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<?php
/**
* Contain everything related to <math> </math> 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", ' ', $this->tex ) );
return "<strong class='error'>$mf ($errmsg$append): $source</strong>\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();
}
}