php封装的mongodb操作类代码

<?php

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */


class mongo_db {

  private $config;
  private $connection;
  private $db;
  private $connection_string;
  private $host;
  private $port;
  private $user;
  private $pass;
  private $dbname;
  private $persist;
  private $persist_key;
  private $selects = array();
  private $wheres = array();
  private $sorts = array();
  private $limit = 999999;
  private $offset = 0;
  private $timeout = 200;
  private $key = 0;
  /**   *  --------------------------------------------------------------------------------   * CONSTRUCTOR * --------------------------------------------------------------------------------   *  * Automatically check if the Mongo PECL extension has been installed/enabled. * Generate the connection string and establish a connection to the MongoDB.  */

  public function __construct() {
    if((IS_NOSQL != 1)){
      return;
    }
    if (!class_exists('Mongo')) {
      //$this->error("The MongoDB PECL extension has not been installed or enabled", 500);
    }
    $configs =wxcity_base::load_config("cache","mongo_db");
    $num = count($configs['connect']);
    $this->timeout = trim($configs['timeout']);
    $keys = wxcity_base::load_config('double');
    $this->key = $keys['mongo_db'];
    $this->config = $configs['connect'][$this->key];
    $status = $this->connect();
    if($status == false)
    {
      for($i = 1; $i < $num; $i++)
      {
        $n = $this->key + $i;
        $key = $n >= $num ? $n - $num : $n;
        $this->config = $configs['connect'][$key];
        $status = $this->connect();
        if($status!=false)
        {
          $keys['mongo_db'] = $key ;
          $this->key = $key;
          $data = "<?php\nreturn ".var_export($keys, true).";\n?>";
          file_put_contents(WHTY_PATH.'configs/double.php', $data, LOCK_EX);
          break;
        }
      }
    }
    if($status==false)
    {
      die('mongoDB not connect');
    }
  }

  function __destruct() {
    if((IS_NOSQL != 1)){
      return;
    }
    if($this->connection)
    {
      $this->connection->close();
    }
  }

  /**   *  --------------------------------------------------------------------------------   * CONNECT TO MONGODB  * --------------------------------------------------------------------------------   *  * Establish a connection to MongoDB using the connection string generated in  * the connection_string() method. If 'mongo_persist_key' was set to true in the  * config file, establish a persistent connection. We allow for only the 'persist'   * option to be set because we want to establish a connection immediately. */
  private function connect() {
    $this->connection_string();
    $options = array('connect'=>true,'timeout'=>$this->timeout);
    try {
      $this->connection = new Mongo($this->connection_string, $options);
      $this->db = $this->connection->{$this->dbname};
      return($this);
    } catch (MongoConnectionException $e) {
      return false;
    }

  }
  /**   *  --------------------------------------------------------------------------------   * BUILD CONNECTION STRING * --------------------------------------------------------------------------------   *  * Build the connection string from the config file.  */
  private function connection_string() {
    $this->host = trim($this->config['hostname']);
    $this->port = trim($this->config['port']);
    $this->user = trim($this->config['username']);
    $this->pass = trim($this->config['password']);
    $this->dbname = trim($this->config['database']);
    $this->persist = trim($this->config['autoconnect']);
    $this->persist_key = trim($this->config['mongo_persist_key']);

    $connection_string = "mongodb://";
    if (emptyempty($this->host)) {
      $this->error("The Host must be set to connect to MongoDB", 500);
    } if (emptyempty($this->dbname)) {
      $this->error("The Database must be set to connect to MongoDB", 500);
    } if (!emptyempty($this->user) && !emptyempty($this->pass)) {
      $connection_string .= "{$this->user}:{$this->pass}@";
    } if (isset($this->port) && !emptyempty($this->port)) {
      $connection_string .= "{$this->host}:{$this->port}";
    } else {
      $connection_string .= "{$this->host}";
    } $this->connection_string = trim($connection_string);
  }

  /**   *  --------------------------------------------------------------------------------   * Switch_db  * --------------------------------------------------------------------------------   *  * Switch from default database to a different db  */
  public function switch_db($database = '') {
    if (emptyempty($database)) {
      $this->error("To switch MongoDB databases, a new database name must be specified", 500);
    } $this->dbname = $database;
    try {
      $this->db = $this->connection->{$this->dbname};
      return(TRUE);
    } catch (Exception $e) {
      $this->error("Unable to switch Mongo Databases: {$e->getMessage()}", 500);
    }
  }

