parsing * @file * @ingroup Parser */ /** * Takes LaTeX fragments, sends them to a helper program (texvc) for rendering * to rasterized PNG and HTML and MathML approximations. An appropriate * rendering form is picked and returned. * * @author Tomasz Wegrzanowski, with additions by Brion Vibber (2003, 2004) * @ingroup Parser */ class MathRenderer { var $mode = MW_MATH_MODERN; var $tex = ''; var $inputhash = ''; var $hash = ''; var $html = ''; var $mathml = ''; var $conservativeness = 0; function __construct( $tex, $params=array() ) { $this->tex = $tex; $this->params = $params; } function setOutputMode( $mode ) { $this->mode = $mode; } function render() { global $wgTmpDirectory, $wgInputEncoding; global $wgTexvc, $wgMathCheckFiles, $wgTexvcBackgroundColor; if( $this->mode == MW_MATH_SOURCE ) { # No need to render or parse anything more! return ('$ '.htmlspecialchars( $this->tex ).' $'); } if( $this->tex == '' ) { return; # bug 8372 } if( !$this->_recall() ) { if( $wgMathCheckFiles ) { # Ensure that the temp and output directories are available before continuing... if( !file_exists( $wgTmpDirectory ) ) { if( !wfMkdirParents( $wgTmpDirectory ) ) { return $this->_error( 'math_bad_tmpdir' ); } } elseif( !is_dir( $wgTmpDirectory ) || !is_writable( $wgTmpDirectory ) ) { return $this->_error( 'math_bad_tmpdir' ); } } if( function_exists( 'is_executable' ) && !is_executable( $wgTexvc ) ) { return $this->_error( 'math_notexvc' ); } $cmd = $wgTexvc . ' ' . escapeshellarg( $wgTmpDirectory ).' '. escapeshellarg( $wgTmpDirectory ).' '. escapeshellarg( $this->tex ).' '. escapeshellarg( $wgInputEncoding ).' '. escapeshellarg( $wgTexvcBackgroundColor ); if ( wfIsWindows() ) { # Invoke it within cygwin sh, because texvc expects sh features in its default shell $cmd = 'sh -c ' . wfEscapeShellArg( $cmd ); } wfDebug( "TeX: $cmd\n" ); $contents = `$cmd`; wfDebug( "TeX output:\n $contents\n---\n" ); if (strlen($contents) == 0) { return $this->_error( 'math_unknown_error' ); } $retval = substr ($contents, 0, 1); $errmsg = ''; if (($retval == 'C') || ($retval == 'M') || ($retval == 'L')) { if ($retval == 'C') { $this->conservativeness = 2; } else if ($retval == 'M') { $this->conservativeness = 1; } else { $this->conservativeness = 0; } $outdata = substr ($contents, 33); $i = strpos($outdata, "\000"); $this->html = substr($outdata, 0, $i); $this->mathml = substr($outdata, $i+1); } else if (($retval == 'c') || ($retval == 'm') || ($retval == 'l')) { $this->html = substr ($contents, 33); if ($retval == 'c') { $this->conservativeness = 2; } else if ($retval == 'm') { $this->conservativeness = 1; } else { $this->conservativeness = 0; } $this->mathml = null; } else if ($retval == 'X') { $this->html = null; $this->mathml = substr ($contents, 33); $this->conservativeness = 0; } else if ($retval == '+') { $this->html = null; $this->mathml = null; $this->conservativeness = 0; } else { $errbit = htmlspecialchars( substr($contents, 1) ); switch( $retval ) { case 'E': $errmsg = $this->_error( 'math_lexing_error', $errbit ); break; case 'S': $errmsg = $this->_error( 'math_syntax_error', $errbit ); break; case 'F': $errmsg = $this->_error( 'math_unknown_function', $errbit ); break; default: $errmsg = $this->_error( 'math_unknown_error', $errbit ); } } if ( !$errmsg ) { $this->hash = substr ($contents, 1, 32); } wfRunHooks( 'MathAfterTexvc', array( &$this, &$errmsg ) ); if ( $errmsg ) { return $errmsg; } if (!preg_match("/^[a-f0-9]{32}$/", $this->hash)) { return $this->_error( 'math_unknown_error' ); } if( !file_exists( "$wgTmpDirectory/{$this->hash}.png" ) ) { return $this->_error( 'math_image_error' ); } if( filesize( "$wgTmpDirectory/{$this->hash}.png" ) == 0 ) { return $this->_error( 'math_image_error' ); } $hashpath = $this->_getHashPath(); if( !file_exists( $hashpath ) ) { if( !