beta-functions

<?php
/**
 * Main WordPress API
 *
 * @package WordPress
 */

/**
 * Converts MySQL DATETIME field to user specified date format.
 *
 * If $dateformatstring has 'G' value, then gmmktime() function will be used to
 * make the time. If $dateformatstring is set to 'U', then mktime() function
 * will be used to make the time.
 *
 * The $translate will only be used, if it is set to true and it is by default
 * and if the $wp_locale object has the month and weekday set.
 *
 * @since 0.71
 *
 * @param string $dateformatstring Either 'G', 'U', or php date format.
 * @param string $mysqlstring Time from mysql DATETIME field.
 * @param bool $translate Optional. Default is true. Will switch format to locale.
 * @return string Date formated by $dateformatstring or locale (if available).
 */
function mysql2date( $dateformatstring, $mysqlstring, $translate = true ) {
	$m = $mysqlstring;
	if ( empty( $m ) )
		return false;

	if ( 'G' == $dateformatstring )
		return strtotime( $m . ' +0000' );

	$i = strtotime( $m );

	if ( 'U' == $dateformatstring )
		return $i;

	if ( $translate )
		return date_i18n( $dateformatstring, $i );
	else
		return date( $dateformatstring, $i );
}

/**
 * Retrieve the current time based on specified type.
 *
 * The 'mysql' type will return the time in the format for MySQL DATETIME field.
 * The 'timestamp' type will return the current timestamp.
 *
 * If $gmt is set to either '1' or 'true', then both types will use GMT time.
 * if $gmt is false, the output is adjusted with the GMT offset in the WordPress option.
 *
 * @since 1.0.0
 *
 * @param string $type Either 'mysql' or 'timestamp'.
 * @param int|bool $gmt Optional. Whether to use GMT timezone. Default is false.
 * @return int|string String if $type is 'gmt', int if $type is 'timestamp'.
 */
function current_time( $type, $gmt = 0 ) {
	switch ( $type ) {
		case 'mysql':
			return ( $gmt ) ? gmdate( 'Y-m-d H:i:s' ) : gmdate( 'Y-m-d H:i:s', ( time() + ( get_option( 'gmt_offset' ) * 3600 ) ) );
			break;
		case 'timestamp':
			return ( $gmt ) ? time() : time() + ( get_option( 'gmt_offset' ) * 3600 );
			break;
	}
}

/**
 * Retrieve the date in localized format, based on timestamp.
 *
 * If the locale specifies the locale month and weekday, then the locale will
 * take over the format for the date. If it isn't, then the date format string
 * will be used instead.
 *
 * @since 0.71
 *
 * @param string $dateformatstring Format to display the date.
 * @param int $unixtimestamp Optional. Unix timestamp.
 * @param bool $gmt Optional, default is false. Whether to convert to GMT for time.
 * @return string The date, translated if locale specifies it.
 */
function date_i18n( $dateformatstring, $unixtimestamp = false, $gmt = false ) {
	global $wp_locale;
	$i = $unixtimestamp;
	// Sanity check for PHP 5.1.0-
	if ( false === $i || intval($i) < 0 ) {
		if ( ! $gmt )
			$i = current_time( 'timestamp' );
		else
			$i = time();
		// we should not let date() interfere with our
		// specially computed timestamp
		$gmt = true;
	}

	// store original value for language with untypical grammars
	// see http://core.trac.wordpress.org/ticket/9396
	$req_format = $dateformatstring;

