tests/phpunit/includes/api/RandomImageGenerator.php

   1 <?php
   2
   3 /*
   4  * RandomImageGenerator -- does what it says on the tin.
   5  * Requires Imagick, the ImageMagick library for PHP, or the command line equivalent (usually 'convert').
   6  *
   7  * Because MediaWiki tests the uniqueness of media upload content, and filenames, it is sometimes useful to generate
   8  * files that are guaranteed (or at least very likely) to be unique in both those ways.
   9  * This generates a number of filenames with random names and random content (colored triangles)
  10  *
  11  * It is also useful to have fresh content because our tests currently run in a "destructive" mode, and don't create a fresh new wiki for each
  12  * test run.
  13  * Consequently, if we just had a few static files we kept re-uploading, we'd get lots of warnings about matching content or filenames,
  14  * and even if we deleted those files, we'd get warnings about archived files.
  15  *
  16  * This can also be used with a cronjob to generate random files all the time -- I use it to have a constant, never ending supply when I'm
  17  * testing interactively.
  18  *
  19  * @file
  20  * @author Neil Kandalgaonkar <neilk@wikimedia.org>
  21  */
  22
  23 /**
  24  * RandomImageGenerator: does what it says on the tin.
  25  * Can fetch a random image, or also write a number of them to disk with random filenames.
  26  */
  27 class RandomImageGenerator {
  28
  29         private $dictionaryFile;
  30         private $minWidth = 400;
  31         private $maxWidth = 800;
  32         private $minHeight = 400;
  33         private $maxHeight = 800;
  34         private $shapesToDraw = 5;
  35         private $imageWriteMethod;
  36
  37         /**
  38          * Orientations: 0th row, 0th column, EXIF orientation code, rotation 2x2 matrix that is opposite of orientation
  39          * n.b. we do not handle the 'flipped' orientations, which is why there is no entry for 2, 4, 5, or 7. Those
  40          * seem to be rare in real images anyway
  41          * (we also would need a non-symmetric shape for the images to test those, like a letter F)
  42          */
  43         private static $orientations = array(
  44                 array(
  45                         '0thRow' => 'top',
  46                         '0thCol' => 'left',
  47                         'exifCode' => 1,
  48                         'counterRotation' => array( array( 1, 0 ), array( 0, 1 ) )
  49                 ),
  50                 array(
  51                         '0thRow' => 'bottom',
  52                         '0thCol' => 'right',
  53                         'exifCode' => 3,
  54                         'counterRotation' => array( array( -1, 0 ), array( 0, -1 ) )
  55                 ),
  56                 array(
  57                         '0thRow' => 'right',
  58                         '0thCol' => 'top',
  59                         'exifCode' => 6,
  60                         'counterRotation' => array( array( 0, 1 ), array( 1, 0 ) )
  61                 ),
  62                 array(
  63                         '0thRow' => 'left',
  64                         '0thCol' => 'bottom',
  65                         'exifCode' => 8,
  66                         'counterRotation' => array( array( 0, -1 ), array( -1, 0 ) )
  67                 )
  68         );
  69
  70
  71         public function __construct( $options = array() ) {
  72                 foreach ( array( 'dictionaryFile', 'minWidth', 'minHeight', 'maxHeight', 'shapesToDraw' ) as $property ) {
  73                         if ( isset( $options[$property] ) ) {
  74                                 $this->$property = $options[$property];
  75                         }
  76                 }
  77
  78                 // find the dictionary file, to generate random names
  79                 if ( !isset( $this->dictionaryFile ) ) {
  80                         foreach ( array( '/usr/share/dict/words', '/usr/dict/words' ) as $dictionaryFile ) {
  81                                 if ( is_file( $dictionaryFile ) and is_readable( $dictionaryFile ) ) {
  82                                         $this->dictionaryFile = $dictionaryFile;
  83                                         break;
  84                                 }
  85                         }
  86                 }
  87                 if ( !isset( $this->dictionaryFile ) ) {
  88                         throw new Exception( "RandomImageGenerator: dictionary file not found or not specified properly" );
  89                 }
  90         }
  91
  92         /**
  93          * Writes random images with random filenames to disk in the directory you specify, or current working directory
  94          *
  95          * @param $number Integer: number of filenames to write
  96          * @param $format String: optional, must be understood by ImageMagick, such as 'jpg' or 'gif'
  97          * @param $dir String: directory, optional (will default to current working directory)
  98          * @return Array: filenames we just wrote
  99          */
 100         function writeImages( $number, $format = 'jpg', $dir = null ) {
 101                 $filenames = $this->getRandomFilenames( $number, $format, $dir );
 102                 $imageWriteMethod = $this->getImageWriteMethod( $format );
 103                 foreach( $filenames as $filename ) {
 104                         $this->{$imageWriteMethod}( $this->getImageSpec(), $format, $filename );
 105                 }
 106                 return $filenames;
 107         }
 108
 109
 110         /**
 111          * Figure out how we write images. This is a factor of both format and the local system
 112          * @param $format (a typical extension like 'svg', 'jpg', etc.)
