<?php
/**
* Wave Framework <http://github.com/kristovaher/Wave-Framework>
* File Handler
*
* File Handler is used for returning a file from web server. It is loaded by Index Controller
* when a request is made to a file that has an extension that has not already been served by
* another Handler (such as Resource and Image handlers). File Handler is usually considered
* for returning documents, videos and audio from the web server. It also allows to return a
* file within a byte range, like in the case of file streams.
*
* @package Index Gateway
* @author Kristo Vaher <kristo@waher.net>
* @copyright Copyright (c) 2012, Kristo Vaher
* @license GNU Lesser General Public License Version 3
* @tutorial /doc/pages/handler_file.htm
* @since 1.5.0
* @version 3.6.4
*/
// INITIALIZATION
// Stopping all requests that did not come from Index Gateway
if(!isset($resourceAddress)){
header('HTTP/1.1 403 Forbidden');
die();
}
// If access control header is set in configuration
if(isset($config['access-control'])){
header('Access-Control-Allow-Origin: '.$config['access-control']);
}
// If filename includes & symbol, then system assumes it should be dynamically generated
$parameters=array_unique(explode('&',$resourceFile));
// Getting the downloadable file name
$resourceFile=array_pop($parameters);
// The amount of non-filenames in the request
$parameterCount=count($parameters);
// Range of bytes to return
// This allows user agent to request only part of the file
if(isset($_SERVER['HTTP_RANGE'])){
$tmp=explode('=',$_SERVER['HTTP_RANGE']);
$bytesData=explode('-',array_pop($tmp));
if(isset($bytesData) && is_numeric($bytesData[0]) && is_numeric($bytesData[1])){
$bytesFrom=$bytesData[0];
$bytesTo=$bytesData[1];
}
}
// No cache flag
$noCache=array_search('nocache',$parameters);
if($noCache!==false){
// Unsetting the key for nocache parameter
unset($parameters[$noCache]);
}
// Web root is the subfolder on public site
$webRoot=str_replace('index.php','',$_SERVER['SCRIPT_NAME']);
// Checking if the file might be loaded from overrides folder
if(preg_match('/^'.str_replace('/','\/',$webRoot).'resources\//',$_SERVER['REQUEST_URI'])){
// Solving possible overrides folder
$overridesFolder=str_replace($webRoot.'resources'.DIRECTORY_SEPARATOR,$webRoot.'overrides'.DIRECTORY_SEPARATOR.'resources'.DIRECTORY_SEPARATOR,$resourceFolder);
if(file_exists($overridesFolder.$resourceFile)){
$resourceFolder=$overridesFolder;
}
}
// Default cache timeout of one month, unless timeout is set
if(!isset($config['resource-cache-timeout'])){
$config['resource-cache-timeout']=31536000; // A year
}
// CHECK FOR PARAMETER SUPPORT
// If more than one parameter is set, it returns 404
// 404 is also returned if file does not actually exist
if($parameterCount>1 || ($parameterCount==1 && !$noCache) || !file_exists($resourceFolder.$resourceFile)){
// Adding log entry
if(isset($logger)){
// Assigning custom log data to logger
$logger->setCustomLogData(array('category'=>'file','response-code'=>'404'));
// Writing log entry
$logger->writeLog();
}
// Returning 404 header
header('HTTP/1.1 404 Not Found');
die();
}
// Last-modified date
$lastModified=filemtime($resourceFolder.$resourceFile);
// NOT MODIFIED CHECK
// Checking if file has been modified or not
if(!$noCache){
// If the request timestamp is exactly the same, then we let the browser know of this
if((isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE'])==$lastModified) || (isset($_SERVER['HTTP_IF_RANGE']) && strtotime($_SERVER['HTTP_IF_RANGE'])==$lastModified)){
// Adding log entry
if(isset($logger)){
// Assigning custom log data to logger
$logger->setCustomLogData(array('cache-used'=>true,'category'=>'image','response-code'=>'304'));
// Writing log entry
$logger->writeLog();
}
// Cache headers (Last modified is never sent with 304 header)
header('Cache-Control: public,max-age='.$config['resource-cache-timeout']);
header('Expires: '.gmdate('D, d M Y H:i:s',($_SERVER['REQUEST_TIME']+$config['resource-cache-timeout'])).' GMT');
