Complex classes like Stream often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use Stream, and based on these observations, apply Extract Interface, too.
| 1 | <?php | ||
| 30 | class Stream implements SeekableIterator | ||
| 31 | { | ||
| 32 | /** | ||
| 33 | * Attached filters | ||
| 34 | * | ||
| 35 | * @var resource[] | ||
| 36 | */ | ||
| 37 | protected $filters = []; | ||
| 38 | |||
| 39 | /** | ||
| 40 | * stream resource | ||
| 41 | * | ||
| 42 | * @var resource | ||
| 43 | */ | ||
| 44 | protected $stream; | ||
| 45 | |||
| 46 | /** | ||
| 47 | * Tell whether the stream should be closed on object destruction | ||
| 48 | * | ||
| 49 | * @var bool | ||
| 50 | */ | ||
| 51 | protected $should_close_stream = false; | ||
| 52 | |||
| 53 | /** | ||
| 54 | * Current iterator value | ||
| 55 | * | ||
| 56 | * @var mixed | ||
| 57 | */ | ||
| 58 | protected $value; | ||
| 59 | |||
| 60 | /** | ||
| 61 | * Current iterator key | ||
| 62 | * | ||
| 63 | * @var int | ||
| 64 | */ | ||
| 65 | protected $offset; | ||
| 66 | |||
| 67 | /** | ||
| 68 | * Flags for the Document | ||
| 69 | * | ||
| 70 | * @var int | ||
| 71 | */ | ||
| 72 | protected $flags = 0; | ||
| 73 | |||
| 74 | /** | ||
| 75 | * the field delimiter (one character only) | ||
| 76 | * | ||
| 77 | * @var string | ||
| 78 | */ | ||
| 79 | protected $delimiter = ','; | ||
| 80 | |||
| 81 | /** | ||
| 82 | * the field enclosure character (one character only) | ||
| 83 | * | ||
| 84 | * @var string | ||
| 85 | */ | ||
| 86 | protected $enclosure = '"'; | ||
| 87 | |||
| 88 | /** | ||
| 89 | * the field escape character (one character only) | ||
| 90 | * | ||
| 91 | * @var string | ||
| 92 | */ | ||
| 93 | protected $escape = '\\'; | ||
| 94 | |||
| 95 | /** | ||
| 96 | * Tell whether the current stream is seekable; | ||
| 97 | * | ||
| 98 | * @var bool | ||
| 99 | */ | ||
| 100 | protected $isSeekable = false; | ||
| 101 | |||
| 102 | /** | ||
| 103 | * New instance | ||
| 104 | * | ||
| 105 | * @param resource $resource stream type resource | ||
| 106 | * | ||
| 107 | * @throws RuntimeException if the argument passed is not a seeakable stream resource | ||
| 108 | */ | ||
| 109 | 32 | public function __construct($resource) | |
| 110 |     { | ||
| 111 | 32 |         if (!is_resource($resource)) { | |
| 112 | 2 |             throw new TypeError(sprintf('Argument passed must be a seekable stream resource, %s given', gettype($resource))); | |
| 113 | } | ||
| 114 | |||
| 115 | 30 |         if ('stream' !== ($type = get_resource_type($resource))) { | |
| 116 | 2 |             throw new TypeError(sprintf('Argument passed must be a seekable stream resource, %s resource given', $type)); | |
| 117 | } | ||
| 118 | |||
| 119 | 28 | $this->isSeekable = stream_get_meta_data($resource)['seekable']; | |
| 120 | 28 | $this->stream = $resource; | |
| 121 | 28 | } | |
| 122 | |||
| 123 | /** | ||
| 124 |      * {@inheritdoc} | ||
| 125 | */ | ||
| 126 | public function __destruct() | ||
| 127 |     { | ||
| 128 | 28 |         $walker = function ($filter): bool { | |
| 129 | 8 | return stream_filter_remove($filter); | |
| 130 | 28 | }; | |
| 131 | |||
| 132 | 28 | array_walk_recursive($this->filters, $walker); | |
| 133 | |||
| 134 | 28 |         if ($this->should_close_stream && is_resource($this->stream)) { | |
| 135 | 18 | fclose($this->stream); | |
| 136 | } | ||
| 137 | |||
| 138 | 28 | unset($this->stream); | |
| 139 | 28 | } | |
| 140 | |||
| 141 | /** | ||
| 142 |      * {@inheritdoc} | ||
