SQLCache::decrement() - Code Metrics - Inspection of "Add TTL param for atomic counters" - Vectorface/cache - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#6)

unknown

created 2020-11-04 18:14 UTC

SQLCache::decrement() B

↳ Parent: SQLCache

Complexity

Conditions	7
Paths	14

Size

Total Lines	30
Code Lines	19

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	12
CRAP Score	9.4499

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
eloc	19
c	1
b	0
f	0
dl	0
loc	30
ccs	12
cts	19
cp	0.6316
rs	8.8333
cc	7
nc	14
nop	3
crap	9.4499

<?php
/** @noinspection SqlResolve */
/** @noinspection SqlWithoutWhere */
/** @noinspection SqlNoDataSourceInspection */
/** @noinspection PhpComposerExtensionStubsInspection */

namespace Vectorface\Cache;

use PDO;
use PDOStatement;
use PDOException;
use Vectorface\Cache\Common\PSR16Util;

/**
 * This cache is slow, according to basic benchmarks:
 *
 * Parameters:
 *   MySQL 5.0, running locally
 *   9-byte key
 *   151-byte value
 *   10000-iteration test
 *
 * Result:
 *   16.7824881077 seconds
 *
 * Conclusion:
 *   Capable of approximately 595.85 requests/second
 */

/**
 * A cache implementation that uses SQL for storage.
 *
 * An example table might look like:
 * CREATE TABLE cache (
 *     entry VARCHAR(64) PRIMARY KEY NOT NULL,
 *     value LONGBLOB,
 *     expires BIGINT UNSIGNED DEFAULT NULL,
 *     KEY expires (expires)
 * ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
 */
class SQLCache implements Cache, AtomicCounter
{
    use PSR16Util;

    /**
     * Hash keys beyond this size
     */
    const MAX_KEY_LEN = 64;

    /**
     * Statement for flushing all entries from the cache.
     */
    const FLUSH_SQL = 'DELETE FROM cache';

    /**
     * Statement for deleting expired entries from the cache.
     */
    const CLEAN_SQL = 'DELETE FROM cache WHERE expires<=UNIX_TIMESTAMP()';

    /**
     * Statement for inserting or updating entries in the cache.
     */
    const SET_SQL = 'INSERT INTO cache (entry,value,expires) VALUES(?,?,?)';

    /**
     * Statement for updating if an entry already exists.
     */
    const UPDATE_SQL = 'UPDATE cache SET value=?, expires=? WHERE entry=?';

    /**
     * Statement for checking if an entry exists
     */
    const HAS_SQL = 'SELECT COUNT(*) AS num FROM cache WHERE entry=? AND expires>=UNIX_TIMESTAMP()';

    /**
     * Statement for retrieving an entry from the cache
     */
    const GET_SQL = 'SELECT value FROM cache WHERE entry=? AND expires>=UNIX_TIMESTAMP()';

    /**
     * Statement for retrieving entries from the cache (no statement caching)
     */
    const MGET_SQL = 'SELECT entry,value FROM cache WHERE entry IN(%s) AND expires>=UNIX_TIMESTAMP()';

    /**
     * Statement for deleting an entry from the cache
     */
    const DELETE_SQL = 'DELETE FROM cache WHERE entry=?';

    /**
     * Statement for deleting entries from the cache (no statement caching)
     */
    const MDELETE_SQL = 'DELETE FROM cache WHERE entry IN(%s)';

    /**
     * The database connection to be used for cache operations.
     *
     * @var PDO
     */
    private $conn;

    /**
     * An associative array of PDO statements used in get/set.
     *
     * @var PDOStatement
     */
    private $statements = [];

    /**
     * Create an instance of the SQL cache.
     *
     * @param PDO $conn The database connection to use for cache operations.
     */
    public function __construct(PDO $conn)
    {
        $this->conn = $conn;
    }

    /**
     * @inheritDoc
     */
    public function get($key, $default = null)
    {
        $key = $this->key($key);
        $key = $this->hashKey($key);

        try {
            $stmt = $this->getStatement(__METHOD__, self::GET_SQL);
            $stmt->execute([$key]);
        } catch (PDOException $e) {
            return $default;
        }
        $result = $stmt->fetchColumn();
        return empty($result) ? $default : unserialize($result);
    }

    /**
     * @inheritDoc
     */
    public function getMultiple($keys, $default = null)
    {
        if (empty($keys)) {
            return [];
        }

