'ICacheHelper' => __DIR__ . '/includes/cache/CacheHelper.php',
'IContextSource' => __DIR__ . '/includes/context/IContextSource.php',
'IDBAccessObject' => __DIR__ . '/includes/dao/IDBAccessObject.php',
- 'IDatabase' => __DIR__ . '/includes/db/IDatabase.php',
+ 'IDatabase' => __DIR__ . '/includes/libs/rdbms/database/IDatabase.php',
'IEContentAnalyzer' => __DIR__ . '/includes/libs/IEContentAnalyzer.php',
'IEUrlExtension' => __DIR__ . '/includes/libs/IEUrlExtension.php',
'IExpiringStore' => __DIR__ . '/includes/libs/objectcache/IExpiringStore.php',
'IJobSpecification' => __DIR__ . '/includes/jobqueue/JobSpecification.php',
- 'ILoadBalancer' => __DIR__ . '/includes/db/loadbalancer/ILoadBalancer.php',
+ 'ILoadBalancer' => __DIR__ . '/includes/libs/rdbms/loadbalancer/ILoadBalancer.php',
'IP' => __DIR__ . '/includes/utils/IP.php',
'IPSet' => __DIR__ . '/includes/compat/IPSetCompat.php',
'IPTC' => __DIR__ . '/includes/media/IPTC.php',
+++ /dev/null
-<?php
-
-/**
- * @defgroup Database Database
- *
- * This file deals with database interface functions
- * and query specifics/optimisations.
- *
- * 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
- */
-
-/**
- * Basic database interface for live and lazy-loaded DB handles
- *
- * @note: IDatabase and DBConnRef should be updated to reflect any changes
- * @ingroup Database
- */
-interface IDatabase {
- /** @var int Callback triggered immediately due to no active transaction */
- const TRIGGER_IDLE = 1;
- /** @var int Callback triggered by COMMIT */
- const TRIGGER_COMMIT = 2;
- /** @var int Callback triggered by ROLLBACK */
- const TRIGGER_ROLLBACK = 3;
-
- /** @var string Transaction is requested by regular caller outside of the DB layer */
- const TRANSACTION_EXPLICIT = '';
- /** @var string Transaction is requested internally via DBO_TRX/startAtomic() */
- const TRANSACTION_INTERNAL = 'implicit';
-
- /** @var string Transaction operation comes from service managing all DBs */
- const FLUSHING_ALL_PEERS = 'flush';
- /** @var string Transaction operation comes from the database class internally */
- const FLUSHING_INTERNAL = 'flush';
-
- /** @var string Do not remember the prior flags */
- const REMEMBER_NOTHING = '';
- /** @var string Remember the prior flags */
- const REMEMBER_PRIOR = 'remember';
- /** @var string Restore to the prior flag state */
- const RESTORE_PRIOR = 'prior';
- /** @var string Restore to the initial flag state */
- const RESTORE_INITIAL = 'initial';
-
- /** @var string Estimate total time (RTT, scanning, waiting on locks, applying) */
- const ESTIMATE_TOTAL = 'total';
- /** @var string Estimate time to apply (scanning, applying) */
- const ESTIMATE_DB_APPLY = 'apply';
-
- /**
- * A string describing the current software version, and possibly
- * other details in a user-friendly way. Will be listed on Special:Version, etc.
- * Use getServerVersion() to get machine-friendly information.
- *
- * @return string Version information from the database server
- */
- public function getServerInfo();
-
- /**
- * Turns buffering of SQL result sets on (true) or off (false). Default is
- * "on".
- *
- * Unbuffered queries are very troublesome in MySQL:
- *
- * - If another query is executed while the first query is being read
- * out, the first query is killed. This means you can't call normal
- * MediaWiki functions while you are reading an unbuffered query result
- * from a normal wfGetDB() connection.
- *
- * - Unbuffered queries cause the MySQL server to use large amounts of
- * memory and to hold broad locks which block other queries.
- *
- * If you want to limit client-side memory, it's almost always better to
- * split up queries into batches using a LIMIT clause than to switch off
- * buffering.
- *
- * @param null|bool $buffer
- * @return null|bool The previous value of the flag
- */
- public function bufferResults( $buffer = null );
-
- /**
- * Gets the current transaction level.
- *
- * Historically, transactions were allowed to be "nested". This is no
- * longer supported, so this function really only returns a boolean.
- *
- * @return int The previous value
- */
- public function trxLevel();
-
- /**
- * Get the UNIX timestamp of the time that the transaction was established
- *
- * This can be used to reason about the staleness of SELECT data
- * in REPEATABLE-READ transaction isolation level.
- *
- * @return float|null Returns null if there is not active transaction
- * @since 1.25
- */
- public function trxTimestamp();
-
- /**
- * @return bool Whether an explicit transaction or atomic sections are still open
- * @since 1.28
- */
- public function explicitTrxActive();
-
- /**
- * Get/set the table prefix.
- * @param string $prefix The table prefix to set, or omitted to leave it unchanged.
- * @return string The previous table prefix.
- */
- public function tablePrefix( $prefix = null );
-
- /**
- * Get/set the db schema.
- * @param string $schema The database schema to set, or omitted to leave it unchanged.
- * @return string The previous db schema.
- */
- public function dbSchema( $schema = null );
-
- /**
- * Get properties passed down from the server info array of the load
- * balancer.
- *
- * @param string $name The entry of the info array to get, or null to get the
- * whole array
- *
- * @return array|mixed|null
- */
- public function getLBInfo( $name = null );
-
- /**
- * Set the LB info array, or a member of it. If called with one parameter,
- * the LB info array is set to that parameter. If it is called with two
- * parameters, the member with the given name is set to the given value.
- *
- * @param string $name
- * @param array $value
- */
- public function setLBInfo( $name, $value = null );
-
- /**
- * Returns true if this database does an implicit sort when doing GROUP BY
- *
- * @return bool
- */
- public function implicitGroupby();
-
- /**
- * Returns true if this database does an implicit order by when the column has an index
- * For example: SELECT page_title FROM page LIMIT 1
- *
- * @return bool
- */
- public function implicitOrderby();
-
- /**
- * Return the last query that went through IDatabase::query()
- * @return string
- */
- public function lastQuery();
-
- /**
- * Returns true if the connection may have been used for write queries.
- * Should return true if unsure.
- *
- * @return bool
- */
- public function doneWrites();
-
- /**
- * Returns the last time the connection may have been used for write queries.
- * Should return a timestamp if unsure.
- *
- * @return int|float UNIX timestamp or false
- * @since 1.24
- */
- public function lastDoneWrites();
-
- /**
- * @return bool Whether there is a transaction open with possible write queries
- * @since 1.27
- */
- public function writesPending();
-
- /**
- * Returns true if there is a transaction open with possible write
- * queries or transaction pre-commit/idle callbacks waiting on it to finish.
- * This does *not* count recurring callbacks, e.g. from setTransactionListener().
- *
- * @return bool
- */
- public function writesOrCallbacksPending();
-
- /**
- * Get the time spend running write queries for this transaction
- *
- * High times could be due to scanning, updates, locking, and such
- *
- * @param string $type IDatabase::ESTIMATE_* constant [default: ESTIMATE_ALL]
- * @return float|bool Returns false if not transaction is active
- * @since 1.26
- */
- public function pendingWriteQueryDuration( $type = self::ESTIMATE_TOTAL );
-
- /**
- * Get the list of method names that did write queries for this transaction
- *
- * @return array
- * @since 1.27
- */
- public function pendingWriteCallers();
-
- /**
- * Is a connection to the database open?
- * @return bool
- */
- public function isOpen();
-
- /**
- * Set a flag for this connection
- *
- * @param int $flag DBO_* constants from Defines.php:
- * - DBO_DEBUG: output some debug info (same as debug())
- * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
- * - DBO_TRX: automatically start transactions
- * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
- * and removes it in command line mode
- * - DBO_PERSISTENT: use persistant database connection
- * @param string $remember IDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]
- */
- public function setFlag( $flag, $remember = self::REMEMBER_NOTHING );
-
- /**
- * Clear a flag for this connection
- *
- * @param int $flag DBO_* constants from Defines.php:
- * - DBO_DEBUG: output some debug info (same as debug())
- * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
- * - DBO_TRX: automatically start transactions
- * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
- * and removes it in command line mode
- * - DBO_PERSISTENT: use persistant database connection
- * @param string $remember IDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]
- */
- public function clearFlag( $flag, $remember = self::REMEMBER_NOTHING );
-
- /**
- * Restore the flags to their prior state before the last setFlag/clearFlag call
- *
- * @param string $state IDatabase::RESTORE_* constant. [default: RESTORE_PRIOR]
- * @since 1.28
- */
- public function restoreFlags( $state = self::RESTORE_PRIOR );
-
- /**
- * Returns a boolean whether the flag $flag is set for this connection
- *
- * @param int $flag DBO_* constants from Defines.php:
- * - DBO_DEBUG: output some debug info (same as debug())
- * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
- * - DBO_TRX: automatically start transactions
- * - DBO_PERSISTENT: use persistant database connection
- * @return bool
- */
- public function getFlag( $flag );
-
- /**
- * General read-only accessor
- *
- * @param string $name
- * @return string
- */
- public function getProperty( $name );
-
- /**
- * @return string
- */
- public function getWikiID();
-
- /**
- * Get the type of the DBMS, as it appears in $wgDBtype.
- *
- * @return string
- */
- public function getType();
-
- /**
- * Open a connection to the database. Usually aborts on failure
- *
- * @param string $server Database server host
- * @param string $user Database user name
- * @param string $password Database user password
- * @param string $dbName Database name
- * @return bool
- * @throws DBConnectionError
- */
- public function open( $server, $user, $password, $dbName );
-
- /**
- * 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.
- *
- * @param ResultWrapper|stdClass $res Object as returned from IDatabase::query(), etc.
- * @return stdClass|bool
- * @throws DBUnexpectedError Thrown if the database returns an error
- */
- public function fetchObject( $res );
-
- /**
- * 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.
- *
- * @param ResultWrapper $res Result object as returned from IDatabase::query(), etc.
- * @return array|bool
- * @throws DBUnexpectedError Thrown if the database returns an error
- */
- public function fetchRow( $res );
-
- /**
- * Get the number of rows in a result object
- *
- * @param mixed $res A SQL result
- * @return int
- */
- public function numRows( $res );
-
- /**
- * Get the number of fields in a result object
- * @see http://www.php.net/mysql_num_fields
- *
- * @param mixed $res A SQL result
- * @return int
- */
- public function numFields( $res );
-
- /**
- * Get a field name in a result object
- * @see http://www.php.net/mysql_field_name
- *
- * @param mixed $res A SQL result
- * @param int $n
- * @return string
- */
- public function fieldName( $res, $n );
-
- /**
- * Get the inserted value of an auto-increment row
- *
- * The value inserted should be fetched from nextSequenceValue()
- *
- * Example:
- * $id = $dbw->nextSequenceValue( 'page_page_id_seq' );
- * $dbw->insert( 'page', [ 'page_id' => $id ] );
- * $id = $dbw->insertId();
- *
- * @return int
- */
- public function insertId();
-
- /**
- * Change the position of the cursor in a result object
- * @see http://www.php.net/mysql_data_seek
- *
- * @param mixed $res A SQL result
- * @param int $row
- */
- public function dataSeek( $res, $row );
-
- /**
- * Get the last error number
- * @see http://www.php.net/mysql_errno
- *
- * @return int
- */
- public function lastErrno();
-
- /**
- * Get a description of the last error
- * @see http://www.php.net/mysql_error
- *
- * @return string
- */
- public function lastError();
-
- /**
- * mysql_fetch_field() wrapper
- * Returns false if the field doesn't exist
- *
- * @param string $table Table name
- * @param string $field Field name
- *
- * @return Field
- */
- public function fieldInfo( $table, $field );
-
- /**
- * Get the number of rows affected by the last write query
- * @see http://www.php.net/mysql_affected_rows
- *
- * @return int
- */
- public function affectedRows();
-
- /**
- * Returns a wikitext link to the DB's website, e.g.,
- * return "[http://www.mysql.com/ MySQL]";
- * Should at least contain plain text, if for some reason
- * your database has no website.
- *
- * @return string Wikitext of a link to the server software's web site
- */
- public function getSoftwareLink();
-
- /**
- * A string describing the current software version, like from
- * mysql_get_server_info().
- *
- * @return string Version information from the database server.
- */
- public function getServerVersion();
-
- /**
- * Closes a database connection.
- * if it is open : commits any open transactions
- *
- * @throws MWException
- * @return bool Operation success. true if already closed.
- */
- public function close();
-
- /**
- * @param string $error Fallback error message, used if none is given by DB
- * @throws DBConnectionError
- */
- public function reportConnectionError( $error = 'Unknown error' );
-
- /**
- * Run an SQL query and return the result. Normally throws a DBQueryError
- * on failure. If errors are ignored, returns false instead.
- *
- * In new code, the query wrappers select(), insert(), update(), delete(),
- * etc. should be used where possible, since they give much better DBMS
- * independence and automatically quote or validate user input in a variety
- * of contexts. This function is generally only useful for queries which are
- * explicitly DBMS-dependent and are unsupported by the query wrappers, such
- * as CREATE TABLE.
- *
- * However, the query wrappers themselves should call this function.
- *
- * @param string $sql SQL query
- * @param string $fname Name of the calling function, for profiling/SHOW PROCESSLIST
- * comment (you can use __METHOD__ or add some extra info)
- * @param bool $tempIgnore Whether to avoid throwing an exception on errors...
- * maybe best to catch the exception instead?
- * @throws MWException
- * @return bool|ResultWrapper True for a successful write query, ResultWrapper object
- * for a successful read query, or false on failure if $tempIgnore set
- */
- public function query( $sql, $fname = __METHOD__, $tempIgnore = false );
-
- /**
- * Report a query error. Log the error, and if neither the object ignore
- * flag nor the $tempIgnore flag is set, throw a DBQueryError.
- *
- * @param string $error
- * @param int $errno
- * @param string $sql
- * @param string $fname
- * @param bool $tempIgnore
- * @throws DBQueryError
- */
- public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false );
-
- /**
- * Free a result object returned by query() or select(). It's usually not
- * necessary to call this, just use unset() or let the variable holding
- * the result object go out of scope.
- *
- * @param mixed $res A SQL result
- */
- public function freeResult( $res );
-
- /**
- * A SELECT wrapper which returns a single field from a single result row.
- *
- * Usually throws a DBQueryError on failure. If errors are explicitly
- * ignored, returns false on failure.
- *
- * If no result rows are returned from the query, false is returned.
- *
- * @param string|array $table Table name. See IDatabase::select() for details.
- * @param string $var The field name to select. This must be a valid SQL
- * fragment: do not use unvalidated user input.
- * @param string|array $cond The condition array. See IDatabase::select() for details.
- * @param string $fname The function name of the caller.
- * @param string|array $options The query options. See IDatabase::select() for details.
- *
- * @return bool|mixed The value from the field, or false on failure.
- */
- public function selectField(
- $table, $var, $cond = '', $fname = __METHOD__, $options = []
- );
-
- /**
- * A SELECT wrapper which returns a list of single field values from result rows.
- *
- * Usually throws a DBQueryError on failure. If errors are explicitly
- * ignored, returns false on failure.
- *
- * If no result rows are returned from the query, false is returned.
- *
- * @param string|array $table Table name. See IDatabase::select() for details.
- * @param string $var The field name to select. This must be a valid SQL
- * fragment: do not use unvalidated user input.
- * @param string|array $cond The condition array. See IDatabase::select() for details.
- * @param string $fname The function name of the caller.
- * @param string|array $options The query options. See IDatabase::select() for details.
- *
- * @return bool|array The values from the field, or false on failure
- * @since 1.25
- */
- public function selectFieldValues(
- $table, $var, $cond = '', $fname = __METHOD__, $options = []
- );
-
- /**
- * Execute a SELECT query constructed using the various parameters provided.
- * See below for full details of the parameters.
- *
- * @param string|array $table Table name
- * @param string|array $vars Field names
- * @param string|array $conds Conditions
- * @param string $fname Caller function name
- * @param array $options Query options
- * @param array $join_conds Join conditions
- *
- *
- * @param string|array $table
- *
- * May be either an array of table names, or a single string holding a table
- * name. If an array is given, table aliases can be specified, for example:
- *
- * [ 'a' => 'user' ]
- *
- * This includes the user table in the query, with the alias "a" available
- * for use in field names (e.g. a.user_name).
- *
- * All of the table names given here are automatically run through
- * DatabaseBase::tableName(), which causes the table prefix (if any) to be
- * added, and various other table name mappings to be performed.
- *
- * Do not use untrusted user input as a table name. Alias names should
- * not have characters outside of the Basic multilingual plane.
- *
- * @param string|array $vars
- *
- * May be either a field name or an array of field names. The field names
- * can be complete fragments of SQL, for direct inclusion into the SELECT
- * query. If an array is given, field aliases can be specified, for example:
- *
- * [ 'maxrev' => 'MAX(rev_id)' ]
- *
- * This includes an expression with the alias "maxrev" in the query.
- *
- * If an expression is given, care must be taken to ensure that it is
- * DBMS-independent.
- *
- * Untrusted user input must not be passed to this parameter.
- *
- * @param string|array $conds
- *
- * May be either a string containing a single condition, or an array of
- * conditions. If an array is given, the conditions constructed from each
- * element are combined with AND.
- *
- * Array elements may take one of two forms:
- *
- * - Elements with a numeric key are interpreted as raw SQL fragments.
- * - Elements with a string key are interpreted as equality conditions,
- * where the key is the field name.
- * - If the value of such an array element is a scalar (such as a
- * string), it will be treated as data and thus quoted appropriately.
