AbstractCursor::rewind() - Code Metrics - Inspection of "Remove reference to generators on cursor destructi..." - alcaeus/mongo-php-adapter - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — master (#262)

by Andreas

created 2019-11-07 19:01 UTC

AbstractCursor::rewind() A

↳ Parent: AbstractCursor

Complexity

Conditions	1
Paths	1

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	7
CRAP Score	1

Importance

Changes

Metric	Value
cc	1
nc	1
nop	0
dl	0
loc	9
rs	9.9666
c	0
b	0
f	0
ccs	7
cts	7
cp	1
crap	1

<?php
/*
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

namespace Alcaeus\MongoDbAdapter;

use Alcaeus\MongoDbAdapter\Helper\ReadPreference;
use MongoDB\Collection;
use MongoDB\Driver\Cursor;

/**
 * @internal
 */
abstract class AbstractCursor
{
    use ReadPreference;

    /**
     * @var int|null
     */
    protected $batchSize = null;

    /**
     * @var Collection
     */
    protected $collection;

    /**
     * @var \MongoClient
     */
    protected $connection;

    /**
     * @var Cursor
     */
    protected $cursor;

    /**
     * @var \MongoDB\Database
     */
    protected $db;

    /**
     * @var \Iterator
     */
    protected $iterator;

    /**
     * @var string
     */
    protected $ns;

    /**
     * @var bool
     */
    protected $startedIterating = false;

    /**
     * @var bool
     */
    protected $cursorNeedsAdvancing = true;

    /**
     * @var mixed
     */
    private $current = null;

    /**
     * @var mixed
     */
    private $key = null;

    /**
     * @var mixed
     */
    private $valid = false;

    /**
     * @var int
     */
    protected $position = 0;

    /**
     * @var array
     */
    protected $optionNames = [
        'batchSize',
        'readPreference',
    ];

    /**
     * @return Cursor
     */
    abstract protected function ensureCursor();

    /**
     * @return array
     */
    abstract protected function getCursorInfo();

    /**
     * Create a new cursor
     * @link http://www.php.net/manual/en/mongocursor.construct.php
     * @param \MongoClient $connection Database connection.
     * @param string $ns Full name of database and collection.
     */
    public function __construct(\MongoClient $connection, $ns)
    {
        $this->connection = $connection;
        $this->ns = $ns;

        $nsParts = explode('.', $ns);
        $dbName = array_shift($nsParts);
        $collectionName = implode('.', $nsParts);

        $this->db = $connection->selectDB($dbName)->getDb();

        if ($collectionName) {
            $this->collection = $connection->selectCollection($dbName, $collectionName)->getCollection();
        }
    }

    public function __destruct()
    {
        $this->iterator = null;
    }

    /**
     * Returns the current element
     * @link http://www.php.net/manual/en/mongocursor.current.php
     * @return array
     */
    public function current()
    {
        return $this->current;
    }

    /**
     * Returns the current result's _id
     * @link http://www.php.net/manual/en/mongocursor.key.php
     * @return string The current result's _id as a string.
     */
    public function key()
    {
        return $this->key;
    }

    /**
     * Advances the cursor to the next result, and returns that result
     * @link http://www.php.net/manual/en/mongocursor.next.php
     * @throws \MongoConnectionException
     * @throws \MongoCursorTimeoutException
     * @return array Returns the next object
     */
    public function next()
    {
        if (! $this->startedIterating) {

            $this->ensureIterator();
            $this->startedIterating = true;
        } else {
            if ($this->cursorNeedsAdvancing) {
                $this->ensureIterator()->next();
            }

            $this->cursorNeedsAdvancing = true;
            $this->position++;
        }

        return $this->storeIteratorState();
    }

    /**
     * Returns the cursor to the beginning of the result set
     * @throws \MongoConnectionException
     * @throws \MongoCursorTimeoutException
     * @return void
     */
    public function rewind()
    {
        // We can recreate the cursor to allow it to be rewound
        $this->reset();
        $this->startedIterating = true;
        $this->position = 0;
        $this->ensureIterator()->rewind();
        $this->storeIteratorState();
    }

    /**
     * Checks if the cursor is reading a valid result.
     * @link http://www.php.net/manual/en/mongocursor.valid.php
     * @return boolean If the current result is not null.
     */
    public function valid()
    {
        return $this->valid;
    }

