includes/libs/rdbms/database/DBConnRef.php
<?php
namespace Wikimedia\Rdbms;
use InvalidArgumentException;
/**
* Helper class used for automatically re-using IDatabase connections and lazily
* establishing the actual network connection to a database host.
*
* It does this by deferring to ILoadBalancer::getConnectionInternal, which in
* turn ensures we share and re-use a single connection for a given database
* wherever possible.
*
* This class previously used an RAII-style pattern where connections would be
* claimed from a pool, and then added back to the pool for re-use only after
* the calling code's variable for this object went out of scope (a __destruct
* got called when the calling function returns or throws). This is no longer
* needed today as LoadBalancer now permits re-use internally even for
* overlapping callers, where two pieces of code may both obtain their own
* DBConnRef object and where both are used alternatingly, and yet still share
* the same connection.
*
* @par Example:
* @code
* function getRowData() {
* $conn = $this->lb->getConnection( DB_REPLICA );
* $row = $conn->select( ... );
* return $row ? (array)$row : false;
* }
* @endcode
*
* @ingroup Database
* @since 1.22
*/
class DBConnRef implements IMaintainableDatabase {
/** @var ILoadBalancer */
private $lb;
/** @var Database|null Live connection handle */
private $conn;
/**
* @var array Map of (DBConnRef::FLD_* constant => connection parameter)
* @phan-var array{0:int,1:array|string|false,2:DatabaseDomain,3:int}
*/
private $params;
/** @var int One of DB_PRIMARY/DB_REPLICA */
private $role;
/**
* @var int Reference to the $modcount passed to the constructor.
* $conn is valid if $modCountRef and $modCountFix are the same.
*/
private $modCountRef;
/**
* @var int Last known good value of $modCountRef
* $conn is valid if $modCountRef and $modCountFix are the same.
*/
private $modCountFix;
private const FLD_INDEX = 0;
private const FLD_GROUPS = 1;
private const FLD_DOMAIN = 2;
private const FLD_FLAGS = 3;
/**
* @internal May not be used outside Rdbms LoadBalancer
* @param ILoadBalancer $lb Connection manager for $conn
* @param array $params [server index, query groups, domain, flags]
* @param int $role The type of connection asked for; one of DB_PRIMARY/DB_REPLICA
* @param null|int &$modcount Reference to a modification counter. This is for
* LoadBalancer::reconfigure to indicate that a new connection should be acquired.
*/
public function __construct( ILoadBalancer $lb, $params, $role, &$modcount = 0 ) {
if ( !is_array( $params ) || count( $params ) < 4 || $params[self::FLD_DOMAIN] === false ) {
throw new InvalidArgumentException( "Missing lazy connection arguments." );
}
$params[self::FLD_DOMAIN] = DatabaseDomain::newFromId( $params[self::FLD_DOMAIN] );
$this->lb = $lb;
$this->params = $params;
$this->role = $role;
// $this->conn is valid as long as $this->modCountRef and $this->modCountFix are the same.
$this->modCountRef = &$modcount; // remember reference
$this->modCountFix = $modcount; // remember current value
}
/**
* Connect to the database if we are not already connected.
*/
public function ensureConnection() {
if ( $this->modCountFix !== $this->modCountRef ) {
// Discard existing connection, unless we are in an ongoing transaction.
// This is triggered by LoadBalancer::reconfigure(), to allow changed settings
// to take effect. The primary use case are replica servers being taken out of
// rotation, or the primary database changing.
if ( !$this->conn->trxLevel() ) {
$this->conn->close();
$this->conn = null;
}
}
if ( $this->conn === null ) {
$this->conn = $this->lb->getConnectionInternal(
$this->params[self::FLD_INDEX],
$this->params[self::FLD_GROUPS],
$this->params[self::FLD_DOMAIN]->getId(),
$this->params[self::FLD_FLAGS]
);
$this->modCountFix = $this->modCountRef;
}
if ( !$this->params[self::FLD_DOMAIN]->equals( $this->conn->getDomainID() ) ) {
// The underlying connection handle is likely being shared by other DBConnRef
// instances in a load balancer. Make sure that each one routes queries by their
// owner function to the domain that the owner expects.
