ConsulConfig::computePossibleMachineId() - Code Metrics - Inspection of "Added consul configuration with tests." - Gendoria/cruftflake - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( b6560c...9b1dc4 )

by Tomasz

created 2016-02-19 16:12 UTC

ConsulConfig::computePossibleMachineId() B

↳ Parent: ConsulConfig

Complexity

Conditions	6
Paths	10

Size

Total Lines	20
Code Lines	13

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	12
CRAP Score	6.105

Importance

Changes	1
Bugs	0	Features	1

Metric	Value
c	1
b	0
f	1
dl	0
loc	20
ccs	12
cts	14
cp	0.8571
rs	8.8571
cc	6
eloc	13
nc	10
nop	1
crap	6.105

<?php

/**
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

namespace Gendoria\CruftFlake\Config;

use RuntimeException;

/**
 * Description of ConsulConfig
 *
 * @author Tomasz Struczyński <[email protected]>
 */
class ConsulConfig implements ConfigInterface
{
    const DEFAULT_KV_PREFIX = 'service/CruftFlake/machines/';
    
    /**
     * CURL requestor.
     * 
     * @var ConsulCurl
     */
    private $curl;
    
    private $kvPrefix = self::DEFAULT_KV_PREFIX;
    
    /**
     * Consul session ID.
     * 
     * @var string
     */
    private $sessionId = "";
    
    private $sessionTTL;
    
    /**
     * Last successfull check.
     * 
     * @var integer|null
     */
    private $lastSuccessfullCheck = null;
    
    /**
     * Machine ID.
     * 
     * @var integer
     */
    private $machineId;
    
    function __construct(ConsulCurl $curl, $sessionTTL = 600, $kvPrefix = self::DEFAULT_KV_PREFIX)

    {
        $this->curl = $curl;
        $this->kvPrefix = $kvPrefix;
        $this->sessionTTL = (int)$sessionTTL;
        //If we cannot connect to Consul on start, we have a problem.
        $this->createSession();
        $this->lastSuccessfullCheck = time();
    }

    /**
     * On object destruction, we have to destroy session.
     */
    public function __destruct()
    {
        $this->destroySession();
    }

    /**
     * {@inheritdoc}
     */
    public function getMachine()
    {
        if (!$this->machineId) {
            $this->machineId = $this->acquireMachineId();
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;
}
        }
        return $this->machineId;
    }

    /**
     * Configuration heartbeat. 
     * 
     * Heartbeat connects periodically to Consul to renew session and check its validity.
     * 
     * @return bool True, if configuration data had been changed during heartbeat.
     * 
     * @throws RuntimeException Thrown, when we could not create new session and it was needed.
     */
    public function heartbeat()
    {
        //If we have last successfull check recently new, we don't have to do anything
        if ($this->lastSuccessfullCheck && time() - $this->lastSuccessfullCheck < $this->sessionTTL / 2 ) {
0   == false // true
0   == null  // true
123 == false // false
123 == null  // false

// It is often better to use strict comparison
0 === false // false
0 === null  // false
            return false;
        }
        //If session reneval succeedes, update last successfull check.
        if ($this->curl->performPutRequest("/session/renew/".$this->sessionId)) {
            $this->lastSuccessfullCheck = time();
            return false;
        }
        //Ok, we don't have a valid session. We have to create new one and signal update.
        try {
            $this->createSession();
            $this->lastSuccessfullCheck = time();
            $this->machineId = null;
            return true;
        } catch (RuntimeException $e) {
            //We could not create new session. We can work for some time in 'detached' mode,
            //but if our TTL time runs out, we have to throw an exception.
            if (!$this->lastSuccessfullCheck || time() - $this->lastSuccessfullCheck >= $this->sessionTTL) {
0   == false // true
0   == null  // true
123 == false // false
123 == null  // false