- * If it is null, an IS NULL clause will be added.
- * - If the value is an array, an IN (...) clause will be constructed
- * from its non-null elements, and an IS NULL clause will be added
- * if null is present, such that the field may match any of the
- * elements in the array. The non-null elements will be quoted.
- *
- * Note that expressions are often DBMS-dependent in their syntax.
- * DBMS-independent wrappers are provided for constructing several types of
- * expression commonly used in condition queries. See:
- * - IDatabase::buildLike()
- * - IDatabase::conditional()
- *
- * Untrusted user input is safe in the values of string keys, however untrusted
- * input must not be used in the array key names or in the values of numeric keys.
- * Escaping of untrusted input used in values of numeric keys should be done via
- * IDatabase::addQuotes()
- *
- * @param string|array $options
- *
- * Optional: Array of query options. Boolean options are specified by
- * including them in the array as a string value with a numeric key, for
- * example:
- *
- * [ 'FOR UPDATE' ]
- *
- * The supported options are:
- *
- * - OFFSET: Skip this many rows at the start of the result set. OFFSET
- * with LIMIT can theoretically be used for paging through a result set,
- * but this is discouraged in MediaWiki for performance reasons.
- *
- * - LIMIT: Integer: return at most this many rows. The rows are sorted
- * and then the first rows are taken until the limit is reached. LIMIT
- * is applied to a result set after OFFSET.
- *
- * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
- * changed until the next COMMIT.
- *
- * - DISTINCT: Boolean: return only unique result rows.
- *
- * - GROUP BY: May be either an SQL fragment string naming a field or
- * expression to group by, or an array of such SQL fragments.
- *
- * - HAVING: May be either an string containing a HAVING clause or an array of
- * conditions building the HAVING clause. If an array is given, the conditions
- * constructed from each element are combined with AND.
- *
- * - ORDER BY: May be either an SQL fragment giving a field name or
- * expression to order by, or an array of such SQL fragments.
- *
- * - USE INDEX: This may be either a string giving the index name to use
- * for the query, or an array. If it is an associative array, each key
- * gives the table name (or alias), each value gives the index name to
- * use for that table. All strings are SQL fragments and so should be
- * validated by the caller.
- *
- * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
- * instead of SELECT.
- *
- * And also the following boolean MySQL extensions, see the MySQL manual
- * for documentation:
- *
- * - LOCK IN SHARE MODE
- * - STRAIGHT_JOIN
- * - HIGH_PRIORITY
- * - SQL_BIG_RESULT
- * - SQL_BUFFER_RESULT
- * - SQL_SMALL_RESULT
- * - SQL_CALC_FOUND_ROWS
- * - SQL_CACHE
- * - SQL_NO_CACHE
- *
- *
- * @param string|array $join_conds
- *
- * Optional associative array of table-specific join conditions. In the
- * most common case, this is unnecessary, since the join condition can be
- * in $conds. However, it is useful for doing a LEFT JOIN.
- *
- * The key of the array contains the table name or alias. The value is an
- * array with two elements, numbered 0 and 1. The first gives the type of
- * join, the second is the same as the $conds parameter. Thus it can be
- * an SQL fragment, or an array where the string keys are equality and the
- * numeric keys are SQL fragments all AND'd together. For example:
- *
- * [ 'page' => [ 'LEFT JOIN', 'page_latest=rev_id' ] ]
- *
- * @return ResultWrapper|bool If the query returned no rows, a ResultWrapper
- * with no rows in it will be returned. If there was a query error, a
- * DBQueryError exception will be thrown, except if the "ignore errors"
- * option was set, in which case false will be returned.
- */
- public function select(
- $table, $vars, $conds = '', $fname = __METHOD__,
- $options = [], $join_conds = []
- );
-
- /**
- * The equivalent of IDatabase::select() except that the constructed SQL
- * is returned, instead of being immediately executed. This can be useful for
- * doing UNION queries, where the SQL text of each query is needed. In general,
- * however, callers outside of Database classes should just use select().
- *
- * @param string|array $table Table name
- * @param string|array $vars Field names
- * @param string|array $conds Conditions
- * @param string $fname Caller function name
- * @param string|array $options Query options
- * @param string|array $join_conds Join conditions
- *
- * @return string SQL query string.
- * @see IDatabase::select()
- */
- public function selectSQLText(
- $table, $vars, $conds = '', $fname = __METHOD__,
- $options = [], $join_conds = []
- );
-
- /**
- * Single row SELECT wrapper. Equivalent to IDatabase::select(), except
- * that a single row object is returned. If the query returns no rows,
- * false is returned.
- *
- * @param string|array $table Table name
- * @param string|array $vars Field names
- * @param array $conds Conditions
- * @param string $fname Caller function name
- * @param string|array $options Query options
- * @param array|string $join_conds Join conditions
- *
- * @return stdClass|bool
- */
- public function selectRow( $table, $vars, $conds, $fname = __METHOD__,
- $options = [], $join_conds = []
- );
-
- /**
- * Estimate the number of rows in dataset
- *
- * MySQL allows you to estimate the number of rows that would be returned
- * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
- * index cardinality statistics, and is notoriously inaccurate, especially
- * when large numbers of rows have recently been added or deleted.
- *
- * For DBMSs that don't support fast result size estimation, this function
- * will actually perform the SELECT COUNT(*).
- *
- * Takes the same arguments as IDatabase::select().
- *
- * @param string $table Table name
- * @param string $vars Unused
- * @param array|string $conds Filters on the table
- * @param string $fname Function name for profiling
- * @param array $options Options for select
- * @return int Row count
- */
- public function estimateRowCount(
- $table, $vars = '*', $conds = '', $fname = __METHOD__, $options = []
- );
-
- /**
- * Get the number of rows in dataset
- *
- * This is useful when trying to do COUNT(*) but with a LIMIT for performance.
- *
- * Takes the same arguments as IDatabase::select().
- *
- * @since 1.27 Added $join_conds parameter
- *
- * @param array|string $tables Table names
- * @param string $vars Unused
- * @param array|string $conds Filters on the table
- * @param string $fname Function name for profiling
- * @param array $options Options for select
- * @param array $join_conds Join conditions (since 1.27)
- * @return int Row count
- */
- public function selectRowCount(
- $tables, $vars = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
- );
-
- /**
- * Determines whether a field exists in a table
- *
- * @param string $table Table name
- * @param string $field Filed to check on that table
- * @param string $fname Calling function name (optional)
- * @return bool Whether $table has filed $field
- */
- public function fieldExists( $table, $field, $fname = __METHOD__ );
-
- /**
- * Determines whether an index exists
- * Usually throws a DBQueryError on failure
- * If errors are explicitly ignored, returns NULL on failure
- *
- * @param string $table
- * @param string $index
- * @param string $fname
- * @return bool|null
- */
- public function indexExists( $table, $index, $fname = __METHOD__ );
-
- /**
- * Query whether a given table exists
- *
- * @param string $table
- * @param string $fname
- * @return bool
- */
- public function tableExists( $table, $fname = __METHOD__ );
-
- /**
- * Determines if a given index is unique
- *
- * @param string $table
- * @param string $index
- *
- * @return bool
- */
- public function indexUnique( $table, $index );
-
- /**
- * INSERT wrapper, inserts an array into a table.
- *
- * $a may be either:
- *
- * - A single associative array. The array keys are the field names, and
- * the values are the values to insert. The values are treated as data
- * and will be quoted appropriately. If NULL is inserted, this will be
- * converted to a database NULL.
- * - An array with numeric keys, holding a list of associative arrays.
- * This causes a multi-row INSERT on DBMSs that support it. The keys in
- * each subarray must be identical to each other, and in the same order.
- *
- * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
- * returns success.
- *
- * $options is an array of options, with boolean options encoded as values
- * with numeric keys, in the same style as $options in
- * IDatabase::select(). Supported options are:
- *
- * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
- * any rows which cause duplicate key errors are not inserted. It's
- * possible to determine how many rows were successfully inserted using
- * IDatabase::affectedRows().
- *
- * @param string $table Table name. This will be passed through
- * DatabaseBase::tableName().
- * @param array $a Array of rows to insert
- * @param string $fname Calling function name (use __METHOD__) for logs/profiling
- * @param array $options Array of options
- *
- * @return bool
- */
- public function insert( $table, $a, $fname = __METHOD__, $options = [] );
-
- /**
- * UPDATE wrapper. Takes a condition array and a SET array.
- *
- * @param string $table Name of the table to UPDATE. This will be passed through
- * DatabaseBase::tableName().
- * @param array $values An array of values to SET. For each array element,
- * the key gives the field name, and the value gives the data to set
- * that field to. The data will be quoted by IDatabase::addQuotes().
- * @param array $conds An array of conditions (WHERE). See
- * IDatabase::select() for the details of the format of condition
- * arrays. Use '*' to update all rows.
- * @param string $fname The function name of the caller (from __METHOD__),
- * for logging and profiling.
- * @param array $options An array of UPDATE options, can be:
- * - IGNORE: Ignore unique key conflicts
- * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
- * @return bool
- */
- public function update( $table, $values, $conds, $fname = __METHOD__, $options = [] );
-
- /**
- * Makes an encoded list of strings from an array
- *
- * @param array $a Containing the data
- * @param int $mode Constant
- * - LIST_COMMA: Comma separated, no field names
- * - LIST_AND: ANDed WHERE clause (without the WHERE). See the
- * documentation for $conds in IDatabase::select().
- * - LIST_OR: ORed WHERE clause (without the WHERE)
- * - LIST_SET: Comma separated with field names, like a SET clause
- * - LIST_NAMES: Comma separated field names
- * @throws MWException|DBUnexpectedError
- * @return string
- */
- public function makeList( $a, $mode = LIST_COMMA );
-
- /**
- * Build a partial where clause from a 2-d array such as used for LinkBatch.
- * The keys on each level may be either integers or strings.
- *
- * @param array $data Organized as 2-d
- * [ baseKeyVal => [ subKeyVal => [ignored], ... ], ... ]
- * @param string $baseKey Field name to match the base-level keys to (eg 'pl_namespace')
- * @param string $subKey Field name to match the sub-level keys to (eg 'pl_title')
- * @return string|bool SQL fragment, or false if no items in array
- */
- public function makeWhereFrom2d( $data, $baseKey, $subKey );
-
- /**
- * @param string $field
- * @return string
- */
- public function bitNot( $field );
-
- /**
- * @param string $fieldLeft
- * @param string $fieldRight
- * @return string
- */
- public function bitAnd( $fieldLeft, $fieldRight );
-
- /**
- * @param string $fieldLeft
- * @param string $fieldRight
- * @return string
- */
- public function bitOr( $fieldLeft, $fieldRight );
-
- /**
- * Build a concatenation list to feed into a SQL query
- * @param array $stringList List of raw SQL expressions; caller is
- * responsible for any quoting
- * @return string
- */
- public function buildConcat( $stringList );
-
- /**
- * Build a GROUP_CONCAT or equivalent statement for a query.
- *
- * This is useful for combining a field for several rows into a single string.
- * NULL values will not appear in the output, duplicated values will appear,
- * and the resulting delimiter-separated values have no defined sort order.
- * Code using the results may need to use the PHP unique() or sort() methods.
- *
- * @param string $delim Glue to bind the results together
- * @param string|array $table Table name
- * @param string $field Field name
- * @param string|array $conds Conditions
- * @param string|array $join_conds Join conditions
- * @return string SQL text
- * @since 1.23
- */
- public function buildGroupConcatField(
- $delim, $table, $field, $conds = '', $join_conds = []
- );
-
- /**
- * Change the current database
- *
- * @param string $db
- * @return bool Success or failure
- */
- public function selectDB( $db );
-
- /**
- * Get the current DB name
- * @return string
- */
- public function getDBname();
-
- /**
- * Get the server hostname or IP address
- * @return string
- */
- public function getServer();
-
- /**
- * Adds quotes and backslashes.
- *
- * @param string|Blob $s
- * @return string
- */
- public function addQuotes( $s );
-
- /**
- * LIKE statement wrapper, receives a variable-length argument list with
- * parts of pattern to match containing either string literals that will be
- * escaped or tokens returned by anyChar() or anyString(). Alternatively,
- * the function could be provided with an array of aforementioned
- * parameters.
- *
- * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns
- * a LIKE clause that searches for subpages of 'My page title'.
- * Alternatively:
- * $pattern = [ 'My_page_title/', $dbr->anyString() ];
- * $query .= $dbr->buildLike( $pattern );
- *
- * @since 1.16
- * @return string Fully built LIKE statement
- */
- public function buildLike();
-
- /**
- * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
- *
- * @return LikeMatch
- */
- public function anyChar();
-
- /**
- * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
- *
- * @return LikeMatch
- */
- public function anyString();
-
- /**
- * Returns an appropriately quoted sequence value for inserting a new row.
- * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
- * subclass will return an integer, and save the value for insertId()
- *
- * Any implementation of this function should *not* involve reusing
- * sequence numbers created for rolled-back transactions.
- * See http://bugs.mysql.com/bug.php?id=30767 for details.
- * @param string $seqName
- * @return null|int
- */
- public function nextSequenceValue( $seqName );
-
- /**
- * REPLACE query wrapper.
- *
- * REPLACE is a very handy MySQL extension, which functions like an INSERT
- * except that when there is a duplicate key error, the old row is deleted
- * and the new row is inserted in its place.
- *
- * We simulate this with standard SQL with a DELETE followed by INSERT. To
- * perform the delete, we need to know what the unique indexes are so that
- * we know how to find the conflicting rows.
- *
- * It may be more efficient to leave off unique indexes which are unlikely
- * to collide. However if you do this, you run the risk of encountering
- * errors which wouldn't have occurred in MySQL.
- *
- * @param string $table The table to replace the row(s) in.
- * @param array $uniqueIndexes Is an array of indexes. Each element may be either
- * a field name or an array of field names
- * @param array $rows Can be either a single row to insert, or multiple rows,
- * in the same format as for IDatabase::insert()
- * @param string $fname Calling function name (use __METHOD__) for logs/profiling
- */
- public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ );
-
- /**
- * INSERT ON DUPLICATE KEY UPDATE wrapper, upserts an array into a table.
- *
- * This updates any conflicting rows (according to the unique indexes) using
- * the provided SET clause and inserts any remaining (non-conflicted) rows.
- *
- * $rows may be either:
- * - A single associative array. The array keys are the field names, and
- * the values are the values to insert. The values are treated as data
- * and will be quoted appropriately. If NULL is inserted, this will be
- * converted to a database NULL.
- * - An array with numeric keys, holding a list of associative arrays.
- * This causes a multi-row INSERT on DBMSs that support it. The keys in
- * each subarray must be identical to each other, and in the same order.
- *
- * It may be more efficient to leave off unique indexes which are unlikely
- * to collide. However if you do this, you run the risk of encountering
- * errors which wouldn't have occurred in MySQL.
- *
- * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
- * returns success.
- *
- * @since 1.22
- *
- * @param string $table Table name. This will be passed through DatabaseBase::tableName().
- * @param array $rows A single row or list of rows to insert
- * @param array $uniqueIndexes List of single field names or field name tuples
- * @param array $set An array of values to SET. For each array element, the
- * key gives the field name, and the value gives the data to set that
- * field to. The data will be quoted by IDatabase::addQuotes().
- * @param string $fname Calling function name (use __METHOD__) for logs/profiling
- * @throws Exception
- * @return bool
- */
- public function upsert(
- $table, array $rows, array $uniqueIndexes, array $set, $fname = __METHOD__
- );
-
- /**
- * DELETE where the condition is a join.
- *
- * MySQL overrides this to use a multi-table DELETE syntax, in other databases
- * we use sub-selects
- *
- * For safety, an empty $conds will not delete everything. If you want to
- * delete all rows where the join condition matches, set $conds='*'.
- *
- * DO NOT put the join condition in $conds.
- *
- * @param string $delTable The table to delete from.
- * @param string $joinTable The other table.
- * @param string $delVar The variable to join on, in the first table.
- * @param string $joinVar The variable to join on, in the second table.
- * @param array $conds Condition array of field names mapped to variables,
- * ANDed together in the WHERE clause
- * @param string $fname Calling function name (use __METHOD__) for logs/profiling
- * @throws DBUnexpectedError
- */
- public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
- $fname = __METHOD__
- );
-
- /**
- * DELETE query wrapper.
- *
- * @param array $table Table name
- * @param string|array $conds Array of conditions. See $conds in IDatabase::select()
- * for the format. Use $conds == "*" to delete all rows
- * @param string $fname Name of the calling function
- * @throws DBUnexpectedError
- * @return bool|ResultWrapper
- */
- public function delete( $table, $conds, $fname = __METHOD__ );
-
- /**
- * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
- * into another table.
- *
- * @param string $destTable The table name to insert into
- * @param string|array $srcTable May be either a table name, or an array of table names
- * to include in a join.
- *
- * @param array $varMap Must be an associative array of the form
- * [ 'dest1' => 'source1', ... ]. Source items may be literals
- * rather than field names, but strings should be quoted with
- * IDatabase::addQuotes()
- *
- * @param array $conds Condition array. See $conds in IDatabase::select() for
- * the details of the format of condition arrays. May be "*" to copy the
- * whole table.
- *
- * @param string $fname The function name of the caller, from __METHOD__
- *
- * @param array $insertOptions Options for the INSERT part of the query, see
- * IDatabase::insert() for details.
- * @param array $selectOptions Options for the SELECT part of the query, see
- * IDatabase::select() for details.
- *
- * @return ResultWrapper
- */
- public function insertSelect( $destTable, $srcTable, $varMap, $conds,
- $fname = __METHOD__,
- $insertOptions = [], $selectOptions = []
- );
-
- /**
- * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
- * within the UNION construct.
