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PHK Manager |  |
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| Size: | 6663 |
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<?php
//=============================================================================
//
// Copyright Francois Laupretre <phk@tekwire.net>
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
//=============================================================================
/**
* @copyright Francois Laupretre <phk@tekwire.net>
* @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, V 2.0
* @category PHK
* @package PHK
*///==========================================================================
namespace PHK\Virtual {
if (!class_exists('PHK\Virtual\DC',false))
{
//=============================================================================
/**
* Data container
*
* Contains string data and supports compression.
*
* API status: Private
* Included in the PHK PHP runtime: Yes
* Implemented in the extension: No
*///==========================================================================
class DC // Data Container
{
private $csz; // Compressed size
private $rsz; // Real size
private $flags; // Compression method
private $off; // Offset
private $data=null; // Data cache (null if unset)
private $fspace=null;
//---------
const COMPRESS_TYPE=7; // Space reserved for 8 compression types
const COMPRESS_NONE=0;
const COMPRESS_GZIP=1;
const COMPRESS_BZIP2=2;
private static $compression_method_names=array('none','gzip','bzip2');
private static $compression_needed_extensions=array(null,'zlib','bz2');
//---------
// Clears the data cache
public function clearCache()
{
$data=null;
}
//---------
public function setFspace($fspace)
{
$this->fspace=$fspace;
}
//---------
private function compressionType()
{
return $this->flags & self::COMPRESS_TYPE;
}
//---------
// Uncompress a buffer, given the compression method
private function expand($buf)
{
$ctype=$this->compressionType();
if ($buf==='' || $ctype==self::COMPRESS_NONE) return $buf;
switch($ctype)
{
case self::COMPRESS_BZIP2:
if(is_int($rbuf=bzdecompress($buf)))
throw new \Exception("Cannot bzdecompress data - Error code $buf");
break;
case self::COMPRESS_GZIP:
if(($rbuf=gzuncompress($buf))===false)
throw new \Exception("Cannot gzuncompress data");
break;
default:
throw new \Exception("Unknown compression method : $ctype");
}
return $rbuf;
}
//---
// Read/uncompress/verify and cache data
public function read()
{
if (is_null($this->data))
{
if ($this->rsz==0) $this->data=''; // Empty file
else
{
$rbuf=$this->expand($this->fspace->readBlock($this->off,$this->csz));
if (strlen($rbuf)!=$this->rsz) throw new \Exception('Wrong expanded size');
$this->data=$rbuf;
}
}
return $this->data;
}
//---
private static function compressionRatio($rsz,$csz)
{
return ($rsz==0) ? '-' : (round(($csz/$rsz)*100));
}
//---
public function flagString()
{
if ($ctype=$this->flags & self::COMPRESS_TYPE)
return 'compress/'.self::$compression_method_names[$ctype]
.' ('.self::compressionRatio($this->rsz,$this->csz).'%)';
return '';
}
//---
public function size() { return $this->rsz; }
//---
public function import($edata)
{
list($this->flags,$this->csz,$this->rsz,$this->off)
=array_values(unpack('va/V3b',$edata));
$this->data=null; // Must be reset as the object is created as an empty file
}
//---
public function __construct()
{
$this->setFlags(0);
$this->setData('');
$this->csz=$this->off=null;
}
//---
// Set only the DC flags
public function setFlags($flags)
{
$this->flags=($flags & \PHK\Virtual\Node::TN_DC_FLAG_MASK);
}
//---
public function setData($data)
{
$this->rsz=strlen($this->data=$data);
}
// <CREATOR> //---------------
public function getNeededExtensions(\PHK\Build\Creator $phk
,\PHK\Tools\ItemLister $item_lister)
{
if (!is_null($ext=self::$compression_needed_extensions
[$this->flags & self::COMPRESS_TYPE]))
$item_lister->add($ext,true);
}
//---
public function appendData($data)
{
$this->data.=$data;
$this->rsz+=strlen($data);
}
//---
public function export(\PHK\Build\Creator $phk,\PHK\Build\DataStacker $stacker)
{
$cbuf=$this->compress($this->data,$phk);
$this->csz=strlen($cbuf);
$this->off=$stacker->offset;
$stacker->push($cbuf);
return pack('vV3',$this->flags,$this->csz,$this->rsz,$this->off);
}
//------
private function denyCompress($msg,$buf)
{
\PHK\Tools\Util::trace(" No compression: $msg");
$this->flags &= ~self::COMPRESS_TYPE; // Set to COMPRESS_NONE
return $buf;
}
//------
private function compress($buf,\PHK\Build\Creator $phk)
{
if (!($ctype=$this->compressionType())) return $buf;
$comp_min_size=$phk->option('compress_min_size');
$comp_max_size=$phk->option('compress_max_size');
$comp_ratio_limit=$phk->option('compress_ratio_limit');
if ($buf==='') return $this->denyCompress('Empty file',$buf);
if ((!is_null($comp_min_size)) && (strlen($buf) < $comp_min_size))
return $this->denyCompress('File too small',$buf);
if ((!is_null($comp_max_size)) && (strlen($buf) > $comp_max_size))
return $this->denyCompress('File too large',$buf);
switch($ctype)
{
case self::COMPRESS_BZIP2:
\PHK\Tools\Util::loadExtension('bz2');
\PHK\Tools\Util::trace(" Compressing (bzip2)");
if(is_int($cbuf=bzcompress($buf,9)))
throw new \Exception("Cannot bzcompress data - Error code $buf");
break;
case self::COMPRESS_GZIP:
\PHK\Tools\Util::loadExtension('zlib');
\PHK\Tools\Util::trace(" Compressing (gzip)");
if(($cbuf=gzcompress($buf))===false)
throw new \Exception("Cannot gzcompress data");
break;
default:
throw new \Exception("Unknown compression method : $ctype");
}
// Default: Deny if compressed buffer is larger than 90% of original
if (is_null($comp_ratio_limit)) $comp_ratio_limit=90;
if (($r=self::compressionRatio(strlen($buf),strlen($cbuf))) >$comp_ratio_limit)
return $this->denyCompress("Compression ratio exceeded ($r%)",$buf);
return $cbuf;
}
// </CREATOR> //---------------
//---
} // End of class
//===========================================================================
} // End of class_exists
//===========================================================================
} // End of namespace
//===========================================================================
?>