includes/libs/rdbms/database/DatabaseDomain.php

   1 <?php
   2 /**
   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.
   7  *
   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.
  12  *
  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
  17  *
  18  * @file
  19  * @ingroup Database
  20  */
  21
  22 /**
  23  * Class to handle database/prefix specification for IDatabase domains
  24  */
  25 class DatabaseDomain {
  26         /** @var string|null */
  27         private $database;
  28         /** @var string|null */
  29         private $schema;
  30         /** @var string */
  31         private $prefix;
  32
  33         /** @var string Cache of convertToString() */
  34         private $equivalentString;
  35
  36         /**
  37          * @param string|null $database Database name
  38          * @param string|null $schema Schema name
  39          * @param string $prefix Table prefix
  40          */
  41         public function __construct( $database, $schema, $prefix ) {
  42                 if ( $database !== null && ( !is_string( $database ) || !strlen( $database ) ) ) {
  43                         throw new InvalidArgumentException( "Database must be null or a non-empty string." );
  44                 }
  45                 $this->database = $database;
  46                 if ( $schema !== null && ( !is_string( $schema ) || !strlen( $schema ) ) ) {
  47                         throw new InvalidArgumentException( "Schema must be null or a non-empty string." );
  48                 }
  49                 $this->schema = $schema;
  50                 if ( !is_string( $prefix ) ) {
  51                         throw new InvalidArgumentException( "Prefix must be a string." );
  52                 }
  53                 $this->prefix = $prefix;
  54                 $this->equivalentString = $this->convertToString();
  55         }
  56
  57         /**
  58          * @param DatabaseDomain|string $domain Result of DatabaseDomain::toString()
  59          * @return DatabaseDomain
  60          */
  61         public static function newFromId( $domain ) {
  62                 if ( $domain instanceof self ) {
  63                         return $domain;
  64                 }
  65
  66                 $parts = array_map( [ __CLASS__, 'decode' ], explode( '-', $domain ) );
  67
  68                 $schema = null;
  69                 $prefix = '';
  70
  71                 if ( count( $parts ) == 1 ) {
  72                         $database = $parts[0];
  73                 } elseif ( count( $parts ) == 2 ) {
  74                         list( $database, $prefix ) = $parts;
  75                 } elseif ( count( $parts ) == 3 ) {
  76                         list( $database, $schema, $prefix ) = $parts;
  77                 } else {
  78                         throw new InvalidArgumentException( "Domain has too few or too many parts." );
  79                 }
  80
  81                 if ( $database === '' ) {
  82                         $database = null;
  83                 }
  84
  85                 return new self( $database, $schema, $prefix );
  86         }
  87
  88         /**
  89          * @return DatabaseDomain
  90          */
  91         public static function newUnspecified() {
  92                 return new self( null, null, '' );
  93         }
  94
  95         /**
  96          * @param DatabaseDomain|string $other
  97          * @return bool
  98          */
  99         public function equals( $other ) {
 100                 if ( $other instanceof DatabaseDomain ) {
 101                         return (
 102                                 $this->database === $other->database &&
 103                                 $this->schema === $other->schema &&
 104                                 $this->prefix === $other->prefix
 105                         );
 106                 }
 107
 108                 return ( $this->equivalentString === $other );
 109         }
 110
 111         /**
 112          * @return string|null Database name
 113          */
 114         public function getDatabase() {
 115                 return $this->database;
 116         }
 117
 118         /**
 119          * @return string|null Database schema
 120          */
 121         public function getSchema() {
 122                 return $this->schema;
 123         }
 124
 125         /**
 126          * @return string Table prefix
 127          */
 128         public function getTablePrefix() {
 129                 return $this->prefix;
 130         }
 131
 132         /**
 133          * @return string
 134          */
 135         public function getId() {
 136                 return $this->equivalentString;
 137         }
 138
 139         /**
 140          * @return string
 141          */
 142         private function convertToString() {
 143                 $parts = [ $this->database ];
 144                 if ( $this->schema !== null ) {
 145                         $parts[] = $this->schema;
 146                 }
 147                 if ( $this->prefix != '' ) {
 148                         $parts[] = $this->prefix;
 149                 }
 150
 151                 return implode( '-', array_map( [ __CLASS__, 'encode' ], $parts ) );
 152         }
 153
 154         private static function encode( $decoded ) {
 155                 $encoded = '';
 156
 157                 $length = strlen( $decoded );
 158                 for ( $i = 0; $i < $length; ++$i ) {
 159                         $char = $decoded[$i];
 160                         if ( $char === '-' ) {
 161                                 $encoded .= '?h';
 162                         } elseif ( $char === '?' ) {
 163                                 $encoded .= '??';
 164                         } else {
 165                                 $encoded .= $char;
 166                         }
 167                 }
 168
 169                 return $encoded;
 170         }
 171
 172         private static function decode( $encoded ) {
 173                 $decoded = '';
 174
 175                 $length = strlen( $encoded );
 176                 for ( $i = 0; $i < $length; ++$i ) {
 177                         $char = $encoded[$i];
 178                         if ( $char === '?' ) {
 179                                 $nextChar = isset( $encoded[$i + 1] ) ? $encoded[$i + 1] : null;
 180                                 if ( $nextChar === 'h' ) {
 181                                         $decoded .= '-';
 182                                         ++$i;
 183                                 } elseif ( $nextChar === '?' ) {
 184                                         $decoded .= '?';
 185                                         ++$i;
 186                                 } else {
 187                                         $decoded .= $char;
 188                                 }
 189                         } else {
 190                                 $decoded .= $char;
 191                         }
 192                 }
 193
 194                 return $decoded;
 195         }
 196
 197         /**
 198          * @return string
 199          */
 200         function __toString() {
 201                 return $this->getId();
 202         }
 203 }