CacheSubscriber::addResponseHeaders() - Code Metrics - Inspection of "Add cache client and tests" - ochi51/cybozu-http - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — cache ( 3de9ec )

by Yuichi

created 2016-06-08 10:56 UTC

CacheSubscriber::addResponseHeaders() A

↳ Parent: CacheSubscriber

Complexity

Conditions	2
Paths	2

Size

Total Lines	12
Code Lines	8

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	1

Metric	Value
c	1
b	0
f	1
dl	0
loc	12
rs	9.4285
cc	2
eloc	8
nc	2
nop	2

<?php

namespace CybozuHttp\Subscriber;

use CybozuHttp\Subscriber\Cache\CacheStorage;
use GuzzleHttp\Event\HasEmitterInterface;
use GuzzleHttp\Event\BeforeEvent;
use GuzzleHttp\Event\CompleteEvent;
use GuzzleHttp\Event\RequestEvents;
use GuzzleHttp\Event\SubscriberInterface;
use GuzzleHttp\Message\RequestInterface;
use GuzzleHttp\Message\ResponseInterface;

/**
 * @author ochi51 <[email protected]>
 */
class CacheSubscriber implements SubscriberInterface
{
    /** @var CacheStorage $cache Object used to cache responses */
    protected $storage;

    /**
     * @param CacheStorage $cache    Cache storage
     */
    public function __construct(CacheStorage $cache)
    {
        $this->storage = $cache;
    }

    /**
     * @param HasEmitterInterface $subject
     * @param CacheStorage|null $storage
     * @return array
     */
    public static function attach(HasEmitterInterface $subject, CacheStorage $storage)
    {
        $emitter = $subject->getEmitter();
        $cache = new self($storage);
        $emitter->attach($cache);

        return ['subscriber' => $cache, 'storage' => $storage];
    }

    /**
     * @return array
     */
    public function getEvents()
    {
        return [
            'before'   => ['onBefore', RequestEvents::LATE],
            'complete' => ['onComplete', RequestEvents::EARLY]
        ];
    }

    /**
     * Checks if a request can be cached, and if so, intercepts with a cached
     * response is available.
     */
    public function onBefore(BeforeEvent $event)
    {
        $request = $event->getRequest();

        if (!($response = $this->storage->fetch($request))) {
            $this->cacheMiss($request);
            return;
        }

        $request->getConfig()->set('cache_lookup', 'HIT');
        $request->getConfig()->set('cache_hit', true);
        $event->intercept($response);
    }

    /**
     * Checks if the request and response can be cached, and if so, store it
     */
    public function onComplete(CompleteEvent $event)
    {
        $request = $event->getRequest();
        $response = $event->getResponse();

        // Cache the response if it can be cached and isn't already
        if ($request->getConfig()->get('cache_lookup') === 'MISS') {
            $this->storage->cache($request, $response);
/** @return stdClass|null */
function mayReturnNull() { }

function doesNotAcceptNull(stdClass $x) { }

// With potential error.
function withoutCheck() {
    $x = mayReturnNull();
    doesNotAcceptNull($x); // Potential error here.
}

// Safe - Alternative 1
function withCheck1() {
    $x = mayReturnNull();
    if ( ! $x instanceof stdClass) {
        throw new \LogicException('$x must be defined.');
    }
    doesNotAcceptNull($x);
}

// Safe - Alternative 2
function withCheck2() {
    $x = mayReturnNull();
    if ($x instanceof stdClass) {
        doesNotAcceptNull($x);
    }
}
        }

        $this->addResponseHeaders($request, $response);
/** @return stdClass|null */
function mayReturnNull() { }

function doesNotAcceptNull(stdClass $x) { }

// With potential error.
function withoutCheck() {
    $x = mayReturnNull();
    doesNotAcceptNull($x); // Potential error here.
}

// Safe - Alternative 1
function withCheck1() {
    $x = mayReturnNull();
    if ( ! $x instanceof stdClass) {
        throw new \LogicException('$x must be defined.');
    }
    doesNotAcceptNull($x);
}

// Safe - Alternative 2
function withCheck2() {
    $x = mayReturnNull();
    if ($x instanceof stdClass) {
        doesNotAcceptNull($x);
    }
}
    }

    private function cacheMiss(RequestInterface $request)
    {
        $request->getConfig()->set('cache_lookup', 'MISS');
    }

    private function addResponseHeaders(RequestInterface $request, ResponseInterface $response)
    {
        $params = $request->getConfig();
        $lookup = $params['cache_lookup'] . ' from GuzzleCache';
        $response->addHeader('X-Cache-Lookup', $lookup);

        if ($params['cache_hit'] === true) {
            $response->addHeader('X-Cache', 'HIT from GuzzleCache');
        } else {
            $response->addHeader('X-Cache', 'MISS from GuzzleCache');
        }
    }
}