- * @return bool
- */
- public function unionSupportsOrderAndLimit();
-
- /**
- * Construct a UNION query
- * This is used for providing overload point for other DB abstractions
- * not compatible with the MySQL syntax.
- * @param array $sqls SQL statements to combine
- * @param bool $all Use UNION ALL
- * @return string SQL fragment
- */
- public function unionQueries( $sqls, $all );
-
- /**
- * Returns an SQL expression for a simple conditional. This doesn't need
- * to be overridden unless CASE isn't supported in your DBMS.
- *
- * @param string|array $cond SQL expression which will result in a boolean value
- * @param string $trueVal SQL expression to return if true
- * @param string $falseVal SQL expression to return if false
- * @return string SQL fragment
- */
- public function conditional( $cond, $trueVal, $falseVal );
-
- /**
- * Returns a comand for str_replace function in SQL query.
- * Uses REPLACE() in MySQL
- *
- * @param string $orig Column to modify
- * @param string $old Column to seek
- * @param string $new Column to replace with
- *
- * @return string
- */
- public function strreplace( $orig, $old, $new );
-
- /**
- * Determines how long the server has been up
- *
- * @return int
- */
- public function getServerUptime();
-
- /**
- * Determines if the last failure was due to a deadlock
- *
- * @return bool
- */
- public function wasDeadlock();
-
- /**
- * Determines if the last failure was due to a lock timeout
- *
- * @return bool
- */
- public function wasLockTimeout();
-
- /**
- * Determines if the last query error was due to a dropped connection and should
- * be dealt with by pinging the connection and reissuing the query.
- *
- * @return bool
- */
- public function wasErrorReissuable();
-
- /**
- * Determines if the last failure was due to the database being read-only.
- *
- * @return bool
- */
- public function wasReadOnlyError();
-
- /**
- * Wait for the replica DB to catch up to a given master position
- *
- * @param DBMasterPos $pos
- * @param int $timeout The maximum number of seconds to wait for synchronisation
- * @return int|null Zero if the replica DB was past that position already,
- * greater than zero if we waited for some period of time, less than
- * zero if it timed out, and null on error
- */
- public function masterPosWait( DBMasterPos $pos, $timeout );
-
- /**
- * Get the replication position of this replica DB
- *
- * @return DBMasterPos|bool False if this is not a replica DB.
- */
- public function getSlavePos();
-
- /**
- * Get the position of this master
- *
- * @return DBMasterPos|bool False if this is not a master
- */
- public function getMasterPos();
-
- /**
- * @return bool Whether the DB is marked as read-only server-side
- * @since 1.28
- */
- public function serverIsReadOnly();
-
- /**
- * Run a callback as soon as the current transaction commits or rolls back.
- * An error is thrown if no transaction is pending. Queries in the function will run in
- * AUTO-COMMIT mode unless there are begin() calls. Callbacks must commit any transactions
- * that they begin.
- *
- * This is useful for combining cooperative locks and DB transactions.
- *
- * The callback takes one argument:
- * - How the transaction ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_ROLLBACK)
- *
- * @param callable $callback
- * @return mixed
- * @since 1.28
- */
- public function onTransactionResolution( callable $callback );
-
- /**
- * Run a callback as soon as there is no transaction pending.
- * If there is a transaction and it is rolled back, then the callback is cancelled.
- * Queries in the function will run in AUTO-COMMIT mode unless there are begin() calls.
- * Callbacks must commit any transactions that they begin.
- *
- * This is useful for updates to different systems or when separate transactions are needed.
- * For example, one might want to enqueue jobs into a system outside the database, but only
- * after the database is updated so that the jobs will see the data when they actually run.
- * It can also be used for updates that easily cause deadlocks if locks are held too long.
- *
- * Updates will execute in the order they were enqueued.
- *
- * The callback takes one argument:
- * - How the transaction ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_IDLE)
- *
- * @param callable $callback
- * @since 1.20
- */
- public function onTransactionIdle( callable $callback );
-
- /**
- * Run a callback before the current transaction commits or now if there is none.
- * If there is a transaction and it is rolled back, then the callback is cancelled.
- * Callbacks must not start nor commit any transactions. If no transaction is active,
- * then a transaction will wrap the callback.
- *
- * This is useful for updates that easily cause deadlocks if locks are held too long
- * but where atomicity is strongly desired for these updates and some related updates.
- *
- * Updates will execute in the order they were enqueued.
- *
- * @param callable $callback
- * @since 1.22
- */
- public function onTransactionPreCommitOrIdle( callable $callback );
-
- /**
- * Run a callback each time any transaction commits or rolls back
- *
- * The callback takes two arguments:
- * - IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_ROLLBACK
- * - This IDatabase object
- * Callbacks must commit any transactions that they begin.
- *
- * Registering a callback here will not affect writesOrCallbacks() pending
- *
- * @param string $name Callback name
- * @param callable|null $callback Use null to unset a listener
- * @return mixed
- * @since 1.28
- */
- public function setTransactionListener( $name, callable $callback = null );
-
- /**
- * Begin an atomic section of statements
- *
- * If a transaction has been started already, just keep track of the given
- * section name to make sure the transaction is not committed pre-maturely.
- * This function can be used in layers (with sub-sections), so use a stack
- * to keep track of the different atomic sections. If there is no transaction,
- * start one implicitly.
- *
- * The goal of this function is to create an atomic section of SQL queries
- * without having to start a new transaction if it already exists.
- *
- * Atomic sections are more strict than transactions. With transactions,
- * attempting to begin a new transaction when one is already running results
- * in MediaWiki issuing a brief warning and doing an implicit commit. All
- * atomic levels *must* be explicitly closed using IDatabase::endAtomic(),
- * and any database transactions cannot be began or committed until all atomic
- * levels are closed. There is no such thing as implicitly opening or closing
- * an atomic section.
- *
- * @since 1.23
- * @param string $fname
- * @throws DBError
- */
- public function startAtomic( $fname = __METHOD__ );
-
- /**
- * Ends an atomic section of SQL statements
- *
- * Ends the next section of atomic SQL statements and commits the transaction
- * if necessary.
- *
- * @since 1.23
- * @see IDatabase::startAtomic
- * @param string $fname
- * @throws DBError
- */
- public function endAtomic( $fname = __METHOD__ );
-
- /**
- * Run a callback to do an atomic set of updates for this database
- *
- * The $callback takes the following arguments:
- * - This database object
- * - The value of $fname
- *
- * If any exception occurs in the callback, then rollback() will be called and the error will
- * be re-thrown. It may also be that the rollback itself fails with an exception before then.
- * In any case, such errors are expected to terminate the request, without any outside caller
- * attempting to catch errors and commit anyway. Note that any rollback undoes all prior
- * atomic section and uncommitted updates, which trashes the current request, requiring an
- * error to be displayed.
- *
- * This can be an alternative to explicit startAtomic()/endAtomic() calls.
- *
- * @see DatabaseBase::startAtomic
- * @see DatabaseBase::endAtomic
- *
- * @param string $fname Caller name (usually __METHOD__)
- * @param callable $callback Callback that issues DB updates
- * @return mixed $res Result of the callback (since 1.28)
- * @throws DBError
- * @throws RuntimeException
- * @throws UnexpectedValueException
- * @since 1.27
- */
- public function doAtomicSection( $fname, callable $callback );
-
- /**
- * Begin a transaction. If a transaction is already in progress,
- * that transaction will be committed before the new transaction is started.
- *
- * Only call this from code with outer transcation scope.
- * See https://www.mediawiki.org/wiki/Database_transactions for details.
- * Nesting of transactions is not supported.
- *
- * Note that when the DBO_TRX flag is set (which is usually the case for web
- * requests, but not for maintenance scripts), any previous database query
- * will have started a transaction automatically.
- *
- * Nesting of transactions is not supported. Attempts to nest transactions
- * will cause a warning, unless the current transaction was started
- * automatically because of the DBO_TRX flag.
- *
- * @param string $fname Calling function name
- * @param string $mode A situationally valid IDatabase::TRANSACTION_* constant [optional]
- * @throws DBError
- */
- public function begin( $fname = __METHOD__, $mode = self::TRANSACTION_EXPLICIT );
-
- /**
- * Commits a transaction previously started using begin().
- * If no transaction is in progress, a warning is issued.
- *
- * Only call this from code with outer transcation scope.
- * See https://www.mediawiki.org/wiki/Database_transactions for details.
- * Nesting of transactions is not supported.
- *
- * @param string $fname
- * @param string $flush Flush flag, set to situationally valid IDatabase::FLUSHING_*
- * constant to disable warnings about explicitly committing implicit transactions,
- * or calling commit when no transaction is in progress.
- *
- * This will trigger an exception if there is an ongoing explicit transaction.
- *
- * Only set the flush flag if you are sure that these warnings are not applicable,
- * and no explicit transactions are open.
- *
- * @throws DBUnexpectedError
- */
- public function commit( $fname = __METHOD__, $flush = '' );
-
- /**
- * Rollback a transaction previously started using begin().
- * If no transaction is in progress, a warning is issued.
- *
- * Only call this from code with outer transcation scope.
- * See https://www.mediawiki.org/wiki/Database_transactions for details.
- * Nesting of transactions is not supported. If a serious unexpected error occurs,
- * throwing an Exception is preferrable, using a pre-installed error handler to trigger
- * rollback (in any case, failure to issue COMMIT will cause rollback server-side).
- *
- * @param string $fname Calling function name
- * @param string $flush Flush flag, set to a situationally valid IDatabase::FLUSHING_*
- * constant to disable warnings about calling rollback when no transaction is in
- * progress. This will silently break any ongoing explicit transaction. Only set the
- * flush flag if you are sure that it is safe to ignore these warnings in your context.
- * @throws DBUnexpectedError
- * @since 1.23 Added $flush parameter
- */
- public function rollback( $fname = __METHOD__, $flush = '' );
-
- /**
- * Commit any transaction but error out if writes or callbacks are pending
- *
- * This is intended for clearing out REPEATABLE-READ snapshots so that callers can
- * see a new point-in-time of the database. This is useful when one of many transaction
- * rounds finished and significant time will pass in the script's lifetime. It is also
- * useful to call on a replica DB after waiting on replication to catch up to the master.
- *
- * @param string $fname Calling function name
- * @throws DBUnexpectedError
- * @since 1.28
- */
- public function flushSnapshot( $fname = __METHOD__ );
-
- /**
- * List all tables on the database
- *
- * @param string $prefix Only show tables with this prefix, e.g. mw_
- * @param string $fname Calling function name
- * @throws MWException
- * @return array
- */
- public function listTables( $prefix = null, $fname = __METHOD__ );
-
- /**
- * Convert a timestamp in one of the formats accepted by wfTimestamp()
- * to the format used for inserting into timestamp fields in this DBMS.
- *
- * The result is unquoted, and needs to be passed through addQuotes()
- * before it can be included in raw SQL.
- *
- * @param string|int $ts
- *
- * @return string
- */
- public function timestamp( $ts = 0 );
-
- /**
- * Convert a timestamp in one of the formats accepted by wfTimestamp()
- * to the format used for inserting into timestamp fields in this DBMS. If
- * NULL is input, it is passed through, allowing NULL values to be inserted
- * into timestamp fields.
- *
- * The result is unquoted, and needs to be passed through addQuotes()
- * before it can be included in raw SQL.
- *
- * @param string|int $ts
- *
- * @return string
- */
- public function timestampOrNull( $ts = null );
-
- /**
- * Ping the server and try to reconnect if it there is no connection
- *
- * @param float|null &$rtt Value to store the estimated RTT [optional]
- * @return bool Success or failure
- */
- public function ping( &$rtt = null );
-
- /**
- * Get replica DB lag. Currently supported only by MySQL.
- *
- * Note that this function will generate a fatal error on many
- * installations. Most callers should use LoadBalancer::safeGetLag()
- * instead.
- *
- * @return int|bool Database replication lag in seconds or false on error
- */
- public function getLag();
-
- /**
- * Get the replica DB lag when the current transaction started
- * or a general lag estimate if not transaction is active
- *
- * This is useful when transactions might use snapshot isolation
- * (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
- * is this lag plus transaction duration. If they don't, it is still
- * safe to be pessimistic. In AUTO-COMMIT mode, this still gives an
- * indication of the staleness of subsequent reads.
- *
- * @return array ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
- * @since 1.27
- */
- public function getSessionLagStatus();
-
- /**
- * Return the maximum number of items allowed in a list, or 0 for unlimited.
- *
- * @return int
- */
- public function maxListLen();
-
- /**
- * Some DBMSs have a special format for inserting into blob fields, they
- * don't allow simple quoted strings to be inserted. To insert into such
- * a field, pass the data through this function before passing it to
- * IDatabase::insert().
- *
- * @param string $b
- * @return string
- */
- public function encodeBlob( $b );
-
- /**
- * Some DBMSs return a special placeholder object representing blob fields
- * in result objects. Pass the object through this function to return the
- * original string.
- *
- * @param string|Blob $b
- * @return string
- */
- public function decodeBlob( $b );
-
- /**
- * Override database's default behavior. $options include:
- * 'connTimeout' : Set the connection timeout value in seconds.
- * May be useful for very long batch queries such as
- * full-wiki dumps, where a single query reads out over
- * hours or days.
- *
- * @param array $options
- * @return void
- */
- public function setSessionOptions( array $options );
-
- /**
- * Set variables to be used in sourceFile/sourceStream, in preference to the
- * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
- * all. If it's set to false, $GLOBALS will be used.
- *
- * @param bool|array $vars Mapping variable name to value.
- */
- public function setSchemaVars( $vars );
-
- /**
- * Check to see if a named lock is available (non-blocking)
- *
- * @param string $lockName Name of lock to poll
- * @param string $method Name of method calling us
- * @return bool
- * @since 1.20
- */
- public function lockIsFree( $lockName, $method );
-
- /**
- * Acquire a named lock
- *
- * Named locks are not related to transactions
- *
- * @param string $lockName Name of lock to aquire
- * @param string $method Name of the calling method
- * @param int $timeout Acquisition timeout in seconds
- * @return bool
- */
- public function lock( $lockName, $method, $timeout = 5 );
-
- /**
- * Release a lock
- *
- * Named locks are not related to transactions
- *
- * @param string $lockName Name of lock to release
- * @param string $method Name of the calling method
- *
- * @return int Returns 1 if the lock was released, 0 if the lock was not established
- * by this thread (in which case the lock is not released), and NULL if the named
- * lock did not exist
- */
- public function unlock( $lockName, $method );
-
- /**
- * Acquire a named lock, flush any transaction, and return an RAII style unlocker object
- *
- * Only call this from outer transcation scope and when only one DB will be affected.
- * See https://www.mediawiki.org/wiki/Database_transactions for details.
- *
- * This is suitiable for transactions that need to be serialized using cooperative locks,
- * where each transaction can see each others' changes. Any transaction is flushed to clear
- * out stale REPEATABLE-READ snapshot data. Once the returned object falls out of PHP scope,
- * the lock will be released unless a transaction is active. If one is active, then the lock
- * will be released when it either commits or rolls back.
- *
- * If the lock acquisition failed, then no transaction flush happens, and null is returned.
- *
- * @param string $lockKey Name of lock to release
- * @param string $fname Name of the calling method
- * @param int $timeout Acquisition timeout in seconds
- * @return ScopedCallback|null
- * @throws DBUnexpectedError
- * @since 1.27
- */
- public function getScopedLockAndFlush( $lockKey, $fname, $timeout );
-
- /**
- * Check to see if a named lock used by lock() use blocking queues
- *
- * @return bool
- * @since 1.26
- */
- public function namedLocksEnqueue();
-
- /**
- * Find out when 'infinity' is. Most DBMSes support this. This is a special
- * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
- * because "i" sorts after all numbers.
- *
- * @return string
- */
- public function getInfinity();
-
- /**
- * Encode an expiry time into the DBMS dependent format
- *
- * @param string $expiry Timestamp for expiry, or the 'infinity' string
- * @return string
- */
- public function encodeExpiry( $expiry );
-
- /**
- * Decode an expiry time into a DBMS independent format
- *
- * @param string $expiry DB timestamp field value for expiry
- * @param int $format TS_* constant, defaults to TS_MW
- * @return string
- */
- public function decodeExpiry( $expiry, $format = TS_MW );
-
- /**
- * Allow or deny "big selects" for this session only. This is done by setting
- * the sql_big_selects session variable.
- *
- * This is a MySQL-specific feature.
- *
- * @param bool|string $value True for allow, false for deny, or "default" to
- * restore the initial value
- */
- public function setBigSelects( $value = true );
-
- /**
- * @return bool Whether this DB is read-only
- * @since 1.27
- */
- public function isReadOnly();
-}
+++ /dev/null
-<?php
-/**
- * Database load balancing interface
- *
- * 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
- * @author Aaron Schulz
- */
-
-/**
- * Interface for database load balancing object that manages IDatabase handles
- *
- * @since 1.28
- * @ingroup Database
- */
-interface ILoadBalancer {
- /**
- * @param array $params Array with keys:
- * - servers : Required. Array of server info structures.
- * - loadMonitor : Name of a class used to fetch server lag and load.
