anonymous//classes/Backend/Database.php$0 - Code Metrics - Inspection of "Update CHANGELOG.md" - MarwanAlsoltany/velox - Measure and Improve Code Quality continuously with Scrutinizer

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by Marwan

created 2021-12-20 22:27 UTC

anonymous//classes/Backend/Database.php$0 A

↳ Parent: Database::getStatementClass()

Complexity

Total Complexity

Size/Duplication

Total Lines	19
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
c	1
b	0
f	0
dl	0
loc	19
ccs	8
cts	8
cp	1
rs	10
wmc	2

<?php

/**
 * @author Marwan Al-Soltany <[email protected]>
 * @copyright Marwan Al-Soltany 2021
 * For the full copyright and license information, please view
 * the LICENSE file that was distributed with this source code.
 */

declare(strict_types=1);

namespace MAKS\Velox\Backend;

/**
 * A class that represents the database and handles database operations.
 *
 * Example:
 * ```
 * $database = Database::instance();
 * $database->query('SELECT * FROM `users`');
 * $database->prepare('SELECT * FROM `users` WHERE `job` = :job LIMIT 5')->execute([':job' => 'Developer'])->fetchAll();
 * $database->perform('SELECT * FROM `users` WHERE `title` LIKE :title AND `id` > :id', ['title' => 'Dr.%', 'id' => 1])->fetchAll();
 * ```
 *
 * @package Velox\Backend
 * @since 1.3.0
 * @api
 */
class Database extends \PDO
{
    /**
     * Current open database connections.
     */
    protected static array $connections;

    /**
     * A cache to hold prepared statements.
     */
    protected array $cache;

    protected string $dsn;
    protected ?string $username;
    protected ?string $password;
    protected ?array $options;


    /**
     * Class constructor.
     *
     * Adds some default options to the PDO connection.
     *
     * @param string $dsn
     * @param string|null $username
     * @param string|null $password
     * @param array|null $options
     */
    protected function __construct(string $dsn, ?string $username = null, ?string $password = null, ?array $options = null)
    {
        $this->dsn      = $dsn;
        $this->username = $username;
        $this->password = $password;
        $this->options  = $options;

        $this->cache = [];

        parent::__construct($dsn, $username, $password, $options);

        $this->setAttribute(static::ATTR_ERRMODE, static::ERRMODE_EXCEPTION);
        $this->setAttribute(static::ATTR_DEFAULT_FETCH_MODE, static::FETCH_ASSOC);
        $this->setAttribute(static::ATTR_EMULATE_PREPARES, false);
        $this->setAttribute(static::MYSQL_ATTR_FOUND_ROWS, true);
        $this->setAttribute(static::ATTR_STATEMENT_CLASS, [$this->getStatementClass()]);
    }


    /**
     * Returns a singleton instance of the `Database` class based on connection credentials.
     * This method makes sure that a single connection is opened and reused for each connection credentials set (DSN, User, Password, ...).
     *
     * @param string|null $dsn The DSN string.
     * @param string|null $username [optional] The database username.
     * @param string|null $password [optional] The database password.
     * @param array|null $options [optional] PDO options.
     *
     * @return static
     */
    final public static function connect(string $dsn, ?string $username = null, ?string $password = null, ?array $options = null): Database
    {
        $connection = md5(serialize(func_get_args()));

        if (!isset(static::$connections[$connection])) {
            static::$connections[$connection] = new static($dsn, $username, $password, $options);
        }

        return static::$connections[$connection];
    }

    /**
     * Returns the singleton instance of the `Database` class using credentials found in `{database}` config.
     *
     * @return static
     *
     * @codeCoverageIgnore This method is overridden (mocked) in tests.
     */
    public static function instance(): Database
    {
        $databaseConfig = Config::get('database', []);

        try {
            return static::connect(
                $databaseConfig['dsn'] ?? '',
                $databaseConfig['username'] ?? null,
                $databaseConfig['password'] ?? null,
                $databaseConfig['options'] ?? null
            );
        } catch (\PDOException $error) {
            // connection can't be established (incorrect config), return a fake instance
            return static::mock();
        }
    }

