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