- * - readOnlyReason : Reason the master DB is read-only if so [optional]
- * - waitTimeout : Maximum time to wait for replicas for consistency [optional]
- * - srvCache : BagOStuff object [optional]
- * - wanCache : WANObjectCache object [optional]
- * @throws MWException
- */
- public function __construct( array $params );
-
- /**
- * Get the index of the reader connection, which may be a replica DB
- * This takes into account load ratios and lag times. It should
- * always return a consistent index during a given invocation
- *
- * Side effect: opens connections to databases
- * @param string|bool $group Query group, or false for the generic reader
- * @param string|bool $wiki Wiki ID, or false for the current wiki
- * @throws MWException
- * @return bool|int|string
- */
- public function getReaderIndex( $group = false, $wiki = false );
-
- /**
- * Set the master wait position
- * If a DB_REPLICA connection has been opened already, waits
- * Otherwise sets a variable telling it to wait if such a connection is opened
- * @param DBMasterPos $pos
- */
- public function waitFor( $pos );
-
- /**
- * Set the master wait position and wait for a "generic" replica DB to catch up to it
- *
- * This can be used a faster proxy for waitForAll()
- *
- * @param DBMasterPos $pos
- * @param int $timeout Max seconds to wait; default is mWaitTimeout
- * @return bool Success (able to connect and no timeouts reached)
- */
- public function waitForOne( $pos, $timeout = null );
-
- /**
- * Set the master wait position and wait for ALL replica DBs to catch up to it
- * @param DBMasterPos $pos
- * @param int $timeout Max seconds to wait; default is mWaitTimeout
- * @return bool Success (able to connect and no timeouts reached)
- */
- public function waitForAll( $pos, $timeout = null );
-
- /**
- * Get any open connection to a given server index, local or foreign
- * Returns false if there is no connection open
- *
- * @param int $i Server index
- * @return IDatabase|bool False on failure
- */
- public function getAnyOpenConnection( $i );
-
- /**
- * Get a connection by index
- * This is the main entry point for this class.
- *
- * @param int $i Server index
- * @param array|string|bool $groups Query group(s), or false for the generic reader
- * @param string|bool $wiki Wiki ID, or false for the current wiki
- *
- * @throws MWException
- * @return IDatabase
- */
- public function getConnection( $i, $groups = [], $wiki = false );
-
- /**
- * Mark a foreign connection as being available for reuse under a different
- * DB name or prefix. This mechanism is reference-counted, and must be called
- * the same number of times as getConnection() to work.
- *
- * @param IDatabase $conn
- * @throws MWException
- */
- public function reuseConnection( $conn );
-
- /**
- * Get a database connection handle reference
- *
- * The handle's methods wrap simply wrap those of a IDatabase handle
- *
- * @see LoadBalancer::getConnection() for parameter information
- *
- * @param int $db
- * @param array|string|bool $groups Query group(s), or false for the generic reader
- * @param string|bool $wiki Wiki ID, or false for the current wiki
- * @return DBConnRef
- */
- public function getConnectionRef( $db, $groups = [], $wiki = false );
-
- /**
- * Get a database connection handle reference without connecting yet
- *
- * The handle's methods wrap simply wrap those of a IDatabase handle
- *
- * @see LoadBalancer::getConnection() for parameter information
- *
- * @param int $db
- * @param array|string|bool $groups Query group(s), or false for the generic reader
- * @param string|bool $wiki Wiki ID, or false for the current wiki
- * @return DBConnRef
- */
- public function getLazyConnectionRef( $db, $groups = [], $wiki = false );
-
- /**
- * Open a connection to the server given by the specified index
- * Index must be an actual index into the array.
- * If the server is already open, returns it.
- *
- * On error, returns false, and the connection which caused the
- * error will be available via $this->mErrorConnection.
- *
- * @note If disable() was called on this LoadBalancer, this method will throw a DBAccessError.
- *
- * @param int $i Server index
- * @param string|bool $wiki Wiki ID, or false for the current wiki
- * @return IDatabase|bool Returns false on errors
- */
- public function openConnection( $i, $wiki = false );
-
- /**
- * @return int
- */
- public function getWriterIndex();
-
- /**
- * Returns true if the specified index is a valid server index
- *
- * @param string $i
- * @return bool
- */
- public function haveIndex( $i );
-
- /**
- * Returns true if the specified index is valid and has non-zero load
- *
- * @param string $i
- * @return bool
- */
- public function isNonZeroLoad( $i );
-
- /**
- * Get the number of defined servers (not the number of open connections)
- *
- * @return int
- */
- public function getServerCount();
-
- /**
- * Get the host name or IP address of the server with the specified index
- * Prefer a readable name if available.
- * @param string $i
- * @return string
- */
- public function getServerName( $i );
-
- /**
- * Return the server info structure for a given index, or false if the index is invalid.
- * @param int $i
- * @return array|bool
- */
- public function getServerInfo( $i );
-
- /**
- * Sets the server info structure for the given index. Entry at index $i
- * is created if it doesn't exist
- * @param int $i
- * @param array $serverInfo
- */
- public function setServerInfo( $i, array $serverInfo );
-
- /**
- * Get the current master position for chronology control purposes
- * @return DBMasterPos|bool Returns false if not applicable
- */
- public function getMasterPos();
-
- /**
- * Disable this load balancer. All connections are closed, and any attempt to
- * open a new connection will result in a DBAccessError.
- */
- public function disable();
-
- /**
- * Close all open connections
- */
- public function closeAll();
-
- /**
- * Close a connection
- *
- * Using this function makes sure the LoadBalancer knows the connection is closed.
- * If you use $conn->close() directly, the load balancer won't update its state.
- *
- * @param IDatabase $conn
- */
- public function closeConnection( IDatabase $conn );
-
- /**
- * Commit transactions on all open connections
- * @param string $fname Caller name
- * @throws DBExpectedError
- */
- public function commitAll( $fname = __METHOD__ );
-
- /**
- * Perform all pre-commit callbacks that remain part of the atomic transactions
- * and disable any post-commit callbacks until runMasterPostTrxCallbacks()
- *
- * Use this only for mutli-database commits
- */
- public function finalizeMasterChanges();
-
- /**
- * Perform all pre-commit checks for things like replication safety
- *
- * Use this only for mutli-database commits
- *
- * @param array $options Includes:
- * - maxWriteDuration : max write query duration time in seconds
- * @throws DBTransactionError
- */
- public function approveMasterChanges( array $options );
-
- /**
- * Flush any master transaction snapshots and set DBO_TRX (if DBO_DEFAULT is set)
- *
- * The DBO_TRX setting will be reverted to the default in each of these methods:
- * - commitMasterChanges()
- * - rollbackMasterChanges()
- * - commitAll()
- * This allows for custom transaction rounds from any outer transaction scope.
- *
- * @param string $fname
- * @throws DBExpectedError
- */
- public function beginMasterChanges( $fname = __METHOD__ );
-
- /**
- * Issue COMMIT on all master connections where writes where done
- * @param string $fname Caller name
- * @throws DBExpectedError
- */
- public function commitMasterChanges( $fname = __METHOD__ );
-
- /**
- * Issue all pending post-COMMIT/ROLLBACK callbacks
- *
- * Use this only for mutli-database commits
- *
- * @param integer $type IDatabase::TRIGGER_* constant
- * @return Exception|null The first exception or null if there were none
- */
- public function runMasterPostTrxCallbacks( $type );
-
- /**
- * Issue ROLLBACK only on master, only if queries were done on connection
- * @param string $fname Caller name
- * @throws DBExpectedError
- */
- public function rollbackMasterChanges( $fname = __METHOD__ );
-
- /**
- * Suppress all pending post-COMMIT/ROLLBACK callbacks
- *
- * Use this only for mutli-database commits
- *
- * @return Exception|null The first exception or null if there were none
- */
- public function suppressTransactionEndCallbacks();
-
- /**
- * Commit all replica DB transactions so as to flush any REPEATABLE-READ or SSI snapshot
- *
- * @param string $fname Caller name
- */
- public function flushReplicaSnapshots( $fname = __METHOD__ );
-
- /**
- * @return bool Whether a master connection is already open
- */
- public function hasMasterConnection();
-
- /**
- * Determine if there are pending changes in a transaction by this thread
- * @return bool
- */
- public function hasMasterChanges();
-
- /**
- * Get the timestamp of the latest write query done by this thread
- * @return float|bool UNIX timestamp or false
- */
- public function lastMasterChangeTimestamp();
-
- /**
- * Check if this load balancer object had any recent or still
- * pending writes issued against it by this PHP thread
- *
- * @param float $age How many seconds ago is "recent" [defaults to mWaitTimeout]
- * @return bool
- */
- public function hasOrMadeRecentMasterChanges( $age = null );
-
- /**
- * Get the list of callers that have pending master changes
- *
- * @return string[] List of method names
- */
- public function pendingMasterChangeCallers();
-
- /**
- * @note This method will trigger a DB connection if not yet done
- * @param string|bool $wiki Wiki ID, or false for the current wiki
- * @return bool Whether the generic connection for reads is highly "lagged"
- */
- public function getLaggedReplicaMode( $wiki = false );
-
- /**
- * @note This method will never cause a new DB connection
- * @return bool Whether any generic connection used for reads was highly "lagged"
- */
- public function laggedReplicaUsed();
-
- /**
- * @note This method may trigger a DB connection if not yet done
- * @param string|bool $wiki Wiki ID, or false for the current wiki
- * @param IDatabase|null DB master connection; used to avoid loops [optional]
- * @return string|bool Reason the master is read-only or false if it is not
- */
- public function getReadOnlyReason( $wiki = false, IDatabase $conn = null );
-
- /**
- * Disables/enables lag checks
- * @param null|bool $mode
- * @return bool
- */
- public function allowLagged( $mode = null );
-
- /**
- * @return bool
- */
- public function pingAll();
-
- /**
- * Call a function with each open connection object
- * @param callable $callback
- * @param array $params
- */
- public function forEachOpenConnection( $callback, array $params = [] );
-
- /**
- * Call a function with each open connection object to a master
- * @param callable $callback
- * @param array $params
- */
- public function forEachOpenMasterConnection( $callback, array $params = [] );
-
- /**
- * Call a function with each open replica DB connection object
- * @param callable $callback
- * @param array $params
- */
- public function forEachOpenReplicaConnection( $callback, array $params = [] );
-
- /**
- * Get the hostname and lag time of the most-lagged replica DB
- *
- * This is useful for maintenance scripts that need to throttle their updates.
- * May attempt to open connections to replica DBs on the default DB. If there is
- * no lag, the maximum lag will be reported as -1.
- *
- * @param bool|string $wiki Wiki ID, or false for the default database
- * @return array ( host, max lag, index of max lagged host )
- */
- public function getMaxLag( $wiki = false );
-
- /**
- * Get an estimate of replication lag (in seconds) for each server
- *
- * Results are cached for a short time in memcached/process cache
- *
- * Values may be "false" if replication is too broken to estimate
- *
- * @param string|bool $wiki
- * @return int[] Map of (server index => float|int|bool)
- */
- public function getLagTimes( $wiki = false );
-
- /**
- * Get the lag in seconds for a given connection, or zero if this load
- * balancer does not have replication enabled.
- *
- * This should be used in preference to Database::getLag() in cases where
- * replication may not be in use, since there is no way to determine if
- * replication is in use at the connection level without running
- * potentially restricted queries such as SHOW SLAVE STATUS. Using this
- * function instead of Database::getLag() avoids a fatal error in this
- * case on many installations.
- *
- * @param IDatabase $conn
- * @return int|bool Returns false on error
- */
- public function safeGetLag( IDatabase $conn );
-
- /**
- * Wait for a replica DB to reach a specified master position
- *
- * This will connect to the master to get an accurate position if $pos is not given
- *
- * @param IDatabase $conn Replica DB
- * @param DBMasterPos|bool $pos Master position; default: current position
- * @param integer|null $timeout Timeout in seconds [optional]
- * @return bool Success
- */
- public function safeWaitForMasterPos( IDatabase $conn, $pos = false, $timeout = null );
-
- /**
- * Clear the cache for slag lag delay times
- *
- * This is only used for testing
- */
- public function clearLagTimeCache();
-
- /**
- * Set a callback via IDatabase::setTransactionListener() on
- * all current and future master connections of this load balancer
- *
- * @param string $name Callback name
- * @param callable|null $callback
- */
- public function setTransactionListener( $name, callable $callback = null );
-}
*
* @file
*/
+use Wikimedia\Assert\Assert;
/**
* Class for handling updates to the site_stats table
*/
-class SiteStatsUpdate implements DeferrableUpdate {
+class SiteStatsUpdate implements DeferrableUpdate, MergeableUpdate {
/** @var int */
protected $edits = 0;
-
/** @var int */
protected $pages = 0;
-
/** @var int */
protected $articles = 0;
-
/** @var int */
protected $users = 0;
-
/** @var int */
protected $images = 0;
+ private static $counters = [ 'edits', 'pages', 'articles', 'users', 'images' ];
+
// @todo deprecate this constructor
function __construct( $views, $edits, $good, $pages = 0, $users = 0 ) {
$this->edits = $edits;
$this->users = $users;
}
+ public function merge( MergeableUpdate $update ) {
+ /** @var SiteStatsUpdate $update */
+ Assert::parameterType( __CLASS__, $update, '$update' );
+
+ foreach ( self::$counters as $field ) {
+ $this->$field += $update->$field;
+ }
+ }
+
/**
* @param array $deltas
* @return SiteStatsUpdate
public static function factory( array $deltas ) {
$update = new self( 0, 0, 0 );
- $fields = [ 'views', 'edits', 'pages', 'articles', 'users', 'images' ];
- foreach ( $fields as $field ) {
+ foreach ( self::$counters as $field ) {
if ( isset( $deltas[$field] ) && $deltas[$field] ) {
$update->$field = $deltas[$field];
}
--- /dev/null
+<?php
+
+/**
+ * @defgroup Database Database
+ *
+ * This file deals with database interface functions
+ * and query specifics/optimisations.
+ *
+ * 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
+ */
+
+/**
+ * Basic database interface for live and lazy-loaded DB handles
+ *
+ * @note: IDatabase and DBConnRef should be updated to reflect any changes
+ * @ingroup Database
+ */
+interface IDatabase {
+ /** @var int Callback triggered immediately due to no active transaction */
+ const TRIGGER_IDLE = 1;
+ /** @var int Callback triggered by COMMIT */
+ const TRIGGER_COMMIT = 2;
+ /** @var int Callback triggered by ROLLBACK */
+ const TRIGGER_ROLLBACK = 3;
+
+ /** @var string Transaction is requested by regular caller outside of the DB layer */
+ const TRANSACTION_EXPLICIT = '';
+ /** @var string Transaction is requested internally via DBO_TRX/startAtomic() */
+ const TRANSACTION_INTERNAL = 'implicit';
+
+ /** @var string Transaction operation comes from service managing all DBs */
+ const FLUSHING_ALL_PEERS = 'flush';
+ /** @var string Transaction operation comes from the database class internally */
+ const FLUSHING_INTERNAL = 'flush';
+
+ /** @var string Do not remember the prior flags */
+ const REMEMBER_NOTHING = '';
+ /** @var string Remember the prior flags */
+ const REMEMBER_PRIOR = 'remember';
+ /** @var string Restore to the prior flag state */
+ const RESTORE_PRIOR = 'prior';
+ /** @var string Restore to the initial flag state */
+ const RESTORE_INITIAL = 'initial';
+
+ /** @var string Estimate total time (RTT, scanning, waiting on locks, applying) */
+ const ESTIMATE_TOTAL = 'total';
+ /** @var string Estimate time to apply (scanning, applying) */
+ const ESTIMATE_DB_APPLY = 'apply';
+
+ /**
+ * A string describing the current software version, and possibly
+ * other details in a user-friendly way. Will be listed on Special:Version, etc.
+ * Use getServerVersion() to get machine-friendly information.
+ *
+ * @return string Version information from the database server
+ */
+ public function getServerInfo();
+
+ /**
+ * Turns buffering of SQL result sets on (true) or off (false). Default is
+ * "on".
+ *
+ * Unbuffered queries are very troublesome in MySQL:
+ *
+ * - If another query is executed while the first query is being read
+ * out, the first query is killed. This means you can't call normal
+ * MediaWiki functions while you are reading an unbuffered query result
+ * from a normal wfGetDB() connection.
+ *
+ * - Unbuffered queries cause the MySQL server to use large amounts of
+ * memory and to hold broad locks which block other queries.
+ *
+ * If you want to limit client-side memory, it's almost always better to
+ * split up queries into batches using a LIMIT clause than to switch off
+ * buffering.
+ *
+ * @param null|bool $buffer
+ * @return null|bool The previous value of the flag
+ */
+ public function bufferResults( $buffer = null );
+
+ /**
+ * Gets the current transaction level.
+ *
+ * Historically, transactions were allowed to be "nested". This is no
+ * longer supported, so this function really only returns a boolean.
+ *
+ * @return int The previous value
+ */
+ public function trxLevel();
+
+ /**
+ * Get the UNIX timestamp of the time that the transaction was established
+ *
+ * This can be used to reason about the staleness of SELECT data
+ * in REPEATABLE-READ transaction isolation level.
+ *
+ * @return float|null Returns null if there is not active transaction
+ * @since 1.25
+ */
+ public function trxTimestamp();
+
+ /**
+ * @return bool Whether an explicit transaction or atomic sections are still open
+ * @since 1.28
+ */
+ public function explicitTrxActive();
+
+ /**
+ * Get/set the table prefix.
+ * @param string $prefix The table prefix to set, or omitted to leave it unchanged.
+ * @return string The previous table prefix.
+ */
+ public function tablePrefix( $prefix = null );
+
+ /**
+ * Get/set the db schema.
+ * @param string $schema The database schema to set, or omitted to leave it unchanged.
+ * @return string The previous db schema.
+ */
+ public function dbSchema( $schema = null );
+
+ /**
+ * Get properties passed down from the server info array of the load
+ * balancer.
+ *
+ * @param string $name The entry of the info array to get, or null to get the
+ * whole array
+ *
+ * @return array|mixed|null
+ */
+ public function getLBInfo( $name = null );
+
+ /**
+ * Set the LB info array, or a member of it. If called with one parameter,
+ * the LB info array is set to that parameter. If it is called with two
+ * parameters, the member with the given name is set to the given value.
