23s2s

✏️ Editing: class-ai1wm-database.php

<?php
/**
 * Copyright (C) 2014-2020 ServMask Inc.
 *
 * 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 * ███████╗███████╗██████╗ ██╗   ██╗███╗   ███╗ █████╗ ███████╗██╗  ██╗
 * ██╔════╝██╔════╝██╔══██╗██║   ██║████╗ ████║██╔══██╗██╔════╝██║ ██╔╝
 * ███████╗█████╗  ██████╔╝██║   ██║██╔████╔██║███████║███████╗█████╔╝
 * ╚════██║██╔══╝  ██╔══██╗╚██╗ ██╔╝██║╚██╔╝██║██╔══██║╚════██║██╔═██╗
 * ███████║███████╗██║  ██║ ╚████╔╝ ██║ ╚═╝ ██║██║  ██║███████║██║  ██╗
 * ╚══════╝╚══════╝╚═╝  ╚═╝  ╚═══╝  ╚═╝     ╚═╝╚═╝  ╚═╝╚══════╝╚═╝  ╚═╝
 */

if ( ! defined( 'ABSPATH' ) ) {
	die( 'Kangaroos cannot jump here' );
}

abstract class Ai1wm_Database {

/**
	 * WordPress database handler
	 *
	 * @var object
	 */
	protected $wpdb = null;

/**
	 * Old table prefixes
	 *
	 * @var array
	 */
	protected $old_table_prefixes = array();

/**
	 * New table prefixes
	 *
	 * @var array
	 */
	protected $new_table_prefixes = array();

/**
	 * Old column prefixes
	 *
	 * @var array
	 */
	protected $old_column_prefixes = array();

/**
	 * New column prefixes
	 *
	 * @var array
	 */
	protected $new_column_prefixes = array();

/**
	 * Old replace values
	 *
	 * @var array
	 */
	protected $old_replace_values = array();

/**
	 * New replace values
	 *
	 * @var array
	 */
	protected $new_replace_values = array();

/**
	 * Old raw replace values
	 *
	 * @var array
	 */
	protected $old_replace_raw_values = array();

/**
	 * New raw replace values
	 *
	 * @var array
	 */
	protected $new_replace_raw_values = array();

/**
	 * Table where clauses
	 *
	 * @var array
	 */
	protected $table_where_clauses = array();

/**
	 * Table prefix columns
	 *
	 * @var array
	 */
	protected $table_prefix_columns = array();

/**
	 * Include table prefixes
	 *
	 * @var array
	 */
	protected $include_table_prefixes = array();

/**
	 * Exclude table prefixes
	 *
	 * @var array
	 */
	protected $exclude_table_prefixes = array();

/**
	 * List all tables that should not be affected by the timeout of the current request
	 *
	 * @var array
	 */
	protected $atomic_tables = array();

/**
	 * Visual Composer
	 *
	 * @var boolean
	 */
	protected $visual_composer = false;

/**
	 * Oxygen Builder
	 *
	 * @var boolean
	 */
	protected $oxygen_builder = false;

/**
	 * BeTheme Responsive
	 *
	 * @var boolean
	 */
	protected $betheme_responsive = false;

/**
	 * Optimize Press
	 *
	 * @var boolean
	 */
	protected $optimize_press = false;

/**
	 * Constructor
	 *
	 * @param object $wpdb WPDB instance
	 */
	public function __construct( $wpdb ) {
		$this->wpdb = $wpdb;

// Check Microsoft SQL Server support
		if ( is_resource( $this->wpdb->dbh ) ) {
			if ( get_resource_type( $this->wpdb->dbh ) === 'SQL Server Connection' ) {
				throw new Ai1wm_Database_Exception(
					'Your WordPress installation uses Microsoft SQL Server. ' .
					'To use All-in-One WP Migration, please change your installation to MySQL and try again. ' .
					'<a href="https://help.servmask.com/knowledgebase/microsoft-sql-server/" target="_blank">Technical details</a>',
					501
				);
			}
		}

// Set database host (HyberDB)
		if ( empty( $this->wpdb->dbhost ) ) {
			if ( isset( $this->wpdb->last_used_server['host'] ) ) {
				$this->wpdb->dbhost = $this->wpdb->last_used_server['host'];
			}
		}

// Set database name (HyperDB)
		if ( empty( $this->wpdb->dbname ) ) {
			if ( isset( $this->wpdb->last_used_server['name'] ) ) {
				$this->wpdb->dbname = $this->wpdb->last_used_server['name'];
			}
		}
	}

