryLimit;
        $this->nestingLimit = $nestingLimit;
    }

    public function shouldRetry(Exception $exception, Callable $callable, $context) {

        if (!$this->canRetry($context)) {
            return false;
        }
        $this->nestingLimit--;
        $strategy = $this->errorCodeStrategy($this->errorCode($exception));
        $res = $this->applyStrategy($strategy, $context);
        $this->nestingLimit++;
        return $res;
    }

    public function retryLimit()
    {
        return $this->retryLimit > 0 ? (int) $this->retryLimit : 0;
    }

    private function canRetry($context)
    {
        return $this->retryLimit > 0 &&
            $this->nestingLimit > 0 &&
            (!$context instanceof RetryConnection || $context->transactionLevel() === 0);
    }

    private function errorCodeStrategy($errorCode)
    {
        $strategy = (object) [
            'retry' => true,
            'wait' => 0,
            'changeServer' => false,
            'reconnect' => false,
        ];
        $errorCodeStrategies = $this->errorCodeStrategies();
        if (array_key_exists($errorCode, $errorCodeStrategies)) {
            foreach ($errorCodeStrategies[$errorCode] as $behavior => $value) {
                $strategy->$behavior = $value;
            }
            return $strategy;
        }
        return (object) ['retry' => false];
    }

    private function applyStrategy(stdClass $strategy, $context) {
        if ($strategy->retry === false || !$this->changeServer($strategy, $context)) {
            return false;
        }
        sleep($strategy->wait);
        $this->reconnect($strategy, $context);
        $this->retryLimit--;
        return true;
    }

    private function changeServer(stdClass $strategy, $context)
    {
        if (!$strategy->changeServer) {
            return true;
        }
        if (!$context instanceof RetryConnection) {
            return false;
        }
        $wrappedConnection = $context->wrappedConnection();
        if ($wrappedConnection instanceof MasterSlavesConnection && !$wrappedConnection->isConnectedToMaster()) {
            $wrappedConnection->disableCurrentSlave();
            return true;
        }
        return false;
    }

    private function reconnect(stdClass $strategy, $context)
    {
        if ($strategy->reconnect && $context instanceof Connection) {
            $context->close();
interface User
{
    /** @return string */
    public function getPassword();
}

class MyUser implements User
{
    public function getPassword()
    {
        // return something
    }

    public function getDisplayName()
    {
        // return some name.
    }
}

class AuthSystem
{
    public function authenticate(User $user)
    {
        $this->logger->info(sprintf('Authenticating %s.', $user->getDisplayName()));
        // do something.
    }
}
        }
    }

    protected abstract function errorCodeStrategies();
    protected abstract function errorCode(Exception $exception);
}