    /**
     * Limits the number of elements returned in one batch.
     *
     * @link http://docs.php.net/manual/en/mongocursor.batchsize.php
     * @param int|null $batchSize The number of results to return per batch
     * @return $this Returns this cursor.
     */
    public function batchSize($batchSize)
    {
        $this->batchSize = $batchSize;

        return $this;
    }

    /**
     * Checks if there are documents that have not been sent yet from the database for this cursor
     * @link http://www.php.net/manual/en/mongocursor.dead.php
     * @return boolean Returns if there are more results that have not been sent to the client, yet.
     */
    public function dead()
    {
        return $this->ensureCursor()->isDead();
    }

    /**
     * @return array
     */
    public function info()
    {
        return $this->getCursorInfo() + $this->getIterationInfo();
    }

    /**
     * @link http://www.php.net/manual/en/mongocursor.setreadpreference.php
     * @param string $readPreference
     * @param array $tags
     * @return $this Returns this cursor.
     */
    public function setReadPreference($readPreference, $tags = null)
    {
        $this->setReadPreferenceFromParameters($readPreference, $tags);

        return $this;
    }

    /**
     * Sets a client-side timeout for this query
     * @link http://www.php.net/manual/en/mongocursor.timeout.php
     * @param int $ms The number of milliseconds for the cursor to wait for a response. By default, the cursor will wait forever.
     * @return $this Returns this cursor
     */
    public function timeout($ms)

    {
        trigger_error('The ' . __METHOD__ . ' method is not implemented in mongo-php-adapter', E_USER_WARNING);
        return $this;
    }

    /**
     * Applies all options set on the cursor, overwriting any options that have already been set
     *
     * @param array $optionNames Array of option names to be applied (will be read from properties)
     * @return array
     */
    protected function getOptions($optionNames = null)
    {
        $options = [];

        if ($optionNames === null) {
            $optionNames = $this->optionNames;
        }

        foreach ($optionNames as $option) {
            $converter = 'convert' . ucfirst($option);
            $value = method_exists($this, $converter) ? $this->$converter() : $this->$option;

            if ($value === null) {
                continue;
            }

            $options[$option] = $value;
        }

        return $options;
    }

    /**
     * @return \Iterator
     */
    protected function ensureIterator()
    {
        if ($this->iterator === null) {
            // MongoDB\Driver\Cursor needs to be wrapped into a \Generator so that a valid \Iterator with working implementations of
            // next, current, valid, key and rewind is returned. These methods don't work if we wrap the Cursor inside an \IteratorIterator
            $this->iterator = $this->wrapTraversable($this->ensureCursor());
        }

        return $this->iterator;
    }

    /**
     * @param \Traversable $traversable
     * @return \Generator
     */
    protected function wrapTraversable(\Traversable $traversable)
    {
        foreach ($traversable as $key => $value) {
            yield $key => $value;
        }
    }

    /**
     * @throws \MongoCursorException
     */
    protected function errorIfOpened()
    {
        if ($this->cursor === null) {
            return;
        }

        throw new \MongoCursorException('cannot modify cursor after beginning iteration.');
    }

    /**
     * @return array
     */
    protected function getIterationInfo()
    {
        $iterationInfo = [
            'started_iterating' => $this->cursor !== null,
        ];

        if ($this->cursor !== null) {
            switch ($this->cursor->getServer()->getType()) {
                case \MongoDB\Driver\Server::TYPE_RS_ARBITER:
                    $typeString = 'ARBITER';
                    break;
                case \MongoDB\Driver\Server::TYPE_MONGOS:
                    $typeString = 'MONGOS';
                    break;
                case \MongoDB\Driver\Server::TYPE_RS_PRIMARY:
                    $typeString = 'PRIMARY';
                    break;
                case \MongoDB\Driver\Server::TYPE_RS_SECONDARY:
                    $typeString = 'SECONDARY';
                    break;
                default:
                    $typeString = 'STANDALONE';
            }

            $cursorId = (string) $this->cursor->getId();
            $iterationInfo += [
                'id' => (int) $cursorId,
                'at' => $this->position,
                'numReturned' => $this->position, // This can't be obtained from the new cursor
                'server' => sprintf('%s:%d;-;.;%d', $this->cursor->getServer()->getHost(), $this->cursor->getServer()->getPort(), getmypid()),
                'host' => $this->cursor->getServer()->getHost(),
                'port' => $this->cursor->getServer()->getPort(),
                'connection_type_desc' => $typeString,
            ];
        }

        return $iterationInfo;
    }

    /**
     * @throws \Exception
     */
    protected function notImplemented()
    {
        throw new \Exception('Not implemented');
    }