	$datefunc = $gmt? 'gmdate' : 'date';

	if ( ( !empty( $wp_locale->month ) ) && ( !empty( $wp_locale->weekday ) ) ) {
		$datemonth = $wp_locale->get_month( $datefunc( 'm', $i ) );
		$datemonth_abbrev = $wp_locale->get_month_abbrev( $datemonth );
		$dateweekday = $wp_locale->get_weekday( $datefunc( 'w', $i ) );
		$dateweekday_abbrev = $wp_locale->get_weekday_abbrev( $dateweekday );
		$datemeridiem = $wp_locale->get_meridiem( $datefunc( 'a', $i ) );
		$datemeridiem_capital = $wp_locale->get_meridiem( $datefunc( 'A', $i ) );
		$dateformatstring = ' '.$dateformatstring;
		$dateformatstring = preg_replace( "/([^\\\])D/", "\\1" . backslashit( $dateweekday_abbrev ), $dateformatstring );
		$dateformatstring = preg_replace( "/([^\\\])F/", "\\1" . backslashit( $datemonth ), $dateformatstring );
		$dateformatstring = preg_replace( "/([^\\\])l/", "\\1" . backslashit( $dateweekday ), $dateformatstring );
		$dateformatstring = preg_replace( "/([^\\\])M/", "\\1" . backslashit( $datemonth_abbrev ), $dateformatstring );
		$dateformatstring = preg_replace( "/([^\\\])a/", "\\1" . backslashit( $datemeridiem ), $dateformatstring );
		$dateformatstring = preg_replace( "/([^\\\])A/", "\\1" . backslashit( $datemeridiem_capital ), $dateformatstring );

		$dateformatstring = substr( $dateformatstring, 1, strlen( $dateformatstring ) -1 );
	}
	$timezone_formats = array( 'P', 'I', 'O', 'T', 'Z', 'e' );
	$timezone_formats_re = implode( '|', $timezone_formats );
	if ( preg_match( "/$timezone_formats_re/", $dateformatstring ) && wp_timezone_supported() ) {
		$timezone_string = get_option( 'timezone_string' );
		if ( $timezone_string ) {
			$timezone_object = timezone_open( $timezone_string );
			$date_object = date_create( null, $timezone_object );
			foreach( $timezone_formats as $timezone_format ) {
				if ( false !== strpos( $dateformatstring, $timezone_format ) ) {
					$formatted = date_format( $date_object, $timezone_format );
					$dateformatstring = ' '.$dateformatstring;
					$dateformatstring = preg_replace( "/([^\\\])$timezone_format/", "\\1" . backslashit( $formatted ), $dateformatstring );
					$dateformatstring = substr( $dateformatstring, 1, strlen( $dateformatstring ) -1 );
				}
			}
		}
	}
	$j = @$datefunc( $dateformatstring, $i );
	// allow plugins to redo this entirely for languages with untypical grammars
	$j = apply_filters('date_i18n', $j, $req_format, $i, $gmt);
	return $j;
}

/**
 * Convert integer number to format based on the locale.
 *
 * @since 2.3.0
 *
 * @param int $number The number to convert based on locale.
 * @param int $decimals Precision of the number of decimal places.
 * @return string Converted number in string format.
 */
function number_format_i18n( $number, $decimals = 0 ) {
	global $wp_locale;
	$formatted = number_format( $number, absint( $decimals ), $wp_locale->number_format['decimal_point'], $wp_locale->number_format['thousands_sep'] );
	return apply_filters( 'number_format_i18n', $formatted );
}

/**
 * Convert number of bytes largest unit bytes will fit into.
 *
 * It is easier to read 1kB than 1024 bytes and 1MB than 1048576 bytes. Converts
 * number of bytes to human readable number by taking the number of that unit
 * that the bytes will go into it. Supports TB value.
 *
 * Please note that integers in PHP are limited to 32 bits, unless they are on
 * 64 bit architecture, then they have 64 bit size. If you need to place the
 * larger size then what PHP integer type will hold, then use a string. It will
 * be converted to a double, which should always have 64 bit length.
 *
 * Technically the correct unit names for powers of 1024 are KiB, MiB etc.
 * @link http://en.wikipedia.org/wiki/Byte
 *
 * @since 2.3.0
 *
 * @param int|string $bytes Number of bytes. Note max integer size for integers.
 * @param int $decimals Precision of number of decimal places. Deprecated.
 * @return bool|string False on failure. Number string on success.
 */
function size_format( $bytes, $decimals = 0 ) {
	$quant = array(
		// ========================= Origin ====
		'TB' => 1099511627776,  // pow( 1024, 4)
		'GB' => 1073741824,     // pow( 1024, 3)
		'MB' => 1048576,        // pow( 1024, 2)
		'kB' => 1024,           // pow( 1024, 1)
		'B ' => 1,              // pow( 1024, 0)
	);
	foreach ( $quant as $unit => $mag )
		if ( doubleval($bytes) >= $mag )
			return number_format_i18n( $bytes / $mag, $decimals ) . ' ' . $unit;

