| 1 |
<?php |
| 2 |
|
| 3 |
/** |
| 4 |
* SQLite database configurator. |
| 5 |
* |
| 6 |
* This class initializes and configures the SQLite database, so that it can be |
| 7 |
* used by the SQLite driver to translate and emulate MySQL queries in SQLite. |
| 8 |
* |
| 9 |
* The configurator ensures that tables required for emulating MySQL behaviors |
| 10 |
* are created and populated with necessary data. It is also able to partially |
| 11 |
* repair and update these tables and metadata in case of database corruption. |
| 12 |
*/ |
| 13 |
class WP_SQLite_Configurator { |
| 14 |
/** |
| 15 |
* The SQLite driver instance. |
| 16 |
* |
| 17 |
* @var WP_PDO_MySQL_On_SQLite |
| 18 |
*/ |
| 19 |
private $driver; |
| 20 |
|
| 21 |
/** |
| 22 |
* A service for managing MySQL INFORMATION_SCHEMA tables in SQLite. |
| 23 |
* |
| 24 |
* @var WP_SQLite_Information_Schema_Builder |
| 25 |
*/ |
| 26 |
private $schema_builder; |
| 27 |
|
| 28 |
/** |
| 29 |
* A service for reconstructing the MySQL INFORMATION_SCHEMA tables in SQLite. |
| 30 |
* |
| 31 |
* @var WP_SQLite_Information_Schema_Reconstructor |
| 32 |
*/ |
| 33 |
private $schema_reconstructor; |
| 34 |
|
| 35 |
/** |
| 36 |
* Constructor. |
| 37 |
* |
| 38 |
* @param WP_PDO_MySQL_On_SQLite $driver The SQLite driver instance. |
| 39 |
* @param WP_SQLite_Information_Schema_Builder $schema_builder The information schema builder instance. |
| 40 |
*/ |
| 41 |
public function __construct( |
| 42 |
WP_PDO_MySQL_On_SQLite $driver, |
| 43 |
WP_SQLite_Information_Schema_Builder $schema_builder |
| 44 |
) { |
| 45 |
$this->driver = $driver; |
| 46 |
$this->schema_builder = $schema_builder; |
| 47 |
$this->schema_reconstructor = new WP_SQLite_Information_Schema_Reconstructor( |
| 48 |
$driver, |
| 49 |
$schema_builder |
| 50 |
); |
| 51 |
} |
| 52 |
|
| 53 |
/** |
| 54 |
* Ensure that the SQLite database is configured. |
| 55 |
* |
| 56 |
* This method checks if the database is configured for the latest SQLite |
| 57 |
* driver version, and if it is not, it will configure the database. |
| 58 |
*/ |
| 59 |
public function ensure_database_configured(): void { |
| 60 |
$version = SQLITE_DRIVER_VERSION; |
| 61 |
$db_version = $this->driver->get_saved_driver_version(); |
| 62 |
if ( version_compare( $version, $db_version ) > 0 ) { |
| 63 |
$this->configure_database(); |
| 64 |
} |
| 65 |
} |
| 66 |
|
| 67 |
/** |
| 68 |
* Configure the SQLite database. |
| 69 |
* |
| 70 |
* This method creates tables used for emulating MySQL behaviors in SQLite, |
| 71 |
* and populates them with necessary data. When it is used with an already |
| 72 |
* configured database, it will update the configuration as per the current |
| 73 |
* SQLite driver version and attempt to repair any configuration corruption. |
| 74 |
*/ |
| 75 |
public function configure_database(): void { |
| 76 |
// Use an EXCLUSIVE transaction to prevent multiple connections |
| 77 |
