高效mongodb的php分页类（不使用skip）

<?php
function show_error($message, $status_code = 500, $heading = 'An Error Was Encountered')
{
        echo $message, $status_code,PHP_EOL;
        exit;
}

//MongoDB操作类
class DB
{

 private $CI;
 private $config_file = 'MongoDB';

 private $connection;
 private $db;
 private $connection_string;

 private $collection = '';
 private $host;
 private $port;
 private $user;
 private $pass;
 private $dbname;
 private $key;
 private $persist;
 private $persist_key;

 private $selects = array();
 private $wheres = array();
 private $sorts = array();
 private $page_sorts = array();

 private $limit = 999999;
 private $offset = 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($MONGODB_CONFIG)
 {
  if(!class_exists('Mongo'))
  {
   show_error("The MongoDB PECL extension has not been installed or enabled", 500);
  }
  /**
        $config['mongo_host'] = '221.234.43.144';
        $config['mongo_port'] = 27017;
        $config['mongo_db'] = 'test';
        $config['mongo_user'] = '';
        $config['mongo_pass'] = '';
        $config['mongo_persist'] = TRUE;
         *
         */
  $this->connection_string($MONGODB_CONFIG);
  $this->connect();
 }

 

 /**
  * --------------------------------------------------------------------------------
  * Switch_db
  * --------------------------------------------------------------------------------
  *
  * Switch from default database to a different db
  */

 public function switch_db($database = '')
 {
  if(empty($database))
  {
   show_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 $e)
  {
   show_error("Unable to switch Mongo Databases: {$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(!empty($includes))
   {
    foreach($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($wheres = array())
  {
   foreach($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 ( $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);
  }

 /**
  * --------------------------------------------------------------------------------
  * 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($fields = array())
  {
   foreach($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(), $limit = 99999)
  {
   return($this->where($where)->limit($limit)->get($collection));
  }

 /**
  * --------------------------------------------------------------------------------
  * GET
  * --------------------------------------------------------------------------------
  *
  * Get the documents based upon the passed parameters
  *
  * @usage = $this->mongo_db->get('foo', array('bar' => 'something'));
  */

  public function get($collection = "")
  {
   if(empty($collection))
   {
    show_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($collection = "")
  {
   if(empty($collection))
   {
    show_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);
  }

 /**
  * 自增ID实现
  * return insert_id
  */
 private function insert_inc($table)
 {
  $update = array('$inc'=>array('id'=>1));
  $query = array('table'=>$table);
  $command = array(
  'findandmodify'=>'_increase',
  'update'=>$update,
  'query'=>$query,
  'new'=>true,
  'upsert'=>true
  );
  $id = $this->db->command($command);
  return $id['value']['id'];
 }

 /**
  * --------------------------------------------------------------------------------
  * INSERT
  * --------------------------------------------------------------------------------
  *
  * Insert a new document into the passed collection
  *
  * @usage = $this->mongo_db->insert('foo', $data = array());
  */

  public function insert($collection = "", $data = array()) {
   if(empty($collection))
   {
    show_error("No Mongo collection selected to insert into", 500);
   }

   if(count($data) == 0 || !is_array($data))
   {
    show_error("Nothing to insert into Mongo collection or insert is not an array", 500);
   }

   try
   {
   $inc = $this->insert_inc($collection);
   $data['_id'] = $inc;
    $result = $this->db->{$collection}->insert($data, array('fsync' => TRUE));
    if($result['ok'] || $result){
    return true;
   }
   else{
    return false;
   }
   }
   catch(MongoCursorException $e)
   {
    show_error("Insert of data into MongoDB failed: {$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(), $flage = false)
  {
   if(empty($collection))
   {
    show_error("No Mongo collection selected to update", 500);
  }
   if(count($data) == 0 || !is_array($data))
   {
    show_error("Nothing to update in Mongo collection or update is not an array", 500);
  }
  unset($data['_id']);
  if($flage){
   $arr = $this->wheres;
   unset($arr['_id']);
   if(is_array($arr)){
    foreach($arr as $key => $w){
     unset($data[$key]);
    }
   }
  }
  try
   {
    $res = $this->db->{$collection}->update($this->wheres, array('$set' => $data), array('fsync' => TRUE, 'multiple' => FALSE));
   $this->clear();
   return $res;
   } 
   catch(MongoCursorException $e)
   {
    show_error("Update of data into MongoDB failed: {$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 = "", $data = array()) {
   if(empty($collection))
   {
    show_error("No Mongo collection selected to update", 500);
   }