| 143 | */ | ||
| 144 | 2 | public function __clone() | |
| 145 |     { | ||
| 146 | 2 |         throw new Exception(sprintf('An object of class %s cannot be cloned', get_class($this))); | |
| 147 | } | ||
| 148 | |||
| 149 | /** | ||
| 150 |      * {@inheritdoc} | ||
| 151 | */ | ||
| 152 | 2 | public function __debugInfo() | |
| 153 |     { | ||
| 154 | 2 | return stream_get_meta_data($this->stream) + [ | |
| 155 | 2 | 'delimiter' => $this->delimiter, | |
| 156 | 2 | 'enclosure' => $this->enclosure, | |
| 157 | 2 | 'escape' => $this->escape, | |
| 158 | 2 | 'stream_filters' => array_keys($this->filters), | |
| 159 | ]; | ||
| 160 | } | ||
| 161 | |||
| 162 | /** | ||
| 163 | * Return a new instance from a file path | ||
| 164 | * | ||
| 165 | * @param string $path file path | ||
| 166 | * @param string $open_mode the file open mode flag | ||
| 167 | * @param resource|null $context the resource context | ||
| 168 | * | ||
| 169 | * @throws Exception if the stream resource can not be created | ||
| 170 | * | ||
| 171 | * @return static | ||
| 172 | */ | ||
| 173 | 12 | public static function createFromPath(string $path, string $open_mode = 'r', $context = null): self | |
| 174 |     { | ||
| 175 | 12 | $args = [$path, $open_mode]; | |
| 176 | 12 |         if (null !== $context) { | |
| 177 | 2 | $args[] = false; | |
| 178 | 2 | $args[] = $context; | |
| 179 | } | ||
| 180 | |||
| 181 | 12 |         if (!$resource = @fopen(...$args)) { | |
| 182 | 2 | throw new Exception(error_get_last()['message']); | |
| 183 | } | ||
| 184 | |||
| 185 | 10 | $instance = new static($resource); | |
| 186 | 10 | $instance->should_close_stream = true; | |
| 187 | |||
| 188 | 10 | return $instance; | |
| 189 | } | ||
| 190 | |||
| 191 | /** | ||
| 192 | * Return a new instance from a string | ||
| 193 | * | ||
| 194 | * @param string $content the CSV document as a string | ||
| 195 | * | ||
| 196 | * @return static | ||
| 197 | */ | ||
| 198 | 10 | public static function createFromString(string $content): self | |
| 199 |     { | ||
| 200 | 10 |         $resource = fopen('php://temp', 'r+'); | |
| 201 | 10 | fwrite($resource, $content); | |
| 202 | |||
| 203 | 10 | $instance = new static($resource); | |
| 204 | 10 | $instance->should_close_stream = true; | |
| 205 | |||
| 206 | 10 | return $instance; | |
| 207 | } | ||
| 208 | |||
| 209 | /** | ||
| 210 | * append a filter | ||
| 211 | * | ||
| 212 | * @see http://php.net/manual/en/function.stream-filter-append.php | ||
| 213 | * | ||
| 214 | * @param string $filtername | ||
| 215 | * @param int $read_write | ||
| 216 | * @param mixed $params | ||
| 217 | * | ||
| 218 | * @throws Exception if the filter can not be appended | ||
| 219 | */ | ||
| 220 | 10 | public function appendFilter(string $filtername, int $read_write, $params = null) | |
| 221 |     { | ||
| 222 | 10 | $res = @stream_filter_append($this->stream, $filtername, $read_write, $params); | |
| 223 | 10 |         if (is_resource($res)) { | |
| 224 | 8 | $this->filters[$filtername][] = $res; | |
| 225 | 8 | return; | |
| 226 | } | ||
| 227 | |||
| 228 | 2 | throw new Exception(error_get_last()['message']); | |
| 229 | } | ||
| 230 | |||
| 231 | /** | ||
| 232 | * Set CSV control | ||
| 233 | * | ||
| 234 | * @see http://php.net/manual/en/splfileobject.setcsvcontrol.php | ||
| 235 | * | ||
| 236 | * @param string $delimiter | ||
| 237 | * @param string $enclosure | ||
| 238 | * @param string $escape | ||
| 239 | */ | ||
