--- /dev/null
+<?php
+/**
+ * Functions related to the output of file content.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ */
+use Wikimedia\Timestamp\ConvertibleTimestamp;
+
+/**
+ * Functions related to the output of file content
+ *
+ * @since 1.28
+ */
+class HTTPFileStreamer {
+ /** @var string */
+ protected $path;
+ /** @var callable */
+ protected $obResetFunc;
+ /** @var callable */
+ protected $streamMimeFunc;
+
+ // Do not send any HTTP headers unless requested by caller (e.g. body only)
+ const STREAM_HEADLESS = 1;
+ // Do not try to tear down any PHP output buffers
+ const STREAM_ALLOW_OB = 2;
+
+ /**
+ * @param string $path Local filesystem path to a file
+ * @param array $params Options map, which includes:
+ * - obResetFunc : alternative callback to clear the output buffer
+ * - streamMimeFunc : alternative method to determine the content type from the path
+ */
+ public function __construct( $path, array $params = [] ) {
+ $this->path = $path;
+ $this->obResetFunc = isset( $params['obResetFunc'] )
+ ? $params['obResetFunc']
+ : [ __CLASS__, 'resetOutputBuffers' ];
+ $this->streamMimeFunc = isset( $params['streamMimeFunc'] )
+ ? $params['streamMimeFunc']
+ : [ __CLASS__, 'contentTypeFromPath' ];
+ }
+
+ /**
+ * Stream a file to the browser, adding all the headings and fun stuff.
+ * Headers sent include: Content-type, Content-Length, Last-Modified,
+ * and Content-Disposition.
+ *
+ * @param array $headers Any additional headers to send if the file exists
+ * @param bool $sendErrors Send error messages if errors occur (like 404)
+ * @param array $optHeaders HTTP request header map (e.g. "range") (use lowercase keys)
+ * @param int $flags Bitfield of STREAM_* constants
+ * @throws MWException
+ * @return bool Success
+ */
+ public function stream(
+ $headers = [], $sendErrors = true, $optHeaders = [], $flags = 0
+ ) {
+ // Don't stream it out as text/html if there was a PHP error
+ if ( ( ( $flags & self::STREAM_HEADLESS ) == 0 || $headers ) && headers_sent() ) {
+ echo "Headers already sent, terminating.\n";
+ return false;
+ }
+
+ $headerFunc = ( $flags & self::STREAM_HEADLESS )
+ ? function ( $header ) {
+ // no-op
+ }
+ : function ( $header ) {
+ is_int( $header ) ? HttpStatus::header( $header ) : header( $header );
+ };
+
+ MediaWiki\suppressWarnings();
+ $info = stat( $this->path );
+ MediaWiki\restoreWarnings();
+
+ if ( !is_array( $info ) ) {
+ if ( $sendErrors ) {
+ self::send404Message( $this->path, $flags );
+ }
+ return false;
+ }
+
+ // Send Last-Modified HTTP header for client-side caching
+ $mtimeCT = new ConvertibleTimestamp( $info['mtime'] );
+ $headerFunc( 'Last-Modified: ' . $mtimeCT->getTimestamp( TS_RFC2822 ) );
+
+ if ( ( $flags & self::STREAM_ALLOW_OB ) == 0 ) {
+ call_user_func( $this->obResetFunc );
+ }
+
+ $type = call_user_func( $this->streamMimeFunc, $this->path );
+ if ( $type && $type != 'unknown/unknown' ) {
+ $headerFunc( "Content-type: $type" );
+ } else {
+ // Send a content type which is not known to Internet Explorer, to
+ // avoid triggering IE's content type detection. Sending a standard
+ // unknown content type here essentially gives IE license to apply
+ // whatever content type it likes.