1			<?php
2
3			namespace CybozuHttp\Subscriber;
4
5			use CybozuHttp\Subscriber\Cache\CacheStorage;
6			use GuzzleHttp\Event\HasEmitterInterface;
7			use GuzzleHttp\Event\BeforeEvent;
8			use GuzzleHttp\Event\CompleteEvent;
9			use GuzzleHttp\Event\RequestEvents;
10			use GuzzleHttp\Event\SubscriberInterface;
11			use GuzzleHttp\Message\RequestInterface;
12			use GuzzleHttp\Message\ResponseInterface;
13
14			/**
15			* @author ochi51 <[email protected]>
16			*/
17			class CacheSubscriber implements SubscriberInterface
18			{
19			/** @var CacheStorage $cache Object used to cache responses */
20			protected $storage;
21
22			/**
23			* @param CacheStorage $cache Cache storage
24			*/
25			public function __construct(CacheStorage $cache)
26			{
27			$this->storage = $cache;
28			}
29
30			/**
31			* @param HasEmitterInterface $subject
32			* @param CacheStorage\|null $storage
33			* @return array
34			*/
35			public static function attach(HasEmitterInterface $subject, CacheStorage $storage)
36			{
37			$emitter = $subject->getEmitter();
38			$cache = new self($storage);
39			$emitter->attach($cache);
40
41			return ['subscriber' => $cache, 'storage' => $storage];
42			}
43
44			/**
45			* @return array
46			*/
47			public function getEvents()
48			{
49			return [
50			'before' => ['onBefore', RequestEvents::LATE],
51			'complete' => ['onComplete', RequestEvents::EARLY]
52			];
53			}
54
55			/**
56			* Checks if a request can be cached, and if so, intercepts with a cached
57			* response is available.
58			*/
59			public function onBefore(BeforeEvent $event)
60			{
61			$request = $event->getRequest();
62
63			if (!($response = $this->storage->fetch($request))) {
64			$this->cacheMiss($request);
65			return;
66			}
67
68			$request->getConfig()->set('cache_lookup', 'HIT');
69			$request->getConfig()->set('cache_hit', true);
70			$event->intercept($response);
71			}
72
73			/**
74			* Checks if the request and response can be cached, and if so, store it
75			*/
76			public function onComplete(CompleteEvent $event)
77			{
78			$request = $event->getRequest();
79			$response = $event->getResponse();
80
81			// Cache the response if it can be cached and isn't already
82			if ($request->getConfig()->get('cache_lookup') === 'MISS') {
83			$this->storage->cache($request, $response);
			0 ignored issues – show Bug introduced 2016-06-08 11:05 UTC by Report Bug Copy Issue Report It seems like `$response` defined by `$event->getResponse()` on line `79` can be `null`; however, `CybozuHttp\Subscriber\Cache\CacheStorage::cache()` does not accept `null`, maybe add an additional type check? Unless you are absolutely sure that the expression can never be null because of other conditions, we strongly recommend to add an additional type check to your code: /** @return stdClass\|null */ function mayReturnNull() { } function doesNotAcceptNull(stdClass $x) { } // With potential error. function withoutCheck() { $x = mayReturnNull(); doesNotAcceptNull($x); // Potential error here. } // Safe - Alternative 1 function withCheck1() { $x = mayReturnNull(); if ( ! $x instanceof stdClass) { throw new \LogicException('$x must be defined.'); } doesNotAcceptNull($x); } // Safe - Alternative 2 function withCheck2() { $x = mayReturnNull(); if ($x instanceof stdClass) { doesNotAcceptNull($x); } } Loading history...
84			}
85
86			$this->addResponseHeaders($request, $response);
			0 ignored issues – show Bug introduced 2016-06-08 11:05 UTC by Report Bug Copy Issue Report It seems like `$response` defined by `$event->getResponse()` on line `79` can be `null`; however, `CybozuHttp\Subscriber\Ca...r::addResponseHeaders()` does not accept `null`, maybe add an additional type check? Unless you are absolutely sure that the expression can never be null because of other conditions, we strongly recommend to add an additional type check to your code: /** @return stdClass\|null */ function mayReturnNull() { } function doesNotAcceptNull(stdClass $x) { } // With potential error. function withoutCheck() { $x = mayReturnNull(); doesNotAcceptNull($x); // Potential error here. } // Safe - Alternative 1 function withCheck1() { $x = mayReturnNull(); if ( ! $x instanceof stdClass) { throw new \LogicException('$x must be defined.'); } doesNotAcceptNull($x); } // Safe - Alternative 2 function withCheck2() { $x = mayReturnNull(); if ($x instanceof stdClass) { doesNotAcceptNull($x); } } Loading history...
87			}
88
89			private function cacheMiss(RequestInterface $request)
90			{
91			$request->getConfig()->set('cache_lookup', 'MISS');
92			}
93
94			private function addResponseHeaders(RequestInterface $request, ResponseInterface $response)
95			{
96			$params = $request->getConfig();
97			$lookup = $params['cache_lookup'] . ' from GuzzleCache';
98			$response->addHeader('X-Cache-Lookup', $lookup);
99
100			if ($params['cache_hit'] === true) {
101			$response->addHeader('X-Cache', 'HIT from GuzzleCache');
102			} else {
103			$response->addHeader('X-Cache', 'MISS from GuzzleCache');
104			}
105			}
106			}

ochi51 / cybozu-http

Push — cache ( 3de9ec )

CacheSubscriber::addResponseHeaders() A

Complexity

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Duplication

Importance

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