Node::isConnected() - Code Metrics - Inspection of "Reconnect, if the current node has lost its connec..." - mariano/disque-php - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#31)

unknown

created 2016-03-16 00:40 UTC

Node::isConnected() A

↳ Parent: Node

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	1
Bugs	0	Features	1

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

<?php
namespace Disque\Connection\Node;

use Disque\Command\Auth;
use Disque\Command\CommandInterface;
use Disque\Command\Hello;
use Disque\Command\Response\HelloResponse;
use Disque\Connection\ConnectionException;
use Disque\Connection\ConnectionInterface;
use Disque\Connection\Credentials;
use Disque\Connection\AuthenticationException;
use Disque\Connection\Response\ResponseException;

/**
 * Describe one Disque node, its properties and the connection to it
 */
class Node
{
    /**
     * The response Disque returns if password authentication succeeded
     */
    const AUTH_SUCCESS_MESSAGE = 'OK';

    /**
     * The beginning of a response Disque returns if authentication required
     */
    const AUTH_REQUIRED_MESSAGE = 'NOAUTH';

    /**
     * Node prefix boundaries
     */
    const PREFIX_START = 0;
    const PREFIX_LENGTH = 8;

    /**
     * Disque-assigned node priorities
     * @see $priority
     */
    const PRIORITY_OK = 1;
    const PRIORITY_POSSIBLE_FAILURE = 10;
    const PRIORITY_FAILURE = 100;

    /**
     * A fallback node priority if the HELLO response doesn't contain a priority
     * This should not happen, but let's be sure.
     */
    const PRIORITY_FALLBACK = 2;

    /**
     * @var Credentials Credentials of this node - host, port, password
     */
    private $credentials;

    /**
     * @var ConnectionInterface The connection to this node
     */
    private $connection;

    /**
     * @var string Node ID
     */
    private $id;

    /**
     * @var string Node prefix, or the first 8 bytes of the ID
     */
    private $prefix;

    /**
     * @var int Node priority set by Disque, 1-100, lower is better
     *
     * This priority is set by Disque, lower number is better. As of 09/2015
     * there are three possible values:
     *
     * 1 - Node is working correctly
     * 10 - Possible failure (PFAIL) - Node may be failing
     * 100 - Failure (FAIL) - The majority of nodes agree that the node is failing
     *
     * For priority values,
     * @see https://github.com/antirez/disque/blob/master/src/cluster.c, helloCommand()
     *
     * For the difference between PFAIL and FAIL states,
     * @see http://redis.io/topics/cluster-spec#failure-detection
     * @see also https://github.com/antirez/disque/blob/master/src/cluster.c
     * Look for CLUSTER_NODE_PFAIL and CLUSTER_NODE_FAIL
     *
     */
    private $priority = 1;

    /**
     * @var array The result of the HELLO command
     *
     * @see Disque\Command\Response\HelloResponse
     */
    private $hello;

    /**
     * @var int The number of jobs from this node since the last counter reset
     *          This counter can be reset, eg. upon a node switch
     */
    private $jobCount = 0;

    /**
     * @var int The number of jobs from this node during its lifetime
     */
    private $totalJobCount = 0;

    public function __construct(Credentials $credentials, ConnectionInterface $connection)
    {
        $this->credentials = $credentials;
        $this->connection = $connection;
    }

    /**
     * Get the node credentials
     *
     * @return Credentials
     */
    public function getCredentials()
    {
        return $this->credentials;
    }

    /**
     * Get the node connection
     *
     * @return ConnectionInterface
     */
    public function getConnection()
    {
        return $this->connection;
    }

    /**
     * Get the node ID
     *
     * @return string
     */
    public function getId()
    {
        return $this->id;
    }

    /**
     * Get the node prefix - the first 8 bytes from the ID
     *
     * @return string
     */
    public function getPrefix()
    {
        return $this->prefix;
    }

    /**
     * Get the node priority as set by the cluster. 1-100, lower is better.
     *
     * @return int
     */
    public function getPriority()
    {
        return $this->priority;
    }

    /**
     * @param int $priority Disque priority as revealed by a HELLO
     */
    public function setPriority($priority)
    {
        $this->priority = (int) $priority;
    }

    /**
     * Get the node's last HELLO response
     *
     * @return array
     */
    public function getHello()
    {
        return $this->hello;
    }

    /**
     * Get the node job count since the last reset (usually a node switch)
     *
     * @return int
     */
    public function getJobCount()
    {
        return $this->jobCount;
    }

