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我在這裏有一段時間，我試圖在自己（;）之後正確清理，並顯示我的類和方法正在使用多少內存。PHP PDO類內存使用
我遇到的問題是這樣的：
- 看來，清理後，有比上次內存檢查（預返回存儲器））
下面是使用更多內存課堂上，測試頁面，結果（和業績網上說明）
類：
<?php
class o7thDB {
public $Type = 1; // What type of database are we connecting to
public $Host = ''; // The host server we are connecting to
public $Name = ''; // The name of the database
public $User = ''; // The user to login with
public $Pass = ''; // The password to login with
public $Query = ''; // The query to execute
public $Params = array(); // An array of parameters to pass to the query for execution
public $ShouldCache = false; // Should the results be cached?
public $CacheKey = ''; // What should we name the key for this cache?
public $Exceptions = ''; // Returns a string representing the exception that occurred if any
/* Memory Usage Tests */
public $InitialMemory;
public $PreSelectMemory;
public $CreatePDOMemory;
public $PostSelectMemory;
public $PreReturnMemory;
protected $DBHandle;
protected $Cache;
protected function Connect(){
$this->InitialMemory = memory_get_peak_usage();
if(session_status() != PHP_SESSION_ACTIVE){
session_start();
}
$dsn = array();
switch ($this->Type) {
case 1: // MS SQL
$dsn = array("mssql:host=$this->Host;dbname=$this->Name", $this->User, $this->Pass);
break;
case 2: // MS SQL Server
$dsn = array("sqlsrv:server=$this->Host;database=$this->Name", $this->User, $this->Pass);
break;
case 3: // MS Access
$dsn = array("odbc:Driver={Microsoft Access Driver (*.mdb)};Dbq=$this->Name;Uid=$this->User");
break;
case 4: // Oracle
$dsn = array("OCI:dbname=$this->Name;charset=UTF-8", $this->User, $this->Pass);
break;
case 5: // Informix
$dsn = array("informix:DSN=$this->Name", $this->User, $this->Pass);
break;
case 6: // Firebird
$dsn = array("firebird:dbname=$this->Host:$this->Name", $this->User, $this->Pass);
break;
case 7: // MySQL
$dsn = array("mysql:host=$this->Host;dbname=$this->Name", $this->User, $this->Pass);
break;
case 8: // SQLLite
$dsn = array("sqlite:$this->Host");
break;
default: // MySQL
$dsn = array("mysql:host=$this->Host;dbname=$this->Name", $this->User, $this->Pass);
break;
}
try{
$this->DBHandle = new PDO($dsn[0], $dsn[1], $dsn[2]);
$this->DBHandle->setAttribute(PDO::ATTR_PERSISTENT, true);
$this->DBHandle->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$this->CreatePDOMemory = memory_get_peak_usage();
} catch (PDOException $e) {
$this->Exceptions = $e->getMessage();
}
}
// Destroying Everything
public function __destruct(){
unset($this->DBHandle, $this->Cache, $this->Type, $this->Host, $this->Name, $this->User, $this->Pass,
$this->Query, $this->Params, $this->ShouldCache, $this->CacheKey, $this->Exceptions);
}
// Executes a query against the database, returns boolean success
public function Execute(){
}
// Executes a select statement against the database, returns an associative array
public function Select(){
$this->Connect();
$this->PreSelectMemory = memory_get_peak_usage();
$stmt = $this->DBHandle->prepare($this->Query);
$stmt->execute($this->Params);
$ret = $stmt->fetchAll(PDO::FETCH_ASSOC);
$this->PostSelectMemory = memory_get_peak_usage();
if($this->ShouldCache){
$cKey = $this->CacheKey . session_id();
if(isset($this->Cache[$cKey])){
$this->PreReturnMemory = memory_get_peak_usage();
return $this->Cache[$cKey];
}else{
$this->PreReturnMemory = memory_get_peak_usage();
$this->Cache[$cKey] = $ret;
return $ret;
}
}else{
$this->PreReturnMemory = memory_get_peak_usage();
return $ret;
}
$stmt->closeCursor();
unset($stmt, $ret);
}
}
?>
測試頁：
<?php
// Show All Errors
error_reporting(E_ALL);
ini_set('display_errors', '1');
require_once($_SERVER['DOCUMENT_ROOT'] . '/Database/o7th.db.class.php');
// Time the Execution
$mtime = microtime();
$mtime = explode(" ",$mtime);
$mtime = $mtime[1] + $mtime[0];
$starttime = $mtime;
$db = new o7thDB();
$db->Type = 7;
$db->Host = 'localhost';
$db->Name = 'mydb';
$db->User = 'myun';
$db->Pass = 'mypw';
$db->Query = "Select * From `modx_session` Where `data` Like ? Or `id` Like ?";
$db->ShouldCache = true;
$db->CacheKey = 'a';
$db->Params = array('%a%', '%Welcome%');
$ret = $db->Select();
$rCt = count($ret);
echo $rCt . ': Records Returned<br />';
echo $db->Exceptions;
unset($ret);
echo $db->InitialMemory . ': Initial Memory<br />';
echo $db->CreatePDOMemory . ': Create PDO Memory<br />';
echo $db->PreSelectMemory . ': Pre-Select Memory<br />';
echo $db->PostSelectMemory . ': Post-Select Memory<br />';
echo $db->PreReturnMemory . ': Pre-Return Memory<br />';
unset($db);
echo memory_get_peak_usage() .': After all is said and done!<br />';
echo '<hr />';
$mtime = microtime();
$mtime = explode(" ",$mtime);
$mtime = $mtime[1] + $mtime[0];
$endtime = $mtime;
$totaltime = ($endtime - $starttime);
echo "This page was created in ".$totaltime." seconds";
?>
測試頁結果：
21168: Records Returned
288016: Initial Memory
288016: Create PDO Memory
288016: Pre-Select Memory
19209456: Post-Select Memory
19209552: Pre-Return Memory
19209768: After all is said and done!
This page was created in 0.066221952438354 seconds
所以，我的問題是，爲什麼是它的代碼使用更多的內存，一切都清理後？
這可能是一個愚蠢的問題..但是..怎麼是你期待有「PostReturnMemory設置的值'當你的腳本正在返回（並因此不執行當前代碼路徑）？ – ethrbunny 2013-03-22 21:34:05
...並且__destruct被調用時..不是'this'指針會消失嗎？所以'PostDestructMemory'將不再存在了。是嗎？ – ethrbunny 2013-03-22 21:36:53
:)是的，我想盡可能多，但正如你從我發佈的測試頁的代碼中可以看到的，我正在運行內存檢查以及...它仍然在那裏實際上超過什麼張貼爲預迴歸內存......即使在清理結束後仍然存在 – Kevin 2013-03-23 02:37:48