Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
| 1 | <?php  | 
            ||
| 11 | class MysqlAdapter extends AbstractAdapter implements AdapterInterface  | 
            ||
| 12 | { | 
            ||
| 13 | protected DatabaseManager $dbManager;  | 
            ||
| 
                                                                                                    
                        
                         | 
                |||
| 14 | protected string $tableName;  | 
            ||
| 15 | |||
| 16 | public function __construct(array $config = [])  | 
            ||
| 17 |     { | 
            ||
| 18 | $this->validateConnectionOptions($config);  | 
            ||
| 19 | $connectionOptions = $this->getConnectionOptions($config);  | 
            ||
| 20 | |||
| 21 |         if (isset($config['cache_not_found_keys'])) { | 
            ||
| 22 | $this->cacheNotFoundKeys = (bool) $config['cache_not_found_keys'];  | 
            ||
| 23 | }  | 
            ||
| 24 | |||
| 25 | $dbManager = new DatabaseManager();  | 
            ||
| 26 | $dbManager->addConnection(DatabaseManager::DRIVER_MYSQL, $connectionOptions);  | 
            ||
| 27 | |||
| 28 | $this->setDbManager($dbManager);  | 
            ||
| 29 | $this->setTableName($config['table_name']);  | 
            ||
| 30 | |||
| 31 | $this->checkTableCreated($config);  | 
            ||
| 32 | }  | 
            ||
| 33 | |||
| 34 | public function setDbManager(DatabaseManager $dbManager): void  | 
            ||
| 35 |     { | 
            ||
| 36 | $this->dbManager = $dbManager;  | 
            ||
| 37 | }  | 
            ||
| 38 | |||
| 39 | public function setTableName(string $tableName): void  | 
            ||
| 40 |     { | 
            ||
| 41 | $this->tableName = $tableName;  | 
            ||
| 42 | }  | 
            ||
| 43 | |||
| 44 | /**  | 
            ||
| 45 | * @return mixed  | 
            ||
| 46 | */  | 
            ||
| 47 | public function get(string $key)  | 
            ||
| 48 |     { | 
            ||
| 49 |         $sql = sprintf('SELECT `value` FROM `%s` WHERE `key` = :key LIMIT 1', $this->tableName); | 
            ||
| 50 | |||
| 51 | $results = $this->dbManager->fetchColumn($sql, ['key' => $this->addNamespaceToKey($key)], 0);  | 
            ||
| 52 | |||
| 53 |         if (!$results) { | 
            ||
| 54 | throw new KeyNotFoundException();  | 
            ||
| 55 | }  | 
            ||
| 56 | |||
| 57 | return $results[0];  | 
            ||
| 58 | }  | 
            ||
| 59 | |||
| 60 | public function getMulti(array $keys): array  | 
            ||
| 61 |     { | 
            ||
| 62 | $placeholders = array_fill(1, count($keys), '?');  | 
            ||
| 63 |         $sql = sprintf('SELECT `key`, `value` FROM `%s` WHERE `key` IN(%s)', $this->tableName, implode(',', $placeholders)); | 
            ||
| 64 | |||
| 65 | $namespacedKeys = $this->addNamespaceToKeys($keys);  | 
            ||
| 66 | $namespacedData = $this->dbManager->fetchKeyPairs($sql, $namespacedKeys);  | 
            ||
| 67 | |||
| 68 | return $this->removeNamespaceFromKeys($namespacedData);  | 
            ||
| 69 | }  | 
            ||
| 70 | |||
| 71 | /**  | 
            ||
| 72 | * @param mixed $value  | 
            ||
| 73 | */  | 
            ||
| 74 | public function set(string $key, $value): bool  | 
            ||
| 75 |     { | 
            ||
| 76 |         $sql = sprintf('INSERT INTO `%s` (`key`, `value`) VALUES(:key, :value) ON DUPLICATE KEY UPDATE `value` = VALUES(`value`)', $this->tableName); | 
            ||
| 77 | |||
| 78 | $this->dbManager->execute($sql, ['key' => $this->addNamespaceToKey($key), 'value' => $value]);  | 
            ||
| 79 | |||
| 80 | return true;  | 
            ||
| 81 | }  | 
            ||
| 82 | |||
| 83 | public function setMulti(array $data): bool  | 
            ||
| 84 |     { | 
            ||
| 85 | $placeholders = [];  | 
            ||
| 86 | $keyValues = [];  | 
            ||
| 87 |         foreach ($data as $key => $value) { | 
            ||
| 88 | $placeholders[] = '(?, ?)';  | 
            ||
| 89 | $keyValues[] = $this->addNamespaceToKey($key);  | 
            ||
| 90 | $keyValues[] = $value;  | 
            ||
| 91 | }  | 
            ||
| 92 | |||
| 93 | $sql = sprintf(  | 
            ||
| 94 | 'INSERT INTO `%s` (`key`, `value`) VALUES %s ON DUPLICATE KEY UPDATE `value` = VALUES(`value`)',  | 
            ||
| 95 | $this->tableName,  | 
            ||
| 96 |             implode(',', $placeholders) | 
            ||
| 97 | );  | 
            ||
| 98 | |||
| 99 | $this->dbManager->execute($sql, $keyValues);  | 
