public $cache_hits = 0;

protected static $wpdb;

protected static $cache_id;

protected static $wp_query;

protected static $found;

/**

* __construct()

*

* @param $wpdb

* @return \query_cache

*/

public function __construct($wpdb) {

self::$wpdb = $wpdb;

if ( !isset(self::$wpdb->queries) )

self::$wpdb->queries = array();

$host = get_option('home');

if ( preg_match("|^([^/]+://[^/]+)/|", $host, $_host) )

$host = end($_host);

self::$cache_id = $host . preg_replace("/#.*/", '', $_SERVER['REQUEST_URI']);

self::$cache_id = md5(self::$cache_id);

} # __construct()

/**

* __isset()

*

* @param string $var

* @return boolean $isset

**/

function __isset($var) {

return isset(self::$wpdb->$var);

} # __isset()

/**

* __unset()

*

* @param string $var

* @return boolean $isset

**/

function __unset($var) {

unset(self::$wpdb->$var);

} # __unset()

/**

* __get()

*

* @param $var

* @internal param string $name

* @return mixed $value

*/

function __get($var) {

return self::$wpdb->$var;

} # __get()

/**

* __set()

*

* @param string $var

* @param string $value

* @return mixed $value

**/

function __set($var, $value) {

return self::$wpdb->$var = $value;

} # __set()

/**

* __call()

*

* @param string $method

* @param array $args

* @return mixed $out

**/

function __call($method, $args) {

if (strcmp($method, "escape_by_ref") == 0) {

$Args = array();

foreach($args as $k => &$arg){

$Args[$k] = &$arg;

}

return call_user_func_array(array(self::$wpdb, $method), $Args);

}

else

return call_user_func_array(array(self::$wpdb, $method), $args);

} # __call()

/**

* get_var()

*

* @param string $query

* @param int $x which col

* @param int $y which row

* @return mixed $var

**/

function get_var($query = null, $x = 0, $y = 0) {

if ( !$query || $x || $y )

return self::$wpdb->get_var($query, $x, $y);

global $wpdb;

global $wp_the_query;

$var = false;

if ( self::$wp_query === $wp_the_query && $query == 'SELECT FOUND_ROWS()' ) {

if ( self::$found !== false ) {

$var = self::$found;

self::$found = false;

$this->cache_hits++;

}

} elseif ( $wp_the_query->is_page && preg_match("/^SELECT ID FROM $wpdb->posts WHERE post_parent = (\d+) AND post_type = 'page' LIMIT 1$/", $query, $post_id) ) {

$post_id = end($post_id);

$var = $this->get_body_class($post_id, $query);

} elseif ( preg_match("/^SELECT `post_parent` FROM $wpdb->posts WHERE ID = (\d+) LIMIT 1$/", $query, $post_id) ) {

$post_id = end($post_id);

$var = $this->get_post_parent($post_id);

}

return $var !== false ? $var : self::$wpdb->get_var($query);

} # get_var()

/**

* get_body_class()

*

* @param int $post_id

* @param $query

* @return int $is_parent

*/

function get_body_class($post_id, $query) {

$var = false;

$post_id = (int) $post_id;

$post = wp_cache_get($post_id, 'posts');

if ( $post !== false ) {

if ( isset($post->is_parent) ) {

$var = $post->is_parent;

$this->cache_hits++;

} else {

$var = (int) self::$wpdb->get_var($query);

$post->is_parent = $var;

wp_cache_replace($post->ID, $post, 'posts');

}

}

return $var;

} # get_body_class()

/**

* get_post_parent()

*

* @param int $post_id

* @return int $parent_id

**/

function get_post_parent($post_id) {

$var = false;

$post_id = (int) $post_id;

$post = wp_cache_get($post_id, 'posts');

if ( $post !== false ) {

$var = $post->post_parent;

$this->cache_hits++;

# http://core.trac.wordpress.org/ticket/10381

if ( !isset($post->ancestors) && $var && $var != $post->ID )

wp_cache_delete($post_id, 'posts');

}

return $var;

} # get_post_parent()

/**

* get_row()

*

* @param string $query

* @param string $output format

* @param int $y which row

* @return mixed $row

**/

function get_row($query = null, $output = OBJECT, $y = 0) {

if ( !$query || $output != OBJECT || $y )

return self::$wpdb->get_row($query, $output, $y);

global $wpdb;

$row = false;

if ( preg_match("/^SELECT ID, post_name, post_parent FROM $wpdb->posts WHERE ID = (\d+) and post_type='page'$/", $query, $post_id) ) {

# fetch parent page in get_page_by_path()

$post_id = (int) end($post_id);

$row = wp_cache_get($post_id, 'posts');

if ( $row !== false )

$this->cache_hits++;

}

return $row !== false ? $row : self::$wpdb->get_row($query);

} # get_row()

