includes/libs/rdbms/database/IMaintainableDatabase.php

   1 <?php
   2
   3 /**
   4  * This file deals with database interface functions
   5  * and query specifics/optimisations.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  20  * http://www.gnu.org/copyleft/gpl.html
  21  *
  22  * @file
  23  * @ingroup Database
  24  */
  25
  26 /**
  27  * Advanced database interface for IDatabase handles that include maintenance methods
  28  *
  29  * This is useful for type-hints used by installer, upgrader, and background scripts
  30  * that will make use of lower-level and longer-running queries, including schema changes.
  31  *
  32  * @ingroup Database
  33  * @since 1.28
  34  */
  35 interface IMaintainableDatabase extends IDatabase {
  36         /**
  37          * Format a table name ready for use in constructing an SQL query
  38          *
  39          * This does two important things: it quotes the table names to clean them up,
  40          * and it adds a table prefix if only given a table name with no quotes.
  41          *
  42          * All functions of this object which require a table name call this function
  43          * themselves. Pass the canonical name to such functions. This is only needed
  44          * when calling query() directly.
  45          *
  46          * @note This function does not sanitize user input. It is not safe to use
  47          *   this function to escape user input.
  48          * @param string $name Database table name
  49          * @param string $format One of:
  50          *   quoted - Automatically pass the table name through addIdentifierQuotes()
  51          *            so that it can be used in a query.
  52          *   raw - Do not add identifier quotes to the table name
  53          * @return string Full database name
  54          */
  55         public function tableName( $name, $format = 'quoted' );
  56
  57         /**
  58          * Fetch a number of table names into an array
  59          * This is handy when you need to construct SQL for joins
  60          *
  61          * Example:
  62          * extract( $dbr->tableNames( 'user', 'watchlist' ) );
  63          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
  64          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
  65          *
  66          * @return array
  67          */
  68         public function tableNames();
  69
  70         /**
  71          * Fetch a number of table names into an zero-indexed numerical array
  72          * This is handy when you need to construct SQL for joins
  73          *
  74          * Example:
  75          * list( $user, $watchlist ) = $dbr->tableNamesN( 'user', 'watchlist' );
  76          * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
  77          *         WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
  78          *
  79          * @return array
  80          */
  81         public function tableNamesN();
  82
  83         /**
  84          * Returns the size of a text field, or -1 for "unlimited"
  85          *
  86          * @param string $table
  87          * @param string $field
  88          * @return int
  89          */
  90         public function textFieldSize( $table, $field );
  91
  92         /**
  93          * Read and execute SQL commands from a file.
  94          *
  95          * Returns true on success, error string or exception on failure (depending
  96          * on object's error ignore settings).
  97          *
  98          * @param string $filename File name to open
  99          * @param callable|null $lineCallback Optional function called before reading each line
 100          * @param callable|null $resultCallback Optional function called for each MySQL result
 101          * @param bool|string $fname Calling function name or false if name should be
 102          *   generated dynamically using $filename
 103          * @param callable|null $inputCallback Optional function called for each
 104          *   complete line sent
 105          * @return bool|string
 106          * @throws Exception
 107          */
 108         public function sourceFile(
 109                 $filename,
 110                 callable $lineCallback = null,
 111                 callable $resultCallback = null,
 112                 $fname = false,
 113                 callable $inputCallback = null
 114         );
 115
 116         /**
 117          * Read and execute commands from an open file handle.
 118          *
 119          * Returns true on success, error string or exception on failure (depending
 120          * on object's error ignore settings).
 121          *
 122          * @param resource $fp File handle
 123          * @param callable|null $lineCallback Optional function called before reading each query
 124          * @param callable|null $resultCallback Optional function called for each MySQL result
 125          * @param string $fname Calling function name
 126          * @param callable|null $inputCallback Optional function called for each complete query sent
 127          * @return bool|string
 128          */
 129         public function sourceStream(
 130                 $fp,
 131                 callable $lineCallback = null,
 132                 callable $resultCallback = null,
 133                 $fname = __METHOD__,
 134                 callable $inputCallback = null
 135         );
 136
 137         /**
 138          * Called by sourceStream() to check if we've reached a statement end
 139          *
 140          * @param string &$sql SQL assembled so far
 141          * @param string &$newLine New line about to be added to $sql
 142          * @return bool Whether $newLine contains end of the statement
 143          */
 144         public function streamStatementEnd( &$sql, &$newLine );
 145
 146         /**
 147          * Delete a table
 148          * @param string $tableName
 149          * @param string $fName
 150          * @return bool|ResultWrapper
 151          */
 152         public function dropTable( $tableName, $fName = __METHOD__ );
 153
 154         /**
 155          * Perform a deadlock-prone transaction.
 156          *
 157          * This function invokes a callback function to perform a set of write
 158          * queries. If a deadlock occurs during the processing, the transaction
 159          * will be rolled back and the callback function will be called again.
 160          *
 161          * Avoid using this method outside of Job or Maintenance classes.
 162          *
 163          * Usage:
 164          *   $dbw->deadlockLoop( callback, ... );
 165          *
 166          * Extra arguments are passed through to the specified callback function.
 167          * This method requires that no transactions are already active to avoid
 168          * causing premature commits or exceptions.
 169          *
 170          * Returns whatever the callback function returned on its successful,
 171          * iteration, or false on error, for example if the retry limit was
 172          * reached.
 173          *
 174          * @return mixed
 175          * @throws DBUnexpectedError
 176          * @throws Exception
 177          */
 178         public function deadlockLoop();
 179
 180         /**
 181          * Lists all the VIEWs in the database
 182          *
 183          * @param string $prefix Only show VIEWs with this prefix, eg. unit_test_
 184          * @param string $fname Name of calling function
 185          * @throws RuntimeException
 186          * @return array
 187          */
 188         public function listViews( $prefix = null, $fname = __METHOD__ );
 189 }