    /**
     * Returns FQN for a custom `PDOStatement` class.
     *
     * @return string
     */
    private function getStatementClass(): string
    {
        $statement = new class () extends \PDOStatement {
            // Makes method chaining a little bit more convenient.
            public function execute($params = null)
            {
                parent::execute($params);

                return $this;
            }
            // Catches the debug dump instead of printing it out directly.
            public function debugDumpParams()
            {
                ob_start();

                parent::debugDumpParams();

                $dump = ob_get_contents();
                ob_end_clean();

                return $dump;
            }
        };

        return get_class($statement);
    }

    /**
     * Adds caching capabilities for prepared statement.
     * {@inheritDoc}
     */
    public function prepare($query, $options = [])
    {
        $hash = md5($query);

        if (!isset($this->cache[$hash])) {
            $this->cache[$hash] = parent::prepare($query, $options);
        }

        return $this->cache[$hash];
    }

    /**
     * A wrapper method to perform a query on the fly using either `self::query()` or `self::prepare()` + `self::execute()`.
     *
     * @param string $query The query to execute.
     * @param array $params The parameters to bind to the query.
     *
     * @return \PDOStatement
     */
    public function perform(string $query, ?array $params = null): \PDOStatement
    {
        try {
            if (empty($params)) {
                return $this->query($query);
            }

            $statement = $this->prepare($query);
            $statement->execute($params);

            return $statement;
        } catch (\PDOException $error) {
            throw $error;
        }
    }

    /**
     * Serves as a wrapper method to execute some operations in transactional context with the ability to attempt retires.
     *
     * @param callable $callback The callback to execute inside the transaction. This callback will be bound to the `Database` class.
     * @param int $retries The number of times to attempt the transaction. Each retry will be delayed by 1-3 seconds.
     *
     * @return mixed The result of the callback.
     */
    public function transactional(callable $callback, int $retries = 3)
    {
        $callback = \Closure::fromCallable($callback)->bindTo($this);
        $attempts = 0;
        $return   = null;


        do {
            $this->beginTransaction();

            try {
                $return = $callback($this);

                $this->commit();

                break;
            } catch (\Throwable $error) {
                $this->rollBack();

                if (++$attempts === $retries) {
                    throw new \Exception(
                        "Could not complete the transaction after {$retries} attempt(s).",
                        (int)$error->getCode(),
                        $error
                    );
                }

                sleep(rand(1, 3));
            } finally {
                if ($this->inTransaction()) {
                    $this->rollBack();
                }
            }
        } while ($attempts < $retries);

        return $return;
    }

    /**
     * Returns a fake instance of the `Database` class.
     *
     * @return Database This instance will throw an exception if a method is called.
     *
     * @codeCoverageIgnore
     */
    private static function mock()
    {
        return new class () extends Database {
            // only methods that raise an error or throw an exception are overridden
            protected function __construct()
            {
                // constructor arguments are not used
            }
            public function exec($statement)
            {
                static::fail();
            }
            public function prepare($query, $options = [])
            {
                static::fail();
            }
            public function query($query, $fetchMode = null, ...$fetchModeArgs)
            {
                static::fail();
            }
            public function beginTransaction()
            {
                static::fail();
            }
            public function commit()
            {
                static::fail();
            }
            public function rollBack()
            {
                static::fail();
            }
            private static function fail(): void
            {
                throw new \Exception(
                    'The app is currently running using a fake database, all database related operations will fail. ' .
                    'Add valid database credentials using "config/database.php" to resolve this issue'
                );
            }
        };
    }
}