// from attempting to configure the database at the same time. |
| 78 |
$this->driver->execute_sqlite_query( 'BEGIN EXCLUSIVE TRANSACTION' ); |
| 79 |
try { |
| 80 |
$this->ensure_global_variables_table(); |
| 81 |
$this->schema_builder->ensure_information_schema_tables(); |
| 82 |
$this->schema_reconstructor->ensure_correct_information_schema(); |
| 83 |
$this->save_current_driver_version(); |
| 84 |
$this->ensure_database_data(); |
| 85 |
} catch ( Throwable $e ) { |
| 86 |
$this->driver->execute_sqlite_query( 'ROLLBACK' ); |
| 87 |
throw $e; |
| 88 |
} |
| 89 |
$this->driver->execute_sqlite_query( 'COMMIT' ); |
| 90 |
} |
| 91 |
|
| 92 |
/** |
| 93 |
* Ensure that the global variables table exists. |
| 94 |
* |
| 95 |
* This method configures a database table to store MySQL global variables |
| 96 |
* and other internal configuration values. |
| 97 |
*/ |
| 98 |
private function ensure_global_variables_table(): void { |
| 99 |
$this->driver->execute_sqlite_query( |
| 100 |
sprintf( |
| 101 |
'CREATE TABLE IF NOT EXISTS %s (name TEXT PRIMARY KEY, value TEXT)', |
| 102 |
$this->driver->get_connection()->quote_identifier( |
| 103 |
WP_PDO_MySQL_On_SQLite::GLOBAL_VARIABLES_TABLE_NAME |
| 104 |
) |
| 105 |
) |
| 106 |
); |
| 107 |
} |
| 108 |
|
| 109 |
/** |
| 110 |
* Ensure that the database data is correctly populated. |
| 111 |
* |
| 112 |
* This method ensures that the "INFORMATION_SCHEMA.SCHEMATA" table contains |
| 113 |
* records for both the "INFORMATION_SCHEMA" database and the user database. |
| 114 |
* At the moment, only a single user database is supported. |
| 115 |
* |
| 116 |
* Additionally, this method ensures that the user database name is stored |
| 117 |
* correctly in all the information schema tables. |
| 118 |
*/ |
| 119 |
public function ensure_database_data(): void { |
| 120 |
// Get all databases from the "SCHEMATA" table. |
| 121 |
$schemata_table = $this->schema_builder->get_table_name( false, 'schemata' ); |
| 122 |
$databases = $this->driver->execute_sqlite_query( |
| 123 |
sprintf( |
| 124 |
'SELECT SCHEMA_NAME FROM %s', |
| 125 |
$this->driver->get_connection()->quote_identifier( $schemata_table ) |
| 126 |
) |
| 127 |
)->fetchAll( PDO::FETCH_COLUMN ); // phpcs:disable WordPress.DB.RestrictedClasses.mysql__PDO |
| 128 |
|
| 129 |
// Ensure that the "INFORMATION_SCHEMA" database record exists. |
| 130 |
if ( ! in_array( 'information_schema', $databases, true ) ) { |
| 131 |
$this->driver->execute_sqlite_query( |
| 132 |
sprintf( |
| 133 |
'INSERT INTO %s (SCHEMA_NAME, DEFAULT_CHARACTER_SET_NAME, DEFAULT_COLLATION_NAME) VALUES (?, ?, ?)', |
| 134 |
$this->driver->get_connection()->quote_identifier( $schemata_table ) |
| 135 |
), |
| 136 |
// The "INFORMATION_SCHEMA" database stays on "utf8mb3" even in MySQL 8 and 9. |
| 137 |
array( 'information_schema', 'utf8mb3', 'utf8mb3_general_ci' ) |
| 138 |
); |
| 139 |
} |
| 140 |
|
| 141 |
// Get the existing user database name. |
| 142 |
