3 * Efficient concatenated text storage.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
23 use MediaWiki\MediaWikiServices
;
26 * Pointer object for an item within a CGZ blob stored in the text table.
28 class HistoryBlobStub
{
30 * @var array One-step cache variable to hold base blobs; operations that
31 * pull multiple revisions may often pull multiple times from the same
32 * blob. By keeping the last-used one open, we avoid redundant
33 * unserialization and decompression overhead.
35 protected static $blobCache = [];
47 * @param string $hash The content hash of the text
48 * @param int $oldid The old_id for the CGZ object
50 function __construct( $hash = '', $oldid = 0 ) {
55 * Sets the location (old_id) of the main object to which this object
59 function setLocation( $id ) {
64 * Sets the location (old_id) of the referring object
67 function setReferrer( $id ) {
72 * Gets the location of the referring object
75 function getReferrer() {
80 * @return string|false
83 if ( isset( self
::$blobCache[$this->mOldId
] ) ) {
84 $obj = self
::$blobCache[$this->mOldId
];
86 $dbr = wfGetDB( DB_REPLICA
);
87 $row = $dbr->selectRow(
89 [ 'old_flags', 'old_text' ],
90 [ 'old_id' => $this->mOldId
]
97 $flags = explode( ',', $row->old_flags
);
98 if ( in_array( 'external', $flags ) ) {
99 $url = $row->old_text
;
100 $parts = explode( '://', $url, 2 );
101 if ( !isset( $parts[1] ) ||
$parts[1] == '' ) {
104 $row->old_text
= MediaWikiServices
::getInstance()
105 ->getExternalStoreAccess()
106 ->fetchFromURL( $url );
109 if ( !in_array( 'object', $flags ) ) {
113 if ( in_array( 'gzip', $flags ) ) {
114 // This shouldn't happen, but a bug in the compress script
115 // may at times gzip-compress a HistoryBlob object row.
116 $obj = unserialize( gzinflate( $row->old_text
) );
118 $obj = unserialize( $row->old_text
);
121 if ( !is_object( $obj ) ) {
122 // Correct for old double-serialization bug.
123 $obj = unserialize( $obj );
126 // Save this item for reference; if pulling many
127 // items in a row we'll likely use it again.
129 self
::$blobCache = [ $this->mOldId
=> $obj ];
132 return $obj->getItem( $this->mHash
);
136 * Get the content hash
145 // phpcs:ignore Generic.CodeAnalysis.UnconditionalIfStatement.Found
147 // Blobs generated by MediaWiki < 1.5 on PHP 4 were serialized with the
148 // class name coerced to lowercase. We can improve efficiency by adding
149 // autoload entries for the lowercase variants of these classes (T166759).
150 // The code below is never executed, but it is picked up by the AutoloadGenerator
151 // parser, which scans for class_alias() calls.
152 class_alias( HistoryBlobStub
::class, 'historyblobstub' );