1		<?php
2
3		/**
4		* @author Marwan Al-Soltany <[email protected]>
5		* @copyright Marwan Al-Soltany 2021
6		* For the full copyright and license information, please view
7		* the LICENSE file that was distributed with this source code.
8		*/
9
10		declare(strict_types=1);
11
12		namespace MAKS\Velox\Backend;
13
14		/**
15		* A class that represents the database and handles database operations.
16		*
17		* Example:
18		* ```
19		* $database = Database::instance();
20		* $database->query('SELECT * FROM `users`');
21		* $database->prepare('SELECT * FROM `users` WHERE `job` = :job LIMIT 5')->execute([':job' => 'Developer'])->fetchAll();
22		* $database->perform('SELECT * FROM `users` WHERE `title` LIKE :title AND `id` > :id', ['title' => 'Dr.%', 'id' => 1])->fetchAll();
23		* ```
24		*
25		* @package Velox\Backend
26		* @since 1.3.0
27		* @api
28		*/
29		class Database extends \PDO
30		{
31		/**
32		* Current open database connections.
33		*/
34		protected static array $connections;
35
36		/**
37		* A cache to hold prepared statements.
38		*/
39		protected array $cache;
40
41		protected string $dsn;
42		protected ?string $username;
43		protected ?string $password;
44		protected ?array $options;
45
46
47		/**
48		* Class constructor.
49		*
50		* Adds some default options to the PDO connection.
51		*
52		* @param string $dsn
53		* @param string\|null $username
54		* @param string\|null $password
55		* @param array\|null $options
56		*/
57	3	protected function __construct(string $dsn, ?string $username = null, ?string $password = null, ?array $options = null)
58		{
59	3	$this->dsn = $dsn;
60	3	$this->username = $username;
61	3	$this->password = $password;
62	3	$this->options = $options;
63
64	3	$this->cache = [];
65
66	3	parent::__construct($dsn, $username, $password, $options);
67
68	3	$this->setAttribute(static::ATTR_ERRMODE, static::ERRMODE_EXCEPTION);
69	3	$this->setAttribute(static::ATTR_DEFAULT_FETCH_MODE, static::FETCH_ASSOC);
70	3	$this->setAttribute(static::ATTR_EMULATE_PREPARES, false);
71	3	$this->setAttribute(static::MYSQL_ATTR_FOUND_ROWS, true);
72	3	$this->setAttribute(static::ATTR_STATEMENT_CLASS, [$this->getStatementClass()]);
73	3	}
74
75
76		/**
77		* Returns a singleton instance of the `Database` class based on connection credentials.
78		* This method makes sure that a single connection is opened and reused for each connection credentials set (DSN, User, Password, ...).
79		*
80		* @param string\|null $dsn The DSN string.
81		* @param string\|null $username [optional] The database username.
82		* @param string\|null $password [optional] The database password.
83		* @param array\|null $options [optional] PDO options.
84		*
85		* @return static
86		*/
87	55	final public static function connect(string $dsn, ?string $username = null, ?string $password = null, ?array $options = null): Database
88		{
89	55	$connection = md5(serialize(func_get_args()));
90
91	55	if (!isset(static::$connections[$connection])) {
92	3	static::$connections[$connection] = new static($dsn, $username, $password, $options);
93		}
94
95	55	return static::$connections[$connection];
96		}
97
98		/**
99		* Returns the singleton instance of the `Database` class using credentials found in `{database}` config.
100		*
101		* @return static
102		*
103		* @codeCoverageIgnore This method is overridden (mocked) in tests.
104		*/
105		public static function instance(): Database
106		{
107		$databaseConfig = Config::get('database', []);
108
109		try {
110		return static::connect(
111		$databaseConfig['dsn'] ?? '',
112		$databaseConfig['username'] ?? null,
113		$databaseConfig['password'] ?? null,
114		$databaseConfig['options'] ?? null
115		);
116		} catch (\PDOException $error) {
117		// connection can't be established (incorrect config), return a fake instance
118		return static::mock();
119		}
120		}
121
122		/**
123		* Returns FQN for a custom `PDOStatement` class.
124		*
125		* @return string
126		*/
127	31	private function getStatementClass(): string
128		{
129	3	$statement = new class () extends \PDOStatement {
130		// Makes method chaining a little bit more convenient.
131		public function execute($params = null)
132		{
133	31	parent::execute($params);