/**
	 * Set old table prefixes
	 *
	 * @param  array  $prefixes List of table prefixes
	 * @return object
	 */
	public function set_old_table_prefixes( $prefixes ) {
		$this->old_table_prefixes = $prefixes;

return $this;
	}

/**
	 * Get old table prefixes
	 *
	 * @return array
	 */
	public function get_old_table_prefixes() {
		return $this->old_table_prefixes;
	}

/**
	 * Set new table prefixes
	 *
	 * @param  array  $prefixes List of table prefixes
	 * @return object
	 */
	public function set_new_table_prefixes( $prefixes ) {
		$this->new_table_prefixes = $prefixes;

return $this;
	}

/**
	 * Get new table prefixes
	 *
	 * @return array
	 */
	public function get_new_table_prefixes() {
		return $this->new_table_prefixes;
	}

/**
	 * Set old column prefixes
	 *
	 * @param  array  $prefixes List of column prefixes
	 * @return object
	 */
	public function set_old_column_prefixes( $prefixes ) {
		$this->old_column_prefixes = $prefixes;

return $this;
	}

/**
	 * Get old column prefixes
	 *
	 * @return array
	 */
	public function get_old_column_prefixes() {
		return $this->old_column_prefixes;
	}

/**
	 * Set new column prefixes
	 *
	 * @param  array  $prefixes List of column prefixes
	 * @return object
	 */
	public function set_new_column_prefixes( $prefixes ) {
		$this->new_column_prefixes = $prefixes;

return $this;
	}

/**
	 * Get new column prefixes
	 *
	 * @return array
	 */
	public function get_new_column_prefixes() {
		return $this->new_column_prefixes;
	}

/**
	 * Set old replace values
	 *
	 * @param  array  $values List of values
	 * @return object
	 */
	public function set_old_replace_values( $values ) {
		$this->old_replace_values = $values;

return $this;
	}

/**
	 * Get old replace values
	 *
	 * @return array
	 */
	public function get_old_replace_values() {
		return $this->old_replace_values;
	}

/**
	 * Set new replace values
	 *
	 * @param  array  $values List of values
	 * @return object
	 */
	public function set_new_replace_values( $values ) {
		$this->new_replace_values = $values;

return $this;
	}

/**
	 * Get new replace values
	 *
	 * @return array
	 */
	public function get_new_replace_values() {
		return $this->new_replace_values;
	}

/**
	 * Set old replace raw values
	 *
	 * @param  array  $values List of values
	 * @return object
	 */
	public function set_old_replace_raw_values( $values ) {
		$this->old_replace_raw_values = $values;

return $this;
	}

/**
	 * Get old replace raw values
	 *
	 * @return array
	 */
	public function get_old_replace_raw_values() {
		return $this->old_replace_raw_values;
	}

/**
	 * Set new replace raw values
	 *
	 * @param  array  $values List of values
	 * @return object
	 */
	public function set_new_replace_raw_values( $values ) {
		$this->new_replace_raw_values = $values;

return $this;
	}

/**
	 * Get new replace raw values
	 *
	 * @return array
	 */
	public function get_new_replace_raw_values() {
		return $this->new_replace_raw_values;
	}

/**
	 * Set table where clauses
	 *
	 * @param  string $table_name    Table name
	 * @param  array  $where_clauses Table clauses
	 * @return object
	 */
	public function set_table_where_clauses( $table_name, $where_clauses ) {
		$this->table_where_clauses[ strtolower( $table_name ) ] = $where_clauses;

return $this;
	}

/**
	 * Get table where clauses
	 *
	 * @param  string $table_name Table name
	 * @return array
	 */
	public function get_table_where_clauses( $table_name ) {
		if ( isset( $this->table_where_clauses[ strtolower( $table_name ) ] ) ) {
			return $this->table_where_clauses[ strtolower( $table_name ) ];
		}

return array();
	}

/**
	 * Set table prefix columns
	 *
	 * @param  string $table_name     Table name
	 * @param  array  $prefix_columns Table columns
	 * @return object
	 */
	public function set_table_prefix_columns( $table_name, $prefix_columns ) {
		foreach ( $prefix_columns as $column_name ) {
			$this->table_prefix_columns[ strtolower( $table_name ) ][ strtolower( $column_name ) ] = true;
		}

