File "Enterprise_Dbcache_WpdbInjection_Cluster.php"
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Charset: utf-8
<?php
/**
* File: Enterprise_Dbcache_WpdbInjection_Cluster.php
*
* @package W3TC
*/
namespace W3TC;
/**
* Class Enterprise_Dbcache_WpdbInjection_Cluster
*
* Support of database cluster
*
* phpcs:disable PSR2.Classes.PropertyDeclaration.Underscore
* phpcs:disable PSR2.Methods.MethodDeclaration.Underscore
* phpcs:disable WordPress.PHP.NoSilencedErrors.Discouraged
* phpcs:disable WordPress.WP.AlternativeFunctions
* phpcs:disable WordPress.PHP.DontExtract.extract_extract
* phpcs:disable WordPress.DB.RestrictedFunctions
*/
class Enterprise_Dbcache_WpdbInjection_Cluster extends DbCache_WpdbInjection {
/**
* Whether to check with fsockopen prior to mysqli_connect.
*
* @var bool
*/
public $check_tcp_responsiveness = true;
/**
* Minimum number of connections to try before bailing
*
* @var int
*/
public $min_tries = 3;
/**
* Whether to use mysqli_connect with persistence
*
* @var bool
*/
public $persistent = false;
/**
* Cache of tables-to-dataset mapping if blog_dataset callback defined
*
* @var array
*/
private $_blog_to_dataset = array();
/**
* Optional directory of callbacks to determine datasets from queries
*
* @var array
*/
private $_callbacks = array();
/**
* The multi-dimensional array of datasets and servers
*
* @var array
*/
private $_cluster_servers = array();
/**
* Zone where application runs
*
* @var array
*/
private $_current_zone = array(
'name' => 'all',
'zone_priorities' => array( 'all' ),
);
/**
* Established connections
*
* @var array
*/
private $_connections;
/**
* After any SQL_CALC_FOUND_ROWS query, the query "SELECT FOUND_ROWS()"
* is sent and the mysql result resource stored here. The next query
* for FOUND_ROWS() will retrieve this. We do this to prevent any
* intervening queries from making FOUND_ROWS() inaccessible. You may
* prevent this by adding "NO_SELECT_FOUND_ROWS" in a comment.
*
* @var resource
*/
private $_last_found_rows_result;
/**
* The last table that was queried
*
* @var string
*/
private $_last_table;
/**
* Reject reason
*
* @var string|null
*/
private $_reject_reason = null;
/**
* Send Reads To Masters. This disables slave connections while true.
* Otherwise it is an array of written tables.
*
* @var array
*/
private $_send_reads_to_master = false;
/**
* Send all request to master db if user is in administration.
*
* @var bool
*/
public $use_master_in_backend = true;
/**
* Which charset to use for connections
*
* @var string
*/
public $charset = null;
/**
* Which collate to use for connections
*
* @var string
*/
public $collate = null;
/**
* Initializes the database cluster.
*
* @return void
*/
public function initialize() {
global $wpdb_cluster;
$wpdb_cluster = $this;
if ( ! isset( $GLOBALS['w3tc_dbcluster_config'] ) && file_exists( WP_CONTENT_DIR . '/db-cluster-config.php' ) ) {
// The config file resides in WP_CONTENT_DIR.
require WP_CONTENT_DIR . '/db-cluster-config.php';
}
if ( isset( $GLOBALS['w3tc_dbcluster_config'] ) ) {
$this->apply_configuration( $GLOBALS['w3tc_dbcluster_config'] );
} else {
$this->_reject_reason = 'w3tc dbcluster configuration not found, using single-server configuration';
$this->next_injection->initialize();
return;
}
if ( WP_DEBUG ) {
$this->wpdb_mixin->show_errors();
}
$this->wpdb_mixin->dbh = null;
$this->wpdb_mixin->ready = true;
$this->init_charset();
}
/**
* Applies configuration to the database cluster.
*
* @param array $c {
* Configuration array for the database cluster.
*
* @type bool $persistent Whether to enable persistent connections.
* @type bool $check_tcp_responsiveness Whether to check TCP responsiveness.
* @type bool $use_master_in_backend Whether to use the master database in the backend.
* @type string $charset Database character set.
