Current File : //www/varak.net/wiki.varak.net/includes/db/DatabaseUtility.php
<?php
/**
* This file contains database-related utility classes.
*
* 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 Database
*/
/**
* Utility class
* @ingroup Database
*
* This allows us to distinguish a blob from a normal string and an array of strings
*/
class Blob {
/** @var string */
protected $mData;
function __construct( $data ) {
$this->mData = $data;
}
function fetch() {
return $this->mData;
}
}
/**
* Base for all database-specific classes representing information about database fields
* @ingroup Database
*/
interface Field {
/**
* Field name
* @return string
*/
function name();
/**
* Name of table this field belongs to
* @return string
*/
function tableName();
/**
* Database type
* @return string
*/
function type();
/**
* Whether this field can store NULL values
* @return bool
*/
function isNullable();
}
/**
* Result wrapper for grabbing data queried by someone else
* @ingroup Database
*/
class ResultWrapper implements Iterator {
/** @var resource */
public $result;
/** @var DatabaseBase */
protected $db;
/** @var int */
protected $pos = 0;
/** @var object|null */
protected $currentRow = null;
/**
* Create a new result object from a result resource and a Database object
*
* @param DatabaseBase $database
* @param resource|ResultWrapper $result
*/
function __construct( $database, $result ) {
$this->db = $database;
if ( $result instanceof ResultWrapper ) {
$this->result = $result->result;
} else {
$this->result = $result;
}
}
/**
* Get the number of rows in a result object
*
* @return int
*/
function numRows() {
return $this->db->numRows( $this );
}
/**
* Fetch the next row from the given result object, in object form. Fields can be retrieved with
* $row->fieldname, with fields acting like member variables. If no more rows are available,
* false is returned.
*
* @return stdClass|bool
* @throws DBUnexpectedError Thrown if the database returns an error
*/
function fetchObject() {
return $this->db->fetchObject( $this );
}
/**
* Fetch the next row from the given result object, in associative array form. Fields are
* retrieved with $row['fieldname']. If no more rows are available, false is returned.
*
* @return array|bool
* @throws DBUnexpectedError Thrown if the database returns an error
*/
function fetchRow() {
return $this->db->fetchRow( $this );
}
/**
* Free a result object
*/
function free() {
$this->db->freeResult( $this );
unset( $this->result );
unset( $this->db );
}
/**
* Change the position of the cursor in a result object.
* See mysql_data_seek()
*
* @param int $row
*/
function seek( $row ) {
$this->db->dataSeek( $this, $row );
}
/*
* ======= Iterator functions =======
* Note that using these in combination with the non-iterator functions
* above may cause rows to be skipped or repeated.
*/
function rewind() {
if ( $this->numRows() ) {
$this->db->dataSeek( $this, 0 );
}
$this->pos = 0;
$this->currentRow = null;
}
/**
* @return stdClass|array|bool
*/
function current() {
if ( is_null( $this->currentRow ) ) {
$this->next();
}
return $this->currentRow;
}
/**
* @return int
*/
function key() {
return $this->pos;
}
/**
* @return stdClass
*/
function next() {
$this->pos++;
$this->currentRow = $this->fetchObject();
return $this->currentRow;
}
/**
* @return bool
*/
function valid() {
return $this->current() !== false;
}
}
/**
* Overloads the relevant methods of the real ResultsWrapper so it
* doesn't go anywhere near an actual database.
*/
class FakeResultWrapper extends ResultWrapper {
/** @var array */
public $result = [];
/** @var null And it's going to stay that way :D */
protected $db = null;
/** @var int */
protected $pos = 0;
/** @var array|stdClass|bool */
protected $currentRow = null;
/**
* @param array $array
*/
function __construct( $array ) {
$this->result = $array;
}
/**
* @return int
*/
function numRows() {
return count( $this->result );
}
/**
* @return array|bool
*/
function fetchRow() {
if ( $this->pos < count( $this->result ) ) {
$this->currentRow = $this->result[$this->pos];
} else {
$this->currentRow = false;
}
$this->pos++;
if ( is_object( $this->currentRow ) ) {
return get_object_vars( $this->currentRow );
} else {
return $this->currentRow;
}
}
function seek( $row ) {
$this->pos = $row;
}
function free() {
}
/**
* Callers want to be able to access fields with $this->fieldName
* @return bool|stdClass
*/
function fetchObject() {
$this->fetchRow();
if ( $this->currentRow ) {
return (object)$this->currentRow;
} else {
return false;
}
}
function rewind() {
$this->pos = 0;
$this->currentRow = null;
}
/**
* @return bool|stdClass
*/
function next() {
return $this->fetchObject();
}
}
/**
* Used by DatabaseBase::buildLike() to represent characters that have special
* meaning in SQL LIKE clauses and thus need no escaping. Don't instantiate it
* manually, use DatabaseBase::anyChar() and anyString() instead.
*/
class LikeMatch {
/** @var string */
private $str;
/**
* Store a string into a LikeMatch marker object.
*
* @param string $s
*/
public function __construct( $s ) {
$this->str = $s;
}
/**
* Return the original stored string.
*
* @return string
*/
public function toString() {
return $this->str;
}
}
/**
* An object representing a master or slave position in a replicated setup.
*
* The implementation details of this opaque type are up to the database subclass.
*/
interface DBMasterPos {
/**
* @return float UNIX timestamp
* @since 1.25
*/
public function asOfTime();
/**
* @param DBMasterPos $pos
* @return bool Whether this position is at or higher than $pos
* @since 1.27
*/
public function hasReached( DBMasterPos $pos );
/**
* @param DBMasterPos $pos
* @return bool Whether this position appears to be for the same channel as another
* @since 1.27
*/
public function channelsMatch( DBMasterPos $pos );
/**
* @return string
* @since 1.27
*/
public function __toString();
}
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