<?php  
/*** Mongodb类** examples:   
* $mongo = new HMongodb("127.0.0.1:11223"); 
* $mongo->selectDb("test_db"); 
* 创建索引 
* $mongo->ensureIndex("test_table", array("id"=>1), array('unique'=>true)); 
* 获取表的记录 
* $mongo->count("test_table"); 
* 插入记录 
* $mongo->insert("test_table", array("id"=>2, "title"=>"asdqw")); 
* 更新记录 
* $mongo->update("test_table", array("id"=>1),array("id"=>1,"title"=>"bbb")); 
* 更新记录-存在时更新，不存在时添加-相当于set 
* $mongo->update("test_table", array("id"=>1),array("id"=>1,"title"=>"bbb"),array("upsert"=>1)); 
* 查找记录 
* $mongo->find("c", array("title"=>"asdqw"), array("start"=>2,"limit"=>2,"sort"=>array("id"=>1))) 
* 查找一条记录 
* $mongo->findOne("$mongo->findOne("ttt", array("id"=>1))", array("id"=>1)); 
* 删除记录 
* $mongo->remove("ttt", array("title"=>"bbb")); 
* 仅删除一条记录 
* $mongo->remove("ttt", array("title"=>"bbb"), array("justOne"=>1)); 
* 获取Mongo操作的错误信息 
* $mongo->getError(); 
*/  
  
class HMongodb {  
  
    //Mongodb连接  
    var $mongo;  
  
    var $curr_db_name;  
    var $curr_table_name;  
    var $error;  
  
    /** 
    * 构造函数 
    * 支持传入多个mongo_server(1.一个出问题时连接其它的server 2.自动将查询均匀分发到不同server) 
    * 
    * 参数： 
    * $mongo_server:数组或字符串-array("127.0.0.1:1111", "127.0.0.1:2222")-"127.0.0.1:1111" 
    * $connect:初始化mongo对象时是否连接，默认连接 
    * $auto_balance:是否自动做负载均衡，默认是 
    * 
    * 返回值： 
    * 成功：mongo object 
    * 失败：false 
    */  
    function __construct($mongo_server, $connect=true, $auto_balance=true)  
    {  
        if (is_array($mongo_server))  
        {  
            $mongo_server_num = count($mongo_server);  
            if ($mongo_server_num > 1 && $auto_balance)  
            {  
                $prior_server_num = rand(1, $mongo_server_num);  
                $rand_keys = array_rand($mongo_server,$mongo_server_num);  
                $mongo_server_str = $mongo_server[$prior_server_num-1];  
                foreach ($rand_keys as $key)  
                {  
                    if ($key != $prior_server_num - 1)  
                    {  
                        $mongo_server_str .= ',' . $mongo_server[$key];  
                    }  
                }  
            }  
            else  
            {  
                $mongo_server_str = implode(',', $mongo_server);  
            }                  }  
        else  
        {  
            $mongo_server_str = $mongo_server;  
        }  
        try {  
            $this->mongo = new Mongo($mongo_server, array('connect'=>$connect));  
        }  
        catch (MongoConnectionException $e)  
        {  
            $this->error = $e->getMessage();  
            return false;  
        }  
    }  
  
    function getInstance($mongo_server, $flag=array())  
    {  
        static $mongodb_arr;  
        if (emptyempty($flag['tag']))  
        {  
            $flag['tag'] = 'default';          }  
        if (isset($flag['force']) && $flag['force'] == true)  
        {  
            $mongo = new HMongodb($mongo_server);  
            if (emptyempty($mongodb_arr[$flag['tag']]))  
            {  
                $mongodb_arr[$flag['tag']] = $mongo;  
            }  
            return $mongo;  
        }  
        else if (isset($mongodb_arr[$flag['tag']]) && is_resource($mongodb_arr[$flag['tag']]))  
        {  
            return $mongodb_arr[$flag['tag']];  
        }  
        else  
        {  
            $mongo = new HMongodb($mongo_server);  
            $mongodb_arr[$flag['tag']] = $mongo;  
            return $mongo;                  }          }  
  
    /** 
    * 连接mongodb server 
    * 
    * 参数：无 
    * 
    * 返回值： 
    * 成功：true 
    * 失败：false 
    */  
    function connect()  
    {  
        try {  
            $this->mongo->connect();  
            return true