  /**   *  --------------------------------------------------------------------------------   * SELECT FIELDS  * --------------------------------------------------------------------------------   *  * Determine which fields to include OR which to exclude during the query process. * Currently, including and excluding at the same time is not available, so the   * $includes array will take precedence over the $excludes array. If you want to  * only choose fields to exclude, leave $includes an empty array().   *  * @usage: $this->mongo_db->select(array('foo', 'bar'))->get('foobar');  */
  public function select($includes = array(), $excludes = array()) {
    if (!is_array($includes)) {
      $includes = array();
    }
    if (!is_array($excludes)) {
      $excludes = array();
    }
    if (!emptyempty($includes)) {
      foreach ($includes as $col) {
        $this->selects[$col] = 1;
      }
    } else {
      foreach ($excludes as $col) {
        $this->selects[$col] = 0;
      }
    } return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE PARAMETERS   * --------------------------------------------------------------------------------   *  * Get the documents based on these search parameters. The $wheres array should  * be an associative array with the field as the key and the value as the search  * criteria.  *  * @usage = $this->mongo_db->where(array('foo' => 'bar'))->get('foobar');  */
  public function where($wheres = array()) {
    foreach ((array)$wheres as $wh => $val) {
      $this->wheres[$wh] = $val;
    } return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE_IN PARAMETERS * --------------------------------------------------------------------------------   *  * Get the documents where the value of a $field is in a given $in array().   *  * @usage = $this->mongo_db->where_in('foo', array('bar', 'zoo', 'blah'))->get('foobar'); */
  public function where_in($field = "", $in = array()) {
    $this->where_init($field);
    $this->wheres[$field]['$in'] = $in;
    return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE_NOT_IN PARAMETERS * --------------------------------------------------------------------------------   *  * Get the documents where the value of a $field is not in a given $in array().   *  * @usage = $this->mongo_db->where_not_in('foo', array('bar', 'zoo', 'blah'))->get('foobar'); */
  public function where_not_in($field = "", $in = array()) {
    $this->where_init($field);
    $this->wheres[$field]['$nin'] = $in;
    return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE GREATER THAN PARAMETERS  * --------------------------------------------------------------------------------   *  * Get the documents where the value of a $field is greater than $x   *  * @usage = $this->mongo_db->where_gt('foo', 20);   */
  public function where_gt($field = "", $x) {
    $this->where_init($field);
    $this->wheres[$field]['$gt'] = $x;
    return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE GREATER THAN OR EQUAL TO PARAMETERS  * --------------------------------------------------------------------------------   *  * Get the documents where the value of a $field is greater than or equal to $x   *  * @usage = $this->mongo_db->where_gte('foo', 20);  */
  public function where_gte($field = "", $x) {
    $this->where_init($field);
    $this->wheres[$field]['$gte'] = $x;
    return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE LESS THAN PARAMETERS  * --------------------------------------------------------------------------------   *  * Get the documents where the value of a $field is less than $x  *  * @usage = $this->mongo_db->where_lt('foo', 20);   */
  public function where_lt($field = "", $x) {
    $this->where_init($field);
    $this->wheres[$field]['$lt'] = $x;
    return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE LESS THAN OR EQUAL TO PARAMETERS  * --------------------------------------------------------------------------------   *  * Get the documents where the value of a $field is less than or equal to $x  *  * @usage = $this->mongo_db->where_lte('foo', 20);  */
  public function where_lte($field = "", $x) {
    $this->where_init($field);
    $this->wheres[$field]['$lte'] = $x;
    return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE BETWEEN PARAMETERS   * --------------------------------------------------------------------------------   *  * Get the documents where the value of a $field is between $x and $y  *  * @usage = $this->mongo_db->where_between('foo', 20, 30);  */
  public function where_between($field = "", $x, $y) {
    $this->where_init($field);
    $this->wheres[$field]['$gte'] = $x;
    $this->wheres[$field]['$lte'] = $y;
    return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE BETWEEN AND NOT EQUAL TO PARAMETERS  * --------------------------------------------------------------------------------   *  * Get the documents where the value of a $field is between but not equal to $x and $y *  * @usage = $this->mongo_db->where_between_ne('foo', 20, 30);   */
  public function where_between_ne($field = "", $x, $y) {
    $this->where_init($field);
    $this->wheres[$field]['$gt'] = $x;
    $this->wheres[$field]['$lt'] = $y;
    return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE NOT EQUAL TO PARAMETERS  * --------------------------------------------------------------------------------   *  * Get the documents where the value of a $field is not equal to $x   *  * @usage = $this->mongo_db->where_between('foo', 20, 30);  */
  public function where_ne($field = "", $x) {
    $this->where_init($field);
    $this->wheres[$field]['$ne'] = $x;
    return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE OR   * --------------------------------------------------------------------------------   *  * Get the documents where the value of a $field is in one or more values  *  * @usage = $this->mongo_db->where_or('foo', array( 'foo', 'bar', 'blegh' ); */
  public function where_or($field = "", $values) {
    $this->where_init($field);
    $this->wheres[$field]['$or'] = $values;
    return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE AND  * --------------------------------------------------------------------------------   *  * Get the documents where the elements match the specified values *  * @usage = $this->mongo_db->where_and( array ( 'foo' => 1, 'b' => 'someexample' );   */
  public function where_and($elements_values = array()) {
    foreach ((array)$elements_values as $element => $val) {
      $this->wheres[$element] = $val;
    } return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE MOD  * --------------------------------------------------------------------------------   *  * Get the documents where $field % $mod = $result *  * @usage = $this->mongo_db->where_mod( 'foo', 10, 1 );  */
  public function where_mod($field, $num, $result) {
    $this->where_init($field);
    $this->wheres[$field]['$mod'] = array($num, $result);
    return($this);
  }