+ $headerFunc( 'Content-type: application/x-wiki' );
+ }
+
+ // Don't send if client has up to date cache
+ if ( isset( $optHeaders['if-modified-since'] ) ) {
+ $modsince = preg_replace( '/;.*$/', '', $optHeaders['if-modified-since'] );
+ if ( $mtimeCT->getTimestamp( TS_UNIX ) <= strtotime( $modsince ) ) {
+ ini_set( 'zlib.output_compression', 0 );
+ $headerFunc( 304 );
+ return true; // ok
+ }
+ }
+
+ // Send additional headers
+ foreach ( $headers as $header ) {
+ header( $header ); // always use header(); specifically requested
+ }
+
+ if ( isset( $optHeaders['range'] ) ) {
+ $range = self::parseRange( $optHeaders['range'], $info['size'] );
+ if ( is_array( $range ) ) {
+ $headerFunc( 206 );
+ $headerFunc( 'Content-Length: ' . $range[2] );
+ $headerFunc( "Content-Range: bytes {$range[0]}-{$range[1]}/{$info['size']}" );
+ } elseif ( $range === 'invalid' ) {
+ if ( $sendErrors ) {
+ $headerFunc( 416 );
+ $headerFunc( 'Cache-Control: no-cache' );
+ $headerFunc( 'Content-Type: text/html; charset=utf-8' );
+ $headerFunc( 'Content-Range: bytes */' . $info['size'] );
+ }
+ return false;
+ } else { // unsupported Range request (e.g. multiple ranges)
+ $range = null;
+ $headerFunc( 'Content-Length: ' . $info['size'] );
+ }
+ } else {
+ $range = null;
+ $headerFunc( 'Content-Length: ' . $info['size'] );
+ }
+
+ if ( is_array( $range ) ) {
+ $handle = fopen( $this->path, 'rb' );
+ if ( $handle ) {
+ $ok = true;
+ fseek( $handle, $range[0] );
+ $remaining = $range[2];
+ while ( $remaining > 0 && $ok ) {
+ $bytes = min( $remaining, 8 * 1024 );
+ $data = fread( $handle, $bytes );
+ $remaining -= $bytes;
+ $ok = ( $data !== false );
+ print $data;
+ }
+ } else {
+ return false;
+ }
+ } else {
+ return readfile( $this->path ) !== false; // faster
+ }
+
+ return true;
+ }
+
+ /**
+ * Send out a standard 404 message for a file
+ *
+ * @param string $fname Full name and path of the file to stream
+ * @param int $flags Bitfield of STREAM_* constants
+ * @since 1.24
+ */
+ public static function send404Message( $fname, $flags = 0 ) {
+ if ( ( $flags & self::STREAM_HEADLESS ) == 0 ) {
+ HttpStatus::header( 404 );
+ header( 'Cache-Control: no-cache' );
+ header( 'Content-Type: text/html; charset=utf-8' );
+ }
+ $encFile = htmlspecialchars( $fname );
+ $encScript = htmlspecialchars( $_SERVER['SCRIPT_NAME'] );
+ echo "<!DOCTYPE html><html><body>
+ <h1>File not found</h1>
+ <p>Although this PHP script ($encScript) exists, the file requested for output
+ ($encFile) does not.</p>
+ </body></html>
+ ";
+ }
+
+ /**
+ * Convert a Range header value to an absolute (start, end) range tuple
+ *
+ * @param string $range Range header value
+ * @param int $size File size
+ * @return array|string Returns error string on failure (start, end, length)
+ * @since 1.24
+ */
+ public static function parseRange( $range, $size ) {
+ $m = [];
+ if ( preg_match( '#^bytes=(\d*)-(\d*)$#', $range, $m ) ) {
+ list( , $start, $end ) = $m;
+ if ( $start === '' && $end === '' ) {
+ $absRange = [ 0, $size - 1 ];
+ } elseif ( $start === '' ) {
+ $absRange = [ $size - $end, $size - 1 ];
+ } elseif ( $end === '' ) {
+ $absRange = [ $start, $size - 1 ];
+ } else {
+ $absRange = [ $start, $end ];
+ }
+ if ( $absRange[0] >= 0 && $absRange[1] >= $absRange[0] ) {
+ if ( $absRange[0] < $size ) {
+ $absRange[1] = min( $absRange[1], $size - 1 ); // stop at EOF
+ $absRange[2] = $absRange[1] - $absRange[0] + 1;
+ return $absRange;
+ } elseif ( $absRange[0] == 0 && $size == 0 ) {
+ return 'unrecognized'; // the whole file should just be sent
+ }
+ }
+ return 'invalid';
+ }
+ return 'unrecognized';
+ }
+
+ protected static function resetOutputBuffers() {
+ while ( ob_get_status() ) {
+ if ( !ob_end_clean() ) {
+ // Could not remove output buffer handler; abort now
+ // to avoid getting in some kind of infinite loop.
+ break;
+ }
+ }
+ }
+
+ /**
+ * Determine the file type of a file based on the path
+ *
+ * @param string $filename Storage path or file system path
+ * @return null|string
+ */
+ protected static function contentTypeFromPath( $filename ) {
+ $ext = strrchr( $filename, '.' );
+ $ext = $ext === false ? '' : strtolower( substr( $ext, 1 ) );
+
+ switch ( $ext ) {
+ case 'gif':
+ return 'image/gif';
+ case 'png':
+ return 'image/png';
+ case 'jpg':
+ return 'image/jpeg';
+ case 'jpeg':
+ return 'image/jpeg';
+ }
+
+ return 'unknown/unknown';
+ }
+}
scripts.mit.edu / autoinstallsdev / mediawiki.git / blobdiff