        $keys = $this->keys($keys);
        $sqlKeys = array_map([$this, 'hashKey'], $keys);

        try {
            $stmt = $this->conn->prepare(sprintf(
                self::MGET_SQL,
                implode(',', array_fill(0, count($keys), '?'))
            ));
            $stmt->execute($sqlKeys);
            $result = $stmt->fetchAll(PDO::FETCH_KEY_PAIR);
        } catch (PDOException $e) {
            $result = [];
        }

        $return = array_map('unserialize', $result);
        foreach ($keys as $key) {
            if (!isset($return[$key])) {
                $return[$key] = $default;
            }
        }
        return $return;
    }


    /**
     * @inheritDoc
     */
    public function set($key, $value, $ttl = null)
    {
        $key = $this->key($key);
        $key = $this->hashKey($key);
        $ttl = $this->ttl($ttl);
        $ttl = $ttl ? ($ttl + time()) : PHP_INT_MAX;
        $value = serialize($value);

        try {
            $stmt = $this->getStatement(__METHOD__ . ".insert", self::SET_SQL);
            return $stmt->execute([$key, $value, $ttl]);
        } catch (PDOException $e) {
            // Insert can fail if the entry exists; It's normal.
        }

        try {
            $stmt = $this->getStatement(__METHOD__ . ".update", self::UPDATE_SQL);
            $success = $stmt->execute([$value, $ttl, $key]);
            return $success && $stmt->rowCount() === 1;
        } catch (PDOException $e) {
            return false;
        }
    }

    /**
     * @inheritDoc
     */
    public function setMultiple($values, $ttl = null)
    {
        $success = true;
        foreach ($this->values($values) as $key => $value) {
            $success = $this->set($key, $value, $ttl) && $success;
        }
        return $success;
    }

    /**
     * @inheritDoc
     */
    public function delete($key)
    {
        $key = $this->hashKey($this->key($key));

        try {
            $stmt = $this->getStatement(__METHOD__, self::DELETE_SQL);
            return $stmt->execute([$key]);
        } catch (PDOException $e) {
            return false;
        }
    }

    /**
     * @inheritDoc
     */
    public function deleteMultiple($keys)
    {
        if (empty($keys)) {
            return true;
        }

        $keysArray = array_map([$this, 'hashKey'], is_array($keys) ? $keys : iterator_to_array($keys));

        try {
            $stmt = $this->conn->prepare(sprintf(
                self::MDELETE_SQL,
                implode(',', array_fill(0, count($keysArray), '?'))
            ));
            $stmt->execute($keysArray);
        } catch (PDOException $e) {
            return false;
        }
        return true;
    }

    /**
     * @inheritdoc
     */
    public function clean()
    {
        try {
            $this->conn->exec(self::CLEAN_SQL);
        } catch (PDOException $e) {
            return false;
        }
        return true;
    }

    /**
     * @inheritdoc
     */
    public function flush()
    {
        try {
            $this->conn->exec(self::FLUSH_SQL);
        } catch (PDOException $e) {
            return false;
        }
        return true;
    }

    /**
     * @inheritDoc
     */
    public function clear()
    {
        return $this->flush();
    }

    /**
     * @inheritDoc
     */
    public function has($key)
    {
        $key = $this->hashKey($key);

        try {
            $stmt = $this->getStatement(__METHOD__, self::HAS_SQL);
            $stmt->execute([$key]);
        } catch (PDOException $e) {
            return false;
        }
        return $stmt->fetchColumn() ? true : false;
    }

    /**
     * @inheritDoc
     * @throws Exception\CacheException
     */
    public function increment($key, $step = 1, $ttl = null)
    {
        $step = $this->step($step);

        try {
            $result = $this->conn->beginTransaction();
            if (!$result) {
                return false;
            }

            $current = $this->get($key);
            $next = ($current ?? 0) + $step;
            $result = $this->set($key, $next, ($current === null ? $ttl : null));
            if (!$result) {
                $this->conn->rollBack();
                return false;
            }

            $result = $this->conn->commit();
            if (!$result) {
                return false;
            }
        } catch (PDOException $e) {
            if ($this->conn->inTransaction()) {
                $this->conn->rollBack();
            }
            return false;
        }

        return $next;
    }

    /**
     * @inheritDoc
     * @throws Exception\CacheException
     */
    public function decrement($key, $step = 1, $ttl = null)
    {
        $step = $this->step($step);

        try {
            $result = $this->conn->beginTransaction();
            if (!$result) {
                return false;
            }

