3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
16 * http://www.gnu.org/copyleft/gpl.html
21 namespace Wikimedia\Rdbms
;
23 use InvalidArgumentException
;
26 * Class to handle database/prefix specification for IDatabase domains
28 class DatabaseDomain
{
29 /** @var string|null */
31 /** @var string|null */
36 /** @var string Cache of convertToString() */
37 private $equivalentString;
40 * @param string|null $database Database name
41 * @param string|null $schema Schema name
42 * @param string $prefix Table prefix
44 public function __construct( $database, $schema, $prefix ) {
45 if ( $database !== null && ( !is_string( $database ) ||
$database === '' ) ) {
46 throw new InvalidArgumentException( 'Database must be null or a non-empty string.' );
48 $this->database
= $database;
49 if ( $schema !== null && ( !is_string( $schema ) ||
$schema === '' ) ) {
50 throw new InvalidArgumentException( 'Schema must be null or a non-empty string.' );
51 } elseif ( $database === null && $schema !== null ) {
52 throw new InvalidArgumentException( 'Schema must be null if database is null.' );
54 $this->schema
= $schema;
55 if ( !is_string( $prefix ) ) {
56 throw new InvalidArgumentException( 'Prefix must be a string.' );
57 } elseif ( $prefix !== '' && substr( $prefix, -1, 1 ) !== '_' ) {
58 throw new InvalidArgumentException( 'A non-empty prefix must end with "_".' );
60 $this->prefix
= $prefix;
64 * @param DatabaseDomain|string $domain Result of DatabaseDomain::toString()
65 * @return DatabaseDomain
67 public static function newFromId( $domain ) {
68 if ( $domain instanceof self
) {
72 $parts = array_map( [ __CLASS__
, 'decode' ], explode( '-', $domain ) );
77 if ( count( $parts ) == 1 ) {
78 $database = $parts[0];
79 } elseif ( count( $parts ) == 2 ) {
80 list( $database, $prefix ) = $parts;
81 } elseif ( count( $parts ) == 3 ) {
82 list( $database, $schema, $prefix ) = $parts;
84 throw new InvalidArgumentException( "Domain '$domain' has too few or too many parts." );
87 if ( $database === '' ) {
91 if ( $schema === '' ) {
95 return new self( $database, $schema, $prefix );
99 * @return DatabaseDomain
101 public static function newUnspecified() {
102 return new self( null, null, '' );
106 * @param DatabaseDomain|string $other
107 * @return bool Whether the domain instances are the same by value
109 public function equals( $other ) {
110 if ( $other instanceof self
) {
112 $this->database
=== $other->database
&&
113 $this->schema
=== $other->schema
&&
114 $this->prefix
=== $other->prefix
118 return ( $this->getId() === $other );
122 * Check whether the domain $other meets the specifications of this domain
124 * If this instance has a null database specifier, then $other can have any database
125 * specifier, including null. This is likewise true if the schema specifier is null.
126 * This is not transitive like equals() since a domain that explicitly wants a certain
127 * database or schema cannot be satisfied by one of another (nor null). If the prefix
128 * is empty and the DB and schema are both null, then the entire domain is considered
129 * unspecified, and any prefix of $other is considered compatible.
131 * @param DatabaseDomain|string $other
135 public function isCompatible( $other ) {
136 if ( $this->isUnspecified() ) {
137 return true; // even the prefix doesn't matter
140 $other = self
::newFromId( $other );
143 ( $this->database
=== $other->database ||
$this->database
=== null ) &&
144 ( $this->schema
=== $other->schema ||
$this->schema
=== null ) &&
145 $this->prefix
=== $other->prefix
153 public function isUnspecified() {
155 $this->database
=== null && $this->schema
=== null && $this->prefix
=== ''
160 * @return string|null Database name
162 public function getDatabase() {
163 return $this->database
;
167 * @return string|null Database schema
169 public function getSchema() {
170 return $this->schema
;
174 * @return string Table prefix
176 public function getTablePrefix() {
177 return $this->prefix
;
183 public function getId() {
184 if ( $this->equivalentString
=== null ) {
185 $this->equivalentString
= $this->convertToString();
188 return $this->equivalentString
;
194 private function convertToString() {
195 $parts = [ (string)$this->database
];
196 if ( $this->schema
!== null ) {
197 $parts[] = $this->schema
;
199 if ( $this->prefix
!= '' ||
$this->schema
!== null ) {
200 // If there is a schema, then we need the prefix to disambiguate.
201 // For engines like Postgres that use schemas, this awkwardness is hopefully
202 // avoided since it is easy to have one DB per server (to avoid having many users)
203 // and use schema/prefix to have wiki farms. For example, a domain schemes could be
204 // wiki-<project>-<language>, e.g. "wiki-fitness-es"/"wiki-sports-fr"/"wiki-news-en".
205 $parts[] = $this->prefix
;
208 return implode( '-', array_map( [ __CLASS__
, 'encode' ], $parts ) );
211 private static function encode( $decoded ) {
214 $length = strlen( $decoded );
215 for ( $i = 0; $i < $length; ++
$i ) {
216 $char = $decoded[$i];
217 if ( $char === '-' ) {
219 } elseif ( $char === '?' ) {
229 private static function decode( $encoded ) {
232 $length = strlen( $encoded );
233 for ( $i = 0; $i < $length; ++
$i ) {
234 $char = $encoded[$i];
235 if ( $char === '?' ) {
236 $nextChar = $encoded[$i +
1] ??
null;
237 if ( $nextChar === 'h' ) {
240 } elseif ( $nextChar === '?' ) {
257 function __toString() {
258 return $this->getId();