return $this;
	}

/**
	 * Get table prefix columns
	 *
	 * @param  string $table_name Table name
	 * @return array
	 */
	public function get_table_prefix_columns( $table_name ) {
		if ( isset( $this->table_prefix_columns[ strtolower( $table_name ) ] ) ) {
			return $this->table_prefix_columns[ strtolower( $table_name ) ];
		}

return array();
	}

/**
	 * Set include table prefixes
	 *
	 * @param  array  $prefixes List of table prefixes
	 * @return object
	 */
	public function set_include_table_prefixes( $prefixes ) {
		$this->include_table_prefixes = $prefixes;

return $this;
	}

/**
	 * Get include table prefixes
	 *
	 * @return array
	 */
	public function get_include_table_prefixes() {
		return $this->include_table_prefixes;
	}

/**
	 * Set exclude table prefixes
	 *
	 * @param  array  $prefixes List of table prefixes
	 * @return object
	 */
	public function set_exclude_table_prefixes( $prefixes ) {
		$this->exclude_table_prefixes = $prefixes;

return $this;
	}

/**
	 * Get exclude table prefixes
	 *
	 * @return array
	 */
	public function get_exclude_table_prefixes() {
		return $this->exclude_table_prefixes;
	}

/**
	 * Set atomic tables
	 *
	 * @param  array  $tables List of tables
	 * @return object
	 */
	public function set_atomic_tables( $tables ) {
		$this->atomic_tables = $tables;

return $this;
	}

/**
	 * Get atomic tables
	 *
	 * @return array
	 */
	public function get_atomic_tables() {
		return $this->atomic_tables;
	}

/**
	 * Set Visual Composer
	 *
	 * @param  boolean $active Is Visual Composer Active?
	 * @return object
	 */
	public function set_visual_composer( $active ) {
		$this->visual_composer = $active;

return $this;
	}

/**
	 * Get Visual Composer
	 *
	 * @return boolean
	 */
	public function get_visual_composer() {
		return $this->visual_composer;
	}

/**
	 * Set Oxygen Builder
	 *
	 * @param  boolean $active Is Oxygen Builder Active?
	 * @return object
	 */
	public function set_oxygen_builder( $active ) {
		$this->oxygen_builder = $active;

return $this;
	}

/**
	 * Get Oxygen Builder
	 *
	 * @return boolean
	 */
	public function get_oxygen_builder() {
		return $this->oxygen_builder;
	}

/**
	 * Set BeTheme Responsive
	 *
	 * @param  boolean $active Is BeTheme Responsive Active?
	 * @return object
	 */
	public function set_betheme_responsive( $active ) {
		$this->betheme_responsive = $active;

return $this;
	}

/**
	 * Get BeTheme Responsive
	 *
	 * @return boolean
	 */
	public function get_betheme_responsive() {
		return $this->betheme_responsive;
	}

/**
	 * Set Optimize Press
	 *
	 * @param  boolean $active Is Optimize Press Active?
	 * @return object
	 */
	public function set_optimize_press( $active ) {
		$this->optimize_press = $active;

return $this;
	}

/**
	 * Get Optimize Press
	 *
	 * @return boolean
	 */
	public function get_optimize_press() {
		return $this->optimize_press;
	}

/**
	 * Get views
	 *
	 * @return array
	 */
	protected function get_views() {
		static $views = null;

// Get views
		if ( is_null( $views ) ) {
			$views = array();

// Loop over views
			$result = $this->query( "SHOW FULL TABLES FROM `{$this->wpdb->dbname}` WHERE `Table_type` = 'VIEW'" );
			while ( $row = $this->fetch_row( $result ) ) {
				if ( isset( $row[0] ) ) {
					$views[] = $row[0];
				}
			}

// Close result cursor
			$this->free_result( $result );
		}

return $views;
	}

/**
	 * Get base tables
	 *
	 * @return array
	 */
	protected function get_base_tables() {
		static $base_tables = null;

// Get base tables
		if ( is_null( $base_tables ) ) {
			$base_tables = array();

// Loop over base tables
			$result = $this->query( "SHOW FULL TABLES FROM `{$this->wpdb->dbname}` WHERE `Table_type` = 'BASE TABLE'" );
			while ( $row = $this->fetch_row( $result ) ) {
				if ( isset( $row[0] ) ) {
					$base_tables[] = $row[0];
				}
			}

// Close result cursor
			$this->free_result( $result );
		}

return $base_tables;
	}

/**
	 * Get tables
	 *
	 * @return array
	 */
	public function get_tables() {
		$tables = array();