   if(count($data) == 0 || !is_array($data))
   {
    show_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));
   $this->clear();
    return(TRUE);
   }
   catch(MongoCursorException $e)
   {
    show_error("Update of data into MongoDB failed: {$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, $where)
  {
   if(empty($collection))
   {
    show_error("No Mongo collection selected to delete from", 500);
   }
  if(!$where){
   show_error("No data input to delete", 500);
  }
   try
   {
   $this->wheres = $where;
    $this->db->{$collection}->remove($this->wheres);
   $this->clear();
    return(TRUE);
   }
   catch(MongoCursorException $e)
   {
    show_error("Delete of data into MongoDB failed: {$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($collection = "")
  {
     if(empty($collection))
     {
      show_error("No Mongo collection selected to delete from", 500);
    }

   try
   {
    $this->db->{$collection}->remove($this->wheres, array('fsync' => TRUE, 'justOne' => FALSE));
   $this->clear();
    return(TRUE);
   }
   catch(MongoCursorException $e)
   {
    show_error("Delete of data into MongoDB failed: {$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(), $options = array())
 {
  if(empty($collection))
  {
    show_error("No Mongo collection specified to add index to", 500);
   }

   if(empty($keys) || !is_array($keys))
   {
    show_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
   {
    show_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 = "", $keys = array())
 {
  if(empty($collection))
  {
    show_error("No Mongo collection specified to remove index from", 500);
   }

   if(empty($keys) || !is_array($keys))
   {
    show_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
   {
    show_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($collection = "") {
  if(empty($collection))
  {
    show_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($collection = "") {
  if(empty($collection))
  {
    show_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($collection = "")
  {
    if(empty($collection))
   {
      show_error("No Mongo collection specified to drop from database", 500);
    }
    $this->db->{$collection}->drop();
    return TRUE;
  }

 /**
  * --------------------------------------------------------------------------------
  * 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() {
  $options = array();
  if($this->persist === TRUE)
  {
   $options['persist'] = isset($this->persist_key) && !empty($this->persist_key) ? $this->persist_key : 'ci_mongo_persist';
  }

  try
  {
   $this->connection = new Mongo($this->connection_string, $options);
   $this->db = $this->connection->{$this->dbname};
   return($this);
  }
  catch(MongoConnectionException $e)
  {
   show_error("Unable to connect to MongoDB: {$e->getMessage()}", 500);
  }
 }

 /**
  * --------------------------------------------------------------------------------
  * BUILD CONNECTION STRING
  * --------------------------------------------------------------------------------
  *
  * Build the connection string from the config file.
  */

 private function connection_string($MONGODB_CONFIG)
 {

  $this->host = trim($MONGODB_CONFIG['HOST']);
  $this->port = trim($MONGODB_CONFIG['PORT']);
  $this->user = trim($MONGODB_CONFIG['USER']);
  $this->pass = trim($MONGODB_CONFIG['PWD']);
  $this->dbname = trim($MONGODB_CONFIG['DATABASE']);
  $this->persist = trim($MONGODB_CONFIG['PERSIST']);
  $this->persist_key = trim($MONGODB_CONFIG['PERSIST_KEY']);

  $connection_string = "mongodb://";

  if(empty($this->host))
  {
   show_error("The Host must be set to connect to MongoDB", 500);
  }

  if(empty($this->dbname))
  {
   show_error("The Database must be set to connect to MongoDB", 500);
  }

  if(!empty($this->user) && !empty($this->pass))
  {
   $connection_string .= "{$this->user}:{$this->pass}@";
  }

  if(isset($this->port) && !empty($this->port))
  {
   $connection_string .= "{$this->host}:{$this->port}/{$this->dbname}";
  }
  else
  {
   $connection_string .= "{$this->host}";
  }

  $this->connection_string = trim($connection_string);
 }

 /**
  * --------------------------------------------------------------------------------
  * 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();
   }
 }

 /**
  * --------------------------------------------------------------------------------
  * 设置表
  * --------------------------------------------------------------------------------
  *  参数：
  *  $table 表名
  */
 public function set_table($table){
  $this->collection = $table;
 }

 /**
  * --------------------------------------------------------------------------------
  * 获取表名
  * --------------------------------------------------------------------------------
  */
 public function get_table(){
  return $this->collection;
 }

 /**
  * --------------------------------------------------------------------------------
  * 设置表排序
  * --------------------------------------------------------------------------------
  *  参数：
  *  $orderby 排序
  */
 public function set_orderby($orderby){
  $this->page_sorts = $orderby;
 }

 
 /**
  * --------------------------------------------------------------------------------
  * 获取左边结果集
  * --------------------------------------------------------------------------------
  *  参数：
  *  $left 左边显示的个数
  *  $last 定位当前页的值
  *  $size 页面大小
  */
 public function get_left($left, $last, $size = PAGE_SIZE){
  if($last){
   $order = $this->nor_orderby();
   if($this->page_sorts[$this->key] == -1){
    $this->where_gt($this->key, $last);
   } else {
     $this->where_lt($this->key, $last);
   }
   return $this->limit($left * $size)->order_by($order)->get($this->collection);
  }
 }

