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Diffstat (limited to 'includes/db/DatabaseUtility.php')
| -rw-r--r-- | includes/db/DatabaseUtility.php | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/includes/db/DatabaseUtility.php b/includes/db/DatabaseUtility.php new file mode 100644 index 00000000..d1bced6b --- /dev/null +++ b/includes/db/DatabaseUtility.php @@ -0,0 +1,268 @@ +<?php +/** + * Utility class. + * @ingroup Database + */ +class DBObject { + public $mData; + + function __construct( $data ) { + $this->mData = $data; + } + + function isLOB() { + return false; + } + + function data() { + return $this->mData; + } +} + +/** + * Utility class + * @ingroup Database + * + * This allows us to distinguish a blob from a normal string and an array of strings + */ +class Blob { + private $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 $db, $result, $pos = 0, $currentRow = null; + + /** + * Create a new result object from a result resource and a Database object + * + * @param DatabaseBase $database + * @param resource $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 integer + */ + 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. + * + * @return object + * @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']. + * + * @return Array + * @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 $row integer + */ + 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; + } + + function current() { + if ( is_null( $this->currentRow ) ) { + $this->next(); + } + return $this->currentRow; + } + + function key() { + return $this->pos; + } + + function next() { + $this->pos++; + $this->currentRow = $this->fetchObject(); + return $this->currentRow; + } + + 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 $result = array(); + var $db = null; // And it's going to stay that way :D + var $pos = 0; + var $currentRow = null; + + function __construct( $array ) { + $this->result = $array; + } + + /** + * @return int + */ + function numRows() { + return count( $this->result ); + } + + function fetchRow() { + if ( $this->pos < count( $this->result ) ) { + $this->currentRow = $this->result[$this->pos]; + } else { + $this->currentRow = false; + } + $this->pos++; + return $this->currentRow; + } + + function seek( $row ) { + $this->pos = $row; + } + + function free() {} + + // Callers want to be able to access fields with $this->fieldName + function fetchObject() { + $this->fetchRow(); + if ( $this->currentRow ) { + return (object)$this->currentRow; + } else { + return false; + } + } + + function rewind() { + $this->pos = 0; + $this->currentRow = null; + } + + 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 { + 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. + */ +interface DBMasterPos { +} + |