// Get lower case table names
		$lower_case_table_names = $this->get_lower_case_table_names();

// Get base tables and views
		foreach ( array_merge( $this->get_base_tables(), $this->get_views() ) as $table_name ) {

// Include table prefixes
			if ( $this->get_include_table_prefixes() ) {
				$include = false;

// Check table prefixes
				foreach ( $this->get_include_table_prefixes() as $prefix ) {
					if ( $lower_case_table_names ) {
						if ( stripos( $table_name, $prefix ) === 0 ) {
							$include = true;
							break;
						}
					} else {
						if ( strpos( $table_name, $prefix ) === 0 ) {
							$include = true;
							break;
						}
					}
				}

// Skip current table
				if ( $include === false ) {
					continue;
				}
			}

// Exclude table prefixes
			if ( $this->get_exclude_table_prefixes() ) {
				$exclude = false;

// Check table prefixes
				foreach ( $this->get_exclude_table_prefixes() as $prefix ) {
					if ( $lower_case_table_names ) {
						if ( stripos( $table_name, $prefix ) === 0 ) {
							$exclude = true;
							break;
						}
					} else {
						if ( strpos( $table_name, $prefix ) === 0 ) {
							$exclude = true;
							break;
						}
					}
				}

// Skip current table
				if ( $exclude === true ) {
					continue;
				}
			}

$tables[] = $table_name;
		}

return $tables;
	}

/**
	 * Export database into a file
	 *
	 * @param  string  $file_name    File name
	 * @param  integer $table_index  Table index
	 * @param  integer $table_offset Table offset
	 * @param  integer $table_rows   Table rows
	 * @return boolean
	 */
	public function export( $file_name, &$table_index = 0, &$table_offset = 0, &$table_rows = 0 ) {
		// Set file handler
		$file_handler = ai1wm_open( $file_name, 'ab' );

// Write headers
		if ( $table_index === 0 ) {
			ai1wm_write( $file_handler, $this->get_header() );
		}

// Start time
		$start = microtime( true );

// Flag to hold if all tables have been processed
		$completed = true;

// Set SQL Mode
		$this->query( "SET SESSION sql_mode = ''" );

// Get tables
		$tables = $this->get_tables();

// Get views
		$views = $this->get_views();

// Export tables
		for ( ; $table_index < count( $tables ); ) {

// Get table name
			$table_name = $tables[ $table_index ];

// Replace table name prefixes
			$new_table_name = $this->replace_table_prefixes( $table_name, 0 );

// Loop over tables and views
			if ( in_array( $table_name, $views ) ) {

// Get create view statement
				if ( $table_offset === 0 ) {

// Write view drop statement
					$drop_view = "\nDROP VIEW IF EXISTS `{$new_table_name}`;\n";

// Write drop view statement
					ai1wm_write( $file_handler, $drop_view );

// Get create view statement
					$create_view = $this->get_create_view( $table_name );

// Replace create view name
					$create_view = $this->replace_view_name( $create_view, $table_name, $new_table_name );

// Replace create view identifiers
					$create_view = $this->replace_view_identifiers( $create_view );

// Replace create view options
					$create_view = $this->replace_view_options( $create_view );

// Write create view statement
					ai1wm_write( $file_handler, $create_view );

// Write end of statement
					ai1wm_write( $file_handler, ";\n\n" );
				}

// Set curent table index
				$table_index++;

// Set current table offset
				$table_offset = 0;

} else {

// Get create table statement
				if ( $table_offset === 0 ) {

// Write table drop statement
					$drop_table = "\nDROP TABLE IF EXISTS `{$new_table_name}`;\n";

// Write table statement
					ai1wm_write( $file_handler, $drop_table );

// Get create table statement
					$create_table = $this->get_create_table( $table_name );

// Replace create table name
					$create_table = $this->replace_table_name( $create_table, $table_name, $new_table_name );

// Replace create table constraints
					$create_table = $this->replace_table_constraints( $create_table );

// Replace create table options
					$create_table = $this->replace_table_options( $create_table );

// Write create table statement
					ai1wm_write( $file_handler, $create_table );

// Write end of statement
					ai1wm_write( $file_handler, ";\n\n" );
				}

// Get primary keys
				$primary_keys = $this->get_primary_keys( $table_name );

// Get table columns
				$table_columns = $this->get_column_types( $table_name );