@wfMkdirParents( $hashpath, 0755 ) ) { return $this->_error( 'math_bad_output' ); } } elseif( !is_dir( $hashpath ) || !is_writable( $hashpath ) ) { return $this->_error( 'math_bad_output' ); } if( !rename( "$wgTmpDirectory/{$this->hash}.png", "$hashpath/{$this->hash}.png" ) ) { return $this->_error( 'math_output_error' ); } # Now save it back to the DB: if ( !wfReadOnly() ) { $outmd5_sql = pack('H32', $this->hash); $md5_sql = pack('H32', $this->md5); # Binary packed, not hex $dbw = wfGetDB( DB_MASTER ); $dbw->replace( 'math', array( 'math_inputhash' ), array( 'math_inputhash' => $dbw->encodeBlob($md5_sql), 'math_outputhash' => $dbw->encodeBlob($outmd5_sql), 'math_html_conservativeness' => $this->conservativeness, 'math_html' => $this->html, 'math_mathml' => $this->mathml, ), __METHOD__ ); } // If we're replacing an older version of the image, make sure it's current. global $wgUseSquid; if ( $wgUseSquid ) { $urls = array( $this->_mathImageUrl() ); $u = new SquidUpdate( $urls ); $u->doUpdate(); } } return $this->_doRender(); } function _error( $msg, $append = '' ) { $mf = htmlspecialchars( wfMsg( 'math_failure' ) ); $errmsg = htmlspecialchars( wfMsg( $msg ) ); $source = htmlspecialchars( str_replace( "\n", ' ', $this->tex ) ); return "$mf ($errmsg$append): $source\n"; } function _recall() { global $wgMathDirectory, $wgMathCheckFiles; $this->md5 = md5( $this->tex ); $dbr = wfGetDB( DB_SLAVE ); $rpage = $dbr->selectRow( 'math', array( 'math_outputhash','math_html_conservativeness','math_html','math_mathml' ), array( 'math_inputhash' => $dbr->encodeBlob(pack("H32", $this->md5))), # Binary packed, not hex __METHOD__ ); if( $rpage !== false ) { # Tailing 0x20s can get dropped by the database, add it back on if necessary: $xhash = unpack( 'H32md5', $dbr->decodeBlob($rpage->math_outputhash) . " " ); $this->hash = $xhash ['md5']; $this->conservativeness = $rpage->math_html_conservativeness; $this->html = $rpage->math_html; $this->mathml = $rpage->math_mathml; $filename = $this->_getHashPath() . "/{$this->hash}.png"; if( !$wgMathCheckFiles ) { // Short-circuit the file existence & migration checks return true; } if( file_exists( $filename ) ) { if( filesize( $filename ) == 0 ) { // Some horrible error corrupted stuff :( @unlink( $filename ); } else { return true; } } if( file_exists( $wgMathDirectory . "/{$this->hash}.png" ) ) { $hashpath = $this->_getHashPath(); if( !file_exists( $hashpath ) ) { if( !@wfMkdirParents( $hashpath, 0755 ) ) { return false; } } elseif( !is_dir( $hashpath ) || !is_writable( $hashpath ) ) { return false; } if ( function_exists( "link" ) ) { return link ( $wgMathDirectory . "/{$this->hash}.png", $hashpath . "/{$this->hash}.png" ); } else { return rename ( $wgMathDirectory . "/{$this->hash}.png", $hashpath . "/{$this->hash}.png" ); } } } # Missing from the database and/or the render cache return false; } /** * Select among PNG, HTML, or MathML output depending on */ function _doRender() { if( $this->mode == MW_MATH_MATHML && $this->mathml != '' ) { return Xml::tags( 'math', $this->_attribs( 'math', array( 'xmlns' => 'http://www.w3.org/1998/Math/MathML' ) ), $this->mathml ); } if (($this->mode == MW_MATH_PNG) || ($this->html == '') || (($this->mode == MW_MATH_SIMPLE) && ($this->conservativeness != 2)) || (($this->mode == MW_MATH_MODERN || $this->mode == MW_MATH_MATHML) && ($this->conservativeness == 0))) { return $this->_linkToMathImage(); } else { return Xml::tags( 'span', $this->_attribs( 'span', array( 'class' => 'texhtml' ) ), $this->html ); } } function _attribs( $tag, $defaults=array(), $overrides=array() ) { $attribs = Sanitizer::validateTagAttributes( $this->params, $tag ); $attribs = Sanitizer::mergeAttributes( $defaults, $attribs ); $attribs = Sanitizer::mergeAttributes( $attribs, $overrides ); return $attribs; } function _linkToMathImage() { $url = $this->_mathImageUrl(); return Xml::element( 'img', $this->_attribs( 'img', array( 'class' => 'tex', 'alt' => $this->tex ), array( 'src' => $url ) ) ); } function _mathImageUrl() { global $wgMathPath; $dir = $this->_getHashSubPath(); return "$wgMathPath/$dir/{$this->hash}.png"; } function _getHashPath() { global $wgMathDirectory; $path = $wgMathDirectory .'/' . $this->_getHashSubPath(); wfDebug( "TeX: getHashPath, hash is: $this->hash, path is: $path\n" ); return $path; } function _getHashSubPath() { return substr($this->hash, 0, 1) .'/'. substr($this->hash, 1, 1) .'/'. substr($this->hash, 2, 1); } public static function renderMath( $tex, $params=array() ) { global $wgUser; $math = new MathRenderer( $tex, $params ); $math->setOutputMode( $wgUser->getOption('math')); return $math->render(); } }