 113          */
 114         function getImageWriteMethod( $format ) {
 115                 global $wgUseImageMagick, $wgImageMagickConvertCommand;
 116                 if ( $format === 'svg' ) {
 117                         return 'writeSvg';
 118                 } else {
 119                         // figure out how to write images
 120                         if ( class_exists( 'Imagick' ) ) {
 121                                 return 'writeImageWithApi';
 122                         } elseif ( $wgUseImageMagick && $wgImageMagickConvertCommand && is_executable( $wgImageMagickConvertCommand ) ) {
 123                                 return 'writeImageWithCommandLine';
 124                         }
 125                 }
 126                 throw new Exception( "RandomImageGenerator: could not find a suitable method to write images in '$format' format" );
 127         }
 128
 129         /**
 130          * Return a number of randomly-generated filenames
 131          * Each filename uses two words randomly drawn from the dictionary, like elephantine_spatula.jpg
 132          *
 133          * @param $number Integer: of filenames to generate
 134          * @param $extension String: optional, defaults to 'jpg'
 135          * @param $dir String: optional, defaults to current working directory
 136          * @return Array: of filenames
 137          */
 138         private function getRandomFilenames( $number, $extension = 'jpg', $dir = null ) {
 139                 if ( is_null( $dir ) ) {
 140                         $dir = getcwd();
 141                 }
 142                 $filenames = array();
 143                 foreach( $this->getRandomWordPairs( $number ) as $pair ) {
 144                         $basename = $pair[0] . '_' . $pair[1];
 145                         if ( !is_null( $extension ) ) {
 146                                 $basename .= '.' . $extension;
 147                         }
 148                         $basename = preg_replace( '/\s+/', '', $basename );
 149                         $filenames[] = "$dir/$basename";
 150                 }
 151
 152                 return $filenames;
 153
 154         }
 155
 156
 157         /**
 158          * Generate data representing an image of random size (within limits),
 159          * consisting of randomly colored and sized upward pointing triangles against a random background color
 160          * (This data is used in the writeImage* methods).