* @type string $collate Database collation.
* @type array $filters {
* List of filter callbacks to add.
*
* @type string $function_to_add Function to add as a filter.
* @type string $tag Tag for the filter.
* }
* @type array $databases {
* List of databases to add.
*
* @type array $db Database configuration.
* }
* @type array $zones {
* List of zones to add.
*
* @type array $zone Zone configuration, with 'name' assigned as the key.
* }
* }
*
* @return void
*/
public function apply_configuration( $c ) {
if ( isset( $c['persistent'] ) ) {
$this->persistent = $c['persistent'];
}
if ( isset( $c['check_tcp_responsiveness'] ) ) {
$this->persistent = $c['check_tcp_responsiveness'];
}
if ( isset( $c['use_master_in_backend'] ) ) {
$this->persistent = $c['use_master_in_backend'];
}
if ( isset( $c['charset'] ) ) {
$this->persistent = $c['charset'];
}
if ( isset( $c['collate'] ) ) {
$this->persistent = $c['collate'];
}
if ( isset( $c['filters'] ) && is_array( $c['filters'] ) ) {
foreach ( $c['filters'] as $filter ) {
$this->add_callback( $filter['function_to_add'], $filter['tag'] );
}
}
if ( isset( $c['databases'] ) && is_array( $c['databases'] ) ) {
foreach ( $c['databases'] as $key => $db ) {
$this->add_database( $db );
}
}
if ( isset( $c['zones'] ) && is_array( $c['zones'] ) ) {
foreach ( $c['zones'] as $key => $zone ) {
$zone['name'] = $key;
$this->add_zone( $zone );
}
}
}
/**
* Initializes the charset and collation settings for the database connection.
*
* If DB_CHARSET not set uses utf8
* If DB_COLLATE not set uses utf8_general_ci if multisite.
*
* @return void
*/
public function init_charset() {
if ( function_exists( 'is_multisite' ) && is_multisite() ) {
if ( defined( 'DB_COLLATE' ) && DB_COLLATE ) {
$this->wpdb_mixin->collate = DB_COLLATE;
} else {
$this->wpdb_mixin->collate = 'utf8_general_ci';
}
} elseif ( defined( 'DB_COLLATE' ) ) {
$this->wpdb_mixin->collate = DB_COLLATE;
}
if ( defined( 'DB_CHARSET' ) ) {
$this->wpdb_mixin->charset = DB_CHARSET;
} else {
$this->wpdb_mixin->charset = 'utf8';
}
}
/**
* Adds a zone to the database cluster configuration.
*
* @param array $zone {
* Zone configuration data.
*
* @type array $zone_priorities Zone priority settings. Must be defined.
* }
*
* @throws \Exception If the zone priorities key is not defined.
*
* @return void
*/
public function add_zone( $zone ) {
if ( $this->_is_current_zone( $zone ) ) {
if ( ! isset( $zone['zone_priorities'] ) || ! is_array( $zone['zone_priorities'] ) ) {
die( 'zone_priorities key must be defined' );
}
$this->_current_zone = $zone;
$this->_run_callbacks( 'current_zone_set', $zone );
}
}
/**
* Adds a database to the cluster configuration.
*
* @param array $db {
* Database configuration data.
*
* @type string $dataset Dataset name. Defaults to 'global'.
* @type bool $read Whether the database is for reading. Defaults to true.
* @type bool $write Whether the database is for writing. Defaults to true.
* @type string $zone Availability zone. Defaults to 'all'.
* @type float $timeout Connection timeout. Defaults to 0.2 if not set.
* @type string $name Database name. Defaults to the host if not set.
* @type string $host Database host.
* }
*
* @return void
*/
public function add_database( $db ) {
$dataset = ( isset( $db['dataset'] ) ? $db['dataset'] : 'global' );
unset( $db['dataset'] );
$read = ( isset( $db['read'] ) ? $db['read'] : true );
unset( $db['read'] );
$write = ( isset( $db['write'] ) ? $db['write'] : true );
unset( $db['write'] );
$zone = ( isset( $db['zone'] ) ? $db['zone'] : 'all' );
unset( $db['zone'] );
if ( ! isset( $db['timeout'] ) ) {
$db['timeout'] = 0.2;
}
if ( ! isset( $db['name'] ) ) {
$db['name'] = $db['host'];
}
if ( $read ) {
$this->_cluster_servers[ $dataset ]['read'][ $zone ][] = $db;
}
if ( $write ) {
$this->_cluster_servers[ $dataset ]['write'][ $zone ][] = $db;
}
}
/**
* Adds a callback to a specified group.