134
135	31	return $this;
136		}
137		// Catches the debug dump instead of printing it out directly.
138		public function debugDumpParams()
139		{
140	1	ob_start();
141
142	1	parent::debugDumpParams();
143
144	1	$dump = ob_get_contents();
145	1	ob_end_clean();
146
147	1	return $dump;
148		}
149		};
150
151	3	return get_class($statement);
152		}
153
154		/**
155		* Adds caching capabilities for prepared statement.
156		* {@inheritDoc}
157		*/
158	31	public function prepare($query, $options = [])
159		{
160	31	$hash = md5($query);
161
162	31	if (!isset($this->cache[$hash])) {
163	14	$this->cache[$hash] = parent::prepare($query, $options);
164		}
165
166	31	return $this->cache[$hash];
167		}
168
169		/**
170		* A wrapper method to perform a query on the fly using either `self::query()` or `self::prepare()` + `self::execute()`.
171		*
172		* @param string $query The query to execute.
173		* @param array $params The parameters to bind to the query.
174		*
175		* @return \PDOStatement
176		*/
177	45	public function perform(string $query, ?array $params = null): \PDOStatement
178		{
179		try {
180	45	if (empty($params)) {
181	44	return $this->query($query);
182		}
183
184	31	$statement = $this->prepare($query);
185	31	$statement->execute($params);
186
187	31	return $statement;
188	2	} catch (\PDOException $error) {
189	2	throw $error;
190		}
191		}
192
193		/**
194		* Serves as a wrapper method to execute some operations in transactional context with the ability to attempt retires.
195		*
196		* @param callable $callback The callback to execute inside the transaction. This callback will be bound to the `Database` class.
197		* @param int $retries The number of times to attempt the transaction. Each retry will be delayed by 1-3 seconds.
198		*
199		* @return mixed The result of the callback.
200		*/
201	32	public function transactional(callable $callback, int $retries = 3)
202		{
203	32	$callback = \Closure::fromCallable($callback)->bindTo($this);
204	32	$attempts = 0;
205	32	$return = null;
		0 ignored issues – show Unused Code introduced 2021-09-29 15:34 UTC by Report Bug Copy Issue Report The assignment to `$return` is dead and can be removed. Loading history...
206
207		do {
208	32	$this->beginTransaction();
209
210		try {
211	32	$return = $callback($this);
212
213	31	$this->commit();
214
215	31	break;
216	1	} catch (\Throwable $error) {
217	1	$this->rollBack();
218
219	1	if (++$attempts === $retries) {
220	1	throw new \Exception(
221	1	"Could not complete the transaction after {$retries} attempt(s).",
222	1	(int)$error->getCode(),
223		$error
224		);
225		}
226
227	1	sleep(rand(1, 3));
228	1	} finally {
229	32	if ($this->inTransaction()) {
230	32	$this->rollBack();
231		}
232		}
233	1	} while ($attempts < $retries);
234
235	31	return $return;
236		}
237
238		/**
239		* Returns a fake instance of the `Database` class.
240		*
241		* @return Database This instance will throw an exception if a method is called.
242		*
243		* @codeCoverageIgnore
244		*/
245		private static function mock()
246		{
247		return new class () extends Database {
248		// only methods that raise an error or throw an exception are overridden
249		protected function __construct()
250		{
251		// constructor arguments are not used
252		}
253		public function exec($statement)
254		{
255		static::fail();
256		}
257		public function prepare($query, $options = [])
258		{
259		static::fail();
260		}
261		public function query($query, $fetchMode = null, ...$fetchModeArgs)
262		{
263		static::fail();
264		}
265		public function beginTransaction()
266		{
267		static::fail();
268		}
269		public function commit()
270		{
271		static::fail();
272		}
273		public function rollBack()
274		{
275		static::fail();
276		}
277		private static function fail(): void
278		{
279		throw new \Exception(
280		'The app is currently running using a fake database, all database related operations will fail. ' .
281		'Add valid database credentials using "config/database.php" to resolve this issue'
282		);
283		}
284		};
285		}
286		}
287

MarwanAlsoltany / velox

Push — master ( 48e2e4...58f05f )

anonymous//classes/Backend/Database.php$0 A

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