// It is often better to use strict comparison
0 === false // false
0 === null  // false
                throw $e;
            }
            return false;
        }
    }
    
    private function acquireMachineId()
    {
        //Check, if we don't have existing value for the session
        $currentValue = $this->curl->performGetRequest('/kv/'.$this->kvPrefix.$this->sessionId);
        if (!empty($currentValue['Value'])) {
            return base64_decode($currentValue['Value']);
        }
        //Lock main key to block concurrent checks
        $this->lockKey();
        //Get currently locked machine IDs to check, if we can get a new one. If yes, save it.
        $currentValues = $this->curl->performGetRequest('/kv/'.$this->kvPrefix.'?recurse');
        if (!is_array($currentValues)) {
            $currentValues = array();
        }
        $machineId = $this->computePossibleMachineId($currentValues);
        if (!$this->curl->performPutRequest('/kv/'.$this->kvPrefix.$this->sessionId.'?acquire='.$this->sessionId, $machineId)) {
            throw new RuntimeException("Could not register machine ID on consul.");
        }
        //Release the lock on the main key and return machine ID.
        $this->releaseKey();
        return $machineId;
    }
    
    private function computePossibleMachineId(array $currentValues)
    {
        $usedIds = array();
        foreach ($currentValues as $currentValue) {
            if ($currentValue['Key'] == $this->kvPrefix) {
                continue;
            } elseif ($currentValue['Key'] == $this->sessionId) {
                return base64_decode($currentValue['Value']);
            }
            else {
                $usedIds[] = base64_decode($currentValue['Value']);
            }
        }
        for ($k = 0; $k < 1024; $k++) {
            if (!in_array($k, $usedIds)) {
                return $k;
            }
        }
        throw new RuntimeException("Cannot acquire machine ID - all machine IDs are used up");
    }
    
    private function lockKey()
    {
        //try to acquire the lock on prefix during whole operation.
        do {
            $acquired = $this->curl->performPutRequest('/kv/'.$this->kvPrefix.'?acquire='.$this->sessionId, $this->sessionId);
            if (!$acquired) {
                sleep(1);
            }
        } while (!$acquired);
    }
    
    private function releaseKey()
    {
        $this->curl->performPutRequest('/kv/'.$this->kvPrefix.'?release='.$this->sessionId, $this->sessionId);
    }

    private function createSession()
    {
        $url ='/session/create';
        //We create new session with given TTL and with lock delay equal to half of TTL.
        $payload = array(
            'TTL' => $this->sessionTTL.'s',
            "Behavior" => "delete",
            'LockDelay' => floor($this->sessionTTL/2).'s',
        );
        $returnData = $this->curl->performPutRequest($url, json_encode($payload));
        if (empty($returnData['ID'])) {
            throw new RuntimeException("Cannot create session");
        }
        $this->sessionId = $returnData['ID'];
    }
    
    private function destroySession()
    {
        if ($this->sessionId) {
            $this->curl->performPutRequest("/session/destroy/".$this->sessionId);
        }
    }
}