	return false;
}

/**
 * Get the week start and end from the datetime or date string from mysql.
 *
 * @since 0.71
 *
 * @param string $mysqlstring Date or datetime field type from mysql.
 * @param int $start_of_week Optional. Start of the week as an integer.
 * @return array Keys are 'start' and 'end'.
 */
function get_weekstartend( $mysqlstring, $start_of_week = '' ) {
	$my = substr( $mysqlstring, 0, 4 ); // Mysql string Year
	$mm = substr( $mysqlstring, 8, 2 ); // Mysql string Month
	$md = substr( $mysqlstring, 5, 2 ); // Mysql string day
	$day = mktime( 0, 0, 0, $md, $mm, $my ); // The timestamp for mysqlstring day.
	$weekday = date( 'w', $day ); // The day of the week from the timestamp
	if ( !is_numeric($start_of_week) )
		$start_of_week = get_option( 'start_of_week' );

	if ( $weekday < $start_of_week )
		$weekday += 7;

	$start = $day - 86400 * ( $weekday - $start_of_week ); // The most recent week start day on or before $day
	$end = $start + 604799; // $start + 7 days - 1 second
	return compact( 'start', 'end' );
}

/**
 * Unserialize value only if it was serialized.
 *
 * @since 2.0.0
 *
 * @param string $original Maybe unserialized original, if is needed.
 * @return mixed Unserialized data can be any type.
 */
function maybe_unserialize( $original ) {
	if ( is_serialized( $original ) ) // don't attempt to unserialize data that wasn't serialized going in
		return @unserialize( $original );
	return $original;
}

/**
 * Check value to find if it was serialized.
 *
 * If $data is not an string, then returned value will always be false.
 * Serialized data is always a string.
 *
 * @since 2.0.5
 *
 * @param mixed $data Value to check to see if was serialized.
 * @return bool False if not serialized and true if it was.
 */
function is_serialized( $data ) {
	// if it isn't a string, it isn't serialized
	if ( ! is_string( $data ) )
		return false;
	$data = trim( $data );
 	if ( 'N;' == $data )
		return true;
	$length = strlen( $data );
	if ( $length < 4 )
		return false;
	if ( ':' !== $data[1] )
		return false;
	$lastc = $data[$length-1];
	if ( ';' !== $lastc && '}' !== $lastc )
		return false;
	$token = $data[0];
	switch ( $token ) {
		case 's' :
			if ( '"' !== $data[$length-2] )
				return false;
		case 'a' :
		case 'O' :
			return (bool) preg_match( "/^{$token}:[0-9]+:/s", $data );
		case 'b' :
		case 'i' :
		case 'd' :
			return (bool) preg_match( "/^{$token}:[0-9.E-]+;\$/", $data );
	}
	return false;
}

/**
 * Check whether serialized data is of string type.
 *
 * @since 2.0.5
 *
 * @param mixed $data Serialized data
 * @return bool False if not a serialized string, true if it is.
 */
function is_serialized_string( $data ) {
	// if it isn't a string, it isn't a serialized string
	if ( !is_string( $data ) )
		return false;
	$data = trim( $data );
	if ( preg_match( '/^s:[0-9]+:.*;$/s', $data ) ) // this should fetch all serialized strings
		return true;
	return false;
}