    /**
     * Clears the cursor
     *
     * This is generic but implemented as protected since it's only exposed in MongoCursor
     */
    protected function reset()
    {
        $this->startedIterating = false;
        $this->cursorNeedsAdvancing = true;
        $this->cursor = null;
        $this->iterator = null;
        $this->storeIteratorState();
    }

    /**
     * @return array
     */
    public function __sleep()
    {
        return ['batchSize', 'connection', 'iterator', 'ns', 'optionNames', 'position', 'startedIterating'];
    }

    /**
     * Stores the current cursor element.
     *
     * This is necessary because hasNext() might advance the iterator but we still
     * need to be able to return the current object.
     */
    protected function storeIteratorState()
    {
        if (! $this->startedIterating) {
            $this->current = null;
            $this->key = null;
            $this->valid = false;
            return null;
        }

        $this->current = $this->ensureIterator()->current();
        $this->key = $this->ensureIterator()->key();
        $this->valid = $this->ensureIterator()->valid();

        if ($this->current !== null) {
            $this->current = TypeConverter::toLegacy($this->current);
        }

        return $this->current;
    }
}


1			<?php
2			/*
3			* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
4			* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
5			* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
6			* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
7			* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
8			* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
9			* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
10			* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
11			* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
12			* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
13			* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
14			*/
15
16			namespace Alcaeus\MongoDbAdapter;
17
18			use Alcaeus\MongoDbAdapter\Helper\ReadPreference;
19			use MongoDB\Collection;
20			use MongoDB\Driver\Cursor;
21
22			/**
23			* @internal
24			*/
25			abstract class AbstractCursor
26			{
27			use ReadPreference;
28
29			/**
30			* @var int\|null
31			*/
32			protected $batchSize = null;
33
34			/**
35			* @var Collection
36			*/
37			protected $collection;
38
39			/**
40			* @var \MongoClient
41			*/
42			protected $connection;
43
44			/**
45			* @var Cursor
46			*/
47			protected $cursor;
48
49			/**
50			* @var \MongoDB\Database
51			*/
52			protected $db;
53
54			/**
55			* @var \Iterator
56			*/
57			protected $iterator;
58
59			/**
60			* @var string
61			*/
62			protected $ns;
63
64			/**
65			* @var bool
66			*/
67			protected $startedIterating = false;
68
69			/**
70			* @var bool
71			*/
72			protected $cursorNeedsAdvancing = true;
73
74			/**
75			* @var mixed
76			*/
77			private $current = null;
78
79			/**
80			* @var mixed
81			*/
82			private $key = null;
83
84			/**
85			* @var mixed
86			*/
87			private $valid = false;
88
89			/**
90			* @var int
91			*/
92			protected $position = 0;
93
94			/**
95			* @var array
96			*/
97			protected $optionNames = [
98			'batchSize',
99			'readPreference',
100			];
101
102			/**
103			* @return Cursor
104			*/
105			abstract protected function ensureCursor();
106
107			/**
108			* @return array
109			*/
110			abstract protected function getCursorInfo();
111
112			/**
113			* Create a new cursor
114			* @link http://www.php.net/manual/en/mongocursor.construct.php
115			* @param \MongoClient $connection Database connection.
116			* @param string $ns Full name of database and collection.
117			*/
118	96		public function __construct(\MongoClient $connection, $ns)
119			{
120	96		$this->connection = $connection;
121	96		$this->ns = $ns;
122
123	96		$nsParts = explode('.', $ns);
124	96		$dbName = array_shift($nsParts);
125	96		$collectionName = implode('.', $nsParts);
126
127	96		$this->db = $connection->selectDB($dbName)->getDb();
128
129	96		if ($collectionName) {
130	59		$this->collection = $connection->selectCollection($dbName, $collectionName)->getCollection();
131			}
132	96		}
133
134	94		public function __destruct()
135			{
136	94		$this->iterator = null;
137	94		}
138
139			/**
140			* Returns the current element
141			* @link http://www.php.net/manual/en/mongocursor.current.php
