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<?php
/**
* File containing the ezcArchiveCentralDirectoryHeader class.
*
* @package Archive
* @version 1.4.1
* @copyright Copyright (C) 2005-2010 eZ Systems AS. All rights reserved.
* @license http://ez.no/licenses/new_bsd New BSD License
* @access private
*/
/**
* The ezcArchiveCentralDirectoryEndHeader class represents the Zip central directory end header.
*
* ezcArchiveCentralDirectoryEndHeader can read the header from an ezcArchiveCharacterFile.
*
* The values from the headers are directly accessible via the class properties, and allows
* reading and writing to specific header values.
*
* The entire header can be appended to an ezcArchiveCharacterFile again.
*
* The central directory end header is the last header of the ZIP archive. Some algorithms
* search back to this header in order to find the other headers. The variable comment length
* makes it tricky.
*
* The Central Directory End Header has the following structure:
*
* <pre>
* + ---+---------+------------+------------------------------------+-------------------------------------------------------------------------------+
* | ID | Offset | Field size | Property | Description |
* +----+---------+------------+------------------------------------+-------------------------------------------------------------------------------+
* | | 0 | 4 | - | Central directory header signature |
* | | 4 | 2 | diskNumber | nr of this disk |
* | | 6 | 2 | centralDirectoryDisk | number of the disk with the start of the central directory |
* | | 8 | 2 | totalCentralDirectoryEntriesOnDisk | total number of entries in the central directory on this disk |
* | | 10 | 2 | totalCentralDirectoryEntries | total number of entries in the central directory |
* | | 12 | 4 | centralDirectorySize | size of the central directory |
* | | 16 | 4 | centralDirectoryStart | offset of start of central directory with respect to the starting disk number |
* | X: | 20 | 2 | commentLength | .ZIP file comment length |
* | | 22 | X | comment | .ZIP file comment |
* +----+---------+------------+------------------------------------+-------------------------------------------------------------------------------+
* </pre>
*
*
* The columns of the table are:
* - ID gives a label to a specific field or row in the table.
* - Offset describes the start position of a header field.
* - Field size describes the size of the field in bytes.
* - Property is the name of the property that will be set by the header field.
* - Description explains what this field describes.
*
*
* @package Archive
* @version 1.4.1
* @access private
*/
class ezcArchiveCentralDirectoryEndHeader
{
/**
* Defines the signature of this header.
*/
const magic = 0x06054b50;
/**
* Holds the properties of this class.
*
* @var array(string=>mixed)
*/
private $properties = array();
/**
* Creates and initializes a new header.
*
* If the ezcArchiveCharacterFile $file is null then the header will be empty.
* When an ezcArchiveCharacterFile is given, the file position should be directly after the
* signature of the header. This header will be read from the file and initialized in this class.
*
* @param ezcArchiveCharacterFile $file
*/
public function __construct( ezcArchiveCharacterFile $file = null )
{
if ( !is_null( $file ) )
{
$this->properties = unpack (
"vdiskNumber/".
"vcentralDirectoryDisk/".
"vtotalCentralDirectoryEntriesOnDisk/".
"vtotalCentralDirectoryEntries/".
"VcentralDirectorySize/".
"VcentralDirectoryStart/".
"vcommentLength",
$file->read( 18 ) );
$this->properties["comment"] = $file->read( $this->properties["commentLength"] );
}
else
{
$this->properties["diskNumber"] = 0;
$this->properties["centralDirectoryDisk"] = 0;
$this->properties["totalCentralDirectoryEntries"] = 0;
$this->properties["totalCentralDirectoryEntriesOnDisk"] = 0;
$this->properties["totalCentralDirectorySize"] = 0;
$this->properties["totalCentralDirectoryStart"] = 0;
$this->setComment( "" );
}
}
/**
* Sets the property $name to $value.
*
* @throws ezcBasePropertyNotFoundException if the property does not exist.
* @throws ezcBasePropertyReadOnlyException if the property is read-only
* @param string $name
* @param mixed $value
* @return void
* @ignore
*/
public function __set( $name, $value )
{
switch ( $name )
{
case "diskNumber":
case "centralDirectoryDisk":
case "totalCentralDirectoryEntriesOnDisk":
throw new ezcBasePropertyReadOnlyException( $name );
case "totalCentralDirectoryEntries":
$this->setTotalDirectoryEntries( $value );
break;
case "centralDirectorySize":
case "centralDirectoryStart":
$this->properties[$name] = $value;
break;
case "commentLength":
throw new ezcBasePropertyReadOnlyException( $name );
case "comment":
$this->setComment( $value );
break;
default:
throw new ezcBasePropertyNotFoundException( $name );
}
}
/**
* Returns the value of the property $name.
*
* @throws ezcBasePropertyNotFoundException if the property does not exist.
* @param string $name
* @return mixed
* @ignore
*/
public function __get( $name )
{
switch ( $name )
{
case "diskNumber":
case "centralDirectoryDisk":
case "totalCentralDirectoryEntriesOnDisk":
case "totalCentralDirectoryEntries":
case "centralDirectorySize":
case "centralDirectoryStart":
case "commentLength":
case "comment":
return $this->properties[$name];
default:
throw new ezcBasePropertyNotFoundException( $name );
}
}
/**
* Sets the comment and comment length in the header from the string $comment.
*
* @param string $comment
* @return void
*/
public function setComment( $comment )
{
$this->properties["comment"] = $comment;
$this->properties["commentLength"] = strlen( $comment );
}
/**
* Sets the total directory entries to the int $numberOfEntries.
*
* The properties: diskNumber and centralDirectory will be set to 0.
* The properties: totalCentralDirectoryEntriesOnDisk and totalCentralDirectoryEntries are set to the $numberOfEntries.
*
* @param int $numberOfEntries
* @return void
*/
public function setTotalDirectoryEntries( $numberOfEntries )
{
$this->properties["diskNumber"] = 0;
$this->properties["centralDirectoryDisk"] = 0;
$this->properties["totalCentralDirectoryEntriesOnDisk"] = $numberOfEntries;
$this->properties["totalCentralDirectoryEntries"] = $numberOfEntries;
}
/**
* Serializes this header and appends it to the given ezcArchiveCharacterFile $archiveFile.
*
* @param ezcArchiveCharacterFile $archiveFile
* @return void
*/
public function writeEncodedHeader( $archiveFile )
{
$enc = pack ( "VvvvvVVv",
self::magic,
$this->properties["diskNumber"],
$this->properties["centralDirectoryDisk"],
$this->properties["totalCentralDirectoryEntriesOnDisk"],
$this->properties["totalCentralDirectoryEntries"],
$this->properties["centralDirectorySize"],
$this->properties["centralDirectoryStart"],
$this->properties["commentLength"] );
$archiveFile->write( $enc . $this->properties["comment"] );
}
/**
* Returns true if the given string $string matches with the current signature.
*
* @param string $string
* @return void
*/
public static function isSignature( $string )
{
return $string == pack( "V", self::magic );
}
}
?>
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