*
* @param callable $callback The callback function to add.
* @param string $group The group to associate with the callback. Defaults to 'dataset'.
*
* @return void
*/
public function add_callback( $callback, $group = 'dataset' ) {
$this->_callbacks[ $group ][] = $callback;
}
/**
* Sends all read operations to master servers.
*
* @return void
*/
public function send_reads_to_masters() {
$this->_send_reads_to_master = true;
}
/**
* Determines whether to send operations to master servers.
*
* @return bool True if operations should be sent to masters, otherwise false.
*/
public function send_to_masters() {
return is_admin() && $this->use_master_in_backend;
}
/**
* Establishes a database connection for a query.
*
* phpcs:disable Squiz.PHP.CommentedOutCode.Found
*
* @param string $query The SQL query for which the connection is needed.
* @param bool $use_master Whether to use a master server. Defaults to null.
*
* @return mixed Database connection resource on success, or false on failure.
*
* @throws \Exception If unable to connect to the database.
*/
public function db_connect( $query = '', $use_master = null ) {
if ( empty( $this->_cluster_servers ) ) {
return $this->_db_connect_fallback();
}
$this->wpdb_mixin->dbh = null;
if ( empty( $query ) ) {
return false;
}
$table_from_query = $this->_get_table_from_query( $query );
$this->_last_table = $table_from_query;
$this->wpdb_mixin->table = $table_from_query;
$this->callback_result = $this->_run_callbacks( 'dataset', $query );
if ( ! is_null( $this->callback_result ) ) {
$dataset = $this->callback_result;
} elseif ( isset( $this->_callbacks['blog_dataset'] ) ) {
if ( preg_match( '/^' . $this->wpdb_mixin->base_prefix . '(\d+)_/i', $this->wpdb_mixin->table, $matches ) ) {
$blog_id = $matches[1];
if ( isset( $this->_blog_to_dataset[ $blog_id ] ) ) {
$dataset = $this->_blog_to_dataset[ $blog_id ];
} else {
$this->callback_result = $this->_run_callbacks( 'blog_dataset', $blog_id );
if ( ! is_null( $this->callback_result ) ) {
$dataset = $this->callback_result;
$this->_blog_to_dataset[ $blog_id ] = $dataset;
}
}
}
}
$dataset = ( isset( $dataset ) ? $dataset : 'global' );
$this->dataset = $dataset;
// Determine whether the query must be sent to the master (a writable server).
if ( is_null( $use_master ) ) {
if ( $this->_send_reads_to_master || $this->send_to_masters() ) {
$use_master = true;
} elseif ( defined( 'DONOTBCLUSTER' ) && DONOTBCLUSTER ) {
$use_master = true;
} elseif ( $this->_is_write_query( $query ) ) {
$use_master = true;
} else {
$use_master = false;
}
}
if ( $use_master ) {
$this->dbhname = $dataset . '__w';
$operation = 'write';
} else {
$this->dbhname = $dataset . '__r';
$operation = 'read';
}
// Try to reuse an existing connection.
$dbh = $this->_db_connect_reuse_connection();
if ( is_object( $dbh ) ) {
$this->wpdb_mixin->dbh = $dbh;
return $dbh;
}
if ( empty( $this->_cluster_servers[ $dataset ][ $operation ] ) ) {
return $this->wpdb_mixin->bail( "No databases available for dataset $dataset operation $operation" );
}
// Make a list of at least $this->min_tries connections to try, repeating as necessary.
$servers = array();
$server_count = 0;
$retry_count = 0;
do {
foreach ( $this->_current_zone['zone_priorities'] as $zone ) {
if ( isset( $this->_cluster_servers[ $dataset ][ $operation ][ $zone ] ) ) {
$zone_servers = $this->_cluster_servers[ $dataset ][ $operation ][ $zone ];
if ( is_array( $zone_servers ) ) {
$indexes = array_keys( $zone_servers );
shuffle( $indexes );
foreach ( $indexes as $index ) {
$servers[] = compact( 'zone', 'index' );
}
}
}
}
$server_count = count( $servers );
// Increment the retry count and check if we've exceeded the maximum retries.