1			<?php
2
3			namespace Ez\DbLinker\RetryStrategy;
4
5			use Exception;
6			use stdClass;
7			use Doctrine\DBAL\Driver\Connection;
8			use Ez\DbLinker\Driver\Connection\MasterSlavesConnection;
9			use Ez\DbLinker\Driver\Connection\RetryConnection;
10
11			trait RetryStrategy
12			{
13			private $retryLimit;
14			private $nestingLimit;
15
16			public function __construct($retryLimit = INF, $nestingLimit = 1)
17			{
18			$this->retryLimit = $retryLimit;
19			$this->nestingLimit = $nestingLimit;
20			}
21
22			public function shouldRetry(Exception $exception, Callable $callable, $context) {
			0 ignored issues – show Unused Code introduced 2015-12-01 15:44 UTC by Report Bug Copy Issue Report The parameter `$callable` is not used and could be removed. This check looks from parameters that have been defined for a function or method, but which are not used in the method body. Loading history...
23			if (!$this->canRetry($context)) {
24			return false;
25			}
26			$this->nestingLimit--;
27			$strategy = $this->errorCodeStrategy($this->errorCode($exception));
28			$res = $this->applyStrategy($strategy, $context);
29			$this->nestingLimit++;
30			return $res;
31			}
32
33			public function retryLimit()
34			{
35			return $this->retryLimit > 0 ? (int) $this->retryLimit : 0;
36			}
37
38			private function canRetry($context)
39			{
40			return $this->retryLimit > 0 &&
41			$this->nestingLimit > 0 &&
42			(!$context instanceof RetryConnection \|\| $context->transactionLevel() === 0);
43			}
44
45			private function errorCodeStrategy($errorCode)
46			{
47			$strategy = (object) [
48			'retry' => true,
49			'wait' => 0,
50			'changeServer' => false,
51			'reconnect' => false,
52			];
53			$errorCodeStrategies = $this->errorCodeStrategies();
54			if (array_key_exists($errorCode, $errorCodeStrategies)) {
55			foreach ($errorCodeStrategies[$errorCode] as $behavior => $value) {
56			$strategy->$behavior = $value;
57			}
58			return $strategy;
59			}
60			return (object) ['retry' => false];
61			}
62
63			private function applyStrategy(stdClass $strategy, $context) {
64			if ($strategy->retry === false \|\| !$this->changeServer($strategy, $context)) {
65			return false;
66			}
67			sleep($strategy->wait);
68			$this->reconnect($strategy, $context);
69			$this->retryLimit--;
70			return true;
71			}
72
73			private function changeServer(stdClass $strategy, $context)
74			{
75			if (!$strategy->changeServer) {
76			return true;
77			}
78			if (!$context instanceof RetryConnection) {
79			return false;
80			}
81			$wrappedConnection = $context->wrappedConnection();
82			if ($wrappedConnection instanceof MasterSlavesConnection && !$wrappedConnection->isConnectedToMaster()) {
83			$wrappedConnection->disableCurrentSlave();
84			return true;
85			}
86			return false;
87			}
88
89			private function reconnect(stdClass $strategy, $context)
90			{
91			if ($strategy->reconnect && $context instanceof Connection) {
92			$context->close();
			0 ignored issues – show Bug introduced 2015-12-01 15:44 UTC by Report Bug Copy Issue Report It seems like you code against a concrete implementation and not the interface `Doctrine\DBAL\Driver\Connection` as the method `close()` does only exist in the following implementations of said interface: `Doctrine\DBAL\Connection`, `Doctrine\DBAL\Connections\MasterSlaveConnection`, `Doctrine\DBAL\Portability\Connection`, `Doctrine\DBAL\Sharding\PoolingShardConnection`, `Ez\DbLinker\Driver\Connection\RetryConnection`. Let’s take a look at an example: interface User { /** @return string / public function getPassword(); } class MyUser implements User { public function getPassword() { // return something } public function getDisplayName() { // return some name. } } class AuthSystem { public function authenticate(User $user) { $this->logger->info(sprintf('Authenticating %s.', $user->getDisplayName())); // do something. } } In the above example, the authenticate() method works fine as long as you just pass instances of MyUser. However, if you now also want to pass a different implementation of User which does not have a getDisplayName() method, the code will break. Available Fixes Change the type-hint for the parameter: class AuthSystem { public function authenticate(MyUser $user) { / ... / } } Add an additional type-check: class AuthSystem { public function authenticate(User $user) { if ($user instanceof MyUser) { $this->logger->info(/* ... /); } // or alternatively if ( ! $user instanceof MyUser) { throw new \LogicException( '$user must be an instance of MyUser, ' .'other instances are not supported.' ); } } } Note:* PHP Analyzer uses reverse abstract interpretation to narrow down the types inside the if block in such a case. Add the method to the interface: interface User { /** @return string / public function getPassword(); /* @return string */ public function getDisplayName(); } Loading history...
93			}
94			}
95
96			protected abstract function errorCodeStrategies();
97			protected abstract function errorCode(Exception $exception);
98			}
99

ezweb / dblinker

Pull Request — master (#32)

RetryStrategy::changeServer() B

Complexity

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