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 circles)
  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 $circlesToDraw = 5;
  35         private $imageWriteMethod;
  36
  37         public function __construct( $options = array() ) {
  38                 global $wgUseImageMagick, $wgImageMagickConvertCommand;
  39                 foreach ( array( 'dictionaryFile', 'minWidth', 'minHeight', 'maxHeight', 'circlesToDraw' ) as $property ) {
  40                         if ( isset( $options[$property] ) ) {
  41                                 $this->$property = $options[$property];
  42                         }
  43                 }
  44
  45                 // find the dictionary file, to generate random names
  46                 if ( !isset( $this->dictionaryFile ) ) {
  47                         foreach ( array( '/usr/share/dict/words', '/usr/dict/words' ) as $dictionaryFile ) {
  48                                 if ( is_file( $dictionaryFile ) and is_readable( $dictionaryFile ) ) {
  49                                         $this->dictionaryFile = $dictionaryFile;
  50                                         break;
  51                                 }
  52                         }
  53                 }
  54                 if ( !isset( $this->dictionaryFile ) ) {
  55                         throw new Exception( "RandomImageGenerator: dictionary file not found or not specified properly" );
  56                 }
  57         }
  58
  59         /**
  60          * Writes random images with random filenames to disk in the directory you specify, or current working directory
  61          *
  62          * @param $number Integer: number of filenames to write
  63          * @param $format String: optional, must be understood by ImageMagick, such as 'jpg' or 'gif'
  64          * @param $dir String: directory, optional (will default to current working directory)
  65          * @return Array: filenames we just wrote
  66          */
  67         function writeImages( $number, $format = 'jpg', $dir = null ) {
  68                 $filenames = $this->getRandomFilenames( $number, $format, $dir );
  69                 $imageWriteMethod = $this->getImageWriteMethod( $format );
  70                 foreach( $filenames as $filename ) {
  71                         $this->{$imageWriteMethod}( $this->getImageSpec(), $format, $filename );
  72                 }
  73                 return $filenames;
  74         }
  75
  76
  77         /**
  78          * Figure out how we write images. This is a factor of both format and the local system
  79          * @param $format (a typical extension like 'svg', 'jpg', etc.)
  80          */
  81         function getImageWriteMethod( $format ) {
  82                 if ( $format === 'svg' ) {
  83                         return 'writeSvg';
  84                 } else {
  85                         // figure out how to write images
  86                         if ( class_exists( 'Imagick' ) ) {
  87                                 return 'writeImageWithApi';
  88                         } elseif ( $wgUseImageMagick && $wgImageMagickConvertCommand && is_executable( $wgImageMagickConvertCommand ) ) {
  89                                 return 'writeImageWithCommandLine';
  90                         }
  91                 }
  92                 throw new Exception( "RandomImageGenerator: could not find a suitable method to write images in '$format' format" );
  93         }
  94
  95         /**
  96          * Return a number of randomly-generated filenames
  97          * Each filename uses two words randomly drawn from the dictionary, like elephantine_spatula.jpg
  98          *
  99          * @param $number Integer: of filenames to generate
 100          * @param $extension String: optional, defaults to 'jpg'
 101          * @param $dir String: optional, defaults to current working directory
 102          * @return Array: of filenames
 103          */
 104         private function getRandomFilenames( $number, $extension = 'jpg', $dir = null ) {
 105                 if ( is_null( $dir ) ) {
 106                         $dir = getcwd();
 107                 }
 108                 $filenames = array();
 109                 foreach( $this->getRandomWordPairs( $number ) as $pair ) {
 110                         $basename = $pair[0] . '_' . $pair[1];
 111                         if ( !is_null( $extension ) ) {
 112                                 $basename .= '.' . $extension;
 113                         }
 114                         $basename = preg_replace( '/\s+/', '', $basename );
 115                         $filenames[] = "$dir/$basename";
 116                 }
 117
 118                 return $filenames;
 119
 120         }
 121
 122
 123         /**
 124          * Generate data representing an image of random size (within limits),
 125          * consisting of randomly colored and sized circles against a random background color
 126          * (This data is used in the writeImage* methods).