++$retry_count;
} while ( $server_count < $this->min_tries && $retry_count < 3 );
// Connect to a database server.
$success = false;
$errno = 0;
$dbhname = $this->dbhname;
foreach ( $servers as $zone_index ) {
// $zone, $index.
extract( $zone_index, EXTR_OVERWRITE );
// $host, $user, $password, $name, $read, $write, $timeout
extract( $this->_cluster_servers[ $dataset ][ $operation ][ $zone ][ $index ], EXTR_OVERWRITE );
// Split host:port into $host and $port.
list( $host, $port ) = Util_Content::endpoint_to_host_port( $host, 3306 );
$this->wpdb_mixin->timer_start();
// Connect if necessary or possible.
$tcp_responded = null;
if ( $this->check_tcp_responsiveness ) {
$tcp_responded = $this->_check_tcp_responsiveness( $host, $port, $timeout );
}
$dbh = null;
if ( is_null( $tcp_responded ) || $tcp_responded ) {
$dbh = mysqli_init();
$socket = null;
$client_flags = defined( 'MYSQL_CLIENT_FLAGS' ) ? MYSQL_CLIENT_FLAGS : 0;
if ( WP_DEBUG ) {
mysqli_real_connect( $dbh, $host, $user, $password, null, $port, $socket, $client_flags );
} else {
@mysqli_real_connect( $dbh, $host, $user, $password, null, $port, $socket, $client_flags );
}
}
$elapsed = $this->wpdb_mixin->timer_stop();
if ( ! is_null( $dbh ) ) {
if ( $dbh->connect_errno ) {
$errno = $dbh->connect_errno;
} elseif ( mysqli_select_db( $dbh, $name ) ) {
$this->_connections[ $dbhname ] = array(
'dbh' => $dbh,
'database_name' => $name,
);
$success = true;
break;
}
}
}
if ( ! $success ) {
if ( ! $use_master ) {
return $this->db_connect( $query, true );
}
return $this->wpdb_mixin->bail( "Unable to connect to $host:$port to $operation table '{$this->wpdb_mixin->table}' ($dataset) with $errno" );
}
$dbh = $this->_connections[ $dbhname ]['dbh'];
$this->wpdb_mixin->dbh = $dbh; // needed by $wpdb->_real_escape().
$this->set_charset( $dbh, $this->charset, $this->collate );
$this->set_sql_mode();
return $dbh;
}
/**
* Checks if a given zone is the current zone.
*
* @param array $zone {
* Zone configuration data.
*
* @type string $SERVER_NAME (Obsolete) Specific server name to match.
* @type string[] $server_names List of server names to match. Supports wildcard '*'.
* }
*
* @return bool True if the zone matches the current zone, otherwise false.
*/
public function _is_current_zone( $zone ) {
$server_name = isset( $_SERVER['SERVER_NAME'] ) ? sanitize_text_field( wp_unslash( $_SERVER['SERVER_NAME'] ) ) : '';
// obsolete.
if ( isset( $zone['SERVER_NAME'] ) ) {
if ( $server_name === $zone['SERVER_NAME'] ) {
return true;
}
}
if ( isset( $zone['server_names'] ) ) {
if ( ! is_array( $zone['server_names'] ) ) {
die( 'server_names must be defined as array' );
}
foreach ( $zone['server_names'] as $zone_server_name ) {
if ( '*' === $zone_server_name ) {
return true;
}
if ( $server_name === $zone_server_name ) {
return true;
}
}
}
return false;
}
/**
* Reuses an existing database connection if available.
*
* @return mixed Database connection resource on success, or null if no reusable connection is found.
*/
public function _db_connect_reuse_connection() {
$dbhname = $this->dbhname;
if ( ! isset( $this->_connections[ $dbhname ] ) ) {
return null;
}
$connection = & $this->_connections[ $dbhname ];
$dbh = $connection['dbh'];
if ( ! is_object( $dbh ) ) {
return null;
}
if ( ! mysqli_ping( $dbh ) ) {
// disconnect (ping failed).