 161          * @return {Mixed}
 162          */
 163         public function getImageSpec() {
 164                 $spec = array();
 165
 166                 $spec['width'] = mt_rand( $this->minWidth, $this->maxWidth );
 167                 $spec['height'] = mt_rand( $this->minHeight, $this->maxHeight );
 168                 $spec['fill'] = $this->getRandomColor();
 169
 170                 $diagonalLength = sqrt( pow( $spec['width'], 2 ) + pow( $spec['height'], 2 ) );
 171
 172                 $draws = array();
 173                 for ( $i = 0; $i <= $this->shapesToDraw; $i++ ) {
 174                         $radius = mt_rand( 0, $diagonalLength / 4 );
 175                         if ( $radius == 0 ) {
 176                                 continue;
 177                         }
 178                         $originX = mt_rand( -1 * $radius, $spec['width'] + $radius );
 179                         $originY = mt_rand( -1 * $radius, $spec['height'] + $radius );
 180                         $angle = mt_rand( 0, ( 3.141592/2 ) * $radius ) / $radius;
 181                         $legDeltaX = round( $radius * sin( $angle ) );
 182                         $legDeltaY = round( $radius * cos( $angle ) );
 183
 184                         $draw = array();
 185                         $draw['fill'] = $this->getRandomColor();
 186                         $draw['shape'] = array(
 187                                 array( 'x' => $originX,                 'y' => $originY - $radius ),
 188                                 array( 'x' => $originX + $legDeltaX,    'y' => $originY + $legDeltaY ),
 189                                 array( 'x' => $originX - $legDeltaX,    'y' => $originY + $legDeltaY ),
 190                                 array( 'x' => $originX,                 'y' => $originY - $radius )
 191                         );
 192                         $draws[] = $draw;
 193
 194                 }
 195
 196                 $spec['draws'] = $draws;
 197
 198                 return $spec;
 199         }
 200
 201         /**
 202          * Given array( array('x' => 10, 'y' => 20), array( 'x' => 30, y=> 5 ) )
 203          * returns "10,20 30,5"
 204          * Useful for SVG and imagemagick command line arguments
 205          * @param $shape: Array of arrays, each array containing x & y keys mapped to numeric values
 206          * @return string
 207          */
 208         static function shapePointsToString( $shape ) {
 209                 $points = array();
 210                 foreach ( $shape as $point ) {
 211                         $points[] = $point['x'] . ',' . $point['y'];
 212                 }
 213                 return join( " ", $points );
 214         }
 215
 216         /**
 217          * Based on image specification, write a very simple SVG file to disk.
 218          * Ignores the background spec because transparency is cool. :)
 219          * @param $spec: spec describing background and shapes to draw
 220          * @param $format: file format to write (which is obviously always svg here)
 221          * @param $filename: filename to write to
 222          */
 223         public function writeSvg( $spec, $format, $filename ) {
 224                 $svg = new SimpleXmlElement( '<svg/>' );
 225                 $svg->addAttribute( 'xmlns', 'http://www.w3.org/2000/svg' );
 226                 $svg->addAttribute( 'version', '1.1' );
 227                 $svg->addAttribute( 'width', $spec['width'] );
 228                 $svg->addAttribute( 'height', $spec['height'] );
 229                 $g = $svg->addChild( 'g' );
 230                 foreach ( $spec['draws'] as $drawSpec ) {
 231                         $shape = $g->addChild( 'polygon' );
 232                         $shape->addAttribute( 'fill', $drawSpec['fill'] );
 233                         $shape->addAttribute( 'points', self::shapePointsToString( $drawSpec['shape'] ) );
 234                 };
 235                 if ( ! $fh = fopen( $filename, 'w' ) ) {
 236                         throw new Exception( "couldn't open $filename for writing" );
 237                 }
 238                 fwrite( $fh, $svg->asXML() );
 239                 if ( !fclose($fh) ) {
 240                         throw new Exception( "couldn't close $filename" );
 241                 }
 242         }
 243
 244         /**
 245          * Based on an image specification, write such an image to disk, using Imagick PHP extension
 246          * @param $spec: spec describing background and circles to draw
 247          * @param $format: file format to write
 248          * @param $filename: filename to write to
 249          */
 250         public function writeImageWithApi( $spec, $format, $filename ) {
 251                 // this is a hack because I can't get setImageOrientation() to work. See below.
 252                 global $wgExiv2Command;
 253
 254                 $image = new Imagick();
 255                 /**
 256                  * If the format is 'jpg', will also add a random orientation -- the image will be drawn rotated with triangle points
 257                  * facing in some direction (0, 90, 180 or 270 degrees) and a countering rotation should turn the triangle points upward again
 258                  */
 259                 $orientation = self::$orientations[0]; // default is normal orientation
 260                 if ( $format == 'jpg' ) {
 261                         $orientation = self::$orientations[ array_rand( self::$orientations ) ];
 262                         $spec = self::rotateImageSpec( $spec, $orientation['counterRotation'] );
 263                 }
 264
 265                 $image->newImage( $spec['width'], $spec['height'], new ImagickPixel( $spec['fill'] ) );
 266
 267                 foreach ( $spec['draws'] as $drawSpec ) {
 268                         $draw = new ImagickDraw();
 269                         $draw->setFillColor( $drawSpec['fill'] );
 270                         $draw->polygon( $drawSpec['shape'] );
 271                         $image->drawImage( $draw );
 272                 }
 273
 274                 $image->setImageFormat( $format );
 275
 276                 // this doesn't work, even though it's documented to do so...