    /**
     * Increase the node job counts by the given number
     *
     * @param int $jobsAdded
     */
    public function addJobCount($jobsAdded)
    {
        $this->jobCount += $jobsAdded;
        $this->totalJobCount += $jobsAdded;

    }

    /**
     *  Reset the node job count
     */
    public function resetJobCount()
    {
        $this->jobCount = 0;
    }

    /**
     * Get the total job count since the node instantiation
     *
     * @return int
     */
    public function getTotalJobCount()
    {
        return $this->totalJobCount;
    }

    /**
     * Connect to the node and return the HELLO response
     *
     * This method is idempotent and can be called multiple times
     *
     * @return array The HELLO response
     * @throws ConnectionException
     * @throws AuthenticationException
     */
    public function connect()
    {
        if ($this->connection->isConnected() && !empty($this->hello)) {
            return $this->hello;
        }

        $this->connectToTheNode();
        $this->authenticateWithPassword();

        try {
            $this->sayHello();
        } catch (ResponseException $e) {
            /**
             * If the node requires a password but we didn't supply any,
             * Disque returns a message "NOAUTH Authentication required"
             *
             * HELLO is the first place we would get this error.
             *
             * @see https://github.com/antirez/disque/blob/master/src/server.c
             * Look for "noautherr"
             */
            $message = $e->getMessage();
            if (stripos($message, self::AUTH_REQUIRED_MESSAGE) === 0) {
                throw new AuthenticationException($message);
            }
        }

        return $this->hello;
    }

    /**
     * Check if this object holds a working connection to Disque node
     *
     * @return bool
     */
    public function isConnected()
    {
        return $this->connection->isConnected();
    }

    /**
     * Execute a command on this Disque node
     *
     * @param CommandInterface $command
     * @return mixed Response
     *
     * @throws ConnectionException
     */
    public function execute(CommandInterface $command)
    {
        return $this->connection->execute($command);
    }

    /**
     * Say a new HELLO to the node and parse the response
     *
     * @return array The HELLO response
     *
     * @throws ConnectionException
     */
    public function sayHello()
    {
        $helloCommand = new Hello();
        $helloResponse = $this->connection->execute($helloCommand);
        $this->hello = (array) $helloCommand->parse($helloResponse);

        $this->id = $this->hello[HelloResponse::NODE_ID];
        $this->createPrefix($this->id);

        $this->priority = $this->readPriorityFromHello($this->hello, $this->id);

        return $this->hello;
    }

    /**
     * Connect to the node
     *
     * @throws ConnectionException
     */
    private function connectToTheNode()
    {
        $this->connection->connect(
            $this->credentials->getConnectionTimeout(),
            $this->credentials->getResponseTimeout()
        );
    }

    /**
     * Authenticate with the node with a password, if set
     *
     * @throws AuthenticationException
     */
    private function authenticateWithPassword()
    {
        if ($this->credentials->havePassword()) {
            $authCommand = new Auth();
            $authCommand->setArguments([$this->credentials->getPassword()]);
            $authResponse = $this->connection->execute($authCommand);
            $response = $authCommand->parse($authResponse);
            if ($response !== self::AUTH_SUCCESS_MESSAGE) {
                throw new AuthenticationException();
            }
        }
    }

    /**
     * Create a node prefix from the node ID
     *
     * @param string $id
     */
    private function createPrefix($id)
    {
        $this->prefix = substr($id, self::PREFIX_START, self::PREFIX_LENGTH);
    }

    /**
     * Read out the node's own priority from a HELLO response
     *
     * @param array  $hello The HELLO response
     * @param string $id    Node ID
     *
     * @return int Node priority
     */
    private function readPriorityFromHello($hello, $id)
    {
        foreach ($hello[HelloResponse::NODES] as $node) {
            if ($node[HelloResponse::NODE_ID] === $id) {
                return $node[HelloResponse::NODE_PRIORITY];
            }
        }

        // Node not found in the HELLO? This should not happen.
        // Return a fallback value
        return self::PRIORITY_FALLBACK;
    }
}