+ *
+ * @param string $name
+ * @param array $value
+ */
+ public function setLBInfo( $name, $value = null );
+
+ /**
+ * Returns true if this database does an implicit sort when doing GROUP BY
+ *
+ * @return bool
+ */
+ public function implicitGroupby();
+
+ /**
+ * Returns true if this database does an implicit order by when the column has an index
+ * For example: SELECT page_title FROM page LIMIT 1
+ *
+ * @return bool
+ */
+ public function implicitOrderby();
+
+ /**
+ * Return the last query that went through IDatabase::query()
+ * @return string
+ */
+ public function lastQuery();
+
+ /**
+ * Returns true if the connection may have been used for write queries.
+ * Should return true if unsure.
+ *
+ * @return bool
+ */
+ public function doneWrites();
+
+ /**
+ * Returns the last time the connection may have been used for write queries.
+ * Should return a timestamp if unsure.
+ *
+ * @return int|float UNIX timestamp or false
+ * @since 1.24
+ */
+ public function lastDoneWrites();
+
+ /**
+ * @return bool Whether there is a transaction open with possible write queries
+ * @since 1.27
+ */
+ public function writesPending();
+
+ /**
+ * Returns true if there is a transaction open with possible write
+ * queries or transaction pre-commit/idle callbacks waiting on it to finish.
+ * This does *not* count recurring callbacks, e.g. from setTransactionListener().
+ *
+ * @return bool
+ */
+ public function writesOrCallbacksPending();
+
+ /**
+ * Get the time spend running write queries for this transaction
+ *
+ * High times could be due to scanning, updates, locking, and such
+ *
+ * @param string $type IDatabase::ESTIMATE_* constant [default: ESTIMATE_ALL]
+ * @return float|bool Returns false if not transaction is active
+ * @since 1.26
+ */
+ public function pendingWriteQueryDuration( $type = self::ESTIMATE_TOTAL );
+
+ /**
+ * Get the list of method names that did write queries for this transaction
+ *
+ * @return array
+ * @since 1.27
+ */
+ public function pendingWriteCallers();
+
+ /**
+ * Is a connection to the database open?
+ * @return bool
+ */
+ public function isOpen();
+
+ /**
+ * Set a flag for this connection
+ *
+ * @param int $flag DBO_* constants from Defines.php:
+ * - DBO_DEBUG: output some debug info (same as debug())
+ * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
+ * - DBO_TRX: automatically start transactions
+ * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
+ * and removes it in command line mode
+ * - DBO_PERSISTENT: use persistant database connection
+ * @param string $remember IDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]
+ */
+ public function setFlag( $flag, $remember = self::REMEMBER_NOTHING );
+
+ /**
+ * Clear a flag for this connection
+ *
+ * @param int $flag DBO_* constants from Defines.php:
+ * - DBO_DEBUG: output some debug info (same as debug())
+ * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
+ * - DBO_TRX: automatically start transactions
+ * - DBO_DEFAULT: automatically sets DBO_TRX if not in command line mode
+ * and removes it in command line mode
+ * - DBO_PERSISTENT: use persistant database connection
+ * @param string $remember IDatabase::REMEMBER_* constant [default: REMEMBER_NOTHING]
+ */
+ public function clearFlag( $flag, $remember = self::REMEMBER_NOTHING );
+
+ /**
+ * Restore the flags to their prior state before the last setFlag/clearFlag call
+ *
+ * @param string $state IDatabase::RESTORE_* constant. [default: RESTORE_PRIOR]
+ * @since 1.28
+ */
+ public function restoreFlags( $state = self::RESTORE_PRIOR );
+
+ /**
+ * Returns a boolean whether the flag $flag is set for this connection
+ *
+ * @param int $flag DBO_* constants from Defines.php:
+ * - DBO_DEBUG: output some debug info (same as debug())
+ * - DBO_NOBUFFER: don't buffer results (inverse of bufferResults())
+ * - DBO_TRX: automatically start transactions
+ * - DBO_PERSISTENT: use persistant database connection
+ * @return bool
+ */
+ public function getFlag( $flag );
+
+ /**
+ * General read-only accessor
+ *
+ * @param string $name
+ * @return string
+ */
+ public function getProperty( $name );
+
+ /**
+ * @return string
+ */
+ public function getWikiID();
+
+ /**
+ * Get the type of the DBMS, as it appears in $wgDBtype.
+ *
+ * @return string
+ */
+ public function getType();
+
+ /**
+ * Open a connection to the database. Usually aborts on failure
+ *
+ * @param string $server Database server host
+ * @param string $user Database user name
+ * @param string $password Database user password
+ * @param string $dbName Database name
+ * @return bool
+ * @throws DBConnectionError
+ */
+ public function open( $server, $user, $password, $dbName );
+
+ /**
+ * 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.
+ *
+ * @param ResultWrapper|stdClass $res Object as returned from IDatabase::query(), etc.
+ * @return stdClass|bool
+ * @throws DBUnexpectedError Thrown if the database returns an error
+ */
+ public function fetchObject( $res );
+
+ /**
+ * 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.
+ *
+ * @param ResultWrapper $res Result object as returned from IDatabase::query(), etc.
+ * @return array|bool
+ * @throws DBUnexpectedError Thrown if the database returns an error
+ */
+ public function fetchRow( $res );
+
+ /**
+ * Get the number of rows in a result object
+ *
+ * @param mixed $res A SQL result
+ * @return int
+ */
+ public function numRows( $res );
+
+ /**
+ * Get the number of fields in a result object
+ * @see http://www.php.net/mysql_num_fields
+ *
+ * @param mixed $res A SQL result
+ * @return int
+ */
+ public function numFields( $res );
+
+ /**
+ * Get a field name in a result object
+ * @see http://www.php.net/mysql_field_name
+ *
+ * @param mixed $res A SQL result
+ * @param int $n
+ * @return string
+ */
+ public function fieldName( $res, $n );
+
+ /**
+ * Get the inserted value of an auto-increment row
+ *
+ * The value inserted should be fetched from nextSequenceValue()
+ *
+ * Example:
+ * $id = $dbw->nextSequenceValue( 'page_page_id_seq' );
+ * $dbw->insert( 'page', [ 'page_id' => $id ] );
+ * $id = $dbw->insertId();
+ *
+ * @return int
+ */
+ public function insertId();
+
+ /**
+ * Change the position of the cursor in a result object
+ * @see http://www.php.net/mysql_data_seek
+ *
+ * @param mixed $res A SQL result
+ * @param int $row
+ */
+ public function dataSeek( $res, $row );
+
+ /**
+ * Get the last error number
+ * @see http://www.php.net/mysql_errno
+ *
+ * @return int
+ */
+ public function lastErrno();
+
+ /**
+ * Get a description of the last error
+ * @see http://www.php.net/mysql_error
+ *
+ * @return string
+ */
+ public function lastError();
+
+ /**
+ * mysql_fetch_field() wrapper
+ * Returns false if the field doesn't exist
+ *
+ * @param string $table Table name
+ * @param string $field Field name
+ *
+ * @return Field
+ */
+ public function fieldInfo( $table, $field );
+
+ /**
+ * Get the number of rows affected by the last write query
+ * @see http://www.php.net/mysql_affected_rows
+ *
+ * @return int
+ */
+ public function affectedRows();
+
+ /**
+ * Returns a wikitext link to the DB's website, e.g.,
+ * return "[http://www.mysql.com/ MySQL]";
+ * Should at least contain plain text, if for some reason
+ * your database has no website.
+ *
+ * @return string Wikitext of a link to the server software's web site
+ */
+ public function getSoftwareLink();
+
+ /**
+ * A string describing the current software version, like from
+ * mysql_get_server_info().
+ *
+ * @return string Version information from the database server.
+ */
+ public function getServerVersion();
+
+ /**
+ * Closes a database connection.
+ * if it is open : commits any open transactions
+ *
+ * @throws DBError
+ * @return bool Operation success. true if already closed.
+ */
+ public function close();
+
+ /**
+ * @param string $error Fallback error message, used if none is given by DB
+ * @throws DBConnectionError
+ */
+ public function reportConnectionError( $error = 'Unknown error' );
+
+ /**
+ * Run an SQL query and return the result. Normally throws a DBQueryError
+ * on failure. If errors are ignored, returns false instead.
+ *
+ * In new code, the query wrappers select(), insert(), update(), delete(),
+ * etc. should be used where possible, since they give much better DBMS
+ * independence and automatically quote or validate user input in a variety
+ * of contexts. This function is generally only useful for queries which are
+ * explicitly DBMS-dependent and are unsupported by the query wrappers, such
+ * as CREATE TABLE.
+ *
+ * However, the query wrappers themselves should call this function.
+ *
+ * @param string $sql SQL query
+ * @param string $fname Name of the calling function, for profiling/SHOW PROCESSLIST
+ * comment (you can use __METHOD__ or add some extra info)
+ * @param bool $tempIgnore Whether to avoid throwing an exception on errors...
+ * maybe best to catch the exception instead?
+ * @throws DBError
+ * @return bool|ResultWrapper True for a successful write query, ResultWrapper object
+ * for a successful read query, or false on failure if $tempIgnore set
+ */
+ public function query( $sql, $fname = __METHOD__, $tempIgnore = false );
+
+ /**
+ * Report a query error. Log the error, and if neither the object ignore
+ * flag nor the $tempIgnore flag is set, throw a DBQueryError.
+ *
+ * @param string $error
+ * @param int $errno
+ * @param string $sql
+ * @param string $fname
+ * @param bool $tempIgnore
+ * @throws DBQueryError
+ */
+ public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false );
+
+ /**
+ * Free a result object returned by query() or select(). It's usually not
+ * necessary to call this, just use unset() or let the variable holding
+ * the result object go out of scope.
+ *
+ * @param mixed $res A SQL result
+ */
+ public function freeResult( $res );
+
+ /**
+ * A SELECT wrapper which returns a single field from a single result row.
+ *
+ * Usually throws a DBQueryError on failure. If errors are explicitly
+ * ignored, returns false on failure.
+ *
+ * If no result rows are returned from the query, false is returned.
+ *
+ * @param string|array $table Table name. See IDatabase::select() for details.
+ * @param string $var The field name to select. This must be a valid SQL
+ * fragment: do not use unvalidated user input.
+ * @param string|array $cond The condition array. See IDatabase::select() for details.
+ * @param string $fname The function name of the caller.
+ * @param string|array $options The query options. See IDatabase::select() for details.
+ *
+ * @return bool|mixed The value from the field, or false on failure.
+ */
+ public function selectField(
+ $table, $var, $cond = '', $fname = __METHOD__, $options = []
+ );
+
+ /**
+ * A SELECT wrapper which returns a list of single field values from result rows.
+ *
+ * Usually throws a DBQueryError on failure. If errors are explicitly
+ * ignored, returns false on failure.
+ *
+ * If no result rows are returned from the query, false is returned.
+ *
+ * @param string|array $table Table name. See IDatabase::select() for details.
+ * @param string $var The field name to select. This must be a valid SQL
+ * fragment: do not use unvalidated user input.
+ * @param string|array $cond The condition array. See IDatabase::select() for details.
+ * @param string $fname The function name of the caller.
+ * @param string|array $options The query options. See IDatabase::select() for details.
+ *
+ * @return bool|array The values from the field, or false on failure
+ * @since 1.25
+ */
+ public function selectFieldValues(
+ $table, $var, $cond = '', $fname = __METHOD__, $options = []
+ );
+
+ /**
+ * Execute a SELECT query constructed using the various parameters provided.
+ * See below for full details of the parameters.
+ *
+ * @param string|array $table Table name
+ * @param string|array $vars Field names
+ * @param string|array $conds Conditions
+ * @param string $fname Caller function name
+ * @param array $options Query options
+ * @param array $join_conds Join conditions
+ *
+ *
+ * @param string|array $table
+ *
+ * May be either an array of table names, or a single string holding a table
+ * name. If an array is given, table aliases can be specified, for example:
+ *
+ * [ 'a' => 'user' ]
+ *
+ * This includes the user table in the query, with the alias "a" available
+ * for use in field names (e.g. a.user_name).
+ *
+ * All of the table names given here are automatically run through
+ * DatabaseBase::tableName(), which causes the table prefix (if any) to be
+ * added, and various other table name mappings to be performed.
+ *
+ * Do not use untrusted user input as a table name. Alias names should
+ * not have characters outside of the Basic multilingual plane.
+ *
+ * @param string|array $vars
+ *
+ * May be either a field name or an array of field names. The field names
+ * can be complete fragments of SQL, for direct inclusion into the SELECT
+ * query. If an array is given, field aliases can be specified, for example:
+ *
+ * [ 'maxrev' => 'MAX(rev_id)' ]
+ *
+ * This includes an expression with the alias "maxrev" in the query.
+ *
+ * If an expression is given, care must be taken to ensure that it is
+ * DBMS-independent.
+ *
+ * Untrusted user input must not be passed to this parameter.
+ *
+ * @param string|array $conds
+ *
+ * May be either a string containing a single condition, or an array of
+ * conditions. If an array is given, the conditions constructed from each
+ * element are combined with AND.
+ *
+ * Array elements may take one of two forms:
+ *
+ * - Elements with a numeric key are interpreted as raw SQL fragments.
+ * - Elements with a string key are interpreted as equality conditions,
+ * where the key is the field name.
+ * - If the value of such an array element is a scalar (such as a
+ * string), it will be treated as data and thus quoted appropriately.
+ * If it is null, an IS NULL clause will be added.
+ * - If the value is an array, an IN (...) clause will be constructed
+ * from its non-null elements, and an IS NULL clause will be added
+ * if null is present, such that the field may match any of the
+ * elements in the array. The non-null elements will be quoted.
+ *
+ * Note that expressions are often DBMS-dependent in their syntax.
+ * DBMS-independent wrappers are provided for constructing several types of
+ * expression commonly used in condition queries. See:
+ * - IDatabase::buildLike()
+ * - IDatabase::conditional()
+ *
+ * Untrusted user input is safe in the values of string keys, however untrusted
+ * input must not be used in the array key names or in the values of numeric keys.
+ * Escaping of untrusted input used in values of numeric keys should be done via
+ * IDatabase::addQuotes()
+ *
+ * @param string|array $options
+ *
+ * Optional: Array of query options. Boolean options are specified by
+ * including them in the array as a string value with a numeric key, for
+ * example:
+ *
+ * [ 'FOR UPDATE' ]
+ *
+ * The supported options are:
+ *
+ * - OFFSET: Skip this many rows at the start of the result set. OFFSET
+ * with LIMIT can theoretically be used for paging through a result set,
+ * but this is discouraged in MediaWiki for performance reasons.
+ *
+ * - LIMIT: Integer: return at most this many rows. The rows are sorted
+ * and then the first rows are taken until the limit is reached. LIMIT
+ * is applied to a result set after OFFSET.
+ *
+ * - FOR UPDATE: Boolean: lock the returned rows so that they can't be
+ * changed until the next COMMIT.
+ *
+ * - DISTINCT: Boolean: return only unique result rows.
+ *
+ * - GROUP BY: May be either an SQL fragment string naming a field or
+ * expression to group by, or an array of such SQL fragments.
+ *
+ * - HAVING: May be either an string containing a HAVING clause or an array of
+ * conditions building the HAVING clause. If an array is given, the conditions
+ * constructed from each element are combined with AND.
+ *
+ * - ORDER BY: May be either an SQL fragment giving a field name or
+ * expression to order by, or an array of such SQL fragments.
+ *
+ * - USE INDEX: This may be either a string giving the index name to use
+ * for the query, or an array. If it is an associative array, each key
+ * gives the table name (or alias), each value gives the index name to
+ * use for that table. All strings are SQL fragments and so should be
+ * validated by the caller.
+ *
+ * - EXPLAIN: In MySQL, this causes an EXPLAIN SELECT query to be run,
+ * instead of SELECT.
+ *
+ * And also the following boolean MySQL extensions, see the MySQL manual
+ * for documentation:
+ *
+ * - LOCK IN SHARE MODE
+ * - STRAIGHT_JOIN
+ * - HIGH_PRIORITY
+ * - SQL_BIG_RESULT
+ * - SQL_BUFFER_RESULT
+ * - SQL_SMALL_RESULT
+ * - SQL_CALC_FOUND_ROWS
+ * - SQL_CACHE
+ * - SQL_NO_CACHE
+ *
+ *
+ * @param string|array $join_conds
+ *
+ * Optional associative array of table-specific join conditions. In the
+ * most common case, this is unnecessary, since the join condition can be
+ * in $conds. However, it is useful for doing a LEFT JOIN.
+ *
+ * The key of the array contains the table name or alias. The value is an
+ * array with two elements, numbered 0 and 1. The first gives the type of
+ * join, the second is the same as the $conds parameter. Thus it can be
+ * an SQL fragment, or an array where the string keys are equality and the
+ * numeric keys are SQL fragments all AND'd together. For example:
+ *
+ * [ 'page' => [ 'LEFT JOIN', 'page_latest=rev_id' ] ]
+ *
+ * @return ResultWrapper|bool If the query returned no rows, a ResultWrapper
+ * with no rows in it will be returned. If there was a query error, a
+ * DBQueryError exception will be thrown, except if the "ignore errors"
+ * option was set, in which case false will be returned.
+ */
+ public function select(
+ $table, $vars, $conds = '', $fname = __METHOD__,
+ $options = [], $join_conds = []
+ );
+
+ /**
+ * The equivalent of IDatabase::select() except that the constructed SQL
+ * is returned, instead of being immediately executed. This can be useful for
+ * doing UNION queries, where the SQL text of each query is needed. In general,
+ * however, callers outside of Database classes should just use select().