| 240 | 24 | public function setCsvControl(string $delimiter = ',', string $enclosure = '"', string $escape = '\\') | |
| 241 |     { | ||
| 242 | 24 | list($this->delimiter, $this->enclosure, $this->escape) = $this->filterControl($delimiter, $enclosure, $escape, __METHOD__); | |
| 243 | 24 | } | |
| 244 | |||
| 245 | /** | ||
| 246 | * Filter Csv control characters | ||
| 247 | * | ||
| 248 | * @param string $delimiter CSV delimiter character | ||
| 249 | * @param string $enclosure CSV enclosure character | ||
| 250 | * @param string $escape CSV escape character | ||
| 251 | * @param string $caller caller | ||
| 252 | * | ||
| 253 | * @throws Exception If the Csv control character is not one character only. | ||
| 254 | * | ||
| 255 | * @return array | ||
| 256 | */ | ||
| 257 | 30 | protected function filterControl(string $delimiter, string $enclosure, string $escape, string $caller): array | |
| 258 |     { | ||
| 259 | 30 | $controls = ['delimiter' => $delimiter, 'enclosure' => $enclosure, 'escape' => $escape]; | |
| 260 | 30 |         foreach ($controls as $type => $control) { | |
| 261 | 30 |             if (1 !== strlen($control)) { | |
| 262 | 30 |                 throw new Exception(sprintf('%s() expects %s to be a single character', $caller, $type)); | |
| 263 | } | ||
| 264 | } | ||
| 265 | |||
| 266 | 24 | return array_values($controls); | |
| 267 | } | ||
| 268 | |||
| 269 | /** | ||
| 270 | * Set CSV control | ||
| 271 | * | ||
| 272 | * @see http://php.net/manual/en/splfileobject.getcsvcontrol.php | ||
| 273 | * | ||
| 274 | * @return string[] | ||
| 275 | */ | ||
| 276 | 30 | public function getCsvControl() | |
| 277 |     { | ||
| 278 | 30 | return [$this->delimiter, $this->enclosure, $this->escape]; | |
| 279 | } | ||
| 280 | |||
| 281 | /** | ||
| 282 | * Set CSV stream flags | ||
| 283 | * | ||
| 284 | * @see http://php.net/manual/en/splfileobject.setflags.php | ||
| 285 | * | ||
| 286 | * @param int $flags | ||
| 287 | */ | ||
| 288 | 22 | public function setFlags(int $flags) | |
| 289 |     { | ||
| 290 | 22 | $this->flags = $flags; | |
| 291 | 22 | } | |
| 292 | |||
| 293 | /** | ||
| 294 | * Write a field array as a CSV line | ||
| 295 | * | ||
| 296 | * @see http://php.net/manual/en/splfileobject.fputcsv.php | ||
| 297 | * | ||
| 298 | * @param array $fields | ||
| 299 | * @param string $delimiter | ||
| 300 | * @param string $enclosure | ||
| 301 | * @param string $escape | ||
| 302 | * | ||
| 303 | * @return int|bool | ||
| 304 | */ | ||
| 305 | 14 | public function fputcsv(array $fields, string $delimiter = ',', string $enclosure = '"', string $escape = '\\') | |
| 306 |     { | ||
| 307 | 14 | $controls = $this->filterControl($delimiter, $enclosure, $escape, __METHOD__); | |
| 308 | |||
| 309 | 8 | return fputcsv($this->stream, $fields, ...$controls); | |
| 310 | } | ||
| 311 | |||
| 312 | /** | ||
| 313 | * Get line number | ||
| 314 | * | ||
| 315 | * @see http://php.net/manual/en/splfileobject.key.php | ||
| 316 | * | ||
| 317 | * @return int | ||
| 318 | */ | ||
| 319 | 12 | public function key() | |
| 320 |     { | ||
| 321 | 12 | return $this->offset; | |
| 322 | } | ||
| 323 | |||
| 324 | /** | ||
| 325 | * Read next line | ||
| 326 | * | ||
| 327 | * @see http://php.net/manual/en/splfileobject.next.php | ||
| 328 | * | ||
| 329 | */ | ||
| 330 | 12 | public function next() | |
| 331 |     { | ||
| 332 | 12 | $this->value = false; | |
| 333 | 12 | $this->offset++; | |
| 334 | 12 | } | |
| 335 | |||
| 336 | /** | ||