 277                 // $image->setImageOrientation( $orientation['exifCode'] );
 278
 279                 $image->writeImage( $filename );
 280
 281                 // because the above setImageOrientation call doesn't work... nor can I get an external imagemagick binary to do this either...
 282                 // hacking this for now (only works if you have exiv2 installed, a program to read and manipulate exif)
 283                 if ( $wgExiv2Command ) {
 284                         # Make sure we have exiv2 command
 285                         if( !is_executable( $wgExiv2Command ) ) {
 286                                 throw new MWException( __METHOD__ . ": '$wgExiv2Command' not found or not executable\n" );
 287                         }
 288                         $cmd = wfEscapeShellArg( $wgExiv2Command )
 289                                 . " -M "
 290                                 . wfEscapeShellArg( "set Exif.Image.Orientation " . $orientation['exifCode'] )
 291                                 . " "
 292                                 . wfEscapeShellArg( $filename );
 293
 294                         $retval = 0;
 295                         $err = wfShellExec( $cmd, $retval );
 296                         if ( $retval !== 0 ) {
 297                                 print "Error with $cmd: $retval, $err\n";
 298                         }
 299                 }
 300
 301
 302         }
 303
 304         /**
 305          * Given an image specification, produce rotated version
 306          * This is used when simulating a rotated image capture with EXIF orientation
 307          * @param $spec Object returned by getImageSpec
 308          * @param $matrix 2x2 transformation matrix
 309          * @return transformed Spec
 310          */
 311         private static function rotateImageSpec( &$spec, $matrix ) {
 312                 $tSpec = array();
 313                 $dims = self::matrixMultiply2x2( $matrix, $spec['width'], $spec['height'] );
 314                 $correctionX = 0;
 315                 $correctionY = 0;
 316                 if ( $dims['x'] < 0 ) {
 317                         $correctionX = abs( $dims['x'] );
 318                 }
 319                 if ( $dims['y'] < 0 ) {
 320                         $correctionY = abs( $dims['y'] );
 321                 }
 322                 $tSpec['width'] = abs( $dims['x'] );
 323                 $tSpec['height'] = abs( $dims['y'] );
 324                 $tSpec['fill'] = $spec['fill'];
 325                 $tSpec['draws'] = array();
 326                 foreach( $spec['draws'] as $draw ) {
 327                         $tDraw = array(
 328                                 'fill' => $draw['fill'],
 329                                 'shape' => array()
 330                         );
 331                         foreach( $draw['shape'] as $point ) {
 332                                 $tPoint = self::matrixMultiply2x2( $matrix, $point['x'], $point['y'] );
 333                                 $tPoint['x'] += $correctionX;
 334                                 $tPoint['y'] += $correctionY;
 335                                 $tDraw['shape'][] = $tPoint;
 336                         }
 337                         $tSpec['draws'][] = $tDraw;
 338                 }
 339                 return $tSpec;
 340         }
 341
 342         /**
 343          * Given a matrix and a pair of images, return new position
 344          * @param $matrix: 2x2 rotation matrix
 345          * @param $x: x-coordinate number
 346          * @param $y: y-coordinate number
 347          * @return Array transformed with properties x, y
 348          */
 349         private static function matrixMultiply2x2( $matrix, $x, $y ) {
 350                 return array(
 351                         'x' => $x * $matrix[0][0] + $y * $matrix[0][1],
 352                         'y' => $x * $matrix[1][0] + $y * $matrix[1][1]
 353                 );
 354         }
 355
 356
 357         /**
 358          * Based on an image specification, write such an image to disk, using the command line ImageMagick program ('convert').