/**

* get_results()

*

* @param string $query

* @param string $output format

* @return array $results

**/

function get_results($query = null, $output = OBJECT) {

if ( !$query || $output != OBJECT )

return self::$wpdb->get_results($query, $output);

global $wpdb;

global $wp_the_query;

$results = false;

if ( !isset($wp_the_query) ) {

return self::$wpdb->get_results($query);

} elseif ( self::$wp_query === $wp_the_query && self::$wp_query->request === $query ) {

$results = $this->get_posts($query);

} elseif ( $wp_the_query->is_page && !$wp_the_query->in_the_loop && preg_match("/^SELECT ID, post_name, post_parent FROM $wpdb->posts WHERE post_name = '[^']+' AND \(post_type = 'page' OR post_type = 'attachment'\)$/", $query) ) {

$results = $this->get_page_by_path($query);

} elseif ( $wp_the_query->in_the_loop && preg_match("/^SELECT \* FROM $wpdb->comments WHERE comment_post_ID = (\d+) AND comment_approved = '1' ORDER BY comment_date_gmt ASC ?$/", $query, $post_id) ) {

$post_id = end($post_id);

$results = $this->get_cached_comments($post_id);

} elseif ( $wp_the_query->in_the_loop && preg_match("/^SELECT \* FROM $wpdb->comments WHERE comment_post_ID = (\d+) AND \( ?comment_approved = '1' OR \( .+? AND comment_approved = '0' \) \) ?ORDER BY comment_date_gmt$/", $query, $post_id) ) {

$post_id = end($post_id);

$results = $this->get_uncached_comments($post_id);

}

return $results !== false ? $results : self::$wpdb->get_results($query);

} # get_results()

/**

* get_cached_comments()

*

* @param int $post_id

* @return array $comments

**/

function get_cached_comments($post_id) {

$post_id = (int) $post_id;

$results = wp_cache_get($post_id, 'cached_comments');

if ( $results !== false ) {

$this->cache_hits++;

} else {

global $wpdb;

$results = self::$wpdb->get_results("SELECT * FROM $wpdb->comments WHERE comment_post_ID = $post_id AND comment_approved = '1' ORDER BY comment_date_gmt ASC");

wp_cache_set($post_id, $results, 'cached_comments');

}

return $results;

} # get_cached_comments()

/**

* get_uncached_comments()

*

* @param int $post_id

* @return array $comments

**/

function get_uncached_comments($post_id) {

$post_id = (int) $post_id;

$no_cache = wp_cache_get($post_id, 'uncached_comments');

if ( $no_cache === false ) {

global $wpdb;

$no_cache = (int) self::$wpdb->get_var("SELECT EXISTS( SELECT 1 FROM $wpdb->comments WHERE comment_post_ID = $post_id AND comment_approved = '0' )");

wp_cache_add($post_id, $no_cache, 'uncached_comments');

}

return $no_cache ? false : $this->get_cached_comments($post_id);

} # get_uncached_comments()

/**

* get_page_by_path()

*

* @param string $query

* @return array $results

**/

function get_page_by_path($query) {

$results = false;

$post_id = wp_cache_get(self::$cache_id, 'url2post_id');

if ( $post_id === 0 ) {

$results = array();

$this->cache_hits++;

} elseif ( $post_id ) {

$post = wp_cache_get($post_id, 'posts');

if ( $post !== false ) {

$results = array($post);

$this->cache_hits++;

}

}

return $results;

} # get_page_path()

/**

* get_posts()

*

* @param string $query

* @return array $results

**/

function get_posts($query) {

global $wp_query;

$results = false;

if ( $wp_query->is_preview || $wp_query->is_robots || isset($_GET['trashed']) )

# bail: we don't want to cache this stuff

return $results;

if ( $wp_query->is_singular ) {

$post_id = wp_cache_get(self::$cache_id, 'url2post_id');

if ( $post_id === 0 ) {

$results = array();

$this->cache_hits++;

} elseif ( $post_id ) {

$post = wp_cache_get($post_id, 'posts');

if ( $post !== false ) {

$results = array($post);

$this->cache_hits++;

}

}

if ( $results !== false )

return $results;

if ( isset($_GET['action']) || isset($_GET['doing_wp_cron'])

|| isset($_GET['debug']) || isset($_GET['preview'])

|| ( defined('WP_INSTALLING') && WP_INSTALLING )

|| ( defined('WP_ADMIN') && WP_ADMIN )

|| ( defined('DOING_CRON') && DOING_CRON )

|| ( defined('DOING_AJAX') && DOING_AJAX )

|| $_POST )

return $results;

$results = self::$wpdb->get_results($query);

if ( $results ) {

update_post_cache($results);

$post_id = $results[0]->ID;

} else {

$post_id = 0;

}

if ( !$post_id || $wp_query->is_feed )

