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         public function __construct( $options = array() ) {
  70                 foreach ( array( 'dictionaryFile', 'minWidth', 'minHeight', 'maxWidth', 'maxHeight', 'shapesToDraw' ) as $property ) {
  71                         if ( isset( $options[$property] ) ) {
  72                                 $this->$property = $options[$property];
  73                         }
  74                 }
  75
  76                 // find the dictionary file, to generate random names
  77                 if ( !isset( $this->dictionaryFile ) ) {
  78                         foreach (
  79                                 array(
  80                                         '/usr/share/dict/words',
  81                                         '/usr/dict/words',
  82                                         __DIR__ . '/words.txt'
  83                                 ) as $dictionaryFile
  84                         ) {
  85                                 if ( is_file( $dictionaryFile ) and is_readable( $dictionaryFile ) ) {
  86                                         $this->dictionaryFile = $dictionaryFile;
  87                                         break;
  88                                 }
  89                         }
  90                 }
  91                 if ( !isset( $this->dictionaryFile ) ) {
  92                         throw new Exception( "RandomImageGenerator: dictionary file not found or not specified properly" );
  93                 }
  94         }
  95
  96         /**
  97          * Writes random images with random filenames to disk in the directory you specify, or current working directory
  98          *
  99          * @param $number Integer: number of filenames to write
 100          * @param $format String: optional, must be understood by ImageMagick, such as 'jpg' or 'gif'
 101          * @param $dir String: directory, optional (will default to current working directory)
 102          * @return Array: filenames we just wrote
 103          */
 104         function writeImages( $number, $format = 'jpg', $dir = null ) {
 105                 $filenames = $this->getRandomFilenames( $number, $format, $dir );
 106                 $imageWriteMethod = $this->getImageWriteMethod( $format );
 107                 foreach ( $filenames as $filename ) {
 108                         $this->{$imageWriteMethod}( $this->getImageSpec(), $format, $filename );
 109                 }
 110
 111                 return $filenames;
 112         }
 113
 114         /**
 115          * Figure out how we write images. This is a factor of both format and the local system
 116          *
 117          * @param string $format (a typical extension like 'svg', 'jpg', etc.)
 118          *
 119          * @throws Exception
 120          * @return string
 121          */
 122         function getImageWriteMethod( $format ) {
 123                 global $wgUseImageMagick, $wgImageMagickConvertCommand;
 124                 if ( $format === 'svg' ) {
 125                         return 'writeSvg';
 126                 } else {
 127                         // figure out how to write images
 128                         global $wgExiv2Command;
 129                         if ( class_exists( 'Imagick' ) && $wgExiv2Command && is_executable( $wgExiv2Command ) ) {
 130                                 return 'writeImageWithApi';
 131                         } elseif ( $wgUseImageMagick && $wgImageMagickConvertCommand && is_executable( $wgImageMagickConvertCommand ) ) {
 132                                 return 'writeImageWithCommandLine';
 133                         }
 134                 }
 135                 throw new Exception( "RandomImageGenerator: could not find a suitable method to write images in '$format' format" );
 136         }
 137
 138         /**
 139          * Return a number of randomly-generated filenames
 140          * Each filename uses two words randomly drawn from the dictionary, like elephantine_spatula.jpg
 141          *
 142          * @param $number Integer: of filenames to generate
 143          * @param $extension String: optional, defaults to 'jpg'
 144          * @param $dir String: optional, defaults to current working directory
 145          * @return Array: of filenames
 146          */
 147         private function getRandomFilenames( $number, $extension = 'jpg', $dir = null ) {
 148                 if ( is_null( $dir ) ) {
 149                         $dir = getcwd();
 150                 }
 151                 $filenames = array();
 152                 foreach ( $this->getRandomWordPairs( $number ) as $pair ) {
 153                         $basename = $pair[0] . '_' . $pair[1];
 154                         if ( !is_null( $extension ) ) {
 155                                 $basename .= '.' . $extension;
 156                         }
 157                         $basename = preg_replace( '/\s+/', '', $basename );
 158                         $filenames[] = "$dir/$basename";
 159                 }
 160
 161                 return $filenames;
 162         }
 163
 164         /**
 165          * Generate data representing an image of random size (within limits),
 166          * consisting of randomly colored and sized upward pointing triangles against a random background color
 167          * (This data is used in the writeImage* methods).