            $current = $this->get($key);
            $next = ($current ?? 0) - $step;
            $result = $this->set($key, $next, ($current === null ? $ttl : null));
            if (!$result) {
                $this->conn->rollBack();
                return false;
            }

            $result = $this->conn->commit();
            if (!$result) {
                return false;
            }
        } catch (PDOException $e) {
            if ($this->conn->inTransaction()) {
                $this->conn->rollBack();
            }
            return false;
        }

        return $next;
    }

    /**
     * Get a prepared statement for the given method's SQL.
     *
     * The result is stored internally to limit repeated preparing of SQL.
     *
     * @param string $method The method name to for which this statement applies.
     * @param string $sql The SQL statement associated with the given method.
     * @return PDOStatement Returns the prepared statement for the given method.
     */
    private function getStatement($method, $sql)
    {
        if (empty($this->statements[$method])) {
            $this->statements[$method] = $this->conn->prepare($sql);
        }
        return $this->statements[$method];
    }

    /**
     * Get a unique hash key when the key is too long
     *
     * @param string $key
     * @return string The key, or the hash of the key parameter if it goes beyond maximum length
     * @private Public for testing
     */
    public static function hashKey($key)
    {
        return (strlen($key) > self::MAX_KEY_LEN) ? hash('sha256', $key) : $key;
    }
}