1		<?php
2
3		/**
4		* To change this license header, choose License Headers in Project Properties.
5		* To change this template file, choose Tools \| Templates
6		* and open the template in the editor.
7		*/
8
9		namespace Gendoria\CruftFlake\Config;
10
11		use RuntimeException;
12
13		/**
14		* Description of ConsulConfig
15		*
16		* @author Tomasz Struczyński <[email protected]>
17		*/
18		class ConsulConfig implements ConfigInterface
19		{
20		const DEFAULT_KV_PREFIX = 'service/CruftFlake/machines/';
21
22		/**
23		* CURL requestor.
24		*
25		* @var ConsulCurl
26		*/
27		private $curl;
28
29		private $kvPrefix = self::DEFAULT_KV_PREFIX;
30
31		/**
32		* Consul session ID.
33		*
34		* @var string
35		*/
36		private $sessionId = "";
37
38		private $sessionTTL;
39
40		/**
41		* Last successfull check.
42		*
43		* @var integer\|null
44		*/
45		private $lastSuccessfullCheck = null;
46
47		/**
48		* Machine ID.
49		*
50		* @var integer
51		*/
52		private $machineId;
53
54	7	function __construct(ConsulCurl $curl, $sessionTTL = 600, $kvPrefix = self::DEFAULT_KV_PREFIX)
		0 ignored issues – show Best Practice introduced 2016-02-19 16:15 UTC by Report Bug Copy Issue Report It is generally recommended to explicitly declare the visibility for methods. Adding explicit visibility (`private`, `protected`, or `public`) is generally recommend to communicate to other developers how, and from where this method is intended to be used. Loading history...
55		{
56	7	$this->curl = $curl;
57	7	$this->kvPrefix = $kvPrefix;
58	7	$this->sessionTTL = (int)$sessionTTL;
59		//If we cannot connect to Consul on start, we have a problem.
60	7	$this->createSession();
61	7	$this->lastSuccessfullCheck = time();
62	7	}
63
64		/**
65		* On object destruction, we have to destroy session.
66		*/
67	7	public function __destruct()
68		{
69	7	$this->destroySession();
70	7	}
71
72		/**
73		* {@inheritdoc}
74		*/
75	3	public function getMachine()
76		{
77	3	if (!$this->machineId) {
78	3	$this->machineId = $this->acquireMachineId();
		0 ignored issues – show Documentation Bug introduced 2016-02-19 16:15 UTC by Report Bug Copy Issue Report It seems like `$this->acquireMachineId()` can also be of type `string`. However, the property `$machineId` is declared as type `integer`. Maybe add an additional type check? Our type inference engine has found a suspicous assignment of a value to a property. This check raises an issue when a value that can be of a mixed type is assigned to a property that is type hinted more strictly. For example, imagine you have a variable `$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...
79	2	}
80	2	return $this->machineId;
81		}
82
83		/**
84		* Configuration heartbeat.
85		*
86		* Heartbeat connects periodically to Consul to renew session and check its validity.
87		*
88		* @return bool True, if configuration data had been changed during heartbeat.
89		*
90		* @throws RuntimeException Thrown, when we could not create new session and it was needed.
91		*/
92	4	public function heartbeat()
93		{
94		//If we have last successfull check recently new, we don't have to do anything
95	4	if ($this->lastSuccessfullCheck && time() - $this->lastSuccessfullCheck < $this->sessionTTL / 2 ) {
		0 ignored issues – show Bug Best Practice introduced 2016-02-19 16:15 UTC by Report Bug Copy Issue Report The expression `$this->lastSuccessfullCheck` of type `integer\|null` is loosely compared to `true`; this is ambiguous if the integer can be zero. You might want to explicitly use `!== null` instead. In PHP, under loose comparison (like `==`, or `!=`, or `switch` conditions), values of different types might be equal. For `integer` values, zero is a special case, in particular the following results might be unexpected: 0 == false // true 0 == null // true 123 == false // false 123 == null // false // It is often better to use strict comparison 0 === false // false 0 === null // false Loading history...
96	1	return false;
97		}
98		//If session reneval succeedes, update last successfull check.
99	3	if ($this->curl->performPutRequest("/session/renew/".$this->sessionId)) {
100	1	$this->lastSuccessfullCheck = time();
101	1	return false;
102		}
103		//Ok, we don't have a valid session. We have to create new one and signal update.
