MediaWiki  REL1_31
HTTPFileStreamer.php
Go to the documentation of this file.
1 <?php
22 use Wikimedia\Timestamp\ConvertibleTimestamp;
23 
31  protected $path;
33  protected $obResetFunc;
35  protected $streamMimeFunc;
36 
37  // Do not send any HTTP headers unless requested by caller (e.g. body only)
38  const STREAM_HEADLESS = 1;
39  // Do not try to tear down any PHP output buffers
40  const STREAM_ALLOW_OB = 2;
41 
49  public static function preprocessHeaders( $headers ) {
50  $rawHeaders = [];
51  $optHeaders = [];
52  foreach ( $headers as $name => $header ) {
53  $nameLower = strtolower( $name );
54  if ( in_array( $nameLower, [ 'range', 'if-modified-since' ], true ) ) {
55  $optHeaders[$nameLower] = $header;
56  } else {
57  $rawHeaders[] = "$name: $header";
58  }
59  }
60  return [ $rawHeaders, $optHeaders ];
61  }
62 
69  public function __construct( $path, array $params = [] ) {
70  $this->path = $path;
71  $this->obResetFunc = isset( $params['obResetFunc'] )
72  ? $params['obResetFunc']
73  : [ __CLASS__, 'resetOutputBuffers' ];
74  $this->streamMimeFunc = isset( $params['streamMimeFunc'] )
75  ? $params['streamMimeFunc']
76  : [ __CLASS__, 'contentTypeFromPath' ];
77  }
78 
91  public function stream(
92  $headers = [], $sendErrors = true, $optHeaders = [], $flags = 0
93  ) {
94  // Don't stream it out as text/html if there was a PHP error
95  if ( ( ( $flags & self::STREAM_HEADLESS ) == 0 || $headers ) && headers_sent() ) {
96  echo "Headers already sent, terminating.\n";
97  return false;
98  }
99 
100  $headerFunc = ( $flags & self::STREAM_HEADLESS )
101  ? function ( $header ) {
102  // no-op
103  }
104  : function ( $header ) {
105  is_int( $header ) ? HttpStatus::header( $header ) : header( $header );
106  };
107 
108  Wikimedia\suppressWarnings();
109  $info = stat( $this->path );
110  Wikimedia\restoreWarnings();
111 
112  if ( !is_array( $info ) ) {
113  if ( $sendErrors ) {
114  self::send404Message( $this->path, $flags );
115  }
116  return false;
117  }
118 
119  // Send Last-Modified HTTP header for client-side caching
120  $mtimeCT = new ConvertibleTimestamp( $info['mtime'] );
121  $headerFunc( 'Last-Modified: ' . $mtimeCT->getTimestamp( TS_RFC2822 ) );
122 
123  if ( ( $flags & self::STREAM_ALLOW_OB ) == 0 ) {
124  call_user_func( $this->obResetFunc );
125  }
126 
127  $type = call_user_func( $this->streamMimeFunc, $this->path );
128  if ( $type && $type != 'unknown/unknown' ) {
129  $headerFunc( "Content-type: $type" );
130  } else {
131  // Send a content type which is not known to Internet Explorer, to
132  // avoid triggering IE's content type detection. Sending a standard
133  // unknown content type here essentially gives IE license to apply
134  // whatever content type it likes.