1		<?php
2		namespace Disque\Connection\Node;
3
4		use Disque\Command\Auth;
5		use Disque\Command\CommandInterface;
6		use Disque\Command\Hello;
7		use Disque\Command\Response\HelloResponse;
8		use Disque\Connection\ConnectionException;
9		use Disque\Connection\ConnectionInterface;
10		use Disque\Connection\Credentials;
11		use Disque\Connection\AuthenticationException;
12		use Disque\Connection\Response\ResponseException;
13
14		/**
15		* Describe one Disque node, its properties and the connection to it
16		*/
17		class Node
18		{
19		/**
20		* The response Disque returns if password authentication succeeded
21		*/
22		const AUTH_SUCCESS_MESSAGE = 'OK';
23
24		/**
25		* The beginning of a response Disque returns if authentication required
26		*/
27		const AUTH_REQUIRED_MESSAGE = 'NOAUTH';
28
29		/**
30		* Node prefix boundaries
31		*/
32		const PREFIX_START = 0;
33		const PREFIX_LENGTH = 8;
34
35		/**
36		* Disque-assigned node priorities
37		* @see $priority
38		*/
39		const PRIORITY_OK = 1;
40		const PRIORITY_POSSIBLE_FAILURE = 10;
41		const PRIORITY_FAILURE = 100;
42
43		/**
44		* A fallback node priority if the HELLO response doesn't contain a priority
45		* This should not happen, but let's be sure.
46		*/
47		const PRIORITY_FALLBACK = 2;
48
49		/**
50		* @var Credentials Credentials of this node - host, port, password
51		*/
52		private $credentials;
53
54		/**
55		* @var ConnectionInterface The connection to this node
56		*/
57		private $connection;
58
59		/**
60		* @var string Node ID
61		*/
62		private $id;
63
64		/**
65		* @var string Node prefix, or the first 8 bytes of the ID
66		*/
67		private $prefix;
68
69		/**
70		* @var int Node priority set by Disque, 1-100, lower is better
71		*
72		* This priority is set by Disque, lower number is better. As of 09/2015
73		* there are three possible values:
74		*
75		* 1 - Node is working correctly
76		* 10 - Possible failure (PFAIL) - Node may be failing
77		* 100 - Failure (FAIL) - The majority of nodes agree that the node is failing
78		*
79		* For priority values,
80		* @see https://github.com/antirez/disque/blob/master/src/cluster.c, helloCommand()
81		*
82		* For the difference between PFAIL and FAIL states,
83		* @see http://redis.io/topics/cluster-spec#failure-detection
84		* @see also https://github.com/antirez/disque/blob/master/src/cluster.c
85		* Look for CLUSTER_NODE_PFAIL and CLUSTER_NODE_FAIL
86		*
87		*/
88		private $priority = 1;
89
90		/**
91		* @var array The result of the HELLO command
92		*
93		* @see Disque\Command\Response\HelloResponse
94		*/
95		private $hello;
96
97		/**
98		* @var int The number of jobs from this node since the last counter reset
99		* This counter can be reset, eg. upon a node switch
100		*/
101		private $jobCount = 0;
102
103		/**
104		* @var int The number of jobs from this node during its lifetime
105		*/
106		private $totalJobCount = 0;
107
108	29	public function __construct(Credentials $credentials, ConnectionInterface $connection)
109		{
110	29	$this->credentials = $credentials;
111	29	$this->connection = $connection;
112	29	}
113
114		/**
115		* Get the node credentials
116		*
117		* @return Credentials
118		*/
119	4	public function getCredentials()
120		{
121	4	return $this->credentials;
122		}
123
124		/**
125		* Get the node connection
126		*
127		* @return ConnectionInterface
128		*/
129	4	public function getConnection()
130		{
131	4	return $this->connection;
132		}
133
134		/**
135		* Get the node ID
136		*
137		* @return string
138		*/
139	13	public function getId()
140		{
141	13	return $this->id;
142		}
143
144		/**
145		* Get the node prefix - the first 8 bytes from the ID
146		*
147		* @return string
148		*/
149	2	public function getPrefix()
150		{
151	2	return $this->prefix;
152		}
153
154		/**
155		* Get the node priority as set by the cluster. 1-100, lower is better.
156		*
157		* @return int
158		*/
159	8	public function getPriority()
160		{
161	8	return $this->priority;
162		}
163
164		/**
165		* @param int $priority Disque priority as revealed by a HELLO
166		*/
167	11	public function setPriority($priority)
168		{
169	11	$this->priority = (int) $priority;
170	11	}
171
172		/**
173		* Get the node's last HELLO response
174		*
175		* @return array
176		*/
177	13	public function getHello()
178		{
179	13	return $this->hello;
180		}
181
182		/**
183		* Get the node job count since the last reset (usually a node switch)
184		*
185		* @return int
186		*/
187	6	public function getJobCount()
188		{
189	6	return $this->jobCount;
190		}
191
192		/**
193		* Increase the node job counts by the given number
194		*