104		try {
105	2	$this->createSession();
106	1	$this->lastSuccessfullCheck = time();
107	1	$this->machineId = null;
108	1	return true;
109	1	} catch (RuntimeException $e) {
110		//We could not create new session. We can work for some time in 'detached' mode,
111		//but if our TTL time runs out, we have to throw an exception.
112	1	if (!$this->lastSuccessfullCheck \|\| time() - $this->lastSuccessfullCheck >= $this->sessionTTL) {
		0 ignored issues – show Bug Best Practice introduced 2016-02-19 16:15 UTC by Report Bug Copy Issue Report The expression `$this->lastSuccessfullCheck` of type `integer\|null` is loosely compared to `false`; this is ambiguous if the integer can be zero. You might want to explicitly use `=== null` instead. In PHP, under loose comparison (like `==`, or `!=`, or `switch` conditions), values of different types might be equal. For `integer` values, zero is a special case, in particular the following results might be unexpected: 0 == false // true 0 == null // true 123 == false // false 123 == null // false // It is often better to use strict comparison 0 === false // false 0 === null // false Loading history...
113	1	throw $e;
114		}
115		return false;
116		}
117		}
118
119	3	private function acquireMachineId()
120		{
121		//Check, if we don't have existing value for the session
122	3	$currentValue = $this->curl->performGetRequest('/kv/'.$this->kvPrefix.$this->sessionId);
123	3	if (!empty($currentValue['Value'])) {
124		return base64_decode($currentValue['Value']);
125		}
126		//Lock main key to block concurrent checks
127	3	$this->lockKey();
128		//Get currently locked machine IDs to check, if we can get a new one. If yes, save it.
129	3	$currentValues = $this->curl->performGetRequest('/kv/'.$this->kvPrefix.'?recurse');
130	3	if (!is_array($currentValues)) {
131	1	$currentValues = array();
132	1	}
133	3	$machineId = $this->computePossibleMachineId($currentValues);
134	2	if (!$this->curl->performPutRequest('/kv/'.$this->kvPrefix.$this->sessionId.'?acquire='.$this->sessionId, $machineId)) {
135		throw new RuntimeException("Could not register machine ID on consul.");
136		}
137		//Release the lock on the main key and return machine ID.
138	2	$this->releaseKey();
139	2	return $machineId;
140		}
141
142	3	private function computePossibleMachineId(array $currentValues)
143		{
144	3	$usedIds = array();
145	3	foreach ($currentValues as $currentValue) {
146	2	if ($currentValue['Key'] == $this->kvPrefix) {
147		continue;
148	2	} elseif ($currentValue['Key'] == $this->sessionId) {
149		return base64_decode($currentValue['Value']);
150		}
151		else {
152	2	$usedIds[] = base64_decode($currentValue['Value']);
153		}
154	3	}
155	3	for ($k = 0; $k < 1024; $k++) {
156	3	if (!in_array($k, $usedIds)) {
157	2	return $k;
158		}
159	2	}
160	1	throw new RuntimeException("Cannot acquire machine ID - all machine IDs are used up");
161		}
162
163	3	private function lockKey()
164		{
165		//try to acquire the lock on prefix during whole operation.
166		do {
167	3	$acquired = $this->curl->performPutRequest('/kv/'.$this->kvPrefix.'?acquire='.$this->sessionId, $this->sessionId);
168	3	if (!$acquired) {
169		sleep(1);
170		}
171	3	} while (!$acquired);
172	3	}
173
174	2	private function releaseKey()
175		{
176	2	$this->curl->performPutRequest('/kv/'.$this->kvPrefix.'?release='.$this->sessionId, $this->sessionId);
177	2	}
178
179	7	private function createSession()
180		{
181	7	$url ='/session/create';
182		//We create new session with given TTL and with lock delay equal to half of TTL.
183		$payload = array(
184	7	'TTL' => $this->sessionTTL.'s',
185	7	"Behavior" => "delete",
186	7	'LockDelay' => floor($this->sessionTTL/2).'s',
187	7	);
188	7	$returnData = $this->curl->performPutRequest($url, json_encode($payload));
189	7	if (empty($returnData['ID'])) {
190	1	throw new RuntimeException("Cannot create session");
191		}
192	7	$this->sessionId = $returnData['ID'];
193	7	}
194
195	7	private function destroySession()
196		{
197	7	if ($this->sessionId) {
198	7	$this->curl->performPutRequest("/session/destroy/".$this->sessionId);
199	7	}
200	7	}
201		}
202

Gendoria / cruftflake

Push — master ( b6560c...9b1dc4 )

ConsulConfig::computePossibleMachineId() B

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