 168          * @return {Mixed}
 169          */
 170         public function getImageSpec() {
 171                 $spec = array();
 172
 173                 $spec['width'] = mt_rand( $this->minWidth, $this->maxWidth );
 174                 $spec['height'] = mt_rand( $this->minHeight, $this->maxHeight );
 175                 $spec['fill'] = $this->getRandomColor();
 176
 177                 $diagonalLength = sqrt( pow( $spec['width'], 2 ) + pow( $spec['height'], 2 ) );
 178
 179                 $draws = array();
 180                 for ( $i = 0; $i <= $this->shapesToDraw; $i++ ) {
 181                         $radius = mt_rand( 0, $diagonalLength / 4 );
 182                         if ( $radius == 0 ) {
 183                                 continue;
 184                         }
 185                         $originX = mt_rand( -1 * $radius, $spec['width'] + $radius );
 186                         $originY = mt_rand( -1 * $radius, $spec['height'] + $radius );
 187                         $angle = mt_rand( 0, ( 3.141592 / 2 ) * $radius ) / $radius;
 188                         $legDeltaX = round( $radius * sin( $angle ) );
 189                         $legDeltaY = round( $radius * cos( $angle ) );
 190
 191                         $draw = array();
 192                         $draw['fill'] = $this->getRandomColor();
 193                         $draw['shape'] = array(
 194                                 array( 'x' => $originX, 'y' => $originY - $radius ),
 195                                 array( 'x' => $originX + $legDeltaX, 'y' => $originY + $legDeltaY ),
 196                                 array( 'x' => $originX - $legDeltaX, 'y' => $originY + $legDeltaY ),
 197                                 array( 'x' => $originX, 'y' => $originY - $radius )
 198                         );
 199                         $draws[] = $draw;
 200                 }
 201
 202                 $spec['draws'] = $draws;
 203
 204                 return $spec;
 205         }
 206
 207         /**
 208          * Given array( array('x' => 10, 'y' => 20), array( 'x' => 30, y=> 5 ) )
 209          * returns "10,20 30,5"
 210          * Useful for SVG and imagemagick command line arguments
 211          * @param $shape: Array of arrays, each array containing x & y keys mapped to numeric values
 212          * @return string
 213          */
 214         static function shapePointsToString( $shape ) {
 215                 $points = array();
 216                 foreach ( $shape as $point ) {
 217                         $points[] = $point['x'] . ',' . $point['y'];
 218                 }
 219
 220                 return join( " ", $points );
 221         }
 222
 223         /**
 224          * Based on image specification, write a very simple SVG file to disk.
 225          * Ignores the background spec because transparency is cool. :)
 226          *
 227          * @param array $spec spec describing background and shapes to draw
 228          * @param string $format file format to write (which is obviously always svg here)
 229          * @param string $filename filename to write to
 230          *
 231          * @throws Exception
 232          */
 233         public function writeSvg( $spec, $format, $filename ) {
 234                 $svg = new SimpleXmlElement( '<svg/>' );
 235                 $svg->addAttribute( 'xmlns', 'http://www.w3.org/2000/svg' );
 236                 $svg->addAttribute( 'version', '1.1' );
 237                 $svg->addAttribute( 'width', $spec['width'] );
 238                 $svg->addAttribute( 'height', $spec['height'] );
 239                 $g = $svg->addChild( 'g' );
 240                 foreach ( $spec['draws'] as $drawSpec ) {
 241                         $shape = $g->addChild( 'polygon' );
 242                         $shape->addAttribute( 'fill', $drawSpec['fill'] );
 243                         $shape->addAttribute( 'points', self::shapePointsToString( $drawSpec['shape'] ) );
 244                 }
 245
 246                 if ( !$fh = fopen( $filename, 'w' ) ) {
 247                         throw new Exception( "couldn't open $filename for writing" );
 248                 }
 249                 fwrite( $fh, $svg->asXML() );
 250                 if ( !fclose( $fh ) ) {
 251                         throw new Exception( "couldn't close $filename" );
 252                 }
 253         }
 254
 255         /**
 256          * Based on an image specification, write such an image to disk, using Imagick PHP extension
 257          * @param array $spec spec describing background and circles to draw
 258          * @param string $format file format to write
 259          * @param string $filename filename to write to
 260          */
 261         public function writeImageWithApi( $spec, $format, $filename ) {
 262                 // this is a hack because I can't get setImageOrientation() to work. See below.