// Get prefix columns
				$prefix_columns = $this->get_table_prefix_columns( $table_name );

do {

// Set query
					if ( $primary_keys ) {

// Set table keys
						$table_keys = array();
						foreach ( $primary_keys as $key ) {
							$table_keys[] = sprintf( '`%s`', $key );
						}

$table_keys = implode( ', ', $table_keys );

// Set table where clauses
						$table_where = array( 1 );
						foreach ( $this->get_table_where_clauses( $table_name ) as $clause ) {
							$table_where[] = $clause;
						}

$table_where = implode( ' AND ', $table_where );

// Set query with offset and rows count
						$query = sprintf( 'SELECT t1.* FROM `%s` AS t1 JOIN (SELECT %s FROM `%s` WHERE %s ORDER BY %s LIMIT %d, %d) AS t2 USING (%s)', $table_name, $table_keys, $table_name, $table_where, $table_keys, $table_offset, AI1WM_MAX_SELECT_RECORDS, $table_keys );

} else {

// Set table keys
						$table_keys = 1;

// Set table where clauses
						$table_where = array( 1 );
						foreach ( $this->get_table_where_clauses( $table_name ) as $clause ) {
							$table_where[] = $clause;
						}

$table_where = implode( ' AND ', $table_where );

// Set query with offset and rows count
						$query = sprintf( 'SELECT * FROM `%s` WHERE %s ORDER BY %s LIMIT %d, %d', $table_name, $table_where, $table_keys, $table_offset, AI1WM_MAX_SELECT_RECORDS );
					}

// Run SQL query
					$result = $this->query( $query );

// Repair table data
					if ( $this->errno() === 1194 ) {

// Current table is marked as crashed and should be repaired
						$this->repair_table( $table_name );

// Run SQL query
						$result = $this->query( $query );
					}

// Generate insert statements
					if ( $num_rows = $this->num_rows( $result ) ) {

// Loop over table rows
						while ( $row = $this->fetch_assoc( $result ) ) {

// Write start transaction
							if ( $table_offset % AI1WM_MAX_TRANSACTION_QUERIES === 0 ) {
								ai1wm_write( $file_handler, "START TRANSACTION;\n" );
							}

$items = array();
							foreach ( $row as $key => $value ) {
								// Replace table prefix columns
								if ( isset( $prefix_columns[ strtolower( $key ) ] ) ) {
									$value = $this->replace_column_prefixes( $value, 0 );
								}

$items[] = $this->prepare_table_values( $value, $table_columns[ strtolower( $key ) ] );
							}

// Set table values
							$table_values = implode( ',', $items );

// Set insert statement
							$table_insert = "INSERT INTO `{$new_table_name}` VALUES ({$table_values});\n";

// Write insert statement
							ai1wm_write( $file_handler, $table_insert );

// Set current table offset
							$table_offset++;

// Set current table rows
							$table_rows++;

// Write end of transaction
							if ( $table_offset % AI1WM_MAX_TRANSACTION_QUERIES === 0 ) {
								ai1wm_write( $file_handler, "COMMIT;\n" );
							}
						}
					} else {

// Write end of transaction
						if ( $table_offset % AI1WM_MAX_TRANSACTION_QUERIES !== 0 ) {
							ai1wm_write( $file_handler, "COMMIT;\n" );
						}

// Set curent table index
						$table_index++;

// Set current table offset
						$table_offset = 0;
					}

// Close result cursor
					$this->free_result( $result );

// Time elapsed
					if ( ( $timeout = apply_filters( 'ai1wm_completed_timeout', 10 ) ) ) {
						if ( ( microtime( true ) - $start ) > $timeout ) {
							$completed = false;
							break 2;
						}
					}
				} while ( $num_rows > 0 );
			}
		}

// Close file handler
		ai1wm_close( $file_handler );

return $completed;
	}

/**
	 * Import database from a file
	 *
	 * @param  string  $file_name    File name
	 * @param  integer $query_offset Query offset
	 * @return boolean
	 */
	public function import( $file_name, &$query_offset = 0 ) {
		// Set max allowed packet
		$max_allowed_packet = $this->get_max_allowed_packet();

// Set file handler
		$file_handler = ai1wm_open( $file_name, 'r' );

// Start time
		$start = microtime( true );

// Flag to hold if all tables have been processed
		$completed = true;

// Set SQL Mode
		$this->query( "SET SESSION sql_mode = ''" );

// Set file pointer at the query offset
		if ( fseek( $file_handler, $query_offset ) !== -1 ) {
			$query = null;

// Start transaction
			$this->query( 'START TRANSACTION' );