/**
 * Retrieve option value based on name of option.
 *
 * If the option does not exist or does not have a value, then the return value
 * will be false. This is useful to check whether you need to install an option
 * and is commonly used during installation of plugin options and to test
 * whether upgrading is required.
 *
 * If the option was serialized then it will be unserialized when it is returned.
 *
 * @since 1.5.0
 * @package WordPress
 * @subpackage Option
 * @uses apply_filters() Calls 'pre_option_$option' before checking the option.
 * 	Any value other than false will "short-circuit" the retrieval of the option
 *	and return the returned value. You should not try to override special options,
 * 	but you will not be prevented from doing so.
 * @uses apply_filters() Calls 'option_$option', after checking the option, with
 * 	the option value.
 *
 * @param string $option Name of option to retrieve. Expected to not be SQL-escaped.
 * @return mixed Value set for the option.
 */
function get_option( $option, $default = false ) {
	global $wpdb;

	// Allow plugins to short-circuit options.
	$pre = apply_filters( 'pre_option_' . $option, false );
	if ( false !== $pre )
		return $pre;

	$option = trim($option);
	if ( empty($option) )
		return false;

	if ( defined( 'WP_SETUP_CONFIG' ) )
		return false;

	if ( ! defined( 'WP_INSTALLING' ) ) {
		// prevent non-existent options from triggering multiple queries
		$notoptions = wp_cache_get( 'notoptions', 'options' );
		if ( isset( $notoptions[$option] ) )
			return $default;

		$alloptions = wp_load_alloptions();

		if ( isset( $alloptions[$option] ) ) {
			$value = $alloptions[$option];
		} else {
			$value = wp_cache_get( $option, 'options' );

			if ( false === $value ) {
				$row = $wpdb->get_row( $wpdb->prepare( "SELECT option_value FROM $wpdb->options WHERE option_name = %s LIMIT 1", $option ) );

				// Has to be get_row instead of get_var because of funkiness with 0, false, null values
				if ( is_object( $row ) ) {
					$value = $row->option_value;
					wp_cache_add( $option, $value, 'options' );
				} else { // option does not exist, so we must cache its non-existence
					$notoptions[$option] = true;
					wp_cache_set( 'notoptions', $notoptions, 'options' );
					return $default;
				}
			}
		}
	} else {
		$suppress = $wpdb->suppress_errors();
		$row = $wpdb->get_row( $wpdb->prepare( "SELECT option_value FROM $wpdb->options WHERE option_name = %s LIMIT 1", $option ) );
		$wpdb->suppress_errors( $suppress );
		if ( is_object( $row ) )
			$value = $row->option_value;
		else
			return $default;
	}

	// If home is not set use siteurl.
	if ( 'home' == $option && '' == $value )
		return get_option( 'siteurl' );

	if ( in_array( $option, array('siteurl', 'home', 'category_base', 'tag_base') ) )
		$value = untrailingslashit( $value );

	return apply_filters( 'option_' . $option, maybe_unserialize( $value ) );
}

/**
 * Protect WordPress special option from being modified.
 *
 * Will die if $option is in protected list. Protected options are 'alloptions'
 * and 'notoptions' options.
 *
 * @since 2.2.0
 * @package WordPress
 * @subpackage Option
 *
 * @param string $option Option name.
 */
function wp_protect_special_option( $option ) {
	$protected = array( 'alloptions', 'notoptions' );
	if ( in_array( $option, $protected ) )
		wp_die( sprintf( __( '%s is a protected WP option and may not be modified' ), esc_html( $option ) ) );
}

/**
 * Print option value after sanitizing for forms.
 *
 * @uses attr Sanitizes value.
 * @since 1.5.0
 * @package WordPress
 * @subpackage Option
 *
 * @param string $option Option name.
 */
function form_option( $option ) {
	echo esc_attr( get_option( $option ) );
}