$this->conn->selectDomain( $this->params[self::FLD_DOMAIN] );
}
}
public function __call( $name, array $arguments ) {
$this->ensureConnection();
return $this->conn->$name( ...$arguments );
}
/**
* @return int DB_PRIMARY when this *requires* the primary DB, otherwise DB_REPLICA
* @since 1.33
*/
public function getReferenceRole() {
return $this->role;
}
public function getServerInfo() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getTopologyBasedServerId() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getTopologyRole() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function trxLevel() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function trxTimestamp() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function explicitTrxActive() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function tablePrefix( $prefix = null ) {
if ( $prefix !== null ) {
// Disallow things that might confuse the LoadBalancer tracking
throw $this->getDomainChangeException();
}
if ( $this->conn === null ) {
// Avoid triggering a database connection
$prefix = $this->params[self::FLD_DOMAIN]->getTablePrefix();
} else {
// This will just return the prefix
$prefix = $this->__call( __FUNCTION__, func_get_args() );
}
return $prefix;
}
public function dbSchema( $schema = null ) {
if ( $schema !== null ) {
// Disallow things that might confuse the LoadBalancer tracking
throw $this->getDomainChangeException();
}
if ( $this->conn === null ) {
// Avoid triggering a database connection
$schema = (string)( $this->params[self::FLD_DOMAIN]->getSchema() );
} else {
// This will just return the schema
$schema = $this->__call( __FUNCTION__, func_get_args() );
}
return $schema;
}
public function getLBInfo( $name = null ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function setLBInfo( $nameOrArray, $value = null ) {
// @phan-suppress-previous-line PhanPluginNeverReturnMethod
// Disallow things that might confuse the LoadBalancer tracking
throw $this->getDomainChangeException();
}
public function implicitOrderby() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function lastDoneWrites() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function writesPending() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function writesOrCallbacksPending() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function pendingWriteQueryDuration( $type = self::ESTIMATE_TOTAL ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function pendingWriteCallers() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function isOpen() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function setFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function clearFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function restoreFlags( $state = self::RESTORE_PRIOR ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getFlag( $flag ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getProperty( $name ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getDomainID() {
if ( $this->conn === null ) {
// Avoid triggering a database connection
return $this->params[self::FLD_DOMAIN]->getId();
}
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getType() {
if ( $this->conn === null ) {
// Avoid triggering a database connection
$index = $this->normalizeServerIndex( $this->params[self::FLD_INDEX] );
if ( $index >= 0 ) {
// In theory, if $index is DB_REPLICA, the type could vary
return $this->lb->getServerType( $index );
}
}
return $this->__call( __FUNCTION__, func_get_args() );
}
public function insertId() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function lastErrno() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function lastError() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function affectedRows() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getSoftwareLink() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getServerVersion() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function close( $fname = __METHOD__ ) {
// @phan-suppress-previous-line PhanPluginNeverReturnMethod
throw new DBUnexpectedError( $this->conn, 'Cannot close shared connection.' );
}
public function query( $sql, $fname = __METHOD__, $flags = 0 ) {
if ( $this->role !== ILoadBalancer::DB_PRIMARY ) {
$flags |= IDatabase::QUERY_REPLICA_ROLE;
}
return $this->__call( __FUNCTION__, [ $sql, $fname, $flags ] );
}
public function newSelectQueryBuilder(): SelectQueryBuilder {
// Use $this not $this->conn so that the domain is preserved (T326377)
return new SelectQueryBuilder( $this );
}
public function newUnionQueryBuilder(): UnionQueryBuilder {
// Use $this not $this->conn so that the domain is preserved (T326377)
return new UnionQueryBuilder( $this );
}
public function newUpdateQueryBuilder(): UpdateQueryBuilder {
// Use $this not $this->conn so that the domain is preserved (T326377)
return new UpdateQueryBuilder( $this );
}
public function newDeleteQueryBuilder(): DeleteQueryBuilder {
// Use $this not $this->conn so that the domain is preserved (T326377)
return new DeleteQueryBuilder( $this );
}
public function newInsertQueryBuilder(): InsertQueryBuilder {
// Use $this not $this->conn so that the domain is preserved (T326377)
return new InsertQueryBuilder( $this );
}
public function newReplaceQueryBuilder(): ReplaceQueryBuilder {
// Use $this not $this->conn so that the domain is preserved (T326377)
return new ReplaceQueryBuilder( $this );
}
public function selectField(
$table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function selectFieldValues(
$table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
): array {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function select(
$table, $vars, $conds = '', $fname = __METHOD__,
$options = [], $join_conds = []
) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function selectSQLText(
$table, $vars, $conds = '', $fname = __METHOD__,
$options = [], $join_conds = []
) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function limitResult( $sql, $limit, $offset = false ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function selectRow(
$table, $vars, $conds, $fname = __METHOD__,
$options = [], $join_conds = []
) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function estimateRowCount(
$tables, $vars = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
): int {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function selectRowCount(
$tables, $vars = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