 263                 global $wgExiv2Command;
 264
 265                 $image = new Imagick();
 266                 /**
 267                  * If the format is 'jpg', will also add a random orientation -- the image will be drawn rotated with triangle points
 268                  * facing in some direction (0, 90, 180 or 270 degrees) and a countering rotation should turn the triangle points upward again
 269                  */
 270                 $orientation = self::$orientations[0]; // default is normal orientation
 271                 if ( $format == 'jpg' ) {
 272                         $orientation = self::$orientations[array_rand( self::$orientations )];
 273                         $spec = self::rotateImageSpec( $spec, $orientation['counterRotation'] );
 274                 }
 275
 276                 $image->newImage( $spec['width'], $spec['height'], new ImagickPixel( $spec['fill'] ) );
 277
 278                 foreach ( $spec['draws'] as $drawSpec ) {
 279                         $draw = new ImagickDraw();
 280                         $draw->setFillColor( $drawSpec['fill'] );
 281                         $draw->polygon( $drawSpec['shape'] );
 282                         $image->drawImage( $draw );
 283                 }
 284
 285                 $image->setImageFormat( $format );
 286
 287                 // this doesn't work, even though it's documented to do so...
 288                 // $image->setImageOrientation( $orientation['exifCode'] );
 289
 290                 $image->writeImage( $filename );
 291
 292                 // because the above setImageOrientation call doesn't work... nor can I get an external imagemagick binary to do this either...
 293                 // hacking this for now (only works if you have exiv2 installed, a program to read and manipulate exif)
 294                 if ( $wgExiv2Command ) {
 295                         $cmd = wfEscapeShellArg( $wgExiv2Command )
 296                                 . " -M "
 297                                 . wfEscapeShellArg( "set Exif.Image.Orientation " . $orientation['exifCode'] )
 298                                 . " "
 299                                 . wfEscapeShellArg( $filename );
 300
 301                         $retval = 0;
 302                         $err = wfShellExec( $cmd, $retval );
 303                         if ( $retval !== 0 ) {
 304                                 print "Error with $cmd: $retval, $err\n";
 305                         }
 306                 }
 307         }
 308
 309         /**
 310          * Given an image specification, produce rotated version
 311          * This is used when simulating a rotated image capture with Exif orientation
 312          * @param $spec Object returned by getImageSpec
 313          * @param $matrix 2x2 transformation matrix
 314          * @return array transformed Spec
 315          */
 316         private static function rotateImageSpec( &$spec, $matrix ) {
 317                 $tSpec = array();
 318                 $dims = self::matrixMultiply2x2( $matrix, $spec['width'], $spec['height'] );
 319                 $correctionX = 0;
 320                 $correctionY = 0;
 321                 if ( $dims['x'] < 0 ) {
 322                         $correctionX = abs( $dims['x'] );
 323                 }
 324                 if ( $dims['y'] < 0 ) {
 325                         $correctionY = abs( $dims['y'] );
 326                 }
 327                 $tSpec['width'] = abs( $dims['x'] );
 328                 $tSpec['height'] = abs( $dims['y'] );
 329                 $tSpec['fill'] = $spec['fill'];
 330                 $tSpec['draws'] = array();
 331                 foreach ( $spec['draws'] as $draw ) {
 332                         $tDraw = array(
 333                                 'fill' => $draw['fill'],
 334                                 'shape' => array()
 335                         );
 336                         foreach ( $draw['shape'] as $point ) {
 337                                 $tPoint = self::matrixMultiply2x2( $matrix, $point['x'], $point['y'] );
 338                                 $tPoint['x'] += $correctionX;
 339                                 $tPoint['y'] += $correctionY;
 340                                 $tDraw['shape'][] = $tPoint;
 341                         }
 342                         $tSpec['draws'][] = $tDraw;
 343                 }
 344
 345                 return $tSpec;
 346         }
 347
 348         /**
 349          * Given a matrix and a pair of images, return new position
 350          * @param $matrix: 2x2 rotation matrix
 351          * @param $x: x-coordinate number
 352          * @param $y: y-coordinate number
 353          * @return Array transformed with properties x, y
 354          */
 355         private static function matrixMultiply2x2( $matrix, $x, $y ) {
 356                 return array(
 357                         'x' => $x * $matrix[0][0] + $y * $matrix[0][1],
 358                         'y' => $x * $matrix[1][0] + $y * $matrix[1][1]
 359                 );
 360         }
 361
 362         /**
 363          * Based on an image specification, write such an image to disk, using the command line ImageMagick program ('convert').