/**
 * Loads and caches all autoloaded options, if available or all options.
 *
 * @since 2.2.0
 * @package WordPress
 * @subpackage Option
 *
 * @return array List of all options.
 */
function wp_load_alloptions() {
	global $wpdb;

	if ( !defined( 'WP_INSTALLING' ) || !is_multisite() )
		$alloptions = wp_cache_get( 'alloptions', 'options' );
	else
		$alloptions = false;

	if ( !$alloptions ) {
		$suppress = $wpdb->suppress_errors();
		if ( !$alloptions_db = $wpdb->get_results( "SELECT option_name, option_value FROM $wpdb->options WHERE autoload = 'yes'" ) )
			$alloptions_db = $wpdb->get_results( "SELECT option_name, option_value FROM $wpdb->options" );
		$wpdb->suppress_errors($suppress);
		$alloptions = array();
		foreach ( (array) $alloptions_db as $o ) {
			$alloptions[$o->option_name] = $o->option_value;
		}
		if ( !defined( 'WP_INSTALLING' ) || !is_multisite() )
			wp_cache_add( 'alloptions', $alloptions, 'options' );
	}

	return $alloptions;
}

/**
 * Loads and caches certain often requested site options if is_multisite() and a peristent cache is not being used.
 *
 * @since 3.0.0
 * @package WordPress
 * @subpackage Option
 *
 * @param int $site_id Optional site ID for which to query the options. Defaults to the current site.
 */
function wp_load_core_site_options( $site_id = null ) {
	global $wpdb, $_wp_using_ext_object_cache;

	if ( !is_multisite() || $_wp_using_ext_object_cache || defined( 'WP_INSTALLING' ) )
		return;

	if ( empty($site_id) )
		$site_id = $wpdb->siteid;

	$core_options = array('site_name', 'siteurl', 'active_sitewide_plugins', '_site_transient_timeout_theme_roots', '_site_transient_theme_roots', 'site_admins', 'can_compress_scripts', 'global_terms_enabled' );

	$core_options_in = "'" . implode("', '", $core_options) . "'";
	$options = $wpdb->get_results( $wpdb->prepare("SELECT meta_key, meta_value FROM $wpdb->sitemeta WHERE meta_key IN ($core_options_in) AND site_id = %d", $site_id) );

	foreach ( $options as $option ) {
		$key = $option->meta_key;
		$cache_key = "{$site_id}:$key";
		$option->meta_value = maybe_unserialize( $option->meta_value );

		wp_cache_set( $cache_key, $option->meta_value, 'site-options' );
	}
}

/**
 * Update the value of an option that was already added.
 *
 * You do not need to serialize values. If the value needs to be serialized, then
 * it will be serialized before it is inserted into the database. Remember,
 * resources can not be serialized or added as an option.
 *
 * If the option does not exist, then the option will be added with the option
 * value, but you will not be able to set whether it is autoloaded. If you want
 * to set whether an option is autoloaded, then you need to use the add_option().
 *
 * @since 1.0.0
 * @package WordPress
 * @subpackage Option
 *
 * @uses apply_filters() Calls 'pre_update_option_$option' hook to allow overwriting the
 * 	option value to be stored.
 * @uses do_action() Calls 'update_option' hook before updating the option.
 * @uses do_action() Calls 'update_option_$option' and 'updated_option' hooks on success.
 *
 * @param string $option Option name. Expected to not be SQL-escaped.
 * @param mixed $newvalue Option value. Expected to not be SQL-escaped.
 * @return bool False if value was not updated and true if value was updated.
 */
function update_option( $option, $newvalue ) {
	global $wpdb;

	$option = trim($option);
	if ( empty($option) )
		return false;

	wp_protect_special_option( $option );

	if ( is_object($newvalue) )
		$newvalue = wp_clone($newvalue);

	$newvalue = sanitize_option( $option, $newvalue );
	$oldvalue = get_option( $option );
	$newvalue = apply_filters( 'pre_update_option_' . $option, $newvalue, $oldvalue );

	// If the new and old values are the same, no need to update.
	if ( $newvalue === $oldvalue )
		return false;

	if ( false === $oldvalue )
		return add_option( $option, $newvalue );