 
 /**
  * --------------------------------------------------------------------------------
  * 获取右边结果集
  * --------------------------------------------------------------------------------
  *  参数：
  *  $right 右边显示的个数
  *  $last 定位当前页的值
  *  $size 页面大小
  */
 public function get_right($right, $last, $size = PAGE_SIZE){
  if($last){
   if($this->page_sorts[$this->key] == -1){
    $this->where_lte($this->key, $last);
   } else {
    $this->where_gte($this->key, $last);
   }
  }
  return $this->limit($right * $size + 1)->order_by($this->page_sorts)->get($this->collection);
 }

 /**
  * --------------------------------------------------------------------------------
  * 设置key
  * --------------------------------------------------------------------------------
  *  参数：
  *  $key 设置索引主键
  */
 public function set_key($key){
  $this->key = $key;
 }

 /**
  * --------------------------------------------------------------------------------
  * 求反
  * --------------------------------------------------------------------------------
  */
 private function nor_orderby(){
  foreach($this->page_sorts as $key => $order){
   if($order == -1){
    $orderby[$key] = 1;
   }else{
    $orderby[$key] = -1;
   }  
  }
  return $orderby;
 }

 /**
  * --------------------------------------------------------------------------------
  * 获取上一页的值
  * --------------------------------------------------------------------------------
  *  参数：
  *  $last 定位当前页的值
  *  $size 页面大小
  */
 public function get_prev($last, $size = PAGE_SIZE){
  if($last){
   if($this->page_sorts[$this->key] == 1){
    $this->where_lt($this->key,$last)->order_by(array($this->key => -1));
   } else {
    $this->where_gt($this->key,$last)->order_by(array($this->key => 1));
   }
   $result = $this->limit($size)->get($this->collection);
  }
  return $result[$size - 1][$this->key];
 }

  /**
  * --------------------------------------------------------------------------------
  * 获取下一页的值
  * --------------------------------------------------------------------------------
  *  参数：
  *  $last 定位当前页的值
  *  $size 页面大小
  */
 public function get_next($last, $size = PAGE_SIZE){
  if($last){
   if($this->page_sorts[$this->key] == 1){
    $this->where_gte($this->key,$last);
   } else {
    $this->where_lte($this->key,$last);
   }
  }
  $result = $this->limit($size+1)->order_by($this->page_sorts)->get($this->collection);
  return $result[$size][$this->key];
 }

 /**
  * --------------------------------------------------------------------------------
  * 获取最后一页的值
  * --------------------------------------------------------------------------------
  *  参数：
  *  $size 页面大小
  */
 public function get_last($size = PAGE_SIZE){
  $res = $this->count($this->collection) % $size;
  $order = $this->nor_orderby();
  if($res > 0){
   $result = $this->limit($res)->order_by($order)->get($this->collection);
   return $result[$res - 1][$this->key];
  }else{
   $result = $this->limit($size)->order_by($order)->get($this->collection);
   return $result[$size - 1][$this->key];
  }
 }

 /**
  * --------------------------------------------------------------------------------
  * 分页查询
  * --------------------------------------------------------------------------------
  *  参数：
  *  $last 定位当前页的值
  *  $size 页面大小
  */
 public function page_query($last, $size = PAGE_SIZE){
  if($last){
   if($this->page_sorts[$this->key]==1){
    $this->where_gte($this->key,$last);
   } else {
    $this->where_lte($this->key,$last);
   }
  }
  return $this->limit($size)->order_by($this->page_sorts)->get($this->collection);
 }

 /**
  * 批量执行代码_插入
  * @param String $collection
  * @param 二维数组 $code
  */
 public function execute_insert($collection,$code){
  //将二维数组分成js格式
  $strcode='';
  foreach($code as $k=>$v){
   foreach($v as $kk=>$vv){
    $strcode.='db.getCollection("'.$collection.'").insert({ "'.$kk.'":"'.$vv.'" });';
   }   
  }
 // retrun array([ok]=>1);
  return $this->db->execute($code); 
 }

}
?>

<?php
db = $DB;
  $this->count = $this->db->count($this->db->get_table());
  $url = SITE_ROOT.strtolower(CLASS_NAME).'/'.METHOD_NAME;
  $this->url = $this->url ? $this->url : $url;
  $set = $set ? $set : 5;
  $this->set = $set;
  $size = $size ? $size : PAGE_SIZE;
  $this->size = $size;
  $this->last = $last;
  $this->prev = $DB->get_prev($this->last);
  $this->next = $DB->get_next($this->last);
  //$this->page = GET::UINT('page');
  $this->page = $this->page ? $this->page : 1;
  $this->total = @ceil($this->count / $this->size);
  $this->key = $key;
  $this->orderby = $orderby;
 }

