summaryrefslogtreecommitdiff
path: root/includes/Math.php
blob: 8cf9b8d897709a6f072dbe320beacfef2a474fcb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
<?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();
	}
}