195		* @param int $jobsAdded
196		*/
197	7	public function addJobCount($jobsAdded)
198		{
199	7	$this->jobCount += $jobsAdded;
200	7	$this->totalJobCount += $jobsAdded;
201
202	7	}
203
204		/**
205		* Reset the node job count
206		*/
207	4	public function resetJobCount()
208		{
209	4	$this->jobCount = 0;
210	4	}
211
212		/**
213		* Get the total job count since the node instantiation
214		*
215		* @return int
216		*/
217	4	public function getTotalJobCount()
218		{
219	4	return $this->totalJobCount;
220		}
221
222		/**
223		* Connect to the node and return the HELLO response
224		*
225		* This method is idempotent and can be called multiple times
226		*
227		* @return array The HELLO response
228		* @throws ConnectionException
229		* @throws AuthenticationException
230		*/
231	21	public function connect()
232		{
233	21	if ($this->connection->isConnected() && !empty($this->hello)) {
234		return $this->hello;
235		}
236
237	20	$this->connectToTheNode();
238	18	$this->authenticateWithPassword();
239
240		try {
241	15	$this->sayHello();
242	15	} catch (ResponseException $e) {
243		/**
244		* If the node requires a password but we didn't supply any,
245		* Disque returns a message "NOAUTH Authentication required"
246		*
247		* HELLO is the first place we would get this error.
248		*
249		* @see https://github.com/antirez/disque/blob/master/src/server.c
250		* Look for "noautherr"
251		*/
252	1	$message = $e->getMessage();
253	1	if (stripos($message, self::AUTH_REQUIRED_MESSAGE) === 0) {
254	1	throw new AuthenticationException($message);
255		}
256		}
257
258	13	return $this->hello;
259		}
260
261		/**
262		* Check if this object holds a working connection to Disque node
263		*
264		* @return bool
265		*/
266	11	public function isConnected()
267		{
268	11	return $this->connection->isConnected();
269		}
270
271		/**
272		* Execute a command on this Disque node
273		*
274		* @param CommandInterface $command
275		* @return mixed Response
276		*
277		* @throws ConnectionException
278		*/
279	5	public function execute(CommandInterface $command)
280		{
281	5	return $this->connection->execute($command);
282		}
283
284		/**
285		* Say a new HELLO to the node and parse the response
286		*
287		* @return array The HELLO response
288		*
289		* @throws ConnectionException
290		*/
291	17	public function sayHello()
292		{
293	17	$helloCommand = new Hello();
294	17	$helloResponse = $this->connection->execute($helloCommand);
295	14	$this->hello = (array) $helloCommand->parse($helloResponse);
296
297	14	$this->id = $this->hello[HelloResponse::NODE_ID];
298	14	$this->createPrefix($this->id);
299
300	14	$this->priority = $this->readPriorityFromHello($this->hello, $this->id);
301
302	14	return $this->hello;
303		}
304
305		/**
306		* Connect to the node
307		*
308		* @throws ConnectionException
309		*/
310	20	private function connectToTheNode()
311		{
312	20	$this->connection->connect(
313	20	$this->credentials->getConnectionTimeout(),
314	20	$this->credentials->getResponseTimeout()
315	20	);
316	18	}
317
318		/**
319		* Authenticate with the node with a password, if set
320		*
321		* @throws AuthenticationException
322		*/
323	18	private function authenticateWithPassword()
324		{
325	18	if ($this->credentials->havePassword()) {
326	5	$authCommand = new Auth();
327	5	$authCommand->setArguments([$this->credentials->getPassword()]);
328	5	$authResponse = $this->connection->execute($authCommand);
329	4	$response = $authCommand->parse($authResponse);
330	4	if ($response !== self::AUTH_SUCCESS_MESSAGE) {
331	2	throw new AuthenticationException();
332		}
333	2	}
334	15	}
335
336		/**
337		* Create a node prefix from the node ID
338		*
339		* @param string $id
340		*/
341	14	private function createPrefix($id)
342		{
343	14	$this->prefix = substr($id, self::PREFIX_START, self::PREFIX_LENGTH);
344	14	}
345
346		/**
347		* Read out the node's own priority from a HELLO response
348		*
349		* @param array $hello The HELLO response
350		* @param string $id Node ID
351		*
352		* @return int Node priority
353		*/
354	14	private function readPriorityFromHello($hello, $id)
355		{
356	14	foreach ($hello[HelloResponse::NODES] as $node) {
357	14	if ($node[HelloResponse::NODE_ID] === $id) {
358	14	return $node[HelloResponse::NODE_PRIORITY];
359		}
360	1	}
361
362		// Node not found in the HELLO? This should not happen.
363		// Return a fallback value
364		return self::PRIORITY_FALLBACK;
365		}
366		}
367

mariano / disque-php

Pull Request — master (#31)

Node::isConnected() A

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Duplication

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