 //输出分页链接
 public function get_link(){
  if($this->total != 1){
   $this->get_first();
   $this->get_prev();
   $this->get_center();
   $this->get_next();
   $this->get_last();
   $this->get_turnto();
  }
  if($this->link){
   $this->link = $this->turnto.$this->link.'共'.number_format($this->total).'页 '.number_format($this->count).'条记录';
  }
  if($this->turnto){
   $this->link .= '';
  }
  return $this->link;
 }

 //获取左边显示的个数
 public function get_left(){
  return  $this->left = ($this->set - $this->page >= 0) ? ($this->page - 1) : $this->set;
 }

 //获取右边显示的个数
 public function get_right(){
  return $this->right = ($this->total - $this->page > $this->set) ? $this->set : ($this->total - $this->page);
 }

 //设置左边的结果集
 public function set_left_result($left_result){
  $this->leftresult = $left_result;
 }

 //设置右边的结果集
 public function set_right_result($right_result){
  $this->rightresult = $right_result;
 }

 //设置排序条件
 public function set_orderby($orderby){
  $this->orderby = $orderby;
 }

 //设置最后一页
 public function set_last($last){
  $this->lastd = $last;
 }

 //设置中间显示页码个数
 public function set($set){
  $this->set = $set;
 }

 //获取首页
 private function get_first(){
  if($this->page != 1){
   if($this->total > 0){
    $this->link.='首页';
   }
  }
 }

 //获取上一页
 private function get_prev(){
  if($this->prev){
   $this->link.='上一页';
  }
 }

 //中间显示
 private function get_center(){
  $start = ($this->page - $this->set) <= 0 ? 1 : ($this->page - $this->set); 
  $end = ($this->page + $this->set + 1 >= $this->total) ? $this->total + 1 : ($this->page + $this->set + 1);

  $ii = $this->left;
  $iii = 0;
  //显示左边的
  for($i = $start; $i < $end; $i++, $ii--, $iii++){
   if($this->page == $i){
    $this->link.=''.$i.'';
   }else{
    $the_id = $ii * $this->size - 1;
    if($the_id > 0){
     $this->link.=''.$i.'';
    }else{
     $the_id = ($iii - $this->left) * $this->size;
     $this->link.=''.$i.'';
    }   
   }
  }
 }

 //获取下一页
 private function get_next(){
  if($this->next){
   $this->link.='下一页';
  }
 }

 //获取尾页
 private function get_last(){
  if($this->page != $this->total){
   $this->link.='尾页';
  }
 }

 //跳转到
 private function get_turnto(){
  $this->turnto = '
转到第 <input type="text" name="p" style="width:25px;text-align:center"> 页';
 }

 //求反
 public function nor_orderby(){
  foreach($this->orderby as $key => $order){
   if($order==-1){
    $orderby[$key] = 1;
   }else{
    $orderby[$key] = -1;
   }  
  }
  return $orderby;
 }

 //设置key
 public function set_key($key){
  $this->key = $key;
 }

 //分页操作
 public function show(){
  $this->set_key($this->key);
  $this->set_orderby($this->orderby);
  $left = $this->get_left();
  $right = $this->get_right();
  $leftresult = $this->db->get_left($left, $this->last);
  $rightresult = $this->db->get_right($right, $this->last);
  $this->set_left_result($leftresult);
  $this->set_right_result($rightresult);
  $last = $this->db->get_last();
  $this->set_last($last);
  return $this->get_link();
 }
}
/*      调用例子rockmongo
  global $DB;
  $lastid = GET::UINT('id');
  $table = 'log';
  $key = '_id';
  $orderby = array($key => -1);

  $DB->set_table($table);
  $DB->set_key($key);
  $DB->set_orderby($orderby);

  $log = $DB->page_query($lastid);

  $page = new Page($lastid, $key, $orderby);
  $pager = $page->show();
*/

?>

<?php
  include "page.class.php";
  include "mongodb.class.php";
  define(PAGE_SIZE, 5);//每页大小
  $config['HOST'] = '127.0.0.1';
  $config['PORT'] = 20081;  //mongodb端口
  $config['DATABASE'] = 'domain';//mongodb数据库名
  $config['USER'] = '';
  $config['PWD'] = '';
  $config['PERSIST'] = TRUE;

  $DB = new DB($config);

  $table = 'whois'; //mongodb collection名
  $key = '_id';
  $orderby = array($key => -1);

  $DB->set_table($table);
  $DB->set_key($key);
  $DB->set_orderby($orderby);

  $log = $DB->page_query($lastid,5);

  $page = new Page($lastid, $key, $orderby);

  echo $pager = $page->show();

?>