sqlite-database-integration / wp-includes / sqlite-ast / class-wp-sqlite-configurator.php

class-wp-sqlite-configurator.php in SQLite Database Integration 2.2.3, at wp-includes/sqlite-ast/class-wp-sqlite-configurator.php

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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_SQLite_Driver
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_SQLite_Driver $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_SQLite_Driver $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	} catch ( Throwable $e ) {
85	$this->driver->execute_sqlite_query( 'ROLLBACK' );
86	throw $e;
87	}
88	$this->driver->execute_sqlite_query( 'COMMIT' );
89	}
90
91	/**
92	* Ensure that the global variables table exists.
93	*
94	* This method configures a database table to store MySQL global variables
95	* and other internal configuration values.
96	*/
97	private function ensure_global_variables_table(): void {
98	$this->driver->execute_sqlite_query(
99	sprintf(
100	'CREATE TABLE IF NOT EXISTS %s (name TEXT PRIMARY KEY, value TEXT)',
101	WP_SQLite_Driver::GLOBAL_VARIABLES_TABLE_NAME
102	)
103	);
104	}
105
106	/**
107	* Save the current SQLite driver version.
108	*
109	* This method saves the current SQLite driver version to the database.
110	*/
111	private function save_current_driver_version(): void {
112	$this->driver->execute_sqlite_query(
113	sprintf(
114	'INSERT INTO %s (name, value) VALUES (?, ?) ON CONFLICT(name) DO UPDATE SET value = ?',
115	WP_SQLite_Driver::GLOBAL_VARIABLES_TABLE_NAME
116	),
117	array(
118	WP_SQLite_Driver::DRIVER_VERSION_VARIABLE_NAME,
119	SQLITE_DRIVER_VERSION,
120	SQLITE_DRIVER_VERSION,
121	)
122	);
123	}
124	}
125