Spider::handleSignal() - Code Metrics - Inspection of "Merge pull request #20 from mvdbos/feature/downloa..." - mvdbos/php-spider - Measure and Improve Code Quality continuously with Scrutinizer

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Push — master ( 88bf51...34820f )

by Matthijs

created 2015-12-30 10:16 UTC

Spider::handleSignal() B

↳ Parent: Spider

Complexity

Conditions	5
Paths	5

Size

Total Lines	10
Code Lines	7

Duplication

Lines	0
Ratio	0 %

Importance

Changes	5
Bugs	1	Features	1

Metric	Value
c	5
b	1
f	1
dl	0
loc	10
rs	8.8571
cc	5
eloc	7
nc	5
nop	1

<?php
namespace VDB\Spider;

use Exception;
use Symfony\Component\EventDispatcher\Event;
use Symfony\Component\EventDispatcher\EventDispatcher;
use Symfony\Component\EventDispatcher\EventDispatcherInterface;
use Symfony\Component\EventDispatcher\GenericEvent;
use VDB\Spider\Discoverer\DiscovererSet;
use VDB\Spider\Event\SpiderEvents;
use VDB\Spider\Exception\QueueException;
use VDB\Spider\QueueManager\QueueManagerInterface;
use VDB\Spider\QueueManager\InMemoryQueueManager;
use VDB\Spider\Uri\DiscoveredUri;
use VDB\Spider\Downloader\DownloaderInterface;
use VDB\Spider\Downloader\Downloader;
use VDB\Uri\UriInterface;
use VDB\Uri\Uri;

/**
 *
 */
class Spider
{
    /** @var DownloaderInterface */
    private $downloader;

    /** @var QueueManagerInterface */
    private $queueManager;

    /** @var EventDispatcherInterface */
    private $dispatcher;

    /** @var DiscovererSet */
    private $discovererSet;

    /** @var DiscoveredUri The URI of the site to spider */
    private $seed = array();

    /** @var string the unique id of this spider instance */
    private $spiderId;

    /**
     * @param string $seed the URI to start crawling
     * @param string|null $spiderId
     */
    public function __construct($seed, $spiderId = null)
    {
        $this->setSeed($seed);
        if (null !== $spiderId) {
            $this->spiderId = $spiderId;
        } else {
            $this->spiderId = md5($seed . microtime(true));
        }

        // This makes the spider handle signals gracefully and allows us to do cleanup
        if (php_sapi_name() == 'cli') {
            declare(ticks = 1);
            if (function_exists('pcntl_signal')) {
                pcntl_signal(SIGTERM, array($this, 'handleSignal'));
                pcntl_signal(SIGINT, array($this, 'handleSignal'));
                pcntl_signal(SIGHUP, array($this, 'handleSignal'));
                pcntl_signal(SIGQUIT, array($this, 'handleSignal'));
            }
        }
    }

    /**
     * Starts crawling the URI provided on instantiation
     *
     * @return void
     */
    public function crawl()
    {
        $this->getQueueManager()->addUri($this->seed);
        $this->getDownloader()->getPersistenceHandler()->setSpiderId($this->spiderId);

        $this->doCrawl();
    }

    /**
     * param DiscovererSet $discovererSet
     */
    public function setDiscovererSet(DiscovererSet $discovererSet)
    {
        $this->discovererSet = $discovererSet;
    }

    /**
     * @return DiscovererSet
     */
    public function getDiscovererSet()
    {
        if (!$this->discovererSet) {
            $this->discovererSet = new DiscovererSet();
        }

        return $this->discovererSet;
    }

    /**
     * param QueueManagerInterface $queueManager
     */
    public function setQueueManager(QueueManagerInterface $queueManager)
    {
        $this->queueManager = $queueManager;
    }

    /**
     * @return QueueManagerInterface
     */
    public function getQueueManager()
    {
        if (!$this->queueManager) {
            $this->queueManager = new InMemoryQueueManager();
        }

        return $this->queueManager;
    }

    /**
     * @param DownloaderInterface $downloader
     * @return $this
     */
    public function setDownloader(DownloaderInterface $downloader)
    {
        $this->downloader = $downloader;

        return $this;
    }

    /**
     * @return DownloaderInterface
     */
    public function getDownloader()
    {
        if (!$this->downloader) {
            $this->downloader = new Downloader();
        }
        return $this->downloader;
    }