	$notoptions = wp_cache_get( 'notoptions', 'options' );
	if ( is_array( $notoptions ) && isset( $notoptions[$option] ) ) {
		unset( $notoptions[$option] );
		wp_cache_set( 'notoptions', $notoptions, 'options' );
	}

	$_newvalue = $newvalue;
	$newvalue = maybe_serialize( $newvalue );

	do_action( 'update_option', $option, $oldvalue, $_newvalue );
	if ( ! defined( 'WP_INSTALLING' ) ) {
		$alloptions = wp_load_alloptions();
		if ( isset( $alloptions[$option] ) ) {
			$alloptions[$option] = $_newvalue;
			wp_cache_set( 'alloptions', $alloptions, 'options' );
		} else {
			wp_cache_set( $option, $_newvalue, 'options' );
		}
	}

	$result = $wpdb->update( $wpdb->options, array( 'option_value' => $newvalue ), array( 'option_name' => $option ) );

	if ( $result ) {
		do_action( "update_option_{$option}", $oldvalue, $_newvalue );
		do_action( 'updated_option', $option, $oldvalue, $_newvalue );
		return true;
	}
	return false;
}

/**
 * Add a new option.
 *
 * You do not need to serialize values. If the value needs to be serialized, then
 * it will be serialized before it is inserted into the database. Remember,
 * resources can not be serialized or added as an option.
 *
 * You can create options without values and then add values later. Does not
 * check whether the option has already been added, but does check that you
 * aren't adding a protected WordPress option. Care should be taken to not name
 * options the same as the ones which are protected and to not add options
 * that were already added.
 *
 * @package WordPress
 * @subpackage Option
 * @since 1.0.0
 *
 * @uses do_action() Calls 'add_option' hook before adding the option.
 * @uses do_action() Calls 'add_option_$option' and 'added_option' hooks on success.
 *
 * @param string $option Name of option to add. Expected to not be SQL-escaped.
 * @param mixed $value Optional. Option value, can be anything. Expected to not be SQL-escaped.
 * @param mixed $deprecated Optional. Description. Not used anymore.
 * @param bool $autoload Optional. Default is enabled. Whether to load the option when WordPress starts up.
 * @return null returns when finished.
 */
function add_option( $option, $value = '', $deprecated = '', $autoload = 'yes' ) {
	global $wpdb;

	if ( !empty( $deprecated ) )
		_deprecated_argument( __FUNCTION__, '2.3' );

	$option = trim($option);
	if ( empty($option) )
		return false;

	wp_protect_special_option( $option );

	if ( is_object($value) )
		$value = wp_clone($value);

	$value = sanitize_option( $option, $value );

	// Make sure the option doesn't already exist. We can check the 'notoptions' cache before we ask for a db query
	$notoptions = wp_cache_get( 'notoptions', 'options' );
	if ( !is_array( $notoptions ) || !isset( $notoptions[$option] ) )
		if ( false !== get_option( $option ) )
			return;

	$_value = $value;
	$value = maybe_serialize( $value );
	$autoload = ( 'no' === $autoload ) ? 'no' : 'yes';
	do_action( 'add_option', $option, $_value );
	if ( ! defined( 'WP_INSTALLING' ) ) {
		if ( 'yes' == $autoload ) {
			$alloptions = wp_load_alloptions();
			$alloptions[$option] = $value;
			wp_cache_set( 'alloptions', $alloptions, 'options' );
		} else {
			wp_cache_set( $option, $value, 'options' );
		}
	}

	// This option exists now
	$notoptions = wp_cache_get( 'notoptions', 'options' ); // yes, again... we need it to be fresh
	if ( is_array( $notoptions ) && isset( $notoptions[$option] ) ) {
		unset( $notoptions[$option] );
		wp_cache_set( 'notoptions', $notoptions, 'options' );
	}

	$result = $wpdb->query( $wpdb->prepare( "INSERT INTO `$wpdb->options` (`option_name`, `option_value`, `autoload`) VALUES (%s, %s, %s) ON DUPLICATE KEY UPDATE `option_name` = VALUES(`option_name`), `option_value` = VALUES(`option_value`), `autoload` = VALUES(`autoload`)", $option, $value, $autoload ) );

	if ( $result ) {
		do_action( "add_option_{$option}", $option, $_value );
		do_action( 'added_option', $option, $_value );
		return true;
	}
	return false;
}

