Current File : /www/varak.net/wiki.varak.net/includes/filebackend/filejournal/FileJournal.php
<?php
/**
* @defgroup FileJournal File journal
* @ingroup FileBackend
*/
/**
* File operation journaling.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @ingroup FileJournal
* @author Aaron Schulz
*/
/**
* @brief Class for handling file operation journaling.
*
* Subclasses should avoid throwing exceptions at all costs.
*
* @ingroup FileJournal
* @since 1.20
*/
abstract class FileJournal {
/** @var string */
protected $backend;
/** @var int */
protected $ttlDays;
/**
* Construct a new instance from configuration.
*
* @param array $config Includes:
* 'ttlDays' : days to keep log entries around (false means "forever")
*/
protected function __construct( array $config ) {
$this->ttlDays = isset( $config['ttlDays'] ) ? $config['ttlDays'] : false;
}
/**
* Create an appropriate FileJournal object from config
*
* @param array $config
* @param string $backend A registered file backend name
* @throws Exception
* @return FileJournal
*/
final public static function factory( array $config, $backend ) {
$class = $config['class'];
$jrn = new $class( $config );
if ( !$jrn instanceof self ) {
throw new Exception( "Class given is not an instance of FileJournal." );
}
$jrn->backend = $backend;
return $jrn;
}
/**
* Get a statistically unique ID string
*
* @return string <9 char TS_MW timestamp in base 36><22 random base 36 chars>
*/
final public function getTimestampedUUID() {
$s = '';
for ( $i = 0; $i < 5; $i++ ) {
$s .= mt_rand( 0, 2147483647 );
}
$s = Wikimedia\base_convert( sha1( $s ), 16, 36, 31 );
return substr( Wikimedia\base_convert( wfTimestamp( TS_MW ), 10, 36, 9 ) . $s, 0, 31 );
}
/**
* Log changes made by a batch file operation.
*
* @param array $entries List of file operations (each an array of parameters) which contain:
* op : Basic operation name (create, update, delete)
* path : The storage path of the file
* newSha1 : The final base 36 SHA-1 of the file
* Note that 'false' should be used as the SHA-1 for non-existing files.
* @param string $batchId UUID string that identifies the operation batch
* @return Status
*/
final public function logChangeBatch( array $entries, $batchId ) {
if ( !count( $entries ) ) {
return Status::newGood();
}
return $this->doLogChangeBatch( $entries, $batchId );
}
/**
* @see FileJournal::logChangeBatch()
*
* @param array $entries List of file operations (each an array of parameters)
* @param string $batchId UUID string that identifies the operation batch
* @return Status
*/
abstract protected function doLogChangeBatch( array $entries, $batchId );
/**
* Get the position ID of the latest journal entry
*
* @return int|bool
*/
final public function getCurrentPosition() {
return $this->doGetCurrentPosition();
}
/**
* @see FileJournal::getCurrentPosition()
* @return int|bool
*/
abstract protected function doGetCurrentPosition();
/**
* Get the position ID of the latest journal entry at some point in time
*
* @param int|string $time Timestamp
* @return int|bool
*/
final public function getPositionAtTime( $time ) {
return $this->doGetPositionAtTime( $time );
}
/**
* @see FileJournal::getPositionAtTime()
* @param int|string $time Timestamp
* @return int|bool
*/
abstract protected function doGetPositionAtTime( $time );
/**
* Get an array of file change log entries.
* A starting change ID and/or limit can be specified.
*
* @param int $start Starting change ID or null
* @param int $limit Maximum number of items to return
* @param string &$next Updated to the ID of the next entry.
* @return array List of associative arrays, each having:
* id : unique, monotonic, ID for this change
* batch_uuid : UUID for an operation batch
* backend : the backend name
* op : primitive operation (create,update,delete,null)
* path : affected storage path
* new_sha1 : base 36 sha1 of the new file had the operation succeeded
* timestamp : TS_MW timestamp of the batch change
* Also, $next is updated to the ID of the next entry.
*/
final public function getChangeEntries( $start = null, $limit = 0, &$next = null ) {
$entries = $this->doGetChangeEntries( $start, $limit ? $limit + 1 : 0 );
if ( $limit && count( $entries ) > $limit ) {
$last = array_pop( $entries ); // remove the extra entry
$next = $last['id']; // update for next call
} else {
$next = null; // end of list
}
return $entries;
}
/**
* @see FileJournal::getChangeEntries()
* @param int $start
* @param int $limit
* @return array
*/
abstract protected function doGetChangeEntries( $start, $limit );
/**
* Purge any old log entries
*
* @return Status
*/
final public function purgeOldLogs() {
return $this->doPurgeOldLogs();
}
/**
* @see FileJournal::purgeOldLogs()
* @return Status
*/
abstract protected function doPurgeOldLogs();
}
/**
* Simple version of FileJournal that does nothing
* @since 1.20
*/
class NullFileJournal extends FileJournal {
/**
* @see FileJournal::doLogChangeBatch()
* @param array $entries
* @param string $batchId
* @return Status
*/
protected function doLogChangeBatch( array $entries, $batchId ) {
return Status::newGood();
}
/**
* @see FileJournal::doGetCurrentPosition()
* @return int|bool
*/
protected function doGetCurrentPosition() {
return false;
}
/**
* @see FileJournal::doGetPositionAtTime()
* @param int|string $time Timestamp
* @return int|bool
*/
protected function doGetPositionAtTime( $time ) {
return false;
}
/**
* @see FileJournal::doGetChangeEntries()
* @param int $start
* @param int $limit
* @return array
*/
protected function doGetChangeEntries( $start, $limit ) {
return [];
}
/**
* @see FileJournal::doPurgeOldLogs()
* @return Status
*/
protected function doPurgeOldLogs() {
return Status::newGood();
}
}
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