mongodb的mapreduce用法及php示例代码

/<span>**</span>
     * mapReduce分组
     * 
     * <span>@param</span> string <span>$table_name</span> 表名(要操作的目标集合名)
     * <span>@param</span> string <span>$map</span> 映射函数(生成键&#20540;对序列,作为 reduce 函数参数) 
     * <span>@param</span> string <span>$reduce</span> 统计处理函数
     * <span>@param</span> array  <span>$query</span> 过滤条件 如：array(<span>'uid'</span>=><span>123</span>)
     * <span>@param</span> array  <span>$sort</span> 排序
     * <span>@param</span> number <span>$limit</span> 限制的目标记录数
     * <span>@param</span> string <span>$out</span> 统计结果存放集合 (不指定则使用tmp_mr_res<span>_</span><span>$table_name</span>, <span>1.8</span>以上版本需指定)
     * <span>@param</span> bool   <span>$keeptemp</span> 是否保留临时集合
     * <span>@param</span> string <span>$finalize</span> 最终处理函数 (对reduce返回结果进行最终整理后存入结果集合)
     * <span>@param</span> string <span>$scope</span> 向 <span>map</span>、reduce、finalize 导入外部js变量
     * <span>@param</span> bool   <span>$jsMode</span> 是否减少执行过程中BSON和JS的转换，默认true(注：false时 BSON-->JS-->map-->BSON-->JS-->reduce-->BSON,可处理非常大的mapreduce,<span>//true</span>时BSON-->js-->map-->reduce-->BSON)
     * <span>@param</span> bool   <span>$verbose</span> 是否产生更加详细的服务器日志
     * <span>@param</span> bool   <span>$returnresult</span> 是否返回新的结果集
     * <span>@param</span> array	 &<span>$cmdresult</span> 返回mp命令执行结果 array(<span>"errmsg"</span>=><span>""</span>,<span>"code"</span>=><span>13606</span>,<span>"ok"</span>=><span>0</span>) ok=<span>1</span>表示执行命令成功
     * <span>@return</span><span>*/</span>
    function mapReduce(<span>$table_name</span>,<span>$map</span>,<span>$reduce</span>,<span>$query</span>=null,<span>$sort</span>=null,<span>$limit</span>=<span>0</span>,<span>$out</span>=<span>''</span>,<span>$keeptemp</span>=true,<span>$finalize</span>=null,<span>$scope</span>=null,<span>$jsMode</span>=true,<span>$verbose</span>=true,<span>$returnresult</span>=true,&<span>$cmdresult</span>){
    	<span>if</span>(empty(<span>$table_name</span>) || empty(<span>$map</span>) || empty(<span>$reduce</span>)){
    		<span>return</span> null;
    	}
    	<span>$map</span> = new MongoCode(<span>$map</span>);
    	<span>$reduce</span> = new MongoCode(<span>$reduce</span>);
    	<span>if</span>(empty(<span>$out</span>)){
    		<span>$out</span> = <span>'tmp_mr_res_'</span>.<span>$table_name</span>;
    	}
    	<span>$cmd</span> = array(
    			<span>'mapreduce'</span> => <span>$table_name</span>,
    			<span>'map'</span>       => <span>$map</span>,
    			<span>'reduce'</span>    => <span>$reduce</span>,
    			<span>'out'</span>		=><span>$out</span>
    	);
    	<span>if</span>(!empty(<span>$query</span>) && is_array(<span>$query</span>)){
    		array_push(<span>$cmd</span>, array(<span>'query'</span>=><span>$query</span>));
    	}
    	<span>if</span>(!empty(<span>$sort</span>) && is_array(<span>$sort</span>)){
    		array_push(<span>$cmd</span>, array(<span>'sort'</span>=><span>$query</span>));
    	}
    	<span>if</span>(!empty(<span>$limit</span>) && is_int(<span>$limit</span>) && <span>$limit</span>><span>0</span>){
    		array_push(<span>$cmd</span>, array(<span>'limit'</span>=><span>$limit</span>));
    	}
    	<span>if</span>(!empty(<span>$keeptemp</span>) && is_bool(<span>$keeptemp</span>)){
    		array_push(<span>$cmd</span>, array(<span>'keeptemp'</span>=><span>$keeptemp</span>));
    	}
    	<span>if</span>(!empty(<span>$finalize</span>)){
    		<span>$finalize</span> = new Mongocode(<span>$finalize</span>);
    		array_push(<span>$cmd</span>, array(<span>'finalize'</span>=><span>$finalize</span>));
    	}
    	<span>if</span>(!empty(<span>$scope</span>)){
    		array_push(<span>$cmd</span>, array(<span>'scope'</span>=><span>$scope</span>));
    	}
    	<span>if</span>(!empty(<span>$jsMode</span>) && is_bool(<span>$jsMode</span>)){
    		array_push(<span>$cmd</span>, array(<span>'jsMode'</span>=><span>$jsMode</span>));
    	}
    	<span>if</span>(!empty(<span>$verbose</span>) && is_bool(<span>$verbose</span>)){
    		array_push(<span>$cmd</span>, array(<span>'verbose'</span>=><span>$verbose</span>));
    	}
    	<span>$dbname</span> = <span>$this</span>->curr_db_name;
    	<span>$cmdresult</span> = <span>$this</span>->mongo-><span>$dbname</span>->command(<span>$cmd</span>);
    	<span>if</span>(<span>$returnresult</span>){
    		<span>if</span>(<span>$cmdresult</span> && <span>$cmdresult</span>[<span>'ok'</span>]==<span>1</span>){
    			<span>$result</span> = <span>$this</span>->find(<span>$out</span>, array());
    		}
    	}
    	<span>if</span>(<span>$keeptemp</span>==false){
    		<span>//</span>删除集合
    		<span>$this</span>->mongo-><span>$dbname</span>->dropCollection(<span>$out</span>);
    	}
    	<span>return</span><span>$result</span>;
    }