$this->_disconnect( $dbhname );
return null;
}
return $dbh;
}
/**
* Sets the character set and collation for a database connection.
*
* @param mysqli $dbh The database connection handle.
* @param string $charset Optional. The character set to use. Defaults to null.
* @param string $collate Optional. The collation to use. Defaults to null.
*
* @return void
*/
public function set_charset( $dbh, $charset = null, $collate = null ) {
if ( ! isset( $charset ) ) {
$charset = $this->wpdb_mixin->charset;
}
if ( ! isset( $collate ) ) {
$collate = $this->wpdb_mixin->collate;
}
if ( $this->has_cap( 'collation', $dbh ) && ! empty( $charset ) ) {
if ( function_exists( 'mysqli_set_charset' ) && $this->has_cap( 'set_charset', $dbh ) ) {
mysqli_set_charset( $dbh, $charset );
$this->wpdb_mixin->real_escape = true;
} else {
$query = $this->wpdb_mixin->prepare( 'SET NAMES %s', $charset );
if ( ! empty( $collate ) ) {
$query .= $this->wpdb_mixin->prepare( ' COLLATE %s', $collate );
}
mysqli_query( $dbh, $query );
}
}
}
/**
* Flushes the database cache and resets relevant properties.
*
* @return void
*/
public function flush() {
$this->wpdb_mixin->last_error = '';
$this->num_rows = 0;
$this->next_injection->flush();
}
/**
* Executes a database query and handles various query types.
*
* @param string $query The SQL query to execute.
*
* @return mixed Number of rows affected, number of rows selected, or false on failure.
*/
public function query( $query ) {
// some queries are made before the plugins have been loaded, and thus cannot be filtered with this method.
if ( function_exists( 'apply_filters' ) ) {
$query = apply_filters( 'query', $query );
}
$this->flush();
// Log how the function was called.
$this->wpdb_mixin->func_call = "\$db->query(\"$query\")";
// Keep track of the last query for debug.
$this->wpdb_mixin->last_query = $query;
if ( preg_match( '/^\s*SELECT\s+FOUND_ROWS(\s*)/i', $query ) && is_object( $this->wpdb_mixin->_last_found_rows_result ) ) {
$this->wpdb_mixin->result = $this->wpdb_mixin->_last_found_rows_result;
$elapsed = 0;
} else {
$this->db_connect( $query );
if ( ! is_object( $this->wpdb_mixin->dbh ) ) {
return false;
}
$this->wpdb_mixin->timer_start();
$this->wpdb_mixin->result = mysqli_query( $this->wpdb_mixin->dbh, $query );
$elapsed = $this->wpdb_mixin->timer_stop();
++$this->wpdb_mixin->num_queries;
if ( preg_match( '/^\s*SELECT\s+SQL_CALC_FOUND_ROWS\s/i', $query ) ) {
if ( false === strpos( $query, 'NO_SELECT_FOUND_ROWS' ) ) {
$this->wpdb_mixin->timer_start();
$this->wpdb_mixin->_last_found_rows_result = mysqli_query( $this->wpdb_mixin->dbh, 'SELECT FOUND_ROWS()' );
$elapsed += $this->wpdb_mixin->timer_stop();
++$this->wpdb_mixin->num_queries;
$query .= '; SELECT FOUND_ROWS()';
}
} else {
$this->wpdb_mixin->_last_found_rows_result = null;
}
}
if ( function_exists( 'apply_filters' ) ) {
apply_filters( 'after_query', $query );
}
// If there is an error then take note of it.
$this->wpdb_mixin->last_error = mysqli_error( $this->wpdb_mixin->dbh );
if ( $this->wpdb_mixin->last_error ) {
$this->wpdb_mixin->print_error( $this->wpdb_mixin->last_error );
return false;
}
if ( preg_match( '/^\\s*(insert|delete|update|replace|alter) /i', $query ) ) {
$this->wpdb_mixin->rows_affected = mysqli_affected_rows( $this->wpdb_mixin->dbh );
// Take note of the insert_id.
if ( preg_match( '/^\\s*(insert|replace) /i', $query ) ) {
$this->wpdb_mixin->insert_id = mysqli_insert_id( $this->wpdb_mixin->dbh );
}
// Return number of rows affected.