  /**   *  --------------------------------------------------------------------------------  *  Where size *  --------------------------------------------------------------------------------  *  *  Get the documents where the size of a field is in a given $size int *  *  @usage : $this->mongo_db->where_size('foo', 1)->get('foobar'); */
  public function where_size($field = "", $size = "") {
    $this->_where_init($field);
    $this->wheres[$field]['$size'] = $size;
    return ($this);
  }

  /**   *  --------------------------------------------------------------------------------   * LIKE PARAMETERS * --------------------------------------------------------------------------------   *    * Get the documents where the (string) value of a $field is like a value. The defaults   * allow for a case-insensitive search.   *  * @param $flags  * Allows for the typical regular expression flags:   *   i = case insensitive   *   m = multiline  *   x = can contain comments   *   l = locale  *   s = dotall, "." matches everything, including newlines  *   u = match unicode  *  * @param $enable_start_wildcard  * If set to anything other than TRUE, a starting line character "^" will be prepended * to the search value, representing only searching for a value at the start of   * a new line. *  * @param $enable_end_wildcard * If set to anything other than TRUE, an ending line character "$" will be appended  * to the search value, representing only searching for a value at the end of  * a line. *  * @usage = $this->mongo_db->like('foo', 'bar', 'im', FALSE, TRUE);  */
  public function like($field = "", $value = "", $flags = "i", $enable_start_wildcard = TRUE, $enable_end_wildcard = TRUE) {
    $field = (string) trim($field);
    $this->where_init($field);
    $value = (string) trim($value);
    $value = quotemeta($value);
    if ($enable_start_wildcard !== TRUE) {
      $value = "^" . $value;
    } if ($enable_end_wildcard !== TRUE) {
      $value .= "$";
    } $regex = "/$value/$flags";
    $this->wheres[$field] = new MongoRegex($regex);
    return($this);
  }