 359          *
 360          * Sample command line:
 361          *    $ convert -size 100x60 xc:rgb(90,87,45)  \
 362                  *      -draw 'fill rgb(12,34,56)   polygon 41,39 44,57 50,57 41,39' \
 363                  *      -draw 'fill rgb(99,123,231) circle 59,39 56,57' \
 364                  *      -draw 'fill rgb(240,12,32)  circle 50,21 50,3'  filename.png
 365          *
 366          * @param $spec: spec describing background and shapes to draw
 367          * @param $format: file format to write (unused by this method but kept so it has the same signature as writeImageWithApi)
 368          * @param $filename: filename to write to
 369          */
 370         public function writeImageWithCommandLine( $spec, $format, $filename ) {
 371                 global $wgImageMagickConvertCommand;
 372                 $args = array();
 373                 $args[] = "-size " . wfEscapeShellArg( $spec['width'] . 'x' . $spec['height'] );
 374                 $args[] = wfEscapeShellArg( "xc:" . $spec['fill'] );
 375                 foreach( $spec['draws'] as $draw ) {
 376                         $fill = $draw['fill'];
 377                         $polygon = self::shapePointsToString( $draw['shape'] );
 378                         $drawCommand = "fill $fill  polygon $polygon";
 379                         $args[] = '-draw ' . wfEscapeShellArg( $drawCommand );
 380                 }
 381                 $args[] = wfEscapeShellArg( $filename );
 382
 383                 $command = wfEscapeShellArg( $wgImageMagickConvertCommand ) . " " . implode( " ", $args );
 384                 $retval = null;
 385                 wfShellExec( $command, $retval );
 386                 return ( $retval === 0 );
 387         }
 388
 389         /**
 390          * Generate a string of random colors for ImageMagick or SVG, like "rgb(12, 37, 98)"
 391          *
 392          * @return {String}
 393          */
 394         public function getRandomColor() {
 395                 $components = array();
 396                 for ($i = 0; $i <= 2; $i++ ) {
 397                         $components[] = mt_rand( 0, 255 );
 398                 }
 399                 return 'rgb(' . join(', ', $components) . ')';
 400         }
 401
 402         /**
 403          * Get an array of random pairs of random words, like array( array( 'foo', 'bar' ), array( 'quux', 'baz' ) );
 404          *
 405          * @param $number Integer: number of pairs
 406          * @return Array: of two-element arrays
 407          */
 408         private function getRandomWordPairs( $number ) {
 409                 $lines = $this->getRandomLines( $number * 2 );
 410                 // construct pairs of words
 411                 $pairs = array();
 412                 $count = count( $lines );
 413                 for( $i = 0; $i < $count; $i += 2 )  {
 414                         $pairs[] = array( $lines[$i], $lines[$i+1] );
 415                 }
 416                 return $pairs;
 417         }
 418
 419
 420         /**
 421          * Return N random lines from a file
 422          *
 423          * Will throw exception if the file could not be read or if it had fewer lines than requested.
 424          *
 425          * @param $number_desired Integer: number of lines desired
 426          * @return Array: of exactly n elements, drawn randomly from lines the file
 427          */
 428         private function getRandomLines( $number_desired ) {
 429                 $filepath = $this->dictionaryFile;
 430
 431                 // initialize array of lines
 432                 $lines = array();
 433                 for ( $i = 0; $i < $number_desired; $i++ ) {
 434                         $lines[] = null;
 435                 }
 436
 437                 /*
 438                  * This algorithm obtains N random lines from a file in one single pass. It does this by replacing elements of
 439                  * a fixed-size array of lines, less and less frequently as it reads the file.
 440                  */
 441                 $fh = fopen( $filepath, "r" );
 442                 if ( !$fh ) {
 443                          throw new Exception( "couldn't open $filepath" );
 444                 }
 445                 $line_number = 0;
 446                 $max_index = $number_desired - 1;
 447                 while( !feof( $fh ) ) {
 448                         $line = fgets( $fh );
 449                         if ( $line !== false ) {
 450                                 $line_number++;
 451                                 $line = trim( $line );
 452                                 if ( mt_rand( 0, $line_number ) <= $max_index ) {
 453                                         $lines[ mt_rand( 0, $max_index ) ] = $line;
 454                                 }
 455                         }
 456                 }
 457                 fclose( $fh );
 458                 if ( $line_number < $number_desired ) {
 459                         throw new Exception( "not enough lines in $filepath" );
 460                 }
 461
 462                 return $lines;
 463         }
 464
 465 }