135  $headerFunc( 'Content-type: application/x-wiki' );
136  }
137 
138  // Don't send if client has up to date cache
139  if ( isset( $optHeaders['if-modified-since'] ) ) {
140  $modsince = preg_replace( '/;.*$/', '', $optHeaders['if-modified-since'] );
141  if ( $mtimeCT->getTimestamp( TS_UNIX ) <= strtotime( $modsince ) ) {
142  ini_set( 'zlib.output_compression', 0 );
143  $headerFunc( 304 );
144  return true; // ok
145  }
146  }
147 
148  // Send additional headers
149  foreach ( $headers as $header ) {
150  header( $header ); // always use header(); specifically requested
151  }
152 
153  if ( isset( $optHeaders['range'] ) ) {
154  $range = self::parseRange( $optHeaders['range'], $info['size'] );
155  if ( is_array( $range ) ) {
156  $headerFunc( 206 );
157  $headerFunc( 'Content-Length: ' . $range[2] );
158  $headerFunc( "Content-Range: bytes {$range[0]}-{$range[1]}/{$info['size']}" );
159  } elseif ( $range === 'invalid' ) {
160  if ( $sendErrors ) {
161  $headerFunc( 416 );
162  $headerFunc( 'Cache-Control: no-cache' );
163  $headerFunc( 'Content-Type: text/html; charset=utf-8' );
164  $headerFunc( 'Content-Range: bytes */' . $info['size'] );
165  }
166  return false;
167  } else { // unsupported Range request (e.g. multiple ranges)
168  $range = null;
169  $headerFunc( 'Content-Length: ' . $info['size'] );
170  }
171  } else {
172  $range = null;
173  $headerFunc( 'Content-Length: ' . $info['size'] );
174  }
175 
176  if ( is_array( $range ) ) {
177  $handle = fopen( $this->path, 'rb' );
178  if ( $handle ) {
179  $ok = true;
180  fseek( $handle, $range[0] );
181  $remaining = $range[2];
182  while ( $remaining > 0 && $ok ) {
183  $bytes = min( $remaining, 8 * 1024 );
184  $data = fread( $handle, $bytes );
185  $remaining -= $bytes;
186  $ok = ( $data !== false );
187  print $data;
188  }
189  } else {
190  return false;
191  }
192  } else {
193  return readfile( $this->path ) !== false; // faster
194  }
195 
196  return true;
197  }
198 
206  public static function send404Message( $fname, $flags = 0 ) {
207  if ( ( $flags & self::STREAM_HEADLESS ) == 0 ) {
208  HttpStatus::header( 404 );
209  header( 'Cache-Control: no-cache' );
210  header( 'Content-Type: text/html; charset=utf-8' );
211  }
212  $encFile = htmlspecialchars( $fname );
213  $encScript = htmlspecialchars( $_SERVER['SCRIPT_NAME'] );
214  echo "<!DOCTYPE html><html><body>
215  <h1>File not found</h1>
216  <p>Although this PHP script ($encScript) exists, the file requested for output
217  ($encFile) does not.</p>
218  </body></html>
219  ";
220  }
221 
230  public static function parseRange( $range, $size ) {
231  $m = [];
232  if ( preg_match( '#^bytes=(\d*)-(\d*)$#', $range, $m ) ) {
233  list( , $start, $end ) = $m;
234  if ( $start === '' && $end === '' ) {
235  $absRange = [ 0, $size - 1 ];
236  } elseif ( $start === '' ) {
237  $absRange = [ $size - $end, $size - 1 ];
238  } elseif ( $end === '' ) {
239  $absRange = [ $start, $size - 1 ];
240  } else {
241  $absRange = [ $start, $end ];
242  }
243  if ( $absRange[0] >= 0 && $absRange[1] >= $absRange[0] ) {
244  if ( $absRange[0] < $size ) {
245  $absRange[1] = min( $absRange[1], $size - 1 ); // stop at EOF
246  $absRange[2] = $absRange[1] - $absRange[0] + 1;
247  return $absRange;
248  } elseif ( $absRange[0] == 0 && $size == 0 ) {
249  return 'unrecognized'; // the whole file should just be sent
250  }
251  }
252  return 'invalid';
253  }
254  return 'unrecognized';
255  }
256 
257  protected static function resetOutputBuffers() {
258  while ( ob_get_status() ) {
259  if ( !ob_end_clean() ) {
260  // Could not remove output buffer handler; abort now
261  // to avoid getting in some kind of infinite loop.