$existing_user_db_name = null; |
| 143 |
foreach ( $databases as $database ) { |
| 144 |
if ( 'information_schema' !== strtolower( $database ) ) { |
| 145 |
$existing_user_db_name = $database; |
| 146 |
break; |
| 147 |
} |
| 148 |
} |
| 149 |
|
| 150 |
// Ensure that the user database record exists. |
| 151 |
if ( null === $existing_user_db_name ) { |
| 152 |
$existing_user_db_name = WP_SQLite_Information_Schema_Builder::SAVED_DATABASE_NAME; |
| 153 |
$this->driver->execute_sqlite_query( |
| 154 |
sprintf( |
| 155 |
'INSERT INTO %s (SCHEMA_NAME, DEFAULT_CHARACTER_SET_NAME, DEFAULT_COLLATION_NAME) VALUES (?, ?, ?)', |
| 156 |
$this->driver->get_connection()->quote_identifier( $schemata_table ) |
| 157 |
), |
| 158 |
// @TODO: This should probably be version-dependent. |
| 159 |
// Before MySQL 8, the default was different. |
| 160 |
array( $existing_user_db_name, 'utf8mb4', 'utf8mb4_0900_ai_ci' ) |
| 161 |
); |
| 162 |
} |
| 163 |
|
| 164 |
// Migrate from older versions without dynamic database names. |
| 165 |
$saved_database_name = WP_SQLite_Information_Schema_Builder::SAVED_DATABASE_NAME; |
| 166 |
if ( $saved_database_name !== $existing_user_db_name ) { |
| 167 |
// INFORMATION_SCHEMA.SCHEMATA |
| 168 |
$this->driver->execute_sqlite_query( |
| 169 |
sprintf( |
| 170 |
"UPDATE %s SET SCHEMA_NAME = ? WHERE SCHEMA_NAME != 'information_schema'", |
| 171 |
$this->driver->get_connection()->quote_identifier( $schemata_table ) |
| 172 |
), |
| 173 |
array( $saved_database_name ) |
| 174 |
); |
| 175 |
|
| 176 |
// INFORMATION_SCHEMA.TABLES |
| 177 |
$tables_table = $this->schema_builder->get_table_name( false, 'tables' ); |
| 178 |
$this->driver->execute_sqlite_query( |
| 179 |
sprintf( |
| 180 |
"UPDATE %s SET TABLE_SCHEMA = ? WHERE TABLE_SCHEMA != 'information_schema'", |
| 181 |
$this->driver->get_connection()->quote_identifier( $tables_table ) |
| 182 |
), |
| 183 |
array( $saved_database_name ) |
| 184 |
); |
| 185 |
|
| 186 |
// INFORMATION_SCHEMA.COLUMNS |
| 187 |
$columns_table = $this->schema_builder->get_table_name( false, 'columns' ); |
| 188 |
$this->driver->execute_sqlite_query( |
| 189 |
sprintf( |
| 190 |
"UPDATE %s SET TABLE_SCHEMA = ? WHERE TABLE_SCHEMA != 'information_schema'", |
| 191 |
$this->driver->get_connection()->quote_identifier( $columns_table ) |
| 192 |
), |
| 193 |
array( $saved_database_name ) |
| 194 |
); |
| 195 |
|
| 196 |
// INFORMATION_SCHEMA.STATISTICS |
| 197 |
$statistics_table = $this->schema_builder->get_table_name( false, 'statistics' ); |
| 198 |
$this->driver->execute_sqlite_query( |
| 199 |
sprintf( |
| 200 |
"UPDATE %s SET TABLE_SCHEMA = ?, INDEX_SCHEMA = ? WHERE TABLE_SCHEMA != 'information_schema'", |
| 201 |
$this->driver->get_connection()->quote_identifier( $statistics_table ) |
| 202 |
), |
| 203 |
array( $saved_database_name, $saved_database_name ) |
| 204 |
); |
| 205 |
|
| 206 |
// INFORMATION_SCHEMA.TABLE_CONSTRAINTS |
| 207 |