// Returning 304 header
header('HTTP/1.1 304 Not Modified');
die();
}
}
// DETECTING MIME TYPE
// Currently assumed MIME type
$mimeType='';
// Finding the proper MIME type
if(extension_loaded('fileinfo')){
// This opens MIME type 'magic' resource for use
if($fileInfo=finfo_open(FILEINFO_MIME_TYPE)){
// Finding MIME type with magic resource
$mimeType=finfo_file($fileInfo,$resourceFolder.$resourceFile);
// Resourse is not needed further, so it is closed
finfo_close($fileInfo);
}
} else {
// Since Fileinfo was not available, we use extension-based detection as fallback
if(isset($resourceExtension)){
switch($resourceExtension){
case 'ico':
$mimeType='image/vnd.microsoft.icon;';
break;
case 'zip':
$mimeType='application/zip';
break;
case 'pdf':
$mimeType='application/pdf';
break;
case 'mp3':
$mimeType='audio/mpeg';
break;
case 'gif':
$mimeType='image/gif';
break;
case 'tif':
$mimeType='image/tiff';
break;
}
}
}
// HEADERS
// Assigning MIME type if it was found
if($mimeType && $mimeType!=''){
// Detected mime type is set as content-type header
header('Content-Type: '.$mimeType.';');
} else {
// Octet stream is a general-use unknown resource, and browsers will often attempt to 'download' such a file
header('Content-Type: application/octet-stream;');
header('Content-Disposition: attachment; filename='.$resourceFile);
}
// If cache is used, then proper headers will be sent
if($noCache){
// User agent is told to cache these results for set duration
header('Cache-Control: no-cache,no-store');
header('Expires: '.gmdate('D, d M Y H:i:s',$_SERVER['REQUEST_TIME']).' GMT');
header('Last-Modified: '.gmdate('D, d M Y H:i:s',$lastModified).' GMT');
} else {
// User agent is told to cache these results for set duration
header('Cache-Control: public,max-age='.$config['resource-cache-timeout']);
header('Expires: '.gmdate('D, d M Y H:i:s',($_SERVER['REQUEST_TIME']+$config['resource-cache-timeout'])).' GMT');
header('Last-Modified: '.gmdate('D, d M Y H:i:s',$lastModified).' GMT');
}
// Robots header
if(isset($config['file-robots'])){
// If file-specific robots setting is defined
header('Robots-Tag: '.$config['file-robots'],true);
} elseif(isset($config['robots'])){
// This sets general robots setting, if it is defined in configuration file
header('Robots-Tag: '.$config['robots'],true);
} else {
// If robots setting is not configured, system tells user agent not to cache the file
header('Robots-Tag: noindex,nocache,nofollow,noarchive,noimageindex,nosnippet',true);
}
// OUTPUT
// If user agent only requested part of the file to be returned
if(isset($bytesFrom,$bytesTo)){
// Getting current output length
$contentLength=filesize($resourceFolder.$resourceFile);
if($bytesTo<=$contentLength){
// Required for range response
header('HTTP/1.1 206 Partial Content');
header('Content-Range: bytes '.$bytesFrom.'-'.$bytesTo.'/'.$contentLength);
// Content length is defined that can speed up website requests, letting user agent to determine file size
header('Content-Length: '.($bytesTo-$bytesFrom));
// Returning part of the file
$fileHandle=fopen($resourceFolder.$resourceFile,'r');
fseek($fileHandle,$bytesFrom);
// Returning the data to user agent
echo fread($fileHandle,($bytesTo-$bytesFrom));
} else {
header('HTTP/1.1 416 Requested Range Not Satisfiable');
}
} else {
// Getting current output length
$contentLength=filesize($resourceFolder.$resourceFile);
// Content length is defined that can speed up website requests, letting user agent to determine file size
header('Content-Length: '.$contentLength);
// Returning the file to user agent
readfile($resourceFolder.$resourceFile);
}
// WRITING TO LOG
// If Logger is defined then request is logged and can be used for performance review later
if(isset($logger)){
// Assigning custom log data to logger
$logger->setCustomLogData(array('cache-used'=>false,'category'=>'file','content-length-used'=>$contentLength));
// Writing log entry
$logger->writeLog();
}
?>
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