| 337 | * Rewind the file to the first line | ||
| 338 | * | ||
| 339 | * @see http://php.net/manual/en/splfileobject.rewind.php | ||
| 340 | * | ||
| 341 | */ | ||
| 342 | 24 | public function rewind() | |
| 343 |     { | ||
| 344 | 24 |         if (!$this->isSeekable) { | |
| 345 | 2 |             throw new Exception('The stream resource must be seekable'); | |
| 346 | } | ||
| 347 | |||
| 348 | 22 | rewind($this->stream); | |
| 349 | 22 | $this->offset = 0; | |
| 350 | 22 | $this->value = false; | |
| 351 | 22 |         if ($this->flags & SplFileObject::READ_AHEAD) { | |
| 352 | 12 | $this->current(); | |
| 353 | } | ||
| 354 | 22 | } | |
| 355 | |||
| 356 | /** | ||
| 357 | * Not at EOF | ||
| 358 | * | ||
| 359 | * @see http://php.net/manual/en/splfileobject.valid.php | ||
| 360 | * | ||
| 361 | * @return bool | ||
| 362 | */ | ||
| 363 | 20 | public function valid() | |
| 371 | |||
| 372 | /** | ||
| 373 | * Retrieves the current line of the file. | ||
| 374 | * | ||
| 375 | * @see http://php.net/manual/en/splfileobject.current.php | ||
| 376 | * | ||
| 377 | * @return mixed | ||
| 378 | */ | ||
| 379 | 24 | public function current() | |
| 389 | |||
| 390 | /** | ||
| 391 | * Retrieves the current line as a CSV Record | ||
| 392 | * | ||
| 393 | * @return array|bool | ||
| 394 | */ | ||
| 395 | 22 | protected function getCurrentRecord() | |
| 403 | |||
| 404 | /** | ||
| 405 | * Seek to specified line | ||
| 406 | * | ||
| 407 | * @see http://php.net/manual/en/splfileobject.seek.php | ||
| 408 | * | ||
| 409 | * | ||
| 410 | * @param int $position | ||
| 411 | * @throws Exception if the position is negative | ||
| 412 | */ | ||
| 413 | 10 | public function seek($position) | |
| 414 |     { | ||
| 415 | 10 |         if (!$this->isSeekable) { | |
| 416 | 2 |             throw new Exception('The stream resource must be seekable'); | |
| 417 | } | ||
| 418 | |||
| 432 | |||
| 433 | /** | ||
| 434 | * Output all remaining data on a file pointer | ||
| 435 | * | ||
| 436 | * @see http://php.net/manual/en/splfileobject.fpatssthru.php | ||
| 437 | * | ||
| 438 | * @return int | ||
| 439 | */ | ||
| 440 | 2 | public function fpassthru() | |
| 444 | |||
| 445 | /** | ||
| 446 | * Read from file | ||
| 447 | * | ||
| 448 | * @see http://php.net/manual/en/splfileobject.fread.php | ||
| 449 | * | ||
| 450 | * @param int $length The number of bytes to read | ||
| 451 | * | ||
| 452 | * @return string|false | ||
| 453 | */ | ||
| 454 | 8 | public function fread($length) | |
| 458 | |||
| 459 | /** | ||
| 460 | * Seek to a position | ||
| 461 | * | ||
| 462 | * @see http://php.net/manual/en/splfileobject.fseek.php | ||
| 463 | * | ||
| 464 | * @param int $offset | ||
| 465 | * @param int $whence | ||
| 466 | * | ||
| 467 | * @return int | ||
| 468 | */ | ||
| 469 | 12 | public function fseek(int $offset, int $whence = SEEK_SET) | |
| 477 | |||
| 478 | /** | ||
| 479 | * Write to stream | ||
| 480 | * | ||
| 481 | * @see http://php.net/manual/en/splfileobject.fwrite.php | ||
| 482 | * | ||
| 483 | * @param string $str | ||
| 484 | * @param int $length | ||
| 485 | * | ||
| 486 | * @return int|bool | ||
| 487 | */ | ||
| 488 | 2 | public function fwrite(string $str, int $length = 0) | |
| 492 | |||
| 493 | /** | ||
| 494 | * Flushes the output to a file | ||
| 495 | * | ||
| 496 | * @see http://php.net/manual/en/splfileobject.fwrite.php | ||
| 497 | * | ||
| 498 | * @return bool | ||
| 499 | */ | ||
| 500 | 2 | public function fflush() | |
| 504 | } | ||
| 505 |