$timeout = min(3600, cache_timeout);

elseif ( $wp_query->is_paged || self::$cache_id != md5(get_permalink($post_id)) )

$timeout = cache_timeout;

else

$timeout = 0;

wp_cache_add(self::$cache_id, $post_id, 'url2post_id', $timeout);

} else {

if ( !$wp_query->is_singular && is_user_logged_in() )

$query = self::maybe_strip_private_posts($query);

if ( strpos($query, "'private'") !== false )

# bail: queries that return private posts can't be efficiently cached

return $results;

$posts = wp_cache_get(self::$cache_id, 'url2posts');

$found = wp_cache_get(self::$cache_id, 'url2posts_found');

if ( $posts !== false && $found !== false ) {

$results = $posts;

self::$found = $found;

$this->cache_hits++;

return $results;

}

if ( isset($_GET['action']) || isset($_GET['doing_wp_cron'])

|| isset($_GET['debug']) || isset($_GET['preview'])

|| ( defined('WP_INSTALLING') && WP_INSTALLING )

|| ( defined('WP_ADMIN') && WP_ADMIN )

|| ( defined('DOING_CRON') && DOING_CRON )

|| ( defined('DOING_AJAX') && DOING_AJAX )

|| $_POST )

return $results;

if ( $wp_query->is_home || $wp_query->is_category || $wp_query->is_tag || $wp_query->is_author || $wp_query->is_date || $wp_query->is_feed && !$wp_query->is_singular && !$wp_query->is_archive /* home feed */ ) {

$results = self::$wpdb->get_results($query);

self::$found = self::$wpdb->get_var("SELECT FOUND_ROWS()");

if ( !$results || $wp_query->is_feed || redirect_canonical(null, false) )

$timeout = min(3600, cache_timeout);

elseif ( $wp_query->is_paged )

$timeout = cache_timeout;

else

$timeout = 0;

wp_cache_add(self::$cache_id, $results, 'url2posts', $timeout);

wp_cache_add(self::$cache_id, self::$found, 'url2posts_found', $timeout);

}

}

return $results;

} # get_posts()

/**

* maybe_strip_private_posts()

*

* @param string $posts_request

* @return string $posts_request

**/

static function maybe_strip_private_posts($posts_request) {

global $wpdb;

# optimize the query a bit

$user = wp_get_current_user();

$cap = 'posts';

if ( preg_match("/AND $wpdb->posts.post_type = '([^']+)'/", $posts_request, $cap) ) {

$cap = end($cap);

if ( $cap == 'page' )

$cap = 'pages';

else

$cap = 'posts';

$strip = false;

if ( current_user_can("read_private_$cap") ) {

if ( !self::has_private_posts() )

$strip = " OR $wpdb->posts.post_status = 'private'";

} elseif ( !current_user_can("edit_$cap") || !self::has_private_posts($user->ID) ) {

$strip = " OR $wpdb->posts.post_author = $user->ID AND $wpdb->posts.post_status = 'private'";

}

if ($strip) {

$posts_request = str_replace($strip, '', $posts_request);

}

}

return $posts_request;

} # maybe_strip_private_posts()

/**

* has_private_posts()

*

* @param int $user_id

* @return bool

**/

static function has_private_posts($user_id = null) {

global $wpdb;

$has_private_posts = get_transient('has_private_posts');

if ( $has_private_posts === false ) {

$has_private_posts = intval($wpdb->get_var("SELECT EXISTS( SELECT 1 FROM $wpdb->posts WHERE post_status = 'private' );"));

set_transient('has_private_posts', $has_private_posts);

}

if ( !$user_id )

return $has_private_posts;

elseif ( !$has_private_posts )

return false;

$user_id = intval($user_id);

$has_private_posts = get_user_meta($user_id, 'has_private_posts');

if ( $has_private_posts )

return true;

elseif ( $has_private_posts === array() )

return false;

$has_private_posts = intval($wpdb->get_var("SELECT EXISTS( SELECT 1 FROM $wpdb->posts WHERE post_status = 'private' AND user_id = $user_id );"));

if ( !$has_private_posts )

$has_private_posts = array();

update_user_meta($user_id, 'has_private_posts', $has_private_posts);

return !empty($has_private_posts);

} # has_private_posts()

/**

* pre_get_posts()

*

* @param $wp_query

* @return void

*/

static function pre_get_posts(&$wp_query) {

self::$wp_query = $wp_query;

self::$found = false;

} # pre_get_posts()

/**

* flush()

*

* @param mixed $in

* @return mixed $in

**/

static function flush($in = null) {

wp_cache_delete(self::$cache_id, 'url2post_id');

wp_cache_delete(self::$cache_id, 'url2posts');

wp_cache_delete(self::$cache_id, 'url2posts_found');

return $in;

} # flush()