262  break;
263  }
264  }
265  }
266 
273  protected static function contentTypeFromPath( $filename ) {
274  $ext = strrchr( $filename, '.' );
275  $ext = $ext === false ? '' : strtolower( substr( $ext, 1 ) );
276 
277  switch ( $ext ) {
278  case 'gif':
279  return 'image/gif';
280  case 'png':
281  return 'image/png';
282  case 'jpg':
283  return 'image/jpeg';
284  case 'jpeg':
285  return 'image/jpeg';
286  }
287 
288  return 'unknown/unknown';
289  }
290 }
use
Apache License January AND DISTRIBUTION Definitions License shall mean the terms and conditions for use
Definition: APACHE-LICENSE-2.0.txt:10
array
the array() calling protocol came about after MediaWiki 1.4rc1.
HTTPFileStreamer\$path
string $path
Definition: HTTPFileStreamer.php:31
$params
$params
Definition: styleTest.css.php:40
php
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:37
HTTPFileStreamer
Functions related to the output of file content.
Definition: HTTPFileStreamer.php:29
HTTPFileStreamer\preprocessHeaders
static preprocessHeaders( $headers)
Takes HTTP headers in a name => value format and converts them to the weird format expected by stream...
Definition: HTTPFileStreamer.php:49
HTTPFileStreamer\resetOutputBuffers
static resetOutputBuffers()
Definition: HTTPFileStreamer.php:257
HTTPFileStreamer\parseRange
static parseRange( $range, $size)
Convert a Range header value to an absolute (start, end) range tuple.
Definition: HTTPFileStreamer.php:230
HTTPFileStreamer\STREAM_ALLOW_OB
const STREAM_ALLOW_OB
Definition: HTTPFileStreamer.php:40
list
deferred txt A few of the database updates required by various functions here can be deferred until after the result page is displayed to the user For updating the view updating the linked to tables after a etc PHP does not yet have any way to tell the server to actually return and disconnect while still running these but it might have such a feature in the future We handle these by creating a deferred update object and putting those objects on a global list
Definition: deferred.txt:11
$fname
if(defined( 'MW_SETUP_CALLBACK')) $fname
Customization point after all loading (constants, functions, classes, DefaultSettings,...
Definition: Setup.php:112
HTTPFileStreamer\$streamMimeFunc
callable $streamMimeFunc
Definition: HTTPFileStreamer.php:35
$header
$header
Definition: updateCredits.php:35
HTTPFileStreamer\STREAM_HEADLESS
const STREAM_HEADLESS
Definition: HTTPFileStreamer.php:38
HTTPFileStreamer\send404Message
static send404Message( $fname, $flags=0)
Send out a standard 404 message for a file.
Definition: HTTPFileStreamer.php:206
HTTPFileStreamer\__construct
__construct( $path, array $params=[])
Definition: HTTPFileStreamer.php:69
HTTPFileStreamer\contentTypeFromPath
static contentTypeFromPath( $filename)
Determine the file type of a file based on the path.
Definition: HTTPFileStreamer.php:273
print
print
Definition: opensearch_desc.php:46
$name
Allows to change the fields on the form that will be generated $name
Definition: hooks.txt:302
HttpStatus\header
static header( $code)
Output an HTTP status code header.
Definition: HttpStatus.php:96
HTTPFileStreamer\stream
stream( $headers=[], $sendErrors=true, $optHeaders=[], $flags=0)
Stream a file to the browser, adding all the headings and fun stuff.
Definition: HTTPFileStreamer.php:91
as
This document is intended to provide useful advice for parties seeking to redistribute MediaWiki to end users It s targeted particularly at maintainers for Linux since it s been observed that distribution packages of MediaWiki often break We ve consistently had to recommend that users seeking support use official tarballs instead of their distribution s and this often solves whatever problem the user is having It would be nice if this could such as
Definition: distributors.txt:22
$ext
$ext
Definition: router.php:55
false
processing should stop and the error should be shown to the user * false
Definition: hooks.txt:187
HTTPFileStreamer\$obResetFunc
callable $obResetFunc
Definition: HTTPFileStreamer.php:33
$type
$type
Definition: testCompression.php:48