  public function wheres($where){
    $this->wheres = $where;
  }

  /**   *  --------------------------------------------------------------------------------   * ORDER BY PARAMETERS * --------------------------------------------------------------------------------   *  * Sort the documents based on the parameters passed. To set values to descending order,  * you must pass values of either -1, FALSE, 'desc', or 'DESC', else they will be  * set to 1 (ASC). *  * @usage = $this->mongo_db->where_between('foo', 20, 30);  */
  public function order_by($fields = array()) {
    if (!is_array($fields) || !count($fields)) return ;
    foreach ($fields as $col => $val) {
      if ($val == -1 || $val === FALSE || strtolower($val) == 'desc') {
        $this->sorts[$col] = -1;
      } else {
        $this->sorts[$col] = 1;
      }
    } return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * LIMIT DOCUMENTS * --------------------------------------------------------------------------------   *  * Limit the result set to $x number of documents  *  * @usage = $this->mongo_db->limit($x);  */
  public function limit($x = 99999) {
    if ($x !== NULL && is_numeric($x) && $x >= 1) {
      $this->limit = (int) $x;
    } return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * OFFSET DOCUMENTS   * --------------------------------------------------------------------------------   *  * Offset the result set to skip $x number of documents   *  * @usage = $this->mongo_db->offset($x); */
  public function offset($x = 0) {
    if ($x !== NULL && is_numeric($x) && $x >= 1) {
      $this->offset = (int) $x;
    } return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * GET_WHERE  * --------------------------------------------------------------------------------   *  * Get the documents based upon the passed parameters  *  * @usage = $this->mongo_db->get_where('foo', array('bar' => 'something'));  */
  public function get_where($collection = "", $where = array(), $limit = 99999, $orderby=array()) {
    if (is_array($orderby) || !emptyempty($orderby)) {
      $order_by = $this->order_by($order_by);
    }
    return($this->where($where)->limit($limit)->get($collection));
  }
  public function selectA($collection = "", $limit = 99999, $orderby=array()) {
    if(intval($limit)<1){
      $limit = 999999;
    }
    $order_by = $this->order_by($orderby);
    $re = $this->limit($limit)->get($collection);
    $this->clear();
    return (array)$re;
  }

  public function listinfo($collection = "", $orderby=array(), $page=1, $pagesize=12) {
    $page = max(intval($page), 1);
    $offset = $pagesize * ($page - 1);
    $pagesizes = $offset + $pagesize;
    $this->offset($offset);
    $order_by = $this->order_by($orderby);
    $re = $this->limit($pagesize)->get($collection);
    $this->limit(999999);
    $count = $this->count($collection);
    $this->pages = pages($count, $page, $pagesize);
    return (array)$re;
  }

  /**   *  --------------------------------------------------------------------------------   * GET * --------------------------------------------------------------------------------   *  * Get the documents based upon the passed parameters  *  * @usage = $this->mongo_db->get('foo', array('bar' => 'something')); */
  public function get($collection = "") {
    if (emptyempty($collection)) {
      $this->error("In order to retreive documents from MongoDB, a collection name must be passed", 500);
    } $results = array();
    $documents = $this->db->{$collection}->find($this->wheres, $this->selects)->limit((int) $this->limit)->skip((int) $this->offset)->sort($this->sorts);
    $returns = array();
    foreach ($documents as $doc): $returns[] = $doc;
    endforeach;
    return($returns);
  }

  public function getMy($collection = "") {
    if (emptyempty($collection)) {
      $this->error("In order to retreive documents from MongoDB, a collection name must be passed", 500);
    } $results = array();
    $documents = $this->db->{$collection}->find($this->wheres, $this->selects)->limit((int) $this->limit)->skip((int) $this->offset)->sort($this->sorts);
    $returns = array();
    foreach ($documents as $doc): $returns[] = $doc;
    endforeach;
    $this -> clear();
    return($returns);
  }

  /**   *  --------------------------------------------------------------------------------   * COUNT  * --------------------------------------------------------------------------------   *  * Count the documents based upon the passed parameters   *  * @usage = $this->mongo_db->get('foo'); */
  public function count($collection = "") {
    if (emptyempty($collection)) {
      $this->error("In order to retreive a count of documents from MongoDB, a collection name must be passed", 500);
    } $count = $this->db->{$collection}->find($this->wheres)->limit((int) $this->limit)->skip((int) $this->offset)->count();
    $this->clear();
    return($count);
  }