return $this->wpdb_mixin->rows_affected;
} else {
$i = 0;
$this->wpdb_mixin->col_info = array();
$col_info = array();
while ( $i < @mysqli_num_fields( $this->wpdb_mixin->result ) ) {
$col_info[ $i ] = @mysqli_fetch_field( $this->wpdb_mixin->result );
++$i;
}
$this->wpdb_mixin->col_info = $col_info;
$num_rows = 0;
$this->wpdb_mixin->last_result = array();
do {
$row = @mysqli_fetch_object( $this->wpdb_mixin->result );
if ( $row ) {
$this->wpdb_mixin->last_result[ $num_rows ] = $row;
++$num_rows;
}
} while ( $row );
// Log number of rows the query returned.
$this->num_rows = $num_rows;
// Return number of rows selected.
return $num_rows;
}
}
/**
* Escapes a string for safe insertion into the database.
*
* @param mixed $data The data to escape.
*
* @return string Escaped data.
*/
public function _escape( $data ) {
if ( ! $this->wpdb_mixin->dbh ) {
$this->db_connect( 'SELECT * FROM nothing' );
}
return $this->wpdb_mixin->default__escape( $data );
}
/**
* Prepares a database query by replacing placeholders with provided arguments.
*
* @param string $query The SQL query with placeholders.
* @param array $args The arguments to replace the placeholders.
*
* @return string Prepared query.
*/
public function prepare( $query, $args ) {
if ( ! $this->wpdb_mixin->dbh ) {
$this->db_connect( $query );
}
return $this->wpdb_mixin->default_prepare( $query, $args );
}
/**
* Checks the database version and ensures compatibility with WordPress.
*
* @param mixed $dbh_or_table Optional. Database handle or table name to check.
*
* @return \WP_Error|void WP_Error if the database version is incompatible, void otherwise.
*/
public function check_database_version( $dbh_or_table = false ) {
global $wp_version;
// Make sure the server has MySQL 4.1.2.
$mysqli_version = preg_replace( '|[^0-9\.]|', '', $this->wpdb_mixin->db_version( $dbh_or_table ) );
if ( version_compare( $mysqli_version, '4.1.2', '<' ) ) {
return new \WP_Error(
'database_version',
sprintf(
// Translators: 1 WordPress version.
__(
'<strong>ERROR</strong>: WordPress %1$s requires MySQL 4.1.2 or higher'
),
$wp_version
)
);
}
}
/**
* Determines if the database server supports collation.
*
* @param mixed $dbh_or_table Optional. Database handle or table name to check.
*
* @return bool True if collation is supported, false otherwise.
*/
public function supports_collation( $dbh_or_table = false ) {
return $this->wpdb_mixin->has_cap( 'collation', $dbh_or_table );
}
/**
* Checks if the database server supports a given capability.
*
* @param string $db_cap The database capability to check.
* @param mixed $dbh_or_table Optional. Database handle or table name to check.
*
* @return bool True if the capability is supported, false otherwise.
*/
public function has_cap( $db_cap, $dbh_or_table = false ) {
$version = $this->wpdb_mixin->db_version( $dbh_or_table );
switch ( strtolower( $db_cap ) ) {
case 'collation':
case 'group_concat':
case 'subqueries':
return version_compare( $version, '4.1', '>=' );
case 'set_charset':
return version_compare( $version, '5.0.7', '>=' );
}
return false;
}
/**
* Retrieves the database server version.
*
* @param mixed $dbh_or_table Optional. Database handle or table name to check.
*
* @return string|false Database version string or false on failure.
*/
public function db_version( $dbh_or_table = false ) {
$dbh = null;
if ( ! $dbh_or_table && $this->wpdb_mixin->dbh ) {
$dbh = $this->wpdb_mixin->dbh;
} elseif ( is_object( $dbh_or_table ) ) {
$dbh = $dbh_or_table;
} else {
$dbh = $this->db_connect( "SELECT FROM $dbh_or_table $this->wpdb_mixin->users" );
}
if ( ! is_null( $dbh ) ) {
return preg_replace( '/[^0-9.].*/', '', mysqli_get_server_info( $dbh ) );
}
return false;
}
/**
* Disconnects a specific database connection.