 127          * @return {Mixed}
 128          */
 129         public function getImageSpec() {
 130                 $spec = array();
 131
 132                 $spec['width'] = mt_rand( $this->minWidth, $this->maxWidth );
 133                 $spec['height'] = mt_rand( $this->minHeight, $this->maxHeight );
 134                 $spec['fill'] = $this->getRandomColor();
 135
 136                 $diagonalLength = sqrt( pow( $spec['width'], 2 ) + pow( $spec['height'], 2 ) );
 137
 138                 $draws = array();
 139                 for ( $i = 0; $i <= $this->circlesToDraw; $i++ ) {
 140                         $radius = mt_rand( 0, $diagonalLength / 4 );
 141                         $originX = mt_rand( -1 * $radius, $spec['width'] + $radius );
 142                         $originY = mt_rand( -1 * $radius, $spec['height'] + $radius );
 143                         $perimeterX = $originX + $radius;
 144                         $perimeterY = $originY + $radius;
 145
 146                         $draw = array();
 147                         $draw['fill'] = $this->getRandomColor();
 148                         $draw['circle'] = array(
 149                                 'originX' => $originX,
 150                                 'originY' => $originY,
 151                                 'radius' => $radius,
 152                                 'perimeterX' => $perimeterX,
 153                                 'perimeterY' => $perimeterY
 154                         );
 155                         $draws[] = $draw;
 156
 157                 }
 158
 159                 $spec['draws'] = $draws;
 160
 161                 return $spec;
 162         }
 163
 164
 165         /**
 166          * Based on image specification, write a very simple SVG file to disk.
 167          * Ignores the background spec because transparency is cool. :)
 168          * @param $spec: spec describing background and circles to draw
 169          * @param $format: file format to write (which is obviously always svg here)
 170          * @param $filename: filename to write to
 171          */
 172         public function writeSvg( $spec, $format, $filename ) {
 173                 $svg = new SimpleXmlElement( '<svg/>' );
 174                 $svg->addAttribute( 'xmlns', 'http://www.w3.org/2000/svg' );
 175                 $svg->addAttribute( 'version', '1.1' );
 176                 $svg->addAttribute( 'width', $spec['width'] );
 177                 $svg->addAttribute( 'height', $spec['height'] );
 178                 $g = $svg->addChild( 'g' );
 179                 foreach ( $spec['draws'] as $drawSpec ) {
 180                         $circle = $g->addChild( 'circle' );
 181                         $circle->addAttribute( 'fill', $drawSpec['fill'] );
 182                         $circleSpec = $drawSpec['circle'];
 183                         $circle->addAttribute( 'cx', $circleSpec['originX'] );
 184                         $circle->addAttribute( 'cy', $circleSpec['originY'] );
 185                         $circle->addAttribute( 'r', $circleSpec['radius'] );
 186                 };
 187                 if ( ! $fh = fopen( $filename, 'w' ) ) {
 188                         throw new Exception( "couldn't open $filename for writing" );
 189                 }
 190                 fwrite( $fh, $svg->asXML() );
 191                 if ( !fclose($fh) ) {
 192                         throw new Exception( "couldn't close $filename" );
 193                 }
 194         }
 195
 196         /**
 197          * Based on an image specification, write such an image to disk, using Imagick PHP extension
 198          * @param $spec: spec describing background and circles to draw
 199          * @param $format: file format to write
 200          * @param $filename: filename to write to
 201          */
 202         public function writeImageWithApi( $spec, $format, $filename ) {
 203                 $image = new Imagick();
 204                 $image->newImage( $spec['width'], $spec['height'], new ImagickPixel( $spec['fill'] ) );
 205
 206                 foreach ( $spec['draws'] as $drawSpec ) {
 207                         $draw = new ImagickDraw();
 208                         $draw->setFillColor( $drawSpec['fill'] );
 209                         $circle = $drawSpec['circle'];
 210                         $draw->circle( $circle['originX'], $circle['originY'], $circle['perimeterX'], $circle['perimeterY'] );
 211                         $image->drawImage( $draw );
 212                 }
 213
 214                 $image->setImageFormat( $format );
 215                 $image->writeImage( $filename );
 216         }
 217
 218
 219         /**
 220          * Based on an image specification, write such an image to disk, using the command line ImageMagick program ('convert').