 364          *
 365          * Sample command line:
 366          *  $ convert -size 100x60 xc:rgb(90,87,45) \
 367          *      -draw 'fill rgb(12,34,56)   polygon 41,39 44,57 50,57 41,39' \
 368          *   -draw 'fill rgb(99,123,231) circle 59,39 56,57' \
 369          *   -draw 'fill rgb(240,12,32)  circle 50,21 50,3'  filename.png
 370          *
 371          * @param array $spec spec describing background and shapes to draw
 372          * @param string $format file format to write (unused by this method but kept so it has the same signature as
 373          * writeImageWithApi)
 374          * @param string $filename filename to write to
 375          *
 376          * @return bool
 377          */
 378         public function writeImageWithCommandLine( $spec, $format, $filename ) {
 379                 global $wgImageMagickConvertCommand;
 380                 $args = array();
 381                 $args[] = "-size " . wfEscapeShellArg( $spec['width'] . 'x' . $spec['height'] );
 382                 $args[] = wfEscapeShellArg( "xc:" . $spec['fill'] );
 383                 foreach ( $spec['draws'] as $draw ) {
 384                         $fill = $draw['fill'];
 385                         $polygon = self::shapePointsToString( $draw['shape'] );
 386                         $drawCommand = "fill $fill  polygon $polygon";
 387                         $args[] = '-draw ' . wfEscapeShellArg( $drawCommand );
 388                 }
 389                 $args[] = wfEscapeShellArg( $filename );
 390
 391                 $command = wfEscapeShellArg( $wgImageMagickConvertCommand ) . " " . implode( " ", $args );
 392                 $retval = null;
 393                 wfShellExec( $command, $retval );
 394
 395                 return ( $retval === 0 );
 396         }
 397
 398         /**
 399          * Generate a string of random colors for ImageMagick or SVG, like "rgb(12, 37, 98)"
 400          *
 401          * @return string
 402          */
 403         public function getRandomColor() {
 404                 $components = array();
 405                 for ( $i = 0; $i <= 2; $i++ ) {
 406                         $components[] = mt_rand( 0, 255 );
 407                 }
 408
 409                 return 'rgb(' . join( ', ', $components ) . ')';
 410         }
 411
 412         /**
 413          * Get an array of random pairs of random words, like array( array( 'foo', 'bar' ), array( 'quux', 'baz' ) );
 414          *
 415          * @param $number Integer: number of pairs
 416          * @return Array: of two-element arrays
 417          */
 418         private function getRandomWordPairs( $number ) {
 419                 $lines = $this->getRandomLines( $number * 2 );
 420                 // construct pairs of words
 421                 $pairs = array();
 422                 $count = count( $lines );
 423                 for ( $i = 0; $i < $count; $i += 2 ) {
 424                         $pairs[] = array( $lines[$i], $lines[$i + 1] );
 425                 }
 426
 427                 return $pairs;
 428         }
 429
 430         /**
 431          * Return N random lines from a file
 432          *
 433          * Will throw exception if the file could not be read or if it had fewer lines than requested.
 434          *
 435          * @param int $number_desired number of lines desired
 436          *
 437          * @throws Exception
 438          * @return array of exactly n elements, drawn randomly from lines the file
 439          */
 440         private function getRandomLines( $number_desired ) {
 441                 $filepath = $this->dictionaryFile;
 442
 443                 // initialize array of lines
 444                 $lines = array();
 445                 for ( $i = 0; $i < $number_desired; $i++ ) {
 446                         $lines[] = null;
 447                 }
 448
 449                 /*
 450                  * This algorithm obtains N random lines from a file in one single pass. It does this by replacing elements of
 451                  * a fixed-size array of lines, less and less frequently as it reads the file.
 452                  */
 453                 $fh = fopen( $filepath, "r" );
 454                 if ( !$fh ) {
 455                         throw new Exception( "couldn't open $filepath" );
 456                 }
 457                 $line_number = 0;
 458                 $max_index = $number_desired - 1;
 459                 while ( !feof( $fh ) ) {
 460                         $line = fgets( $fh );
 461                         if ( $line !== false ) {
 462                                 $line_number++;
 463                                 $line = trim( $line );
 464                                 if ( mt_rand( 0, $line_number ) <= $max_index ) {
 465                                         $lines[mt_rand( 0, $max_index )] = $line;
 466                                 }
 467                         }
 468                 }
 469                 fclose( $fh );
 470                 if ( $line_number < $number_desired ) {
 471                         throw new Exception( "not enough lines in $filepath" );
 472                 }
 473
 474                 return $lines;
 475         }
 476 }