$table_constraints_table = $this->schema_builder->get_table_name( false, 'table_constraints' ); |
| 208 |
$this->driver->execute_sqlite_query( |
| 209 |
sprintf( |
| 210 |
"UPDATE %s SET TABLE_SCHEMA = ?, CONSTRAINT_SCHEMA = ? WHERE TABLE_SCHEMA != 'information_schema'", |
| 211 |
$this->driver->get_connection()->quote_identifier( $table_constraints_table ) |
| 212 |
), |
| 213 |
array( $saved_database_name, $saved_database_name ) |
| 214 |
); |
| 215 |
|
| 216 |
// INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS |
| 217 |
$referential_constraints_table = $this->schema_builder->get_table_name( false, 'referential_constraints' ); |
| 218 |
$this->driver->execute_sqlite_query( |
| 219 |
sprintf( |
| 220 |
"UPDATE %s SET CONSTRAINT_SCHEMA = ?, UNIQUE_CONSTRAINT_SCHEMA = ? WHERE CONSTRAINT_SCHEMA != 'information_schema'", |
| 221 |
$this->driver->get_connection()->quote_identifier( $referential_constraints_table ) |
| 222 |
), |
| 223 |
array( $saved_database_name, $saved_database_name ) |
| 224 |
); |
| 225 |
|
| 226 |
// INFORMATION_SCHEMA.KEY_COLUMN_USAGE |
| 227 |
$key_column_usage_table = $this->schema_builder->get_table_name( false, 'key_column_usage' ); |
| 228 |
$this->driver->execute_sqlite_query( |
| 229 |
sprintf( |
| 230 |
"UPDATE %s |
| 231 |
SET |
| 232 |
TABLE_SCHEMA = ?, |
| 233 |
CONSTRAINT_SCHEMA = ?, |
| 234 |
REFERENCED_TABLE_SCHEMA = CASE WHEN REFERENCED_TABLE_SCHEMA IS NULL THEN NULL ELSE ? END |
| 235 |
WHERE TABLE_SCHEMA != 'information_schema'", |
| 236 |
$this->driver->get_connection()->quote_identifier( $key_column_usage_table ) |
| 237 |
), |
| 238 |
array( $saved_database_name, $saved_database_name, $saved_database_name ) |
| 239 |
); |
| 240 |
|
| 241 |
// INFORMATION_SCHEMA.CHECK_CONSTRAINTS |
| 242 |
$check_constraints_table = $this->schema_builder->get_table_name( false, 'check_constraints' ); |
| 243 |
$this->driver->execute_sqlite_query( |
| 244 |
sprintf( |
| 245 |
"UPDATE %s SET CONSTRAINT_SCHEMA = ? WHERE CONSTRAINT_SCHEMA != 'information_schema'", |
| 246 |
$this->driver->get_connection()->quote_identifier( $check_constraints_table ) |
| 247 |
), |
| 248 |
array( $saved_database_name ) |
| 249 |
); |
| 250 |
} |
| 251 |
} |
| 252 |
|
| 253 |
/** |
| 254 |
* Save the current SQLite driver version. |
| 255 |
* |
| 256 |
* This method saves the current SQLite driver version to the database. |
| 257 |
*/ |
| 258 |
private function save_current_driver_version(): void { |
| 259 |
$this->driver->execute_sqlite_query( |
| 260 |
sprintf( |
| 261 |
'INSERT INTO %s (name, value) VALUES (?, ?) ON CONFLICT(name) DO UPDATE SET value = ?', |
| 262 |
$this->driver->get_connection()->quote_identifier( |
| 263 |
WP_PDO_MySQL_On_SQLite::GLOBAL_VARIABLES_TABLE_NAME |
| 264 |
) |
| 265 |
), |
| 266 |
array( |
| 267 |
WP_PDO_MySQL_On_SQLite::DRIVER_VERSION_VARIABLE_NAME, |
| 268 |
SQLITE_DRIVER_VERSION, |
| 269 |
SQLITE_DRIVER_VERSION, |
| 270 |
) |
| 271 |
); |
| 272 |
} |
| 273 |
} |
| 274 |
|
