独孤求败的风格, 上代码:

/**

* Prepare statement loading from Config

* The ctime on dabase instance config could be used to control the expire * of all prepared statments

* Config ctime = now() could be used to force recompile for each bootstrap,

* date +%s could get the value of current seconds from EPOCH

* stmts will be name => query pairs

* Expired will be recompile automatically, any update on config should update ctime as well

*

* @author Anthony.chen

* 2010-2012 reserved

*/

class PSTMT{

public static $instances = array();

/**

* Loading the prepare statment from DB Connection

* The stmts is config linked to DB instance with 'stmts' k=>v array

*

* @return Boolean

*/

public static function prepare($db='default'){

//Getting statment from config

$_config = Pexcel::config('database')->$db;

$_ctime = Arr::get($_config,'ctime',0);

$_configStmts = Arr::get($_config,'stmts',NULL);

if($_configStmts != NULL){//There is statments configured

if(!isset(self::$instances[$db])){

$_sql = 'select name , EXTRACT(EPOCH FROM prepare_time) as ctime from pg_prepared_statements';

$_pstmts = DB::query(DB::SELECT,$_sql,true)->execute($db)->as_array();

if(!$_pstmts){

self::$instances[$db] = array();

}else{

//Log::debug('Before Commpiling,statement Found');

foreach($_pstmts as $_pstmt){

self::$instances[$db][$_pstmt->name] = $_pstmt->ctime;

}

}

}

//Compile the statments

foreach($_configStmts as $stmtName => $stmtQuery){

if(isset(self::$instances[$db][$stmtName])){

if( self::$instances[$db][$stmtName] < $_ctime){

//Log::debug($stmtName.' Expires');

}else{

//Log::debug($stmtName.' Exists');

continue;

}

}

self::compile($stmtName,$stmtQuery,$db);

}

}else{

throw new Error_Exception('stmts not in config!');

}

return True;

}

/**

* Compile the prepared statment

*

* @param String $stmtName, Statement name

* @param String $stmtQuery, Statement query

* @param String $db ,Instance name of database

*

* @return Boolean

*/

public static function compile($stmtName, $stmtQuery,$db ='default'){

if(isset(self::$instances[$db][$stmtName])){ //already Compiled

//Doing Nothing

//Log::debug('DEALLOCATE '.$stmtName);

DB::query(DB::UPDATE,'DEALLOCATE '.$stmtName)->execute($db);

}

$_ret = DB::query(DB::SELECT,$stmtQuery,False,NULL,$stmtName)->execute($db)->count();

//Log::debug(__FUNCTION__.':compiling the pstat:'.$stmtQuery);

self::$instances[$db][$stmtName] = time();

return True;

}

/**

* Execute the prepared statement

*

* @param String $stmtName, Statement Name

* @param Array $params , The parameter to be transfered into query

* @param Boolean $as_object, True to fetch result as object

* @param String $db, Database Instance name

*

* @return Array of result set

*/

public static function execute($stmtName,$params = array(),$as_object = TRUE,$db = 'default'){

if(isset(self::$instances[$db][$stmtName])){

return DB::query(DB::SELECT,NULL,$as_object,$params,$stmtName)->execute($db);

}else{

$_config = Pexcel::config('database')->$db;

$_configStmts = Arr::get($_config,'stmts',NULL);

//Compile the prepared statment

if(isset($_configStmts[$stmtName])){

self::compile($stmtName,$_configStmts[$stmtName],$db);

}else{

return false;

}

return DB::query(DB::SELECT,NULL,$as_object,$params,$stmtName)->execute($db);

}

}

}