            ||
| 100 | |||
| 101 | return true;  | 
            ||
| 102 | }  | 
            ||
| 103 | |||
| 104 | public function contains(string $key): bool  | 
            ||
| 105 |     { | 
            ||
| 106 |         try { | 
            ||
| 107 | $this->get($key);  | 
            ||
| 108 |         } catch (KeyNotFoundException $e) { | 
            ||
| 109 | return false;  | 
            ||
| 110 | }  | 
            ||
| 111 | |||
| 112 | return true;  | 
            ||
| 113 | }  | 
            ||
| 114 | |||
| 115 | public function delete(string $key): bool  | 
            ||
| 116 |     { | 
            ||
| 117 |         $sql = sprintf('DELETE FROM `%s` WHERE `key` = :key', $this->tableName); | 
            ||
| 118 | |||
| 119 | $this->dbManager->execute($sql, ['key' => $this->addNamespaceToKey($key)]);  | 
            ||
| 120 | |||
| 121 | return true;  | 
            ||
| 122 | }  | 
            ||
| 123 | |||
| 124 | public function deleteMulti(array $keys): bool  | 
            ||
| 125 |     { | 
            ||
| 126 | $placeholders = array_fill(1, count($keys), '?');  | 
            ||
| 127 |         $sql = sprintf('DELETE FROM `%s` WHERE `key` IN (%s)', $this->tableName, implode(',', $placeholders)); | 
            ||
| 128 | |||
| 129 | $namespacedKeys = $this->addNamespaceToKeys($keys);  | 
            ||
| 130 | $this->dbManager->execute($sql, $namespacedKeys);  | 
            ||
| 131 | |||
| 132 | return true;  | 
            ||
| 133 | }  | 
            ||
| 134 | |||
| 135 | public function flush(): bool  | 
            ||
| 136 |     { | 
            ||
| 137 |         $sql = sprintf('DELETE FROM `%s`', $this->tableName); | 
            ||
| 138 | |||
| 139 | $this->dbManager->execute($sql);  | 
            ||
| 140 | |||
| 141 | return true;  | 
            ||
| 142 | }  | 
            ||
| 143 | |||
| 144 | /**  | 
            ||
| 145 | * @throws InvalidConfigurationException  | 
            ||
| 146 | */  | 
            ||
| 147 | protected function validateConnectionOptions(array $config): void  | 
            ||
| 148 |     { | 
            ||
| 149 |         if (!isset($config['host'])) { | 
            ||
| 150 |             throw new InvalidConfigurationException('Missing configuration parameter: host'); | 
            ||
| 151 | }  | 
            ||
| 152 | |||
| 153 |         if (!isset($config['port'])) { | 
            ||
| 154 |             throw new InvalidConfigurationException('Missing configuration parameter: port'); | 
            ||
| 155 | }  | 
            ||
| 156 | |||
| 157 |         if (!isset($config['dbname'])) { | 
            ||
| 158 |             throw new InvalidConfigurationException('Missing configuration parameter: dbname'); | 
            ||
| 159 | }  | 
            ||
| 160 | |||
| 161 |         if (!isset($config['username'])) { | 
            ||
| 162 |             throw new InvalidConfigurationException('Missing configuration parameter: username'); | 
            ||
| 163 | }  | 
            ||
| 164 | |||
| 165 |         if (!isset($config['password'])) { | 
            ||
| 166 |             throw new InvalidConfigurationException('Missing configuration parameter: password'); | 
            ||
| 167 | }  | 
            ||
| 168 | |||
| 169 |         if (!isset($config['table_name'])) { | 
            ||
| 170 |             throw new InvalidConfigurationException('Missing configuration parameter: table_name'); | 
            ||
| 171 | }  | 
            ||
| 172 | }  | 
            ||
| 173 | |||
| 174 | protected function checkTableCreated(array $config): void  | 
            ||
| 175 |     { | 
            ||
| 176 |         if (!isset($config['ensure_table_created'])) { | 
            ||
| 177 | $this->dbManager->execute(  | 
            ||
| 178 | 'CREATE TABLE IF NOT EXISTS `key_value` (`key` varchar(255) NOT NULL, `value` varchar(10000) DEFAULT NULL, PRIMARY KEY (`key`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;'  | 
            ||
| 179 | );  | 
            ||
| 180 | }  | 
            ||
| 181 | }  | 
            ||
| 182 | |||
| 183 | protected function getConnectionOptions(array $config): array  | 
            ||
| 184 |     { | 
            ||
| 185 | return [  | 
            ||
| 186 | 'host' => $config['host'],  | 
            ||
| 187 | 'port' => $config['port'],  | 
            ||
| 188 | 'dbname' => $config['dbname'],  | 
            ||
| 189 | 'username' => $config['username'],  | 
            ||
| 190 | 'password' => $config['password'],  | 
            ||
| 191 | ];  | 
            ||
| 194 |