+ *
+ * @param string|array $table Table name
+ * @param string|array $vars Field names
+ * @param string|array $conds Conditions
+ * @param string $fname Caller function name
+ * @param string|array $options Query options
+ * @param string|array $join_conds Join conditions
+ *
+ * @return string SQL query string.
+ * @see IDatabase::select()
+ */
+ public function selectSQLText(
+ $table, $vars, $conds = '', $fname = __METHOD__,
+ $options = [], $join_conds = []
+ );
+
+ /**
+ * Single row SELECT wrapper. Equivalent to IDatabase::select(), except
+ * that a single row object is returned. If the query returns no rows,
+ * false is returned.
+ *
+ * @param string|array $table Table name
+ * @param string|array $vars Field names
+ * @param array $conds Conditions
+ * @param string $fname Caller function name
+ * @param string|array $options Query options
+ * @param array|string $join_conds Join conditions
+ *
+ * @return stdClass|bool
+ */
+ public function selectRow( $table, $vars, $conds, $fname = __METHOD__,
+ $options = [], $join_conds = []
+ );
+
+ /**
+ * Estimate the number of rows in dataset
+ *
+ * MySQL allows you to estimate the number of rows that would be returned
+ * by a SELECT query, using EXPLAIN SELECT. The estimate is provided using
+ * index cardinality statistics, and is notoriously inaccurate, especially
+ * when large numbers of rows have recently been added or deleted.
+ *
+ * For DBMSs that don't support fast result size estimation, this function
+ * will actually perform the SELECT COUNT(*).
+ *
+ * Takes the same arguments as IDatabase::select().
+ *
+ * @param string $table Table name
+ * @param string $vars Unused
+ * @param array|string $conds Filters on the table
+ * @param string $fname Function name for profiling
+ * @param array $options Options for select
+ * @return int Row count
+ */
+ public function estimateRowCount(
+ $table, $vars = '*', $conds = '', $fname = __METHOD__, $options = []
+ );
+
+ /**
+ * Get the number of rows in dataset
+ *
+ * This is useful when trying to do COUNT(*) but with a LIMIT for performance.
+ *
+ * Takes the same arguments as IDatabase::select().
+ *
+ * @since 1.27 Added $join_conds parameter
+ *
+ * @param array|string $tables Table names
+ * @param string $vars Unused
+ * @param array|string $conds Filters on the table
+ * @param string $fname Function name for profiling
+ * @param array $options Options for select
+ * @param array $join_conds Join conditions (since 1.27)
+ * @return int Row count
+ */
+ public function selectRowCount(
+ $tables, $vars = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
+ );
+
+ /**
+ * Determines whether a field exists in a table
+ *
+ * @param string $table Table name
+ * @param string $field Filed to check on that table
+ * @param string $fname Calling function name (optional)
+ * @return bool Whether $table has filed $field
+ */
+ public function fieldExists( $table, $field, $fname = __METHOD__ );
+
+ /**
+ * Determines whether an index exists
+ * Usually throws a DBQueryError on failure
+ * If errors are explicitly ignored, returns NULL on failure
+ *
+ * @param string $table
+ * @param string $index
+ * @param string $fname
+ * @return bool|null
+ */
+ public function indexExists( $table, $index, $fname = __METHOD__ );
+
+ /**
+ * Query whether a given table exists
+ *
+ * @param string $table
+ * @param string $fname
+ * @return bool
+ */
+ public function tableExists( $table, $fname = __METHOD__ );
+
+ /**
+ * Determines if a given index is unique
+ *
+ * @param string $table
+ * @param string $index
+ *
+ * @return bool
+ */
+ public function indexUnique( $table, $index );
+
+ /**
+ * INSERT wrapper, inserts an array into a table.
+ *
+ * $a may be either:
+ *
+ * - A single associative array. The array keys are the field names, and
+ * the values are the values to insert. The values are treated as data
+ * and will be quoted appropriately. If NULL is inserted, this will be
+ * converted to a database NULL.
+ * - An array with numeric keys, holding a list of associative arrays.
+ * This causes a multi-row INSERT on DBMSs that support it. The keys in
+ * each subarray must be identical to each other, and in the same order.
+ *
+ * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
+ * returns success.
+ *
+ * $options is an array of options, with boolean options encoded as values
+ * with numeric keys, in the same style as $options in
+ * IDatabase::select(). Supported options are:
+ *
+ * - IGNORE: Boolean: if present, duplicate key errors are ignored, and
+ * any rows which cause duplicate key errors are not inserted. It's
+ * possible to determine how many rows were successfully inserted using
+ * IDatabase::affectedRows().
+ *
+ * @param string $table Table name. This will be passed through
+ * DatabaseBase::tableName().
+ * @param array $a Array of rows to insert
+ * @param string $fname Calling function name (use __METHOD__) for logs/profiling
+ * @param array $options Array of options
+ *
+ * @return bool
+ */
+ public function insert( $table, $a, $fname = __METHOD__, $options = [] );
+
+ /**
+ * UPDATE wrapper. Takes a condition array and a SET array.
+ *
+ * @param string $table Name of the table to UPDATE. This will be passed through
+ * DatabaseBase::tableName().
+ * @param array $values An array of values to SET. For each array element,
+ * the key gives the field name, and the value gives the data to set
+ * that field to. The data will be quoted by IDatabase::addQuotes().
+ * @param array $conds An array of conditions (WHERE). See
+ * IDatabase::select() for the details of the format of condition
+ * arrays. Use '*' to update all rows.
+ * @param string $fname The function name of the caller (from __METHOD__),
+ * for logging and profiling.
+ * @param array $options An array of UPDATE options, can be:
+ * - IGNORE: Ignore unique key conflicts
+ * - LOW_PRIORITY: MySQL-specific, see MySQL manual.
+ * @return bool
+ */
+ public function update( $table, $values, $conds, $fname = __METHOD__, $options = [] );
+
+ /**
+ * Makes an encoded list of strings from an array
+ *
+ * @param array $a Containing the data
+ * @param int $mode Constant
+ * - LIST_COMMA: Comma separated, no field names
+ * - LIST_AND: ANDed WHERE clause (without the WHERE). See the
+ * documentation for $conds in IDatabase::select().
+ * - LIST_OR: ORed WHERE clause (without the WHERE)
+ * - LIST_SET: Comma separated with field names, like a SET clause
+ * - LIST_NAMES: Comma separated field names
+ * @throws DBError
+ * @return string
+ */
+ public function makeList( $a, $mode = LIST_COMMA );
+
+ /**
+ * Build a partial where clause from a 2-d array such as used for LinkBatch.
+ * The keys on each level may be either integers or strings.
+ *
+ * @param array $data Organized as 2-d
+ * [ baseKeyVal => [ subKeyVal => [ignored], ... ], ... ]
+ * @param string $baseKey Field name to match the base-level keys to (eg 'pl_namespace')
+ * @param string $subKey Field name to match the sub-level keys to (eg 'pl_title')
+ * @return string|bool SQL fragment, or false if no items in array
+ */
+ public function makeWhereFrom2d( $data, $baseKey, $subKey );
+
+ /**
+ * @param string $field
+ * @return string
+ */
+ public function bitNot( $field );
+
+ /**
+ * @param string $fieldLeft
+ * @param string $fieldRight
+ * @return string
+ */
+ public function bitAnd( $fieldLeft, $fieldRight );
+
+ /**
+ * @param string $fieldLeft
+ * @param string $fieldRight
+ * @return string
+ */
+ public function bitOr( $fieldLeft, $fieldRight );
+
+ /**
+ * Build a concatenation list to feed into a SQL query
+ * @param array $stringList List of raw SQL expressions; caller is
+ * responsible for any quoting
+ * @return string
+ */
+ public function buildConcat( $stringList );
+
+ /**
+ * Build a GROUP_CONCAT or equivalent statement for a query.
+ *
+ * This is useful for combining a field for several rows into a single string.
+ * NULL values will not appear in the output, duplicated values will appear,
+ * and the resulting delimiter-separated values have no defined sort order.
+ * Code using the results may need to use the PHP unique() or sort() methods.
+ *
+ * @param string $delim Glue to bind the results together
+ * @param string|array $table Table name
+ * @param string $field Field name
+ * @param string|array $conds Conditions
+ * @param string|array $join_conds Join conditions
+ * @return string SQL text
+ * @since 1.23
+ */
+ public function buildGroupConcatField(
+ $delim, $table, $field, $conds = '', $join_conds = []
+ );
+
+ /**
+ * Change the current database
+ *
+ * @param string $db
+ * @return bool Success or failure
+ */
+ public function selectDB( $db );
+
+ /**
+ * Get the current DB name
+ * @return string
+ */
+ public function getDBname();
+
+ /**
+ * Get the server hostname or IP address
+ * @return string
+ */
+ public function getServer();
+
+ /**
+ * Adds quotes and backslashes.
+ *
+ * @param string|Blob $s
+ * @return string
+ */
+ public function addQuotes( $s );
+
+ /**
+ * LIKE statement wrapper, receives a variable-length argument list with
+ * parts of pattern to match containing either string literals that will be
+ * escaped or tokens returned by anyChar() or anyString(). Alternatively,
+ * the function could be provided with an array of aforementioned
+ * parameters.
+ *
+ * Example: $dbr->buildLike( 'My_page_title/', $dbr->anyString() ) returns
+ * a LIKE clause that searches for subpages of 'My page title'.
+ * Alternatively:
+ * $pattern = [ 'My_page_title/', $dbr->anyString() ];
+ * $query .= $dbr->buildLike( $pattern );
+ *
+ * @since 1.16
+ * @return string Fully built LIKE statement
+ */
+ public function buildLike();
+
+ /**
+ * Returns a token for buildLike() that denotes a '_' to be used in a LIKE query
+ *
+ * @return LikeMatch
+ */
+ public function anyChar();
+
+ /**
+ * Returns a token for buildLike() that denotes a '%' to be used in a LIKE query
+ *
+ * @return LikeMatch
+ */
+ public function anyString();
+
+ /**
+ * Returns an appropriately quoted sequence value for inserting a new row.
+ * MySQL has autoincrement fields, so this is just NULL. But the PostgreSQL
+ * subclass will return an integer, and save the value for insertId()
+ *
+ * Any implementation of this function should *not* involve reusing
+ * sequence numbers created for rolled-back transactions.
+ * See http://bugs.mysql.com/bug.php?id=30767 for details.
+ * @param string $seqName
+ * @return null|int
+ */
+ public function nextSequenceValue( $seqName );
+
+ /**
+ * REPLACE query wrapper.
+ *
+ * REPLACE is a very handy MySQL extension, which functions like an INSERT
+ * except that when there is a duplicate key error, the old row is deleted
+ * and the new row is inserted in its place.
+ *
+ * We simulate this with standard SQL with a DELETE followed by INSERT. To
+ * perform the delete, we need to know what the unique indexes are so that
+ * we know how to find the conflicting rows.
+ *
+ * It may be more efficient to leave off unique indexes which are unlikely
+ * to collide. However if you do this, you run the risk of encountering
+ * errors which wouldn't have occurred in MySQL.
+ *
+ * @param string $table The table to replace the row(s) in.
+ * @param array $uniqueIndexes Is an array of indexes. Each element may be either
+ * a field name or an array of field names
+ * @param array $rows Can be either a single row to insert, or multiple rows,
+ * in the same format as for IDatabase::insert()
+ * @param string $fname Calling function name (use __METHOD__) for logs/profiling
+ */
+ public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ );
+
+ /**
+ * INSERT ON DUPLICATE KEY UPDATE wrapper, upserts an array into a table.
+ *
+ * This updates any conflicting rows (according to the unique indexes) using
+ * the provided SET clause and inserts any remaining (non-conflicted) rows.
+ *
+ * $rows may be either:
+ * - A single associative array. The array keys are the field names, and
+ * the values are the values to insert. The values are treated as data
+ * and will be quoted appropriately. If NULL is inserted, this will be
+ * converted to a database NULL.
+ * - An array with numeric keys, holding a list of associative arrays.
+ * This causes a multi-row INSERT on DBMSs that support it. The keys in
+ * each subarray must be identical to each other, and in the same order.
+ *
+ * It may be more efficient to leave off unique indexes which are unlikely
+ * to collide. However if you do this, you run the risk of encountering
+ * errors which wouldn't have occurred in MySQL.
+ *
+ * Usually throws a DBQueryError on failure. If errors are explicitly ignored,
+ * returns success.
+ *
+ * @since 1.22
+ *
+ * @param string $table Table name. This will be passed through DatabaseBase::tableName().
+ * @param array $rows A single row or list of rows to insert
+ * @param array $uniqueIndexes List of single field names or field name tuples
+ * @param array $set An array of values to SET. For each array element, the
+ * key gives the field name, and the value gives the data to set that
+ * field to. The data will be quoted by IDatabase::addQuotes().
+ * @param string $fname Calling function name (use __METHOD__) for logs/profiling
+ * @throws Exception
+ * @return bool
+ */
+ public function upsert(
+ $table, array $rows, array $uniqueIndexes, array $set, $fname = __METHOD__
+ );
+
+ /**
+ * DELETE where the condition is a join.
+ *
+ * MySQL overrides this to use a multi-table DELETE syntax, in other databases
+ * we use sub-selects
+ *
+ * For safety, an empty $conds will not delete everything. If you want to
+ * delete all rows where the join condition matches, set $conds='*'.
+ *
+ * DO NOT put the join condition in $conds.
+ *
+ * @param string $delTable The table to delete from.
+ * @param string $joinTable The other table.
+ * @param string $delVar The variable to join on, in the first table.
+ * @param string $joinVar The variable to join on, in the second table.
+ * @param array $conds Condition array of field names mapped to variables,
+ * ANDed together in the WHERE clause
+ * @param string $fname Calling function name (use __METHOD__) for logs/profiling
+ * @throws DBUnexpectedError
+ */
+ public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
+ $fname = __METHOD__
+ );
+
+ /**
+ * DELETE query wrapper.
+ *
+ * @param array $table Table name
+ * @param string|array $conds Array of conditions. See $conds in IDatabase::select()
+ * for the format. Use $conds == "*" to delete all rows
+ * @param string $fname Name of the calling function
+ * @throws DBUnexpectedError
+ * @return bool|ResultWrapper
+ */
+ public function delete( $table, $conds, $fname = __METHOD__ );
+
+ /**
+ * INSERT SELECT wrapper. Takes data from a SELECT query and inserts it
+ * into another table.
+ *
+ * @param string $destTable The table name to insert into
+ * @param string|array $srcTable May be either a table name, or an array of table names
+ * to include in a join.
+ *
+ * @param array $varMap Must be an associative array of the form
+ * [ 'dest1' => 'source1', ... ]. Source items may be literals
+ * rather than field names, but strings should be quoted with
+ * IDatabase::addQuotes()
+ *
+ * @param array $conds Condition array. See $conds in IDatabase::select() for
+ * the details of the format of condition arrays. May be "*" to copy the
+ * whole table.
+ *
+ * @param string $fname The function name of the caller, from __METHOD__
+ *
+ * @param array $insertOptions Options for the INSERT part of the query, see
+ * IDatabase::insert() for details.
+ * @param array $selectOptions Options for the SELECT part of the query, see
+ * IDatabase::select() for details.
+ *
+ * @return ResultWrapper
+ */
+ public function insertSelect( $destTable, $srcTable, $varMap, $conds,
+ $fname = __METHOD__,
+ $insertOptions = [], $selectOptions = []
+ );
+
+ /**
+ * Returns true if current database backend supports ORDER BY or LIMIT for separate subqueries
+ * within the UNION construct.
+ * @return bool
+ */
+ public function unionSupportsOrderAndLimit();
+
+ /**
+ * Construct a UNION query
+ * This is used for providing overload point for other DB abstractions
+ * not compatible with the MySQL syntax.
+ * @param array $sqls SQL statements to combine
+ * @param bool $all Use UNION ALL
+ * @return string SQL fragment
+ */
+ public function unionQueries( $sqls, $all );
+
+ /**
+ * Returns an SQL expression for a simple conditional. This doesn't need
+ * to be overridden unless CASE isn't supported in your DBMS.
+ *
+ * @param string|array $cond SQL expression which will result in a boolean value
+ * @param string $trueVal SQL expression to return if true
+ * @param string $falseVal SQL expression to return if false
+ * @return string SQL fragment
+ */
+ public function conditional( $cond, $trueVal, $falseVal );
+
+ /**
+ * Returns a comand for str_replace function in SQL query.
+ * Uses REPLACE() in MySQL
+ *
+ * @param string $orig Column to modify
+ * @param string $old Column to seek
+ * @param string $new Column to replace with
+ *
+ * @return string
+ */
+ public function strreplace( $orig, $old, $new );
+
+ /**
+ * Determines how long the server has been up
+ *
+ * @return int
+ */
+ public function getServerUptime();
+
+ /**
+ * Determines if the last failure was due to a deadlock
+ *
+ * @return bool
+ */
+ public function wasDeadlock();
+
+ /**
+ * Determines if the last failure was due to a lock timeout
+ *
+ * @return bool
+ */
+ public function wasLockTimeout();
+
+ /**
+ * Determines if the last query error was due to a dropped connection and should
+ * be dealt with by pinging the connection and reissuing the query.
+ *
+ * @return bool
+ */
+ public function wasErrorReissuable();
+
+ /**
+ * Determines if the last failure was due to the database being read-only.
+ *
+ * @return bool
+ */
+ public function wasReadOnlyError();
+
+ /**
+ * Wait for the replica DB to catch up to a given master position
+ *
+ * @param DBMasterPos $pos
+ * @param int $timeout The maximum number of seconds to wait for synchronisation
+ * @return int|null Zero if the replica DB was past that position already,
+ * greater than zero if we waited for some period of time, less than
+ * zero if it timed out, and null on error
+ */
+ public function masterPosWait( DBMasterPos $pos, $timeout );
+
+ /**
+ * Get the replication position of this replica DB
+ *
+ * @return DBMasterPos|bool False if this is not a replica DB.
