laipower/wp-content/plugins/w3-total-cache/Enterprise_Dbcache_WpdbInjection_Cluster.php

903 lines
25 KiB
PHP

<?php
namespace W3TC;
/**
* class Enterprise_Dbcache_WpdbInjection_Cluster
* Support of database cluster
*/
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
*/
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 object
*/
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 from array
*/
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 );
}
}
}
/**
* Sets default charset and collate
* If DB_CHARSET not set uses utf8
* If DB_COLLATE not set uses utf8_general_ci if multisite.
*/
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 zone which defines priorities based on current application location
*
* @param array $zone
* keys:
* name
* SERVER_NAME
* zone_priorities array
*/
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 );
}
}
/**
* Add the connection parameters for a database
*
* @param array $db
* keys:
* name
* dataset
* read
* write
* host
* user
* password
* connect_function
* timeout
* zone
*/
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;
}
/**
* Add a callback to a group of callbacks.
* The default group is 'dataset', used to examine
* queries and determine dataset.
*
* @param object $callback
* @param string $group
*/
function add_callback( $callback, $group = 'dataset' ) {
$this->_callbacks[$group][] = $callback;
}
/**
* Set a flag to prevent reading from slaves which might be lagging after a write
*/
function send_reads_to_masters() {
$this->_send_reads_to_master = true;
}
/**
* If requests should be send to master or not.
*
* @return bool
*/
function send_to_masters() {
return is_admin() && $this->use_master_in_backend;
}
/**
* Figure out which database server should handle the query, and connect to it.
*
* @param string $query
* @return resource mysql database connection
*/
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;
$this->_last_table = $this->wpdb_mixin->table = $this->_get_table_from_query( $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 ( $is_write = $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();
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' );
}
}
}
} while ( count( $servers ) < $this->min_tries );
// 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 this is our zone
*
* @param $zone array
* @return boolean
*/
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;
}
/*
* Tries to reuse opened connection
*
* @return resource
*/
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 connection's character set.
*
* @param resource $dbh The resource given by mysqli_connect
* @param string $charset The character set (optional)
* @param string $collate The collation (optional)
*/
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 );
}
}
}
/**
* Kill cached query results
*/
function flush() {
$this->wpdb_mixin->last_error = '';
$this->num_rows = 0;
$this->next_injection->flush();
}
/**
* Basic query. See docs for more details.
*
* @param string $query
* @return int number of rows
*/
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
if ( $this->wpdb_mixin->last_error = mysqli_error( $this->wpdb_mixin->dbh ) ) {
$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();
while ( $row = @mysqli_fetch_object( $this->wpdb_mixin->result ) ) {
$this->wpdb_mixin->last_result[$num_rows] = $row;
$num_rows++;
}
// Log number of rows the query returned
$this->num_rows = $num_rows;
// Return number of rows selected
return $num_rows;
}
}
/**
* Usually it's called from inside other higher-level function
* so connection is available, but sometimes called directly.
* So connection should be initialized
**/
function _escape( $data ) {
if ( !$this->wpdb_mixin->dbh ) {
$this->db_connect( 'SELECT * FROM nothing' );
}
return $this->wpdb_mixin->default__escape( $data );
}
/**
* Prepare calls escape, so database connection required
**/
function prepare( $query, $args ) {
if ( !$this->wpdb_mixin->dbh ) {
$this->db_connect( $query );
}
return $this->wpdb_mixin->default_prepare( $query, $args );
}
/**
* Whether or not MySQL database is at least the required minimum version.
* The additional argument allows the caller to check a specific database.
*
* @param string $dbh_or_table
* @return WP_Error
*/
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( __( '<strong>ERROR</strong>: WordPress %s requires MySQL 4.1.2 or higher' ), $wp_version ) );
}
/**
* This function is called when WordPress is generating the table schema to determine wether or not the current database
* supports or needs the collation statements.
* The additional argument allows the caller to check a specific database.
*
* @param string $dbh_or_table
* @return bool
*/
function supports_collation( $dbh_or_table = false ) {
return $this->wpdb_mixin->has_cap( 'collation', $dbh_or_table );
}
/**
* Generic function to determine if a database supports a particular feature
* The additional argument allows the caller to check a specific database.
*
* @param string $db_cap the feature
* @param bool|string|resource $dbh_or_table the databaese (the current database, the database housing the specified table, or the database of the mysql resource)
* @return bool
*/
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', '>=' );
endswitch;
return false;
}
/**
* The database version number
*
* @param false|string|resource $dbh_or_table the databaese (the current database, the database housing the specified table, or the database of the mysql resource)
* @return false|string false on failure, version number on success
*/
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;
}
/**
* Disconnect and remove connection from open connections list
*
* @param string $dbhname
*/
function _disconnect( $dbhname ) {
if ( isset( $this->_connections[$dbhname] ) ) {
$dbh = $this->_connections[$dbhname]['dbh'];
if ( is_object( $dbh ) )
mysqli_close( $dbh );
unset( $this->_connections[$dbhname] );
}
}
/**
* Check the responsiveness of a tcp/ip daemon
*
* @return (bool) true when $host:$post responds within $float_timeout seconds, else (bool) false
*/
function _check_tcp_responsiveness( $host, $port, $float_timeout ) {
$socket = @ fsockopen( $host, $port, $errno, $errstr, $float_timeout );
if ( $socket === false )
return "[ > $float_timeout ] ($errno) '$errstr'";
fclose( $socket );
return true;
}
/**
* Find the first table name referenced in a query
*
* @param string $q
* @return string table
*/
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];
}
/**
* Determine the likelihood that this query could alter anything
*
* @param string $q
* @return bool
*/
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 );
}
/**
* Callbacks are executed in the order in which they are registered until one
* of them returns something other than null.
*
* @param string $group
* @param array $args
*/
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;
}
}
/**
* Connects to server using default configuration
*
* @return resource mysql database connection
*/
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;
}
function w3tc_footer_comment( $strings ) {
$append = '';
if ( isset( $this->_current_zone['name'] ) && $this->_current_zone['name'] != 'all' )
$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;
}
public function w3tc_usage_statistics_of_request( $storage ) {
}
}