1		<?php
2		/** @noinspection SqlResolve */
3		/** @noinspection SqlWithoutWhere */
4		/** @noinspection SqlNoDataSourceInspection */
5		/** @noinspection PhpComposerExtensionStubsInspection */
6
7		namespace Vectorface\Cache;
8
9		use PDO;
10		use PDOStatement;
11		use PDOException;
12		use Vectorface\Cache\Common\PSR16Util;
13
14		/**
15		* This cache is slow, according to basic benchmarks:
16		*
17		* Parameters:
18		* MySQL 5.0, running locally
19		* 9-byte key
20		* 151-byte value
21		* 10000-iteration test
22		*
23		* Result:
24		* 16.7824881077 seconds
25		*
26		* Conclusion:
27		* Capable of approximately 595.85 requests/second
28		*/
29
30		/**
31		* A cache implementation that uses SQL for storage.
32		*
33		* An example table might look like:
34		* CREATE TABLE cache (
35		* entry VARCHAR(64) PRIMARY KEY NOT NULL,
36		* value LONGBLOB,
37		* expires BIGINT UNSIGNED DEFAULT NULL,
38		* KEY expires (expires)
39		* ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
40		*/
41		class SQLCache implements Cache, AtomicCounter
42		{
43		use PSR16Util;
44
45		/**
46		* Hash keys beyond this size
47		*/
48		const MAX_KEY_LEN = 64;
49
50		/**
51		* Statement for flushing all entries from the cache.
52		*/
53		const FLUSH_SQL = 'DELETE FROM cache';
54
55		/**
56		* Statement for deleting expired entries from the cache.
57		*/
58		const CLEAN_SQL = 'DELETE FROM cache WHERE expires<=UNIX_TIMESTAMP()';
59
60		/**
61		* Statement for inserting or updating entries in the cache.
62		*/
63		const SET_SQL = 'INSERT INTO cache (entry,value,expires) VALUES(?,?,?)';
64
65		/**
66		* Statement for updating if an entry already exists.
67		*/
68		const UPDATE_SQL = 'UPDATE cache SET value=?, expires=? WHERE entry=?';
69
70		/**
71		* Statement for checking if an entry exists
72		*/
73		const HAS_SQL = 'SELECT COUNT(*) AS num FROM cache WHERE entry=? AND expires>=UNIX_TIMESTAMP()';
74
75		/**
76		* Statement for retrieving an entry from the cache
77		*/
78		const GET_SQL = 'SELECT value FROM cache WHERE entry=? AND expires>=UNIX_TIMESTAMP()';
79
80		/**
81		* Statement for retrieving entries from the cache (no statement caching)
82		*/
83		const MGET_SQL = 'SELECT entry,value FROM cache WHERE entry IN(%s) AND expires>=UNIX_TIMESTAMP()';
84
85		/**
86		* Statement for deleting an entry from the cache
87		*/
88		const DELETE_SQL = 'DELETE FROM cache WHERE entry=?';
89
90		/**
91		* Statement for deleting entries from the cache (no statement caching)
92		*/
93		const MDELETE_SQL = 'DELETE FROM cache WHERE entry IN(%s)';
94
95		/**
96		* The database connection to be used for cache operations.
97		*
98		* @var PDO
99		*/
100		private $conn;
101
102		/**
103		* An associative array of PDO statements used in get/set.
104		*
105		* @var PDOStatement
106		*/
107		private $statements = [];
108
109		/**
110		* Create an instance of the SQL cache.
111		*
112		* @param PDO $conn The database connection to use for cache operations.
113		*/
114	21	public function __construct(PDO $conn)
115		{
116	21	$this->conn = $conn;
117	21	}
118
119		/**
120		* @inheritDoc
121		*/
122	17	public function get($key, $default = null)
123		{
124	17	$key = $this->key($key);
125	16	$key = $this->hashKey($key);
126
127		try {
128	16	$stmt = $this->getStatement(__METHOD__, self::GET_SQL);
129	16	$stmt->execute([$key]);
130	1	} catch (PDOException $e) {
131	1	return $default;
132		}
133	16	$result = $stmt->fetchColumn();
134	16	return empty($result) ? $default : unserialize($result);
135		}
136
137		/**
138		* @inheritDoc
139		*/
140	4	public function getMultiple($keys, $default = null)
141		{
142	4	if (empty($keys)) {
143	1	return [];
144		}
145
146	4	$keys = $this->keys($keys);
147	3	$sqlKeys = array_map([$this, 'hashKey'], $keys);
148
149		try {
150	3	$stmt = $this->conn->prepare(sprintf(
151	3	self::MGET_SQL,
152	3	implode(',', array_fill(0, count($keys), '?'))
153		));
154	2	$stmt->execute($sqlKeys);
155	2	$result = $stmt->fetchAll(PDO::FETCH_KEY_PAIR);
156	1	} catch (PDOException $e) {
157	1	$result = [];
158		}
159
160	3	$return = array_map('unserialize', $result);
161	3	foreach ($keys as $key) {
162	3	if (!isset($return[$key])) {
163	3	$return[$key] = $default;
164		}
165		}
166	3	return $return;
167		}
168
169
170		/**
171		* @inheritDoc
172		*/
173	20	public function set($key, $value, $ttl = null)
174		{
175	20	$key = $this->key($key);
176	20	$key = $this->hashKey($key);
177	20	$ttl = $this->ttl($ttl);
178	19	$ttl = $ttl ? ($ttl + time()) : PHP_INT_MAX;
179	19	$value = serialize($value);
180
181		try {
182	19	$stmt = $this->getStatement(__METHOD__ . ".insert", self::SET_SQL);
183	19	return $stmt->execute([$key, $value, $ttl]);
184	5	} catch (PDOException $e) {
185		// Insert can fail if the entry exists; It's normal.
186		}
187
188		try {
189	5	$stmt = $this->getStatement(__METHOD__ . ".update", self::UPDATE_SQL);
190	5	$success = $stmt->execute([$value, $ttl, $key]);