*
* @param string $dbhname The name of the database connection to disconnect.
*
* @return void
*/
public function _disconnect( $dbhname ) {
if ( isset( $this->_connections[ $dbhname ] ) ) {
$dbh = $this->_connections[ $dbhname ]['dbh'];
if ( is_object( $dbh ) ) {
mysqli_close( $dbh );
}
unset( $this->_connections[ $dbhname ] );
}
}
/**
* Checks the TCP responsiveness of a given host and port.
*
* @param string $host The hostname to check.
* @param int $port The port number to check.
* @param float $float_timeout The timeout duration in seconds.
*
* @return string|true A message if unresponsive, true if responsive.
*/
public function _check_tcp_responsiveness( $host, $port, $float_timeout ) {
$socket = @ fsockopen( $host, $port, $errno, $errstr, $float_timeout );
if ( false === $socket ) {
return "[ > $float_timeout ] ($errno) '$errstr'";
}
fclose( $socket );
return true;
}
/**
* Extracts the table name from a SQL query.
*
* @param string $q The SQL query.
*
* @return string|null The table name or null if not found.
*/
public function _get_table_from_query( $q ) {
// Remove characters that can legally trail the table name.
$q = rtrim( $q, ';/-#' );
// allow (select...) union [...] style queries. Use the first queries table name.
$q = ltrim( $q, "\t (" );
// Quickly match most common queries.
if (
preg_match(
'/^\s*(?:'
. 'SELECT.*?\s+FROM'
. '|INSERT(?:\s+IGNORE)?(?:\s+INTO)?'
. '|REPLACE(?:\s+INTO)?'
. '|UPDATE(?:\s+IGNORE)?'
. '|DELETE(?:\s+IGNORE)?(?:\s+FROM)?'
. ')\s+`?(\w+)`?/is',
$q,
$maybe
)
) {
return $maybe[1];
}
// Refer to the previous query.
if ( preg_match( '/^\s*SELECT.*?\s+FOUND_ROWS\(\)/is', $q ) ) {
return $this->_last_table;
}
// SHOW TABLE STATUS LIKE and SHOW TABLE STATUS WHERE Name =.
if (
preg_match(
'/^\s*SHOW\s+TABLE\s+STATUS.+(?:LIKE\s+|WHERE\s+Name\s*=\s*)\W(\w+)\W/is',
$q,
$maybe
)
) {
return $maybe[1];
}
// Big pattern for the rest of the table-related queries in MySQL 5.0.
if (
preg_match(
'/^\s*(?:'
. '(?:EXPLAIN\s+(?:EXTENDED\s+)?)?SELECT.*?\s+FROM'
. '|INSERT(?:\s+LOW_PRIORITY|\s+DELAYED|\s+HIGH_PRIORITY)?(?:\s+IGNORE)?(?:\s+INTO)?'
. '|REPLACE(?:\s+LOW_PRIORITY|\s+DELAYED)?(?:\s+INTO)?'
. '|UPDATE(?:\s+LOW_PRIORITY)?(?:\s+IGNORE)?'
. '|DELETE(?:\s+LOW_PRIORITY|\s+QUICK|\s+IGNORE)*(?:\s+FROM)?'
. '|DESCRIBE|DESC|EXPLAIN|HANDLER'
. '|(?:LOCK|UNLOCK)\s+TABLE(?:S)?'
. '|(?:RENAME|OPTIMIZE|BACKUP|RESTORE|CHECK|CHECKSUM|ANALYZE|OPTIMIZE|REPAIR).*\s+TABLE'
. '|TRUNCATE(?:\s+TABLE)?'
. '|CREATE(?:\s+TEMPORARY)?\s+TABLE(?:\s+IF\s+NOT\s+EXISTS)?'
. '|ALTER(?:\s+IGNORE)?\s+TABLE'
. '|DROP\s+TABLE(?:\s+IF\s+EXISTS)?'