 221          *
 222          * Sample command line:
 223          *    $ convert -size 100x60 xc:rgb(90,87,45)  \
 224                  *      -draw 'fill rgb(12,34,56)   circle 41,39 44,57' \
 225                  *      -draw 'fill rgb(99,123,231) circle 59,39 56,57' \
 226                  *      -draw 'fill rgb(240,12,32)  circle 50,21 50,3'  filename.png
 227          *
 228          * @param $spec: spec describing background and circles to draw
 229          * @param $format: file format to write (unused by this method but kept so it has the same signature as writeImageWithApi)
 230          * @param $filename: filename to write to
 231          */
 232         public function writeImageWithCommandLine( $spec, $format, $filename ) {
 233                 global $wgImageMagickConvertCommand;
 234                 $args = array();
 235                 $args[] = "-size " . wfEscapeShellArg( $spec['width'] . 'x' . $spec['height'] );
 236                 $args[] = wfEscapeShellArg( "xc:" . $spec['fill'] );
 237                 foreach( $spec['draws'] as $draw ) {
 238                         $fill = $draw['fill'];
 239                         $originX = $draw['circle']['originX'];
 240                         $originY = $draw['circle']['originY'];
 241                         $perimeterX = $draw['circle']['perimeterX'];
 242                         $perimeterY = $draw['circle']['perimeterY'];
 243                         $drawCommand = "fill $fill  circle $originX,$originY $perimeterX,$perimeterY";
 244                         $args[] = '-draw ' . wfEscapeShellArg( $drawCommand );
 245                 }
 246                 $args[] = wfEscapeShellArg( $filename );
 247
 248                 $command = wfEscapeShellArg( $wgImageMagickConvertCommand ) . " " . implode( " ", $args );
 249                 $retval = null;
 250                 wfShellExec( $command, $retval );
 251                 return ( $retval === 0 );
 252         }
 253
 254         /**
 255          * Generate a string of random colors for ImageMagick or SVG, like "rgb(12, 37, 98)"
 256          *
 257          * @return {String}
 258          */
 259         public function getRandomColor() {
 260                 $components = array();
 261                 for ($i = 0; $i <= 2; $i++ ) {
 262                         $components[] = mt_rand( 0, 255 );
 263                 }
 264                 return 'rgb(' . join(', ', $components) . ')';
 265         }
 266
 267         /**
 268          * Get an array of random pairs of random words, like array( array( 'foo', 'bar' ), array( 'quux', 'baz' ) );
 269          *
 270          * @param $number Integer: number of pairs
 271          * @return Array: of two-element arrays
 272          */
 273         private function getRandomWordPairs( $number ) {
 274                 $lines = $this->getRandomLines( $number * 2 );
 275                 // construct pairs of words
 276                 $pairs = array();
 277                 $count = count( $lines );
 278                 for( $i = 0; $i < $count; $i += 2 )  {
 279                         $pairs[] = array( $lines[$i], $lines[$i+1] );
 280                 }
 281                 return $pairs;
 282         }
 283
 284
 285         /**
 286          * Return N random lines from a file
 287          *
 288          * Will throw exception if the file could not be read or if it had fewer lines than requested.
 289          *
 290          * @param $number_desired Integer: number of lines desired
 291          * @return Array: of exactly n elements, drawn randomly from lines the file
 292          */
 293         private function getRandomLines( $number_desired ) {
 294                 $filepath = $this->dictionaryFile;
 295
 296                 // initialize array of lines
 297                 $lines = array();
 298                 for ( $i = 0; $i < $number_desired; $i++ ) {
 299                         $lines[] = null;
 300                 }
 301
 302                 /*
 303                  * This algorithm obtains N random lines from a file in one single pass. It does this by replacing elements of
 304                  * a fixed-size array of lines, less and less frequently as it reads the file.
 305                  */
 306                 $fh = fopen( $filepath, "r" );
 307                 if ( !$fh ) {
 308                          throw new Exception( "couldn't open $filepath" );
 309                 }
 310                 $line_number = 0;
 311                 $max_index = $number_desired - 1;
 312                 while( !feof( $fh ) ) {
 313                         $line = fgets( $fh );
 314                         if ( $line !== false ) {
 315                                 $line_number++;
 316                                 $line = trim( $line );
 317                                 if ( mt_rand( 0, $line_number ) <= $max_index ) {
 318                                         $lines[ mt_rand( 0, $max_index ) ] = $line;
 319                                 }
 320                         }
 321                 }
 322                 fclose( $fh );
 323                 if ( $line_number < $number_desired ) {
 324                         throw new Exception( "not enough lines in $filepath" );
 325                 }
 326
 327                 return $lines;
 328         }
 329
 330 }