191	5	return $success && $stmt->rowCount() === 1;
192	1	} catch (PDOException $e) {
193	1	return false;
194		}
195		}
196
197		/**
198		* @inheritDoc
199		*/
200	3	public function setMultiple($values, $ttl = null)
201		{
202	3	$success = true;
203	3	foreach ($this->values($values) as $key => $value) {
204	2	$success = $this->set($key, $value, $ttl) && $success;
205		}
206	2	return $success;
207		}
208
209		/**
210		* @inheritDoc
211		*/
212	5	public function delete($key)
213		{
214	5	$key = $this->hashKey($this->key($key));
215
216		try {
217	5	$stmt = $this->getStatement(__METHOD__, self::DELETE_SQL);
218	5	return $stmt->execute([$key]);
219	1	} catch (PDOException $e) {
220	1	return false;
221		}
222		}
223
224		/**
225		* @inheritDoc
226		*/
227	3	public function deleteMultiple($keys)
228		{
229	3	if (empty($keys)) {
230	1	return true;
231		}
232
233	3	$keysArray = array_map([$this, 'hashKey'], is_array($keys) ? $keys : iterator_to_array($keys));
234
235		try {
236	3	$stmt = $this->conn->prepare(sprintf(
237	3	self::MDELETE_SQL,
238	3	implode(',', array_fill(0, count($keysArray), '?'))
239		));
240	2	$stmt->execute($keysArray);
241	1	} catch (PDOException $e) {
242	1	return false;
243		}
244	2	return true;
245		}
246
247		/**
248		* @inheritdoc
249		*/
250	2	public function clean()
251		{
252		try {
253	2	$this->conn->exec(self::CLEAN_SQL);
254	1	} catch (PDOException $e) {
255	1	return false;
256		}
257	2	return true;
258		}
259
260		/**
261		* @inheritdoc
262		*/
263	7	public function flush()
264		{
265		try {
266	7	$this->conn->exec(self::FLUSH_SQL);
267	1	} catch (PDOException $e) {
268	1	return false;
269		}
270	7	return true;
271		}
272
273		/**
274		* @inheritDoc
275		*/
276	3	public function clear()
277		{
278	3	return $this->flush();
279		}
280
281		/**
282		* @inheritDoc
283		*/
284	2	public function has($key)
285		{
286	2	$key = $this->hashKey($key);
287
288		try {
289	2	$stmt = $this->getStatement(__METHOD__, self::HAS_SQL);
290	1	$stmt->execute([$key]);
291	1	} catch (PDOException $e) {
292	1	return false;
293		}
294	1	return $stmt->fetchColumn() ? true : false;
295		}
296
297		/**
298		* @inheritDoc
299		* @throws Exception\CacheException
300		*/
301	1	public function increment($key, $step = 1, $ttl = null)
302		{
303	1	$step = $this->step($step);
304
305		try {
306	1	$result = $this->conn->beginTransaction();
307	1	if (!$result) {
308		return false;
309		}
310
311	1	$current = $this->get($key);
312	1	$next = ($current ?? 0) + $step;
313	1	$result = $this->set($key, $next, ($current === null ? $ttl : null));
314	1	if (!$result) {
315		$this->conn->rollBack();
316		return false;
317		}
318
319	1	$result = $this->conn->commit();
320	1	if (!$result) {
321	1	return false;
322		}
323		} catch (PDOException $e) {
324		if ($this->conn->inTransaction()) {
325		$this->conn->rollBack();
326		}
327		return false;
328		}
329
330	1	return $next;
331		}
332
333		/**
334		* @inheritDoc
335		* @throws Exception\CacheException
336		*/
337	1	public function decrement($key, $step = 1, $ttl = null)
338		{
339	1	$step = $this->step($step);
340
341		try {
342	1	$result = $this->conn->beginTransaction();
343	1	if (!$result) {
344		return false;
345		}
346
347	1	$current = $this->get($key);
348	1	$next = ($current ?? 0) - $step;
349	1	$result = $this->set($key, $next, ($current === null ? $ttl : null));
350	1	if (!$result) {
351		$this->conn->rollBack();
352		return false;
353		}
354
355	1	$result = $this->conn->commit();
356	1	if (!$result) {
357	1	return false;
358		}
359		} catch (PDOException $e) {
360		if ($this->conn->inTransaction()) {
361		$this->conn->rollBack();
362		}
363		return false;
364		}
365
366	1	return $next;
367		}
368
369		/**
370		* Get a prepared statement for the given method's SQL.
371		*
372		* The result is stored internally to limit repeated preparing of SQL.
373		*
374		* @param string $method The method name to for which this statement applies.
375		* @param string $sql The SQL statement associated with the given method.
376		* @return PDOStatement Returns the prepared statement for the given method.
377		*/
378	19	private function getStatement($method, $sql)
379		{
380	19	if (empty($this->statements[$method])) {
381	19	$this->statements[$method] = $this->conn->prepare($sql);
382		}
383	19	return $this->statements[$method];
384		}
385
386		/**
387		* Get a unique hash key when the key is too long
388		*
389		* @param string $key
390		* @return string The key, or the hash of the key parameter if it goes beyond maximum length
391		* @private Public for testing
392		*/
393	20	public static function hashKey($key)
394		{
395	20	return (strlen($key) > self::MAX_KEY_LEN) ? hash('sha256', $key) : $key;
396		}
397		}
398

Vectorface / cache

Pull Request — master (#6)

SQLCache::decrement() B

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Duplication

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