    /**
     * @param EventDispatcherInterface $eventDispatcher
     * @return $this
     */
    public function setDispatcher(EventDispatcherInterface $eventDispatcher)
    {
        $this->dispatcher = $eventDispatcher;

        return $this;
    }

    /**
     * @return EventDispatcherInterface
     */
    public function getDispatcher()
    {
        if (!$this->dispatcher) {
            $this->dispatcher = new EventDispatcher();
        }
        return $this->dispatcher;
    }

    public function handleSignal($signal)
    {
        switch ($signal) {
            case SIGTERM:
            case SIGKILL:
            case SIGINT:
            case SIGQUIT:
                $this->dispatch(SpiderEvents::SPIDER_CRAWL_USER_STOPPED);
        }
    }

    /**
     * Function that crawls each provided URI
     * It applies all processors and listeners set on the Spider
     *
     * This is a either depth first algorithm as explained here:
     *  https://en.wikipedia.org/wiki/Depth-first_search#Example
     * Note that because we don't do it recursive, but iteratively,
     * results will be in a different order from the example, because
     * we always take the right-most child first, whereas a recursive
     * variant would always take the left-most child first
     *
     * or
     *
     * a breadth first algorithm
     *
     * @return void
     */
    private function doCrawl()
    {
        while ($currentUri = $this->getQueueManager()->next()) {
            if ($this->getDownloader()->isDownLoadLimitExceeded()) {
                break;
            }

            if (!$resource = $this->getDownloader()->download($currentUri)) {
                continue;
            }

            $this->dispatch(
                SpiderEvents::SPIDER_CRAWL_RESOURCE_PERSISTED,
                new GenericEvent($this, array('uri' => $currentUri))
            );

            // Once the document is enqueued, apply the discoverers to look for more links to follow
            $discoveredUris = $this->getDiscovererSet()->discover($resource);

            foreach ($discoveredUris as $uri) {
                try {
                    $this->getQueueManager()->addUri($uri);
                } catch (QueueException $e) {
                    // when the queue size is exceeded, we stop discovering
                    break;
                }
            }
        }
    }

    /**
     * A shortcut for EventDispatcher::dispatch()
     *
     * @param string $eventName
     * @param null|Event $event
     */
    private function dispatch($eventName, Event $event = null)
    {
        $this->getDispatcher()->dispatch($eventName, $event);
    }

    /**
     * @param string $uri
     */
    private function setSeed($uri)
    {
        $this->seed = new DiscoveredUri(new Uri($uri));
        $this->seed->setDepthFound(0);
    }
}