): int {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function lockForUpdate(
$table, $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function fieldExists( $table, $field, $fname = __METHOD__ ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function indexExists( $table, $index, $fname = __METHOD__ ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function tableExists( $table, $fname = __METHOD__ ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function insert( $table, $rows, $fname = __METHOD__, $options = [] ) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function update( $table, $set, $conds, $fname = __METHOD__, $options = [] ) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function buildComparison( string $op, array $conds ): string {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function makeList( array $a, $mode = self::LIST_COMMA ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function factorConds( $condsArray ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function bitNot( $field ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function bitAnd( $fieldLeft, $fieldRight ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function bitOr( $fieldLeft, $fieldRight ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function buildConcat( $stringList ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function buildGroupConcatField(
$delim, $table, $field, $conds = '', $join_conds = []
) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function buildGreatest( $fields, $values ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function buildLeast( $fields, $values ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function buildSubstring( $input, $startPosition, $length = null ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function buildStringCast( $field ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function buildIntegerCast( $field ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function buildExcludedValue( $column ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function buildSelectSubquery(
$table, $vars, $conds = '', $fname = __METHOD__,
$options = [], $join_conds = []
) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function databasesAreIndependent() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function selectDomain( $domain ) {
// @phan-suppress-previous-line PhanPluginNeverReturnMethod
// Disallow things that might confuse the LoadBalancer tracking
throw $this->getDomainChangeException();
}
public function getDBname() {
if ( $this->conn === null ) {
// Avoid triggering a database connection
return $this->params[self::FLD_DOMAIN]->getDatabase();
}
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getServer() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getServerName() {
if ( $this->conn === null ) {
// Avoid triggering a database connection
$index = $this->normalizeServerIndex( $this->params[self::FLD_INDEX] );
if ( $index >= 0 ) {
// If $index is DB_REPLICA, the server name could vary
return $this->lb->getServerName( $index );
}
}
return $this->__call( __FUNCTION__, func_get_args() );
}
public function addQuotes( $s ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function expr( string $field, string $op, $value ): Expression {
return new Expression( $field, $op, $value );
}
public function addIdentifierQuotes( $s ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function buildLike( $param, ...$params ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function anyChar() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function anyString() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function nextSequenceValue( $seqName ) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function replace( $table, $uniqueKeys, $rows, $fname = __METHOD__ ) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function upsert(
$table, array $rows, $uniqueKeys, array $set, $fname = __METHOD__
) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function deleteJoin(
$delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__
) {
$this->assertRoleAllowsWrites();
$this->__call( __FUNCTION__, func_get_args() );
}
public function delete( $table, $conds, $fname = __METHOD__ ) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function insertSelect(
$destTable, $srcTable, $varMap, $conds,
$fname = __METHOD__, $insertOptions = [], $selectOptions = [], $selectJoinConds = []
) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function unionSupportsOrderAndLimit() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function unionQueries( $sqls, $all, $options = [] ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function conditional( $cond, $caseTrueExpression, $caseFalseExpression ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function strreplace( $orig, $old, $new ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function wasDeadlock() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function wasReadOnlyError() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function primaryPosWait( DBPrimaryPos $pos, $timeout ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getPrimaryPos() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function serverIsReadOnly() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function onTransactionResolution( callable $callback, $fname = __METHOD__ ) {
// DB_REPLICA role: caller might want to refresh cache after a REPEATABLE-READ snapshot
return $this->__call( __FUNCTION__, func_get_args() );
}
public function onTransactionCommitOrIdle( callable $callback, $fname = __METHOD__ ) {
// DB_REPLICA role: caller might want to refresh cache after a REPEATABLE-READ snapshot
return $this->__call( __FUNCTION__, func_get_args() );
}
public function onTransactionPreCommitOrIdle( callable $callback, $fname = __METHOD__ ) {
// DB_REPLICA role: caller might want to refresh cache after a cache mutex is released
return $this->__call( __FUNCTION__, func_get_args() );
}
public function onAtomicSectionCancel( callable $callback, $fname = __METHOD__ ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function setTransactionListener( $name, callable $callback = null ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function startAtomic(
$fname = __METHOD__, $cancelable = IDatabase::ATOMIC_NOT_CANCELABLE
) {
// Don't call assertRoleAllowsWrites(); caller might want a REPEATABLE-READ snapshot