/**
 * Removes option by name. Prevents removal of protected WordPress options.
 *
 * @package WordPress
 * @subpackage Option
 * @since 1.2.0
 *
 * @uses do_action() Calls 'delete_option' hook before option is deleted.
 * @uses do_action() Calls 'deleted_option' and 'delete_option_$option' hooks on success.
 *
 * @param string $option Name of option to remove. Expected to not be SQL-escaped.
 * @return bool True, if option is successfully deleted. False on failure.
 */
function delete_option( $option ) {
	global $wpdb;

	wp_protect_special_option( $option );

	// Get the ID, if no ID then return
	$row = $wpdb->get_row( $wpdb->prepare( "SELECT autoload FROM $wpdb->options WHERE option_name = %s", $option ) );
	if ( is_null( $row ) )
		return false;
	do_action( 'delete_option', $option );
	$result = $wpdb->query( $wpdb->prepare( "DELETE FROM $wpdb->options WHERE option_name = %s", $option) );
	if ( ! defined( 'WP_INSTALLING' ) ) {
		if ( 'yes' == $row->autoload ) {
			$alloptions = wp_load_alloptions();
			if ( is_array( $alloptions ) && isset( $alloptions[$option] ) ) {
				unset( $alloptions[$option] );
				wp_cache_set( 'alloptions', $alloptions, 'options' );
			}
		} else {
			wp_cache_delete( $option, 'options' );
		}
	}
	if ( $result ) {
		do_action( "delete_option_$option", $option );
		do_action( 'deleted_option', $option );
		return true;
	}
	return false;
}

/**
 * Delete a transient
 *
 * @since 2.8.0
 * @package WordPress
 * @subpackage Transient
 *
 * @uses do_action() Calls 'delete_transient_$transient' hook before transient is deleted.
 * @uses do_action() Calls 'deleted_transient' hook on success.
 *
 * @param string $transient Transient name. Expected to not be SQL-escaped.
 * @return bool true if successful, false otherwise
 */
function delete_transient( $transient ) {
	global $_wp_using_ext_object_cache;

	do_action( 'delete_transient_' . $transient, $transient );

	if ( $_wp_using_ext_object_cache ) {
		$result = wp_cache_delete( $transient, 'transient' );
	} else {
		$option_timeout = '_transient_timeout_' . $transient;
		$option = '_transient_' . $transient;
		$result = delete_option( $option );
		if ( $result )
			delete_option( $option_timeout );
	}

	if ( $result )
		do_action( 'deleted_transient', $transient );
	return $result;
}

/**
 * Get the value of a transient
 *
 * If the transient does not exist or does not have a value, then the return value
 * will be false.
 *
 * @uses apply_filters() Calls 'pre_transient_$transient' hook before checking the transient.
 * 	Any value other than false will "short-circuit" the retrieval of the transient
 *	and return the returned value.
 * @uses apply_filters() Calls 'transient_$option' hook, after checking the transient, with
 * 	the transient value.
 *
 * @since 2.8.0
 * @package WordPress
 * @subpackage Transient
 *
 * @param string $transient Transient name. Expected to not be SQL-escaped
 * @return mixed Value of transient
 */
function get_transient( $transient ) {
	global $_wp_using_ext_object_cache;

	$pre = apply_filters( 'pre_transient_' . $transient, false );
	if ( false !== $pre )
		return $pre;

	if ( $_wp_using_ext_object_cache ) {
		$value = wp_cache_get( $transient, 'transient' );
	} else {
		$transient_option = '_transient_' . $transient;
		if ( ! defined( 'WP_INSTALLING' ) ) {
			// If option is not in alloptions, it is not autoloaded and thus has a timeout
			$alloptions = wp_load_alloptions();
			if ( !isset( $alloptions[$transient_option] ) ) {
				$transient_timeout = '_transient_timeout_' . $transient;
				if ( get_option( $transient_timeout ) < time() ) {
					delete_option( $transient_option  );
					delete_option( $transient_timeout );
					return false;
				}
			}
		}