. '|CREATE(?:\s+\w+)?\s+INDEX.*\s+ON'
. '|DROP\s+INDEX.*\s+ON'
. '|LOAD\s+DATA.*INFILE.*INTO\s+TABLE'
. '|(?:GRANT|REVOKE).*ON\s+TABLE'
. '|SHOW\s+(?:.*FROM|.*TABLE)'
. ')\s+`?(\w+)`?/is',
$q,
$maybe
)
) {
return $maybe[1];
}
}
/**
* Determines if a query modifies the database.
*
* @param string $q The SQL query.
*
* @return bool True if the query is a write operation, false otherwise.
*/
public function _is_write_query( $q ) {
// Quick and dirty: only SELECT statements are considered read-only.
$q = ltrim( $q, "\r\n\t (" );
return ! preg_match( '/^(?:SELECT|SHOW|DESCRIBE|EXPLAIN)\s/i', $q );
}
/**
* Runs callbacks registered for a specific group.
*
* @param string $group The callback group to run.
* @param mixed $args Optional. Arguments to pass to the callbacks.
*
* @return mixed|null The result of the callback, or null if none.
*/
public function _run_callbacks( $group, $args = null ) {
if ( ! isset( $this->_callbacks[ $group ] ) || ! is_array( $this->_callbacks[ $group ] ) ) {
return null;
}
if ( ! isset( $args ) ) {
$args = array( $this );
} elseif ( is_array( $args ) ) {
$args[] = $this;
} else {
$args = array( $args, $this );
}
foreach ( $this->_callbacks[ $group ] as $func ) {
$result = call_user_func_array( $func, $args );
if ( isset( $result ) ) {
return $result;
}
}
}
/**
* Attempts a fallback database connection.
*
* @return mixed Database handle on success, or void on failure.
*/
public function _db_connect_fallback() {
if ( is_object( $this->wpdb_mixin->dbh ) ) {
return $this->wpdb_mixin->dbh;
}
if (
! defined( 'DB_HOST' ) ||
! defined( 'DB_USER' ) ||
! defined( 'DB_PASSWORD' ) ||
! defined( 'DB_NAME' )
) {
return $this->wpdb_mixin->bail( 'We were unable to query because there was no database defined.' );
}
$this->wpdb_mixin->dbh = mysqli_init();
$port = null;
$socket = null;
$client_flags = defined( 'MYSQL_CLIENT_FLAGS' ) ? MYSQL_CLIENT_FLAGS : 0;
if ( WP_DEBUG ) {
mysqli_real_connect( $this->wpdb_mixin->dbh, DB_HOST, DB_USER, DB_PASSWORD, null, $port, $socket, $client_flags );
} else {
@mysqli_real_connect( $this->wpdb_mixin->dbh, $host, $user, $password, null, $port, $socket, $client_flags );
}
if ( ! is_object( $this->wpdb_mixin->dbh ) ) {
return $this->wpdb_mixin->bail( 'We were unable to connect to the database. (DB_HOST)' );
}
if ( ! mysqli_select_db( $this->wpdb_mixin->dbh, DB_NAME ) ) {
return $this->wpdb_mixin->bail( 'We were unable to select the database.' );
}
if ( ! empty( $this->wpdb_mixin->charset ) ) {
$collation_query = "SET NAMES '{$this->wpdb_mixin->charset}'";
if ( ! empty( $this->wpdb_mixin->collate ) ) {
$collation_query .= " COLLATE '{$this->wpdb_mixin->collate}'";
}
mysqli_query( $this->wpdb_mixin->dbh, $collation_query );
}
return $this->wpdb_mixin->dbh;
}
/**
* Appends footer comments to indicate the use of database clustering.
*
* @param array $strings Existing footer comments.
*
* @return array Footer comments with added database cluster information.
*/
public function w3tc_footer_comment( $strings ) {
$append = '';
if ( isset( $this->_current_zone['name'] ) && 'all' !== $this->_current_zone['name'] ) {
$append .= ' with home zone ' . $this->_current_zone['name'];
}
if ( ! is_null( $this->_reject_reason ) ) {
$append .= ' (' . $this->_reject_reason . ')';
}
$strings[] = 'Database cluster enabled ' . $append;
return $strings;
}
/**
* Records usage statistics for the current request.
*
* @todo Implement usage statistics of requests
*
* @param mixed $storage Storage mechanism for the usage statistics.
*
* @return void
*/
public function w3tc_usage_statistics_of_request( $storage ) {
}
}