return $this->__call( __FUNCTION__, func_get_args() );
}
public function endAtomic( $fname = __METHOD__ ) {
// Don't call assertRoleAllowsWrites(); caller might want a REPEATABLE-READ snapshot
return $this->__call( __FUNCTION__, func_get_args() );
}
public function cancelAtomic( $fname = __METHOD__, AtomicSectionIdentifier $sectionId = null ) {
// Don't call assertRoleAllowsWrites(); caller might want a REPEATABLE-READ snapshot
return $this->__call( __FUNCTION__, func_get_args() );
}
public function doAtomicSection(
$fname, callable $callback, $cancelable = self::ATOMIC_NOT_CANCELABLE
) {
// Don't call assertRoleAllowsWrites(); caller might want a REPEATABLE-READ snapshot
return $this->__call( __FUNCTION__, func_get_args() );
}
public function begin( $fname = __METHOD__, $mode = IDatabase::TRANSACTION_EXPLICIT ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function commit( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function rollback( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function flushSession( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function flushSnapshot( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function timestamp( $ts = 0 ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function timestampOrNull( $ts = null ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function ping( &$rtt = null ) {
return func_num_args()
? $this->__call( __FUNCTION__, [ &$rtt ] )
: $this->__call( __FUNCTION__, [] ); // method cares about null vs missing
}
public function getLag() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getSessionLagStatus() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function encodeBlob( $b ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function decodeBlob( $b ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function setSessionOptions( array $options ) {
$this->__call( __FUNCTION__, func_get_args() );
}
public function setSchemaVars( $vars ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function lockIsFree( $lockName, $method ) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function lock( $lockName, $method, $timeout = 5, $flags = 0 ) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function unlock( $lockName, $method ) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function namedLocksEnqueue() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getInfinity() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function encodeExpiry( $expiry ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function decodeExpiry( $expiry, $format = TS_MW ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function isReadOnly() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function setTableAliases( array $aliases ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function getTableAliases() {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function setIndexAliases( array $aliases ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function tableName( $name, $format = 'quoted' ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function tableNames( ...$tables ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function tableNamesN( ...$tables ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function sourceFile(
$filename,
callable $lineCallback = null,
callable $resultCallback = null,
$fname = false,
callable $inputCallback = null
) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function sourceStream(
$fp,
callable $lineCallback = null,
callable $resultCallback = null,
$fname = __METHOD__,
callable $inputCallback = null
) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function dropTable( $table, $fname = __METHOD__ ) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function truncateTable( $table, $fname = __METHOD__ ) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function truncate( $tables, $fname = __METHOD__ ) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function listViews( $prefix = null, $fname = __METHOD__ ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function textFieldSize( $table, $field ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function streamStatementEnd( &$sql, &$newLine ) {
return $this->__call( __FUNCTION__, [ &$sql, &$newLine ] );
}
public function duplicateTableStructure(
$oldName, $newName, $temporary = false, $fname = __METHOD__
) {
$this->assertRoleAllowsWrites();
return $this->__call( __FUNCTION__, func_get_args() );
}
public function indexUnique( $table, $index, $fname = __METHOD__ ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function listTables( $prefix = null, $fname = __METHOD__ ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function fieldInfo( $table, $field ) {
return $this->__call( __FUNCTION__, func_get_args() );
}
public function __toString() {
if ( $this->conn === null ) {
return $this->getType() . ' object #' . spl_object_id( $this );
}
return $this->__call( __FUNCTION__, func_get_args() );
}
/**
* Error out if the role is not DB_PRIMARY
*
* Note that the underlying connection may or may not itself be read-only.
* It could even be to a writable primary (both server-side and to the application).
* This error is meant for the case when a DB_REPLICA handle was requested but a
* a write was attempted on that handle regardless.
*
* In configurations where the primary DB has some generic read load or is the only server,
* DB_PRIMARY/DB_REPLICA will sometimes (or always) use the same connection to the primary DB.
* This does not effect the role of DBConnRef instances.
* @throws DBReadOnlyRoleError
*/
protected function assertRoleAllowsWrites() {
// DB_PRIMARY is "prima facie" writable
if ( $this->role !== ILoadBalancer::DB_PRIMARY ) {
throw new DBReadOnlyRoleError( $this->conn, "Cannot write with role DB_REPLICA" );
}
}
/**
* @return DBUnexpectedError
*/
protected function getDomainChangeException() {
return new DBUnexpectedError(
$this,
"Cannot directly change the selected DB domain; any underlying connection handle " .
"is owned by a LoadBalancer instance and possibly shared with other callers. " .
"LoadBalancer automatically manages DB domain re-selection of unused handles."
);
}
/**
* @param int $i Specific or virtual (DB_PRIMARY/DB_REPLICA) server index
* @return int|mixed
*/
protected function normalizeServerIndex( $i ) {
return ( $i === ILoadBalancer::DB_PRIMARY ) ? $this->lb->getWriterIndex() : $i;
}
}