		$value = get_option( $transient_option );
	}

	return apply_filters( 'transient_' . $transient, $value );
}

/**
 * Set/update the value of a transient
 *
 * You do not need to serialize values. If the value needs to be serialized, then
 * it will be serialized before it is set.
 *
 * @since 2.8.0
 * @package WordPress
 * @subpackage Transient
 *
 * @uses apply_filters() Calls 'pre_set_transient_$transient' hook to allow overwriting the
 * 	transient value to be stored.
 * @uses do_action() Calls 'set_transient_$transient' and 'setted_transient' hooks on success.
 *
 * @param string $transient Transient name. Expected to not be SQL-escaped.
 * @param mixed $value Transient value. Expected to not be SQL-escaped.
 * @param int $expiration Time until expiration in seconds, default 0
 * @return bool False if value was not set and true if value was set.
 */
function set_transient( $transient, $value, $expiration = 0 ) {
	global $_wp_using_ext_object_cache;

	$value = apply_filters( 'pre_set_transient_' . $transient, $value );

	if ( $_wp_using_ext_object_cache ) {
		$result = wp_cache_set( $transient, $value, 'transient', $expiration );
	} else {
		$transient_timeout = '_transient_timeout_' . $transient;
		$transient = '_transient_' . $transient;
		if ( false === get_option( $transient ) ) {
			$autoload = 'yes';
			if ( $expiration ) {
				$autoload = 'no';
				add_option( $transient_timeout, time() + $expiration, '', 'no' );
			}
			$result = add_option( $transient, $value, '', $autoload );
		} else {
			if ( $expiration )
				update_option( $transient_timeout, time() + $expiration );
			$result = update_option( $transient, $value );
		}
	}
	if ( $result ) {
		do_action( 'set_transient_' . $transient );
		do_action( 'setted_transient', $transient );
	}
	return $result;
}

/**
 * Saves and restores user interface settings stored in a cookie.
 *
 * Checks if the current user-settings cookie is updated and stores it. When no
 * cookie exists (different browser used), adds the last saved cookie restoring
 * the settings.
 *
 * @package WordPress
 * @subpackage Option
 * @since 2.7.0
 */
function wp_user_settings() {

	if ( ! is_admin() )
		return;

	if ( defined('DOING_AJAX') )
		return;

	if ( ! $user = wp_get_current_user() )
		return;

	$settings = get_user_option( 'user-settings', $user->ID );

	if ( isset( $_COOKIE['wp-settings-' . $user->ID] ) ) {
		$cookie = preg_replace( '/[^A-Za-z0-9=&_]/', '', $_COOKIE['wp-settings-' . $user->ID] );

		if ( ! empty( $cookie ) && strpos( $cookie, '=' ) ) {
			if ( $cookie == $settings )
				return;

			$last_time = (int) get_user_option( 'user-settings-time', $user->ID );
			$saved = isset( $_COOKIE['wp-settings-time-' . $user->ID]) ? preg_replace( '/[^0-9]/', '', $_COOKIE['wp-settings-time-' . $user->ID] ) : 0;

			if ( $saved > $last_time ) {
				update_user_option( $user->ID, 'user-settings', $cookie, false );
				update_user_option( $user->ID, 'user-settings-time', time() - 5, false );
				return;
			}
		}
	}

	setcookie( 'wp-settings-' . $user->ID, $settings, time() + 31536000, SITECOOKIEPATH );
	setcookie( 'wp-settings-time-' . $user->ID, time(), time() + 31536000, SITECOOKIEPATH );
	$_COOKIE['wp-settings-' . $user->ID] = $settings;
}

/**
 * Retrieve user interface setting value based on setting name.
 *
 * @package WordPress