1			<?php
2			namespace VDB\Spider;
3
4			use Exception;
5			use Symfony\Component\EventDispatcher\Event;
6			use Symfony\Component\EventDispatcher\EventDispatcher;
7			use Symfony\Component\EventDispatcher\EventDispatcherInterface;
8			use Symfony\Component\EventDispatcher\GenericEvent;
9			use VDB\Spider\Discoverer\DiscovererSet;
10			use VDB\Spider\Event\SpiderEvents;
11			use VDB\Spider\Exception\QueueException;
12			use VDB\Spider\QueueManager\QueueManagerInterface;
13			use VDB\Spider\QueueManager\InMemoryQueueManager;
14			use VDB\Spider\Uri\DiscoveredUri;
15			use VDB\Spider\Downloader\DownloaderInterface;
16			use VDB\Spider\Downloader\Downloader;
17			use VDB\Uri\UriInterface;
18			use VDB\Uri\Uri;
19
20			/**
21			*
22			*/
23			class Spider
24			{
25			/** @var DownloaderInterface */
26			private $downloader;
27
28			/** @var QueueManagerInterface */
29			private $queueManager;
30
31			/** @var EventDispatcherInterface */
32			private $dispatcher;
33
34			/** @var DiscovererSet */
35			private $discovererSet;
36
37			/** @var DiscoveredUri The URI of the site to spider */
38			private $seed = array();
39
40			/** @var string the unique id of this spider instance */
41			private $spiderId;
42
43			/**
44			* @param string $seed the URI to start crawling
45			* @param string\|null $spiderId
46			*/
47			public function __construct($seed, $spiderId = null)
48			{
49			$this->setSeed($seed);
50			if (null !== $spiderId) {
51			$this->spiderId = $spiderId;
52			} else {
53			$this->spiderId = md5($seed . microtime(true));
54			}
55
56			// This makes the spider handle signals gracefully and allows us to do cleanup
57			if (php_sapi_name() == 'cli') {
58			declare(ticks = 1);
59			if (function_exists('pcntl_signal')) {
60			pcntl_signal(SIGTERM, array($this, 'handleSignal'));
61			pcntl_signal(SIGINT, array($this, 'handleSignal'));
62			pcntl_signal(SIGHUP, array($this, 'handleSignal'));
63			pcntl_signal(SIGQUIT, array($this, 'handleSignal'));
64			}
65			}
66			}
67
68			/**
69			* Starts crawling the URI provided on instantiation
70			*
71			* @return void
72			*/
73			public function crawl()
74			{
75			$this->getQueueManager()->addUri($this->seed);
76			$this->getDownloader()->getPersistenceHandler()->setSpiderId($this->spiderId);
77
78			$this->doCrawl();
79			}
80
81			/**
82			* param DiscovererSet $discovererSet
83			*/
84			public function setDiscovererSet(DiscovererSet $discovererSet)
85			{
86			$this->discovererSet = $discovererSet;
87			}
88
89			/**
90			* @return DiscovererSet
91			*/
92			public function getDiscovererSet()
93			{
94			if (!$this->discovererSet) {
95			$this->discovererSet = new DiscovererSet();
96			}
97
98			return $this->discovererSet;
99			}
100
101			/**
102			* param QueueManagerInterface $queueManager
103			*/
104			public function setQueueManager(QueueManagerInterface $queueManager)
105			{
106			$this->queueManager = $queueManager;
107			}
108
109			/**
110			* @return QueueManagerInterface
111			*/
112			public function getQueueManager()
113			{
114			if (!$this->queueManager) {
115			$this->queueManager = new InMemoryQueueManager();
116			}
117
118			return $this->queueManager;
119			}
120
121			/**
122			* @param DownloaderInterface $downloader
123			* @return $this
124			*/
125			public function setDownloader(DownloaderInterface $downloader)
126			{
127			$this->downloader = $downloader;
128
129			return $this;
130			}
131
132			/**
133			* @return DownloaderInterface
134			*/
135			public function getDownloader()
136			{
137			if (!$this->downloader) {
138			$this->downloader = new Downloader();
139			}
140			return $this->downloader;
141			}
142
143			/**
144			* @param EventDispatcherInterface $eventDispatcher
145			* @return $this
146			*/
147			public function setDispatcher(EventDispatcherInterface $eventDispatcher)
148			{
149			$this->dispatcher = $eventDispatcher;
150
151			return $this;
152			}
153
154			/**
155			* @return EventDispatcherInterface
156			*/
157			public function getDispatcher()
158			{
159			if (!$this->dispatcher) {
160			$this->dispatcher = new EventDispatcher();
161			}
162			return $this->dispatcher;
163			}
164
165			public function handleSignal($signal)
166			{
167			switch ($signal) {
168			case SIGTERM:
169			case SIGKILL:
170			case SIGINT:
171			case SIGQUIT:
172			$this->dispatch(SpiderEvents::SPIDER_CRAWL_USER_STOPPED);
173			}
174			}
175
176			/**
177			* Function that crawls each provided URI
178			* It applies all processors and listeners set on the Spider
179			*
180			* This is a either depth first algorithm as explained here:
181			* https://en.wikipedia.org/wiki/Depth-first_search#Example
182			* Note that because we don't do it recursive, but iteratively,
183			* results will be in a different order from the example, because
184			* we always take the right-most child first, whereas a recursive
185			* variant would always take the left-most child first
186			*
187			* or
188			*
189			* a breadth first algorithm
190			*
191			* @return void
192			*/
193			private function doCrawl()
194			{
195			while ($currentUri = $this->getQueueManager()->next()) {
196			if ($this->getDownloader()->isDownLoadLimitExceeded()) {
197			break;
198			}
199
200			if (!$resource = $this->getDownloader()->download($currentUri)) {
201			continue;
202			}
203
204			$this->dispatch(
205			SpiderEvents::SPIDER_CRAWL_RESOURCE_PERSISTED,
206			new GenericEvent($this, array('uri' => $currentUri))
207			);
208
209			// Once the document is enqueued, apply the discoverers to look for more links to follow
210			$discoveredUris = $this->getDiscovererSet()->discover($resource);
211
212			foreach ($discoveredUris as $uri) {
213			try {
214			$this->getQueueManager()->addUri($uri);
215			} catch (QueueException $e) {
216			// when the queue size is exceeded, we stop discovering
217			break;
218			}
219			}
220			}
221			}
222
223			/**
224			* A shortcut for EventDispatcher::dispatch()
225			*
226			* @param string $eventName
227			* @param null\|Event $event
228			*/
229			private function dispatch($eventName, Event $event = null)
230			{
231			$this->getDispatcher()->dispatch($eventName, $event);
232			}
233
234			/**
235			* @param string $uri
236			*/
237			private function setSeed($uri)
238			{
239			$this->seed = new DiscoveredUri(new Uri($uri));
240			$this->seed->setDepthFound(0);
241			}
242			}
243

mvdbos / php-spider

Push — master ( 88bf51...34820f )

Spider::handleSignal() B

Complexity

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Duplication

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