+ */
+ public function getSlavePos();
+
+ /**
+ * Get the position of this master
+ *
+ * @return DBMasterPos|bool False if this is not a master
+ */
+ public function getMasterPos();
+
+ /**
+ * @return bool Whether the DB is marked as read-only server-side
+ * @since 1.28
+ */
+ public function serverIsReadOnly();
+
+ /**
+ * Run a callback as soon as the current transaction commits or rolls back.
+ * An error is thrown if no transaction is pending. Queries in the function will run in
+ * AUTO-COMMIT mode unless there are begin() calls. Callbacks must commit any transactions
+ * that they begin.
+ *
+ * This is useful for combining cooperative locks and DB transactions.
+ *
+ * The callback takes one argument:
+ * - How the transaction ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_ROLLBACK)
+ *
+ * @param callable $callback
+ * @return mixed
+ * @since 1.28
+ */
+ public function onTransactionResolution( callable $callback );
+
+ /**
+ * Run a callback as soon as there is no transaction pending.
+ * If there is a transaction and it is rolled back, then the callback is cancelled.
+ * Queries in the function will run in AUTO-COMMIT mode unless there are begin() calls.
+ * Callbacks must commit any transactions that they begin.
+ *
+ * This is useful for updates to different systems or when separate transactions are needed.
+ * For example, one might want to enqueue jobs into a system outside the database, but only
+ * after the database is updated so that the jobs will see the data when they actually run.
+ * It can also be used for updates that easily cause deadlocks if locks are held too long.
+ *
+ * Updates will execute in the order they were enqueued.
+ *
+ * The callback takes one argument:
+ * - How the transaction ended (IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_IDLE)
+ *
+ * @param callable $callback
+ * @since 1.20
+ */
+ public function onTransactionIdle( callable $callback );
+
+ /**
+ * Run a callback before the current transaction commits or now if there is none.
+ * If there is a transaction and it is rolled back, then the callback is cancelled.
+ * Callbacks must not start nor commit any transactions. If no transaction is active,
+ * then a transaction will wrap the callback.
+ *
+ * This is useful for updates that easily cause deadlocks if locks are held too long
+ * but where atomicity is strongly desired for these updates and some related updates.
+ *
+ * Updates will execute in the order they were enqueued.
+ *
+ * @param callable $callback
+ * @since 1.22
+ */
+ public function onTransactionPreCommitOrIdle( callable $callback );
+
+ /**
+ * Run a callback each time any transaction commits or rolls back
+ *
+ * The callback takes two arguments:
+ * - IDatabase::TRIGGER_COMMIT or IDatabase::TRIGGER_ROLLBACK
+ * - This IDatabase object
+ * Callbacks must commit any transactions that they begin.
+ *
+ * Registering a callback here will not affect writesOrCallbacks() pending
+ *
+ * @param string $name Callback name
+ * @param callable|null $callback Use null to unset a listener
+ * @return mixed
+ * @since 1.28
+ */
+ public function setTransactionListener( $name, callable $callback = null );
+
+ /**
+ * Begin an atomic section of statements
+ *
+ * If a transaction has been started already, just keep track of the given
+ * section name to make sure the transaction is not committed pre-maturely.
+ * This function can be used in layers (with sub-sections), so use a stack
+ * to keep track of the different atomic sections. If there is no transaction,
+ * start one implicitly.
+ *
+ * The goal of this function is to create an atomic section of SQL queries
+ * without having to start a new transaction if it already exists.
+ *
+ * Atomic sections are more strict than transactions. With transactions,
+ * attempting to begin a new transaction when one is already running results
+ * in MediaWiki issuing a brief warning and doing an implicit commit. All
+ * atomic levels *must* be explicitly closed using IDatabase::endAtomic(),
+ * and any database transactions cannot be began or committed until all atomic
+ * levels are closed. There is no such thing as implicitly opening or closing
+ * an atomic section.
+ *
+ * @since 1.23
+ * @param string $fname
+ * @throws DBError
+ */
+ public function startAtomic( $fname = __METHOD__ );
+
+ /**
+ * Ends an atomic section of SQL statements
+ *
+ * Ends the next section of atomic SQL statements and commits the transaction
+ * if necessary.
+ *
+ * @since 1.23
+ * @see IDatabase::startAtomic
+ * @param string $fname
+ * @throws DBError
+ */
+ public function endAtomic( $fname = __METHOD__ );
+
+ /**
+ * Run a callback to do an atomic set of updates for this database
+ *
+ * The $callback takes the following arguments:
+ * - This database object
+ * - The value of $fname
+ *
+ * If any exception occurs in the callback, then rollback() will be called and the error will
+ * be re-thrown. It may also be that the rollback itself fails with an exception before then.
+ * In any case, such errors are expected to terminate the request, without any outside caller
+ * attempting to catch errors and commit anyway. Note that any rollback undoes all prior
+ * atomic section and uncommitted updates, which trashes the current request, requiring an
+ * error to be displayed.
+ *
+ * This can be an alternative to explicit startAtomic()/endAtomic() calls.
+ *
+ * @see DatabaseBase::startAtomic
+ * @see DatabaseBase::endAtomic
+ *
+ * @param string $fname Caller name (usually __METHOD__)
+ * @param callable $callback Callback that issues DB updates
+ * @return mixed $res Result of the callback (since 1.28)
+ * @throws DBError
+ * @throws RuntimeException
+ * @throws UnexpectedValueException
+ * @since 1.27
+ */
+ public function doAtomicSection( $fname, callable $callback );
+
+ /**
+ * Begin a transaction. If a transaction is already in progress,
+ * that transaction will be committed before the new transaction is started.
+ *
+ * Only call this from code with outer transcation scope.
+ * See https://www.mediawiki.org/wiki/Database_transactions for details.
+ * Nesting of transactions is not supported.
+ *
+ * Note that when the DBO_TRX flag is set (which is usually the case for web
+ * requests, but not for maintenance scripts), any previous database query
+ * will have started a transaction automatically.
+ *
+ * Nesting of transactions is not supported. Attempts to nest transactions
+ * will cause a warning, unless the current transaction was started
+ * automatically because of the DBO_TRX flag.
+ *
+ * @param string $fname Calling function name
+ * @param string $mode A situationally valid IDatabase::TRANSACTION_* constant [optional]
+ * @throws DBError
+ */
+ public function begin( $fname = __METHOD__, $mode = self::TRANSACTION_EXPLICIT );
+
+ /**
+ * Commits a transaction previously started using begin().
+ * If no transaction is in progress, a warning is issued.
+ *
+ * Only call this from code with outer transcation scope.
+ * See https://www.mediawiki.org/wiki/Database_transactions for details.
+ * Nesting of transactions is not supported.
+ *
+ * @param string $fname
+ * @param string $flush Flush flag, set to situationally valid IDatabase::FLUSHING_*
+ * constant to disable warnings about explicitly committing implicit transactions,
+ * or calling commit when no transaction is in progress.
+ *
+ * This will trigger an exception if there is an ongoing explicit transaction.
+ *
+ * Only set the flush flag if you are sure that these warnings are not applicable,
+ * and no explicit transactions are open.
+ *
+ * @throws DBUnexpectedError
+ */
+ public function commit( $fname = __METHOD__, $flush = '' );
+
+ /**
+ * Rollback a transaction previously started using begin().
+ * If no transaction is in progress, a warning is issued.
+ *
+ * Only call this from code with outer transcation scope.
+ * See https://www.mediawiki.org/wiki/Database_transactions for details.
+ * Nesting of transactions is not supported. If a serious unexpected error occurs,
+ * throwing an Exception is preferrable, using a pre-installed error handler to trigger
+ * rollback (in any case, failure to issue COMMIT will cause rollback server-side).
+ *
+ * @param string $fname Calling function name
+ * @param string $flush Flush flag, set to a situationally valid IDatabase::FLUSHING_*
+ * constant to disable warnings about calling rollback when no transaction is in
+ * progress. This will silently break any ongoing explicit transaction. Only set the
+ * flush flag if you are sure that it is safe to ignore these warnings in your context.
+ * @throws DBUnexpectedError
+ * @since 1.23 Added $flush parameter
+ */
+ public function rollback( $fname = __METHOD__, $flush = '' );
+
+ /**
+ * Commit any transaction but error out if writes or callbacks are pending
+ *
+ * This is intended for clearing out REPEATABLE-READ snapshots so that callers can
+ * see a new point-in-time of the database. This is useful when one of many transaction
+ * rounds finished and significant time will pass in the script's lifetime. It is also
+ * useful to call on a replica DB after waiting on replication to catch up to the master.
+ *
+ * @param string $fname Calling function name
+ * @throws DBUnexpectedError
+ * @since 1.28
+ */
+ public function flushSnapshot( $fname = __METHOD__ );
+
+ /**
+ * List all tables on the database
+ *
+ * @param string $prefix Only show tables with this prefix, e.g. mw_
+ * @param string $fname Calling function name
+ * @throws DBError
+ * @return array
+ */
+ public function listTables( $prefix = null, $fname = __METHOD__ );
+
+ /**
+ * Convert a timestamp in one of the formats accepted by wfTimestamp()
+ * to the format used for inserting into timestamp fields in this DBMS.
+ *
+ * The result is unquoted, and needs to be passed through addQuotes()
+ * before it can be included in raw SQL.
+ *
+ * @param string|int $ts
+ *
+ * @return string
+ */
+ public function timestamp( $ts = 0 );
+
+ /**
+ * Convert a timestamp in one of the formats accepted by wfTimestamp()
+ * to the format used for inserting into timestamp fields in this DBMS. If
+ * NULL is input, it is passed through, allowing NULL values to be inserted
+ * into timestamp fields.
+ *
+ * The result is unquoted, and needs to be passed through addQuotes()
+ * before it can be included in raw SQL.
+ *
+ * @param string|int $ts
+ *
+ * @return string
+ */
+ public function timestampOrNull( $ts = null );
+
+ /**
+ * Ping the server and try to reconnect if it there is no connection
+ *
+ * @param float|null &$rtt Value to store the estimated RTT [optional]
+ * @return bool Success or failure
+ */
+ public function ping( &$rtt = null );
+
+ /**
+ * Get replica DB lag. Currently supported only by MySQL.
+ *
+ * Note that this function will generate a fatal error on many
+ * installations. Most callers should use LoadBalancer::safeGetLag()
+ * instead.
+ *
+ * @return int|bool Database replication lag in seconds or false on error
+ */
+ public function getLag();
+
+ /**
+ * Get the replica DB lag when the current transaction started
+ * or a general lag estimate if not transaction is active
+ *
+ * This is useful when transactions might use snapshot isolation
+ * (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
+ * is this lag plus transaction duration. If they don't, it is still
+ * safe to be pessimistic. In AUTO-COMMIT mode, this still gives an
+ * indication of the staleness of subsequent reads.
+ *
+ * @return array ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
+ * @since 1.27
+ */
+ public function getSessionLagStatus();
+
+ /**
+ * Return the maximum number of items allowed in a list, or 0 for unlimited.
+ *
+ * @return int
+ */
+ public function maxListLen();
+
+ /**
+ * Some DBMSs have a special format for inserting into blob fields, they
+ * don't allow simple quoted strings to be inserted. To insert into such
+ * a field, pass the data through this function before passing it to
+ * IDatabase::insert().
+ *
+ * @param string $b
+ * @return string
+ */
+ public function encodeBlob( $b );
+
+ /**
+ * Some DBMSs return a special placeholder object representing blob fields
+ * in result objects. Pass the object through this function to return the
+ * original string.
+ *
+ * @param string|Blob $b
+ * @return string
+ */
+ public function decodeBlob( $b );
+
+ /**
+ * Override database's default behavior. $options include:
+ * 'connTimeout' : Set the connection timeout value in seconds.
+ * May be useful for very long batch queries such as
+ * full-wiki dumps, where a single query reads out over
+ * hours or days.
+ *
+ * @param array $options
+ * @return void
+ */
+ public function setSessionOptions( array $options );
+
+ /**
+ * Set variables to be used in sourceFile/sourceStream, in preference to the
+ * ones in $GLOBALS. If an array is set here, $GLOBALS will not be used at
+ * all. If it's set to false, $GLOBALS will be used.
+ *
+ * @param bool|array $vars Mapping variable name to value.
+ */
+ public function setSchemaVars( $vars );
+
+ /**
+ * Check to see if a named lock is available (non-blocking)
+ *
+ * @param string $lockName Name of lock to poll
+ * @param string $method Name of method calling us
+ * @return bool
+ * @since 1.20
+ */
+ public function lockIsFree( $lockName, $method );
+
+ /**
+ * Acquire a named lock
+ *
+ * Named locks are not related to transactions
+ *
+ * @param string $lockName Name of lock to aquire
+ * @param string $method Name of the calling method
+ * @param int $timeout Acquisition timeout in seconds
+ * @return bool
+ */
+ public function lock( $lockName, $method, $timeout = 5 );
+
+ /**
+ * Release a lock
+ *
+ * Named locks are not related to transactions
+ *
+ * @param string $lockName Name of lock to release
+ * @param string $method Name of the calling method
+ *
+ * @return int Returns 1 if the lock was released, 0 if the lock was not established
+ * by this thread (in which case the lock is not released), and NULL if the named
+ * lock did not exist
+ */
+ public function unlock( $lockName, $method );
+
+ /**
+ * Acquire a named lock, flush any transaction, and return an RAII style unlocker object
+ *
+ * Only call this from outer transcation scope and when only one DB will be affected.
+ * See https://www.mediawiki.org/wiki/Database_transactions for details.
+ *
+ * This is suitiable for transactions that need to be serialized using cooperative locks,
+ * where each transaction can see each others' changes. Any transaction is flushed to clear
+ * out stale REPEATABLE-READ snapshot data. Once the returned object falls out of PHP scope,
+ * the lock will be released unless a transaction is active. If one is active, then the lock
+ * will be released when it either commits or rolls back.
+ *
+ * If the lock acquisition failed, then no transaction flush happens, and null is returned.
+ *
+ * @param string $lockKey Name of lock to release
+ * @param string $fname Name of the calling method
+ * @param int $timeout Acquisition timeout in seconds
+ * @return ScopedCallback|null
+ * @throws DBUnexpectedError
+ * @since 1.27
+ */
+ public function getScopedLockAndFlush( $lockKey, $fname, $timeout );
+
+ /**
+ * Check to see if a named lock used by lock() use blocking queues
+ *
+ * @return bool
+ * @since 1.26
+ */
+ public function namedLocksEnqueue();
+
+ /**
+ * Find out when 'infinity' is. Most DBMSes support this. This is a special
+ * keyword for timestamps in PostgreSQL, and works with CHAR(14) as well
+ * because "i" sorts after all numbers.
+ *
+ * @return string
+ */
+ public function getInfinity();
+
+ /**
+ * Encode an expiry time into the DBMS dependent format
+ *
+ * @param string $expiry Timestamp for expiry, or the 'infinity' string
+ * @return string
+ */
+ public function encodeExpiry( $expiry );
+
+ /**
+ * Decode an expiry time into a DBMS independent format
+ *
+ * @param string $expiry DB timestamp field value for expiry
+ * @param int $format TS_* constant, defaults to TS_MW
+ * @return string
+ */
+ public function decodeExpiry( $expiry, $format = TS_MW );
+
+ /**
+ * Allow or deny "big selects" for this session only. This is done by setting
+ * the sql_big_selects session variable.
+ *
+ * This is a MySQL-specific feature.
+ *
+ * @param bool|string $value True for allow, false for deny, or "default" to
+ * restore the initial value
+ */
+ public function setBigSelects( $value = true );
+
+ /**
+ * @return bool Whether this DB is read-only
+ * @since 1.27
+ */
+ public function isReadOnly();
+}
--- /dev/null
+<?php
+/**
+ * Database load balancing interface
+ *
+ * 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
+ * @author Aaron Schulz
+ */
+
+/**
+ * Interface for database load balancing object that manages IDatabase handles
+ *
+ * @since 1.28
+ * @ingroup Database
+ */
+interface ILoadBalancer {
+ /**
+ * @param array $params Array with keys:
+ * - servers : Required. Array of server info structures.
+ * - loadMonitor : Name of a class used to fetch server lag and load.
+ * - readOnlyReason : Reason the master DB is read-only if so [optional]
+ * - waitTimeout : Maximum time to wait for replicas for consistency [optional]
+ * - srvCache : BagOStuff object [optional]
+ * - wanCache : WANObjectCache object [optional]
+ * @throws InvalidArgumentException
+ */
+ public function __construct( array $params );
+
+ /**
+ * Get the index of the reader connection, which may be a replica DB
+ * This takes into account load ratios and lag times. It should
+ * always return a consistent index during a given invocation
+ *
+ * Side effect: opens connections to databases
+ * @param string|bool $group Query group, or false for the generic reader
+ * @param string|bool $wiki Wiki ID, or false for the current wiki
+ * @throws DBError
+ * @return bool|int|string
+ */
+ public function getReaderIndex( $group = false, $wiki = false );
+
+ /**
+ * Set the master wait position
+ * If a DB_REPLICA connection has been opened already, waits
+ * Otherwise sets a variable telling it to wait if such a connection is opened
+ * @param DBMasterPos $pos
+ */
+ public function waitFor( $pos );
+
+ /**
+ * Set the master wait position and wait for a "generic" replica DB to catch up to it
+ *
+ * This can be used a faster proxy for waitForAll()
+ *
+ * @param DBMasterPos $pos
+ * @param int $timeout Max seconds to wait; default is mWaitTimeout
+ * @return bool Success (able to connect and no timeouts reached)
+ */
+ public function waitForOne( $pos, $timeout = null );
+
+ /**
+ * Set the master wait position and wait for ALL replica DBs to catch up to it
+ * @param DBMasterPos $pos
+ * @param int $timeout Max seconds to wait; default is mWaitTimeout
+ * @return bool Success (able to connect and no timeouts reached)
+ */
+ public function waitForAll( $pos, $timeout = null );
+
+ /**
+ * Get any open connection to a given server index, local or foreign
+ * Returns false if there is no connection open
+ *
+ * @param int $i Server index
+ * @return IDatabase|bool False on failure
+ */
+ public function getAnyOpenConnection( $i );
+
+ /**
+ * Get a connection by index
+ * This is the main entry point for this class.