  /**   *  --------------------------------------------------------------------------------   * INSERT  * --------------------------------------------------------------------------------   *  * Insert a new document into the passed collection   *  * @usage = $this->mongo_db->insert('foo', $data = array()); */
  public function insert($collection = "", $data = array(), $name='ID') {
    if (emptyempty($collection)) {
      $this->error("No Mongo collection selected to insert into", 500);
    } if (count($data) == 0 || !is_array($data)) {
      $this->error("Nothing to insert into Mongo collection or insert is not an array", 500);
    } try {
      /**
      wxcity_base::load_sys_class('whtysqs','',0);
      $mongoseq_class = new whtysqs('creaseidsqs');
      $re = $mongoseq_class->query("?name=" . $collection . "&opt=put&data=1");
       **/
      $re = put_sqs('list_mongo_creaseidsqs','1');
      if(is_numeric($re)){
        $re++;
        $data[$name] = intval($re);
      }else{
        $data[$name] = intval(time());
        //die('mongosqs error');
      }
      $this->db->{$collection}->insert($data, array('fsync' => TRUE));
      $this->clear();
      return $data[$name];
    } catch (MongoCursorException $e) {
      $this->error("Insert of data into MongoDB failed: {$e->getMessage()}", 500);
    }
  }

  public function insertWithId($collection = "", $data = array()) {
    if (emptyempty($collection)) {
      $this->error("No Mongo collection selected to insert into", 500);
    } if (count($data) == 0 || !is_array($data)) {
      $this->error("Nothing to insert into Mongo collection or insert is not an array", 500);
    } try {
      $this->db->{$collection}->insert($data, array('fsync' => TRUE));
      $this->clear();
      return 1;
    } catch (MongoCursorException $e) {
      $this->error("Insert of data into MongoDB failed: {$e->getMessage()}", 500);
    }
  }
  /**   *  --------------------------------------------------------------------------------   * UPDATE  * --------------------------------------------------------------------------------   *  * Update a document into the passed collection   *  * @usage = $this->mongo_db->update('foo', $data = array()); */
  public function update($collection = "", $data = array()) {
    if (emptyempty($collection)) {
      $this->error("No Mongo collection selected to update", 500);
    } if (count($data) == 0 || !is_array($data)) {
      $this->error("Nothing to update in Mongo collection or update is not an array", 500);
    } try {
      $this->db->{$collection}->update($this->wheres, array('$set' => $data), array('fsync' => TRUE, 'multiple' => FALSE));
      $this->clear();
      return(TRUE);
    } catch (MongoCursorException $e) {
      $this->error("Update of data into MongoDB failed: {$e->getMessage()}", 500);
    }
  }

  /**   *  --------------------------------------------------------------------------------   * UPDATE_ALL  * --------------------------------------------------------------------------------   *  * Insert a new document into the passed collection   *  * @usage = $this->mongo_db->update_all('foo', $data = array()); */
  public function update_all($collection = "", $data = array()) {
    if (emptyempty($collection)) {
      $this->error("No Mongo collection selected to update", 500);
    } if (count($data) == 0 || !is_array($data)) {
      $this->error("Nothing to update in Mongo collection or update is not an array", 500);
    } try {
      $this->db->{$collection}->update($this->wheres, array('$set' => $data), array('fsync' => TRUE, 'multiple' => TRUE));
      return(TRUE);
    } catch (MongoCursorException $e) {
      $this->error("Update of data into MongoDB failed: {$e->getMessage()}", 500);
    }
  }

  /**   *  --------------------------------------------------------------------------------   * DELETE  * --------------------------------------------------------------------------------   *  * delete document from the passed collection based upon certain criteria  *  * @usage = $this->mongo_db->delete('foo', $data = array()); */
  public function delete($collection = "") {
    if (emptyempty($collection)) {
      $this->error("No Mongo collection selected to delete from", 500);
    } try {
      $this->db->{$collection}->remove($this->wheres, array('fsync' => TRUE, 'justOne' => TRUE));
      $this->clear();
      return(TRUE);
    } catch (MongoCursorException $e) {
      $this->error("Delete of data into MongoDB failed: {$e->getMessage()}", 500);
    }
  }

  /**   *  --------------------------------------------------------------------------------   * DELETE_ALL  * --------------------------------------------------------------------------------   *  * Delete all documents from the passed collection based upon certain criteria *  * @usage = $this->mongo_db->delete_all('foo', $data = array()); */
  public function delete_all($collection = "") {
    if (emptyempty($collection)) {
      $this->error("No Mongo collection selected to delete from", 500);
    } try {
      $this->db->{$collection}->remove($this->wheres, array('fsync' => TRUE, 'justOne' => FALSE));
      return(TRUE);
    } catch (MongoCursorException $e) {
      $this->error("Delete of data into MongoDB failed: {$e->getMessage()}", 500);
    }
  }