// Read database file line by line
			while ( ( $line = fgets( $file_handler ) ) !== false ) {
				$query .= $line;

// End of query
				if ( preg_match( '/;\s*$/S', $query ) ) {
					$query = trim( $query );

// Check max allowed packet
					if ( strlen( $query ) <= $max_allowed_packet ) {

// Skip cache query
						if ( ! $this->is_cache_query( $query ) ) {

// Replace table prefixes
							$query = $this->replace_table_prefixes( $query );

// Replace table collations
							$query = $this->replace_table_collations( $query );

// Replace table values
							$query = $this->replace_table_values( $query );

// Replace raw values
							$query = $this->replace_raw_values( $query );

// Run SQL query
							$this->query( $query );

// Replace table engines (Azure)
							if ( $this->errno() === 1030 ) {

// Replace table engines
								$query = $this->replace_table_engines( $query );

// Run SQL query
								$this->query( $query );
							}

// Replace table row format (MyISAM and InnoDB)
							if ( $this->errno() === 1071 || $this->errno() === 1709 ) {

// Replace table row format
								$query = $this->replace_table_row_format( $query );

// Run SQL query
								$this->query( $query );
							}

// Check max queries per hour
							if ( $this->errno() === 1226 ) {
								if ( stripos( $this->error(), 'max_queries_per_hour' ) !== false ) {
									throw new Ai1wm_Database_Exception(
										'Your WordPress installation has reached the maximum allowed queries per hour set by your server admin or hosting provider. ' .
										'To use All-in-One WP Migration, please increase MySQL max_queries_per_hour limit. ' .
										'<a href="https://help.servmask.com/knowledgebase/mysql-error-codes/#max-queries-per-hour" target="_blank">Technical details</a>',
										503
									);
								} elseif ( stripos( $this->error(), 'max_updates_per_hour' ) !== false ) {
									throw new Ai1wm_Database_Exception(
										'Your WordPress installation has reached the maximum allowed updates per hour set by your server admin or hosting provider. ' .
										'To use All-in-One WP Migration, please increase MySQL max_updates_per_hour limit. ' .
										'<a href="https://help.servmask.com/knowledgebase/mysql-error-codes/#max-updates-per-hour" target="_blank">Technical details</a>',
										503
									);
								} elseif ( stripos( $this->error(), 'max_connections_per_hour' ) !== false ) {
									throw new Ai1wm_Database_Exception(
										'Your WordPress installation has reached the maximum allowed connections per hour set by your server admin or hosting provider. ' .
										'To use All-in-One WP Migration, please increase MySQL max_connections_per_hour limit. ' .
										'<a href="https://help.servmask.com/knowledgebase/mysql-error-codes/#max-connections-per-hour" target="_blank">Technical details</a>',
										503
									);
								} elseif ( stripos( $this->error(), 'max_user_connections' ) !== false ) {
									throw new Ai1wm_Database_Exception(
										'Your WordPress installation has reached the maximum allowed user connections set by your server admin or hosting provider. ' .
										'To use All-in-One WP Migration, please increase MySQL max_user_connections limit. ' .
										'<a href="https://help.servmask.com/knowledgebase/mysql-error-codes/#max-user-connections" target="_blank">Technical details</a>',
										503
									);
								}
							}
						}

// Set query offset
						$query_offset = ftell( $file_handler );

// Time elapsed
						if ( ( $timeout = apply_filters( 'ai1wm_completed_timeout', 10 ) ) ) {
							if ( ! $this->is_atomic_query( $query ) ) {
								if ( ( microtime( true ) - $start ) > $timeout ) {
									$completed = false;
									break;
								}
							}
						}
					}

$query = null;
				}
			}

// End transaction
			$this->query( 'COMMIT' );
		}

// Close file handler
		ai1wm_close( $file_handler );

return $completed;
	}

/**
	 * Flush database
	 *
	 * @return void
	 */
	public function flush() {
		$views = $this->get_views();
		foreach ( $this->get_tables() as $table_name ) {
			if ( in_array( $table_name, $views ) ) {
				$this->query( "DROP VIEW IF EXISTS `{$table_name}`" );
			} else {
				$this->query( "DROP TABLE IF EXISTS `{$table_name}`" );
			}
		}
	}

/**
	 * Get MySQL version
	 *
	 * @return string
	 */
	protected function get_version() {
		$result = $this->query( "SHOW VARIABLES LIKE 'version'" );
		$row    = $this->fetch_assoc( $result );