142			* @return array
143			*/
144	45		public function current()
145			{
146	45		return $this->current;
147			}
148
149			/**
150			* Returns the current result's _id
151			* @link http://www.php.net/manual/en/mongocursor.key.php
152			* @return string The current result's _id as a string.
153			*/
154	29		public function key()
155			{
156	29		return $this->key;
157			}
158
159			/**
160			* Advances the cursor to the next result, and returns that result
161			* @link http://www.php.net/manual/en/mongocursor.next.php
162			* @throws \MongoConnectionException
163			* @throws \MongoCursorTimeoutException
164			* @return array Returns the next object
165			*/
166	47		public function next()
167			{
168	47	View Code Duplication	if (! $this->startedIterating) {
			0 ignored issues – show Duplication introduced 2016-04-08 14:05 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
169	1		$this->ensureIterator();
170	1		$this->startedIterating = true;
171			} else {
172	47		if ($this->cursorNeedsAdvancing) {
173	46		$this->ensureIterator()->next();
174			}
175
176	47		$this->cursorNeedsAdvancing = true;
177	47		$this->position++;
178			}
179
180	47		return $this->storeIteratorState();
181			}
182
183			/**
184			* Returns the cursor to the beginning of the result set
185			* @throws \MongoConnectionException
186			* @throws \MongoCursorTimeoutException
187			* @return void
188			*/
189	78		public function rewind()
190			{
191			// We can recreate the cursor to allow it to be rewound
192	78		$this->reset();
193	78		$this->startedIterating = true;
194	78		$this->position = 0;
195	78		$this->ensureIterator()->rewind();
196	76		$this->storeIteratorState();
197	76		}
198
199			/**
200			* Checks if the cursor is reading a valid result.
201			* @link http://www.php.net/manual/en/mongocursor.valid.php
202			* @return boolean If the current result is not null.
203			*/
204	76		public function valid()
205			{
206	76		return $this->valid;
207			}
208
209			/**
210			* Limits the number of elements returned in one batch.
211			*
212			* @link http://docs.php.net/manual/en/mongocursor.batchsize.php
213			* @param int\|null $batchSize The number of results to return per batch
214			* @return $this Returns this cursor.
215			*/
216	2		public function batchSize($batchSize)
217			{
218	2		$this->batchSize = $batchSize;
219
220	2		return $this;
221			}
222
223			/**
224			* Checks if there are documents that have not been sent yet from the database for this cursor
225			* @link http://www.php.net/manual/en/mongocursor.dead.php
226			* @return boolean Returns if there are more results that have not been sent to the client, yet.
227			*/
228			public function dead()
229			{
230			return $this->ensureCursor()->isDead();
231			}
232
233			/**
234			* @return array
235			*/
236	5		public function info()
237			{
238	5		return $this->getCursorInfo() + $this->getIterationInfo();
239			}
240
241			/**
242			* @link http://www.php.net/manual/en/mongocursor.setreadpreference.php
243			* @param string $readPreference
244			* @param array $tags
245			* @return $this Returns this cursor.
246			*/
247	96		public function setReadPreference($readPreference, $tags = null)
248			{
249	96		$this->setReadPreferenceFromParameters($readPreference, $tags);
250
251	96		return $this;
252			}
253
254			/**
255			* Sets a client-side timeout for this query
256			* @link http://www.php.net/manual/en/mongocursor.timeout.php
257			* @param int $ms The number of milliseconds for the cursor to wait for a response. By default, the cursor will wait forever.
258			* @return $this Returns this cursor
259			*/
260			public function timeout($ms)
			0 ignored issues – show Unused Code introduced 2016-01-01 11:06 UTC by Report Bug Copy Issue Report The parameter `$ms` 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...
261			{
262			trigger_error('The ' . __METHOD__ . ' method is not implemented in mongo-php-adapter', E_USER_WARNING);
263			return $this;
264			}
265
266			/**
267			* Applies all options set on the cursor, overwriting any options that have already been set
268			*
269			* @param array $optionNames Array of option names to be applied (will be read from properties)
270			* @return array
271			*/
272	87		protected function getOptions($optionNames = null)
273			{
274	87		$options = [];
275
276	87		if ($optionNames === null) {