  /**   *  --------------------------------------------------------------------------------   * ADD_INDEX  * --------------------------------------------------------------------------------   *  * Ensure an index of the keys in a collection with optional parameters. To set values to descending order,   * you must pass values of either -1, FALSE, 'desc', or 'DESC', else they will be  * set to 1 (ASC). *  * @usage = $this->mongo_db->add_index($collection, array('first_name' => 'ASC', 'last_name' => -1), array('unique' => TRUE));  */
  public function add_index($collection = "", $keys = array(), $options = array()) {
    if (emptyempty($collection)) {
      $this->error("No Mongo collection specified to add index to", 500);
    } if (emptyempty($keys) || !is_array($keys)) {
      $this->error("Index could not be created to MongoDB Collection because no keys were specified", 500);
    } foreach ($keys as $col => $val) {
      if ($val == -1 || $val === FALSE || strtolower($val) == 'desc') {
        $keys[$col] = -1;
      } else {
        $keys[$col] = 1;
      }
    } if ($this->db->{$collection}->ensureIndex($keys, $options) == TRUE) {
      $this->clear();
      return($this);
    } else {
      $this->error("An error occured when trying to add an index to MongoDB Collection", 500);
    }
  }

  /**   *  --------------------------------------------------------------------------------   * REMOVE_INDEX   * --------------------------------------------------------------------------------   *  * Remove an index of the keys in a collection. To set values to descending order, * you must pass values of either -1, FALSE, 'desc', or 'DESC', else they will be  * set to 1 (ASC). *  * @usage = $this->mongo_db->remove_index($collection, array('first_name' => 'ASC', 'last_name' => -1));  */
  public function remove_index($collection = "", $keys = array()) {
    if (emptyempty($collection)) {
      $this->error("No Mongo collection specified to remove index from", 500);
    } if (emptyempty($keys) || !is_array($keys)) {
      $this->error("Index could not be removed from MongoDB Collection because no keys were specified", 500);
    } if ($this->db->{$collection}->deleteIndex($keys, $options) == TRUE) {
      $this->clear();
      return($this);
    } else {
      $this->error("An error occured when trying to remove an index from MongoDB Collection", 500);
    }
  }

  /**   *  --------------------------------------------------------------------------------   * REMOVE_ALL_INDEXES  * --------------------------------------------------------------------------------   *  * Remove all indexes from a collection.  *  * @usage = $this->mongo_db->remove_all_index($collection);  */
  public function remove_all_indexes($collection = "") {
    if (emptyempty($collection)) {
      $this->error("No Mongo collection specified to remove all indexes from", 500);
    } $this->db->{$collection}->deleteIndexes();
    $this->clear();
    return($this);
  }

  /**   *  --------------------------------------------------------------------------------   * LIST_INDEXES   * --------------------------------------------------------------------------------   *  * Lists all indexes in a collection.  *  * @usage = $this->mongo_db->list_indexes($collection);  */
  public function list_indexes($collection = "") {
    if (emptyempty($collection)) {
      $this->error("No Mongo collection specified to remove all indexes from", 500);
    } return($this->db->{$collection}->getIndexInfo());
  }

  /**   *  --------------------------------------------------------------------------------   * DROP COLLECTION * --------------------------------------------------------------------------------   *  * Removes the specified collection from the database. Be careful because this   * can have some very large issues in production!  */
  public function drop_collection($collection = "") {
    if (emptyempty($collection)) {
      $this->error("No Mongo collection specified to drop from database", 500);
    } $this->db->{$collection}->drop();
    return TRUE;
  }

  /**   *  --------------------------------------------------------------------------------   * CLEAR  * --------------------------------------------------------------------------------   *  * Resets the class variables to default settings  */
  private function clear() {
    $this->selects = array();
    $this->wheres = array();
    $this->limit = NULL;
    $this->offset = NULL;
    $this->sorts = array();
  }

  /**   *  --------------------------------------------------------------------------------   * WHERE INITIALIZER  * --------------------------------------------------------------------------------   *  * Prepares parameters for insertion in $wheres array().  */
  private function where_init($param) {
    if (!isset($this->wheres[$param])) {
      $this->wheres[$param] = array();
    }
  }

  public function error($str, $t) {
    echo $str;
    exit;
  }

}

?>