+ *
+ * @param int $i Server index
+ * @param array|string|bool $groups Query group(s), or false for the generic reader
+ * @param string|bool $wiki Wiki ID, or false for the current wiki
+ *
+ * @throws DBError
+ * @return IDatabase
+ */
+ public function getConnection( $i, $groups = [], $wiki = false );
+
+ /**
+ * Mark a foreign connection as being available for reuse under a different
+ * DB name or prefix. This mechanism is reference-counted, and must be called
+ * the same number of times as getConnection() to work.
+ *
+ * @param IDatabase $conn
+ * @throws InvalidArgumentException
+ */
+ public function reuseConnection( $conn );
+
+ /**
+ * Get a database connection handle reference
+ *
+ * The handle's methods wrap simply wrap those of a IDatabase handle
+ *
+ * @see LoadBalancer::getConnection() for parameter information
+ *
+ * @param int $db
+ * @param array|string|bool $groups Query group(s), or false for the generic reader
+ * @param string|bool $wiki Wiki ID, or false for the current wiki
+ * @return DBConnRef
+ */
+ public function getConnectionRef( $db, $groups = [], $wiki = false );
+
+ /**
+ * Get a database connection handle reference without connecting yet
+ *
+ * The handle's methods wrap simply wrap those of a IDatabase handle
+ *
+ * @see LoadBalancer::getConnection() for parameter information
+ *
+ * @param int $db
+ * @param array|string|bool $groups Query group(s), or false for the generic reader
+ * @param string|bool $wiki Wiki ID, or false for the current wiki
+ * @return DBConnRef
+ */
+ public function getLazyConnectionRef( $db, $groups = [], $wiki = false );
+
+ /**
+ * Open a connection to the server given by the specified index
+ * Index must be an actual index into the array.
+ * If the server is already open, returns it.
+ *
+ * On error, returns false, and the connection which caused the
+ * error will be available via $this->mErrorConnection.
+ *
+ * @note If disable() was called on this LoadBalancer, this method will throw a DBAccessError.
+ *
+ * @param int $i Server index
+ * @param string|bool $wiki Wiki ID, or false for the current wiki
+ * @return IDatabase|bool Returns false on errors
+ */
+ public function openConnection( $i, $wiki = false );
+
+ /**
+ * @return int
+ */
+ public function getWriterIndex();
+
+ /**
+ * Returns true if the specified index is a valid server index
+ *
+ * @param string $i
+ * @return bool
+ */
+ public function haveIndex( $i );
+
+ /**
+ * Returns true if the specified index is valid and has non-zero load
+ *
+ * @param string $i
+ * @return bool
+ */
+ public function isNonZeroLoad( $i );
+
+ /**
+ * Get the number of defined servers (not the number of open connections)
+ *
+ * @return int
+ */
+ public function getServerCount();
+
+ /**
+ * Get the host name or IP address of the server with the specified index
+ * Prefer a readable name if available.
+ * @param string $i
+ * @return string
+ */
+ public function getServerName( $i );
+
+ /**
+ * Return the server info structure for a given index, or false if the index is invalid.
+ * @param int $i
+ * @return array|bool
+ */
+ public function getServerInfo( $i );
+
+ /**
+ * Sets the server info structure for the given index. Entry at index $i
+ * is created if it doesn't exist
+ * @param int $i
+ * @param array $serverInfo
+ */
+ public function setServerInfo( $i, array $serverInfo );
+
+ /**
+ * Get the current master position for chronology control purposes
+ * @return DBMasterPos|bool Returns false if not applicable
+ */
+ public function getMasterPos();
+
+ /**
+ * Disable this load balancer. All connections are closed, and any attempt to
+ * open a new connection will result in a DBAccessError.
+ */
+ public function disable();
+
+ /**
+ * Close all open connections
+ */
+ public function closeAll();
+
+ /**
+ * Close a connection
+ *
+ * Using this function makes sure the LoadBalancer knows the connection is closed.
+ * If you use $conn->close() directly, the load balancer won't update its state.
+ *
+ * @param IDatabase $conn
+ */
+ public function closeConnection( IDatabase $conn );
+
+ /**
+ * Commit transactions on all open connections
+ * @param string $fname Caller name
+ * @throws DBExpectedError
+ */
+ public function commitAll( $fname = __METHOD__ );
+
+ /**
+ * Perform all pre-commit callbacks that remain part of the atomic transactions
+ * and disable any post-commit callbacks until runMasterPostTrxCallbacks()
+ *
+ * Use this only for mutli-database commits
+ */
+ public function finalizeMasterChanges();
+
+ /**
+ * Perform all pre-commit checks for things like replication safety
+ *
+ * Use this only for mutli-database commits
+ *
+ * @param array $options Includes:
+ * - maxWriteDuration : max write query duration time in seconds
+ * @throws DBTransactionError
+ */
+ public function approveMasterChanges( array $options );
+
+ /**
+ * Flush any master transaction snapshots and set DBO_TRX (if DBO_DEFAULT is set)
+ *
+ * The DBO_TRX setting will be reverted to the default in each of these methods:
+ * - commitMasterChanges()
+ * - rollbackMasterChanges()
+ * - commitAll()
+ * This allows for custom transaction rounds from any outer transaction scope.
+ *
+ * @param string $fname
+ * @throws DBExpectedError
+ */
+ public function beginMasterChanges( $fname = __METHOD__ );
+
+ /**
+ * Issue COMMIT on all master connections where writes where done
+ * @param string $fname Caller name
+ * @throws DBExpectedError
+ */
+ public function commitMasterChanges( $fname = __METHOD__ );
+
+ /**
+ * Issue all pending post-COMMIT/ROLLBACK callbacks
+ *
+ * Use this only for mutli-database commits
+ *
+ * @param integer $type IDatabase::TRIGGER_* constant
+ * @return Exception|null The first exception or null if there were none
+ */
+ public function runMasterPostTrxCallbacks( $type );
+
+ /**
+ * Issue ROLLBACK only on master, only if queries were done on connection
+ * @param string $fname Caller name
+ * @throws DBExpectedError
+ */
+ public function rollbackMasterChanges( $fname = __METHOD__ );
+
+ /**
+ * Suppress all pending post-COMMIT/ROLLBACK callbacks
+ *
+ * Use this only for mutli-database commits
+ *
+ * @return Exception|null The first exception or null if there were none
+ */
+ public function suppressTransactionEndCallbacks();
+
+ /**
+ * Commit all replica DB transactions so as to flush any REPEATABLE-READ or SSI snapshot
+ *
+ * @param string $fname Caller name
+ */
+ public function flushReplicaSnapshots( $fname = __METHOD__ );
+
+ /**
+ * @return bool Whether a master connection is already open
+ */
+ public function hasMasterConnection();
+
+ /**
+ * Determine if there are pending changes in a transaction by this thread
+ * @return bool
+ */
+ public function hasMasterChanges();
+
+ /**
+ * Get the timestamp of the latest write query done by this thread
+ * @return float|bool UNIX timestamp or false
+ */
+ public function lastMasterChangeTimestamp();
+
+ /**
+ * Check if this load balancer object had any recent or still
+ * pending writes issued against it by this PHP thread
+ *
+ * @param float $age How many seconds ago is "recent" [defaults to mWaitTimeout]
+ * @return bool
+ */
+ public function hasOrMadeRecentMasterChanges( $age = null );
+
+ /**
+ * Get the list of callers that have pending master changes
+ *
+ * @return string[] List of method names
+ */
+ public function pendingMasterChangeCallers();
+
+ /**
+ * @note This method will trigger a DB connection if not yet done
+ * @param string|bool $wiki Wiki ID, or false for the current wiki
+ * @return bool Whether the generic connection for reads is highly "lagged"
+ */
+ public function getLaggedReplicaMode( $wiki = false );
+
+ /**
+ * @note This method will never cause a new DB connection
+ * @return bool Whether any generic connection used for reads was highly "lagged"
+ */
+ public function laggedReplicaUsed();
+
+ /**
+ * @note This method may trigger a DB connection if not yet done
+ * @param string|bool $wiki Wiki ID, or false for the current wiki
+ * @param IDatabase|null DB master connection; used to avoid loops [optional]
+ * @return string|bool Reason the master is read-only or false if it is not
+ */
+ public function getReadOnlyReason( $wiki = false, IDatabase $conn = null );
+
+ /**
+ * Disables/enables lag checks
+ * @param null|bool $mode
+ * @return bool
+ */
+ public function allowLagged( $mode = null );
+
+ /**
+ * @return bool
+ */
+ public function pingAll();
+
+ /**
+ * Call a function with each open connection object
+ * @param callable $callback
+ * @param array $params
+ */
+ public function forEachOpenConnection( $callback, array $params = [] );
+
+ /**
+ * Call a function with each open connection object to a master
+ * @param callable $callback
+ * @param array $params
+ */
+ public function forEachOpenMasterConnection( $callback, array $params = [] );
+
+ /**
+ * Call a function with each open replica DB connection object
+ * @param callable $callback
+ * @param array $params
+ */
+ public function forEachOpenReplicaConnection( $callback, array $params = [] );
+
+ /**
+ * Get the hostname and lag time of the most-lagged replica DB
+ *
+ * This is useful for maintenance scripts that need to throttle their updates.
+ * May attempt to open connections to replica DBs on the default DB. If there is
+ * no lag, the maximum lag will be reported as -1.
+ *
+ * @param bool|string $wiki Wiki ID, or false for the default database
+ * @return array ( host, max lag, index of max lagged host )
+ */
+ public function getMaxLag( $wiki = false );
+
+ /**
+ * Get an estimate of replication lag (in seconds) for each server
+ *
+ * Results are cached for a short time in memcached/process cache
+ *
+ * Values may be "false" if replication is too broken to estimate
+ *
+ * @param string|bool $wiki
+ * @return int[] Map of (server index => float|int|bool)
+ */
+ public function getLagTimes( $wiki = false );
+
+ /**
+ * Get the lag in seconds for a given connection, or zero if this load
+ * balancer does not have replication enabled.
+ *
+ * This should be used in preference to Database::getLag() in cases where
+ * replication may not be in use, since there is no way to determine if
+ * replication is in use at the connection level without running
+ * potentially restricted queries such as SHOW SLAVE STATUS. Using this
+ * function instead of Database::getLag() avoids a fatal error in this
+ * case on many installations.
+ *
+ * @param IDatabase $conn
+ * @return int|bool Returns false on error
+ */
+ public function safeGetLag( IDatabase $conn );
+
+ /**
+ * Wait for a replica DB to reach a specified master position
+ *
+ * This will connect to the master to get an accurate position if $pos is not given
+ *
+ * @param IDatabase $conn Replica DB
+ * @param DBMasterPos|bool $pos Master position; default: current position
+ * @param integer|null $timeout Timeout in seconds [optional]
+ * @return bool Success
+ */
+ public function safeWaitForMasterPos( IDatabase $conn, $pos = false, $timeout = null );
+
+ /**
+ * Clear the cache for slag lag delay times
+ *
+ * This is only used for testing
+ */
+ public function clearLagTimeCache();
+
+ /**
+ * Set a callback via IDatabase::setTransactionListener() on
+ * all current and future master connections of this load balancer
+ *
+ * @param string $name Callback name
+ * @param callable|null $callback
+ */
+ public function setTransactionListener( $name, callable $callback = null );
+}
sort( $pageNames );
$key = implode( '|', $pageNames );
if ( !isset( $this->titleInfo[$key] ) ) {
- $this->titleInfo[$key] = self::fetchTitleInfo( $dbr, $pageNames, __METHOD__ );
+ $this->titleInfo[$key] = static::fetchTitleInfo( $dbr, $pageNames, __METHOD__ );
}
return $this->titleInfo[$key];
}
- private static function fetchTitleInfo( IDatabase $db, array $pages, $fname = __METHOD__ ) {
+ protected static function fetchTitleInfo( IDatabase $db, array $pages, $fname = __METHOD__ ) {
$titleInfo = [];
$batch = new LinkBatch;
foreach ( $pages as $titleText ) {
}
}
}
- $allInfo = self::fetchTitleInfo( $db, array_keys( $allPages ), __METHOD__ );
+ $allInfo = static::fetchTitleInfo( $db, array_keys( $allPages ), __METHOD__ );
foreach ( $wikiModules as $module ) {
$pages = $module->getPages( $context );
- $info = array_intersect_key( $allInfo, $pages );
+ // Before we intersect, map the names to canonical form (T145673).
+ $intersect = [];
+ foreach ( $pages as $page => $unused ) {
+ $title = Title::newFromText( $page )->getPrefixedText();
+ $intersect[$title] = 1;
+ }
+ $info = array_intersect_key( $allInfo, $intersect );
+
$pageNames = array_keys( $pages );
sort( $pageNames );
$key = implode( '|', $pageNames );
return this.upload.getApi()
.then( function ( api ) {
// 'amenableparser' will expand templates and parser functions server-side.
- // We still do the rest of wikitext parsing here (throught jqueryMsg).
+ // We still do the rest of wikitext parsing here (through jqueryMsg).
return api.loadMessagesIfMissing( [ error.message.key ], { amenableparser: true } )
.then( function () {
if ( !mw.message( error.message.key ).exists() ) {
->setConstructorArgs( [ $resourceLoader, $request ] )
->setMethods( [ 'getDirection' ] )
->getMock();
- $ctx->expects( $this->any() )->method( 'getDirection' )->will(
- $this->returnValue( $dir )
- );
+ $ctx->method( 'getDirection' )->willReturn( $dir );
return $ctx;
}
],
];
}
+
+ /**
+ * @covers ResourceLoaderWikiModule::getTitleInfo
+ */
+ public function testGetTitleInfo() {
+ $pages = [
+ 'MediaWiki:Common.css' => [ 'type' => 'styles' ],
+ 'mediawiki: fallback.css' => [ 'type' => 'styles' ],
+ ];
+ $titleInfo = [
+ 'MediaWiki:Common.css' => [ 'page_len' => 1234 ],
+ 'MediaWiki:Fallback.css' => [ 'page_len' => 0 ],
+ ];
+ $expected = $titleInfo;
+
+ $module = $this->getMockBuilder( 'TestResourceLoaderWikiModule' )
+ ->setMethods( [ 'getPages' ] )
+ ->getMock();
+ $module->method( 'getPages' )->willReturn( $pages );
+ // Can't mock static methods
+ $module::$returnFetchTitleInfo = $titleInfo;
+
+ $context = $this->getMockBuilder( 'ResourceLoaderContext' )
+ ->disableOriginalConstructor()
+ ->getMock();
+
+ $module = TestingAccessWrapper::newFromObject( $module );
+ $this->assertEquals( $expected, $module->getTitleInfo( $context ), 'Title info' );
+ }
+
+ /**
+ * @covers ResourceLoaderWikiModule::getTitleInfo
+ * @covers ResourceLoaderWikiModule::setTitleInfo
+ * @covers ResourceLoaderWikiModule::preloadTitleInfo
+ */
+ public function testGetPreloadedTitleInfo() {
+ $pages = [
+ 'MediaWiki:Common.css' => [ 'type' => 'styles' ],
+ // Regression against T145673. It's impossible to statically declare page names in
+ // a canonical way since the canonical prefix is localised. As such, the preload
+ // cache computed the right cache key, but failed to find the results when
+ // doing an intersect on the canonical result, producing an empty array.
+ 'mediawiki: fallback.css' => [ 'type' => 'styles' ],
+ ];
+ $titleInfo = [
+ 'MediaWiki:Common.css' => [ 'page_len' => 1234 ],
+ 'MediaWiki:Fallback.css' => [ 'page_len' => 0 ],
+ ];
+ $expected = $titleInfo;
+
+ $module = $this->getMockBuilder( 'TestResourceLoaderWikiModule' )
+ ->setMethods( [ 'getPages' ] )
+ ->getMock();
+ $module->method( 'getPages' )->willReturn( $pages );
+ // Can't mock static methods
+ $module::$returnFetchTitleInfo = $titleInfo;
+
+ $rl = new EmptyResourceLoader();
+ $rl->register( 'testmodule', $module );
+ $context = new ResourceLoaderContext( $rl, new FauxRequest() );
+
+ TestResourceLoaderWikiModule::preloadTitleInfo(
+ $context,
+ wfGetDB( DB_REPLICA ),
+ [ 'testmodule' ]
+ );
+
+ $module = TestingAccessWrapper::newFromObject( $module );
+ $this->assertEquals( $expected, $module->getTitleInfo( $context ), 'Title info' );
+ }
+}
+
+class TestResourceLoaderWikiModule extends ResourceLoaderWikiModule {
+ public static $returnFetchTitleInfo = null;
+ protected static function fetchTitleInfo( IDatabase $db, array $pages, $fname = null ) {
+ $ret = self::$returnFetchTitleInfo;
+ self::$returnFetchTitleInfo = null;
+ return $ret;
+ }
}
dépôts / lhc / web / wiklou.git / commitdiff