277	80		$optionNames = $this->optionNames;
278			}
279
280	87		foreach ($optionNames as $option) {
281	87		$converter = 'convert' . ucfirst($option);
282	87		$value = method_exists($this, $converter) ? $this->$converter() : $this->$option;
283
284	87		if ($value === null) {
285	87		continue;
286			}
287
288	82		$options[$option] = $value;
289			}
290
291	87		return $options;
292			}
293
294			/**
295			* @return \Iterator
296			*/
297	80		protected function ensureIterator()
298			{
299	80		if ($this->iterator === null) {
300			// MongoDB\Driver\Cursor needs to be wrapped into a \Generator so that a valid \Iterator with working implementations of
301			// next, current, valid, key and rewind is returned. These methods don't work if we wrap the Cursor inside an \IteratorIterator
302	80		$this->iterator = $this->wrapTraversable($this->ensureCursor());
303			}
304
305	78		return $this->iterator;
306			}
307
308			/**
309			* @param \Traversable $traversable
310			* @return \Generator
311			*/
312	37		protected function wrapTraversable(\Traversable $traversable)
313			{
314	37		foreach ($traversable as $key => $value) {
315	23		yield $key => $value;
316			}
317	37		}
318
319			/**
320			* @throws \MongoCursorException
321			*/
322	25		protected function errorIfOpened()
323			{
324	25		if ($this->cursor === null) {
325	25		return;
326			}
327
328			throw new \MongoCursorException('cannot modify cursor after beginning iteration.');
329			}
330
331			/**
332			* @return array
333			*/
334	5		protected function getIterationInfo()
335			{
336			$iterationInfo = [
337	5		'started_iterating' => $this->cursor !== null,
338			];
339
340	5		if ($this->cursor !== null) {
341	5		switch ($this->cursor->getServer()->getType()) {
342			case \MongoDB\Driver\Server::TYPE_RS_ARBITER:
343			$typeString = 'ARBITER';
344			break;
345			case \MongoDB\Driver\Server::TYPE_MONGOS:
346			$typeString = 'MONGOS';
347			break;
348			case \MongoDB\Driver\Server::TYPE_RS_PRIMARY:
349			$typeString = 'PRIMARY';
350			break;
351			case \MongoDB\Driver\Server::TYPE_RS_SECONDARY:
352			$typeString = 'SECONDARY';
353			break;
354			default:
355	5		$typeString = 'STANDALONE';
356			}
357
358	5		$cursorId = (string) $this->cursor->getId();
359			$iterationInfo += [
360	5		'id' => (int) $cursorId,
361	5		'at' => $this->position,
362	5		'numReturned' => $this->position, // This can't be obtained from the new cursor
363	5		'server' => sprintf('%s:%d;-;.;%d', $this->cursor->getServer()->getHost(), $this->cursor->getServer()->getPort(), getmypid()),
364	5		'host' => $this->cursor->getServer()->getHost(),
365	5		'port' => $this->cursor->getServer()->getPort(),
366	5		'connection_type_desc' => $typeString,
367			];
368			}
369
370	5		return $iterationInfo;
371			}
372
373			/**
374			* @throws \Exception
375			*/
376			protected function notImplemented()
377			{
378			throw new \Exception('Not implemented');
379			}
380
381			/**
382			* Clears the cursor
383			*
384			* This is generic but implemented as protected since it's only exposed in MongoCursor
385			*/
386	79		protected function reset()
387			{
388	79		$this->startedIterating = false;
389	79		$this->cursorNeedsAdvancing = true;
390	79		$this->cursor = null;
391	79		$this->iterator = null;
392	79		$this->storeIteratorState();
393	79		}
394
395			/**
396			* @return array
397			*/
398	3		public function __sleep()
399			{
400	3		return ['batchSize', 'connection', 'iterator', 'ns', 'optionNames', 'position', 'startedIterating'];
401			}
402
403			/**
404			* Stores the current cursor element.
405			*
406			* This is necessary because hasNext() might advance the iterator but we still
407			* need to be able to return the current object.
408			*/
409	80		protected function storeIteratorState()
410			{
411	80		if (! $this->startedIterating) {
412	79		$this->current = null;
413	79		$this->key = null;
414	79		$this->valid = false;
415	79		return null;
416			}
417
418	78		$this->current = $this->ensureIterator()->current();
419	78		$this->key = $this->ensureIterator()->key();
420	78		$this->valid = $this->ensureIterator()->valid();
421
422	78		if ($this->current !== null) {
423	47		$this->current = TypeConverter::toLegacy($this->current);
424			}
425
426	78		return $this->current;
427			}
428			}
429

alcaeus / mongo-php-adapter

Pull Request — master (#262)

AbstractCursor::rewind() A

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