Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
Complex classes like AbstractStream 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 AbstractStream, and based on these observations, apply Extract Interface, too.
1 | <?php |
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19 | abstract class AbstractStream implements StreamInterface |
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20 | { |
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21 | |||
22 | /** |
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23 | * @var resource |
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24 | */ |
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25 | protected $stream; |
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26 | |||
27 | /** |
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28 | * Reads all data from the stream into a string, from the beginning to end. |
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29 | * |
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30 | * This method MUST attempt to seek to the beginning of the stream before |
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31 | * reading data and read the stream until the end is reached. |
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32 | * |
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33 | * Warning: This could attempt to load a large amount of data into memory. |
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34 | * |
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35 | * This method MUST NOT raise an exception in order to conform with PHP's |
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36 | * string casting operations. |
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37 | * |
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38 | * @see http://php.net/manual/en/language.oop5.magic.php#object.tostring |
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39 | * @return string |
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40 | */ |
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41 | public function __toString() |
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54 | |||
55 | /** |
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56 | * Closes the stream and any underlying resources. |
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57 | * |
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58 | * @return void |
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59 | */ |
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60 | public function close() |
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65 | |||
66 | /** |
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67 | * Separates any underlying resources from the stream. |
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68 | * |
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69 | * After the stream has been detached, the stream is in an unusable state. |
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70 | * |
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71 | * @return resource|null Underlying PHP stream, if any |
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72 | */ |
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73 | public function detach() |
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79 | |||
80 | /** |
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81 | * Get the size of the stream if known. |
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82 | * |
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83 | * @return int|null Returns the size in bytes if known, or null if unknown. |
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84 | */ |
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85 | public function getSize() |
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92 | |||
93 | /** |
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94 | * Returns the current position of the file read/write pointer |
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95 | * |
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96 | * @return int Position of the file pointer |
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97 | * @throws RuntimeException on error. |
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98 | */ |
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99 | View Code Duplication | public function tell() |
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114 | |||
115 | /** |
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116 | * Returns true if the stream is at the end of the stream. |
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117 | * |
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118 | * @return bool |
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119 | */ |
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120 | public function eof() |
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128 | |||
129 | /** |
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130 | * Returns whether or not the stream is seekable. |
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131 | * |
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132 | * @return bool |
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133 | */ |
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134 | public function isSeekable() |
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143 | |||
144 | /** |
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145 | * Seek to a position in the stream. |
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146 | * |
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147 | * @link http://www.php.net/manual/en/function.fseek.php |
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148 | * @param int $offset Stream offset |
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149 | * @param int $whence Specifies how the cursor position will be calculated |
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150 | * based on the seek offset. Valid values are identical to the built-in |
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151 | * PHP $whence values for `fseek()`. SEEK_SET: Set position equal to |
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152 | * offset bytes SEEK_CUR: Set position to current location plus offset |
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153 | * SEEK_END: Set position to end-of-stream plus offset. |
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154 | * @throws RuntimeException on failure. |
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155 | * |
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156 | * @return bool |
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157 | */ |
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158 | public function seek($offset, $whence = SEEK_SET) |
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172 | |||
173 | /** |
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174 | * Seek to the beginning of the stream. |
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175 | * |
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176 | * If the stream is not seekable, this method will raise an exception; |
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177 | * otherwise, it will perform a seek(0). |
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178 | * |
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179 | * @see seek() |
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180 | * @link http://www.php.net/manual/en/function.fseek.php |
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181 | * @throws \RuntimeException on failure. |
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182 | */ |
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183 | public function rewind() |
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187 | |||
188 | /** |
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189 | * Returns whether or not the stream is writable. |
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190 | * |
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191 | * @return bool |
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192 | */ |
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193 | public function isWritable() |
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208 | |||
209 | /** |
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210 | * Write data to the stream. |
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211 | * |
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212 | * @param string $string The string that is to be written. |
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213 | * @return int Returns the number of bytes written to the stream. |
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214 | * @throws RuntimeException on failure. |
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215 | */ |
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216 | View Code Duplication | public function write($string) |
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230 | |||
231 | /** |
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232 | * Returns whether or not the stream is readable. |
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233 | * |
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234 | * @return bool |
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235 | */ |
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236 | public function isReadable() |
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245 | |||
246 | /** |
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247 | * Read data from the stream. |
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248 | * |
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249 | * @param int $length Read up to $length bytes from the object and return |
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250 | * them. Fewer than $length bytes may be returned if underlying stream |
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251 | * call returns fewer bytes. |
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252 | * @return string Returns the data read from the stream, or an empty string |
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253 | * if no bytes are available. |
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254 | * @throws RuntimeException if an error occurs. |
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255 | */ |
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256 | View Code Duplication | public function read($length) |
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270 | |||
271 | /** |
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272 | * Returns the remaining contents in a string |
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273 | * |
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274 | * @return string |
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275 | * @throws RuntimeException if unable to read or an error occurs while |
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276 | * reading. |
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277 | */ |
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278 | View Code Duplication | public function getContents() |
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289 | |||
290 | /** |
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291 | * Get stream metadata as an associative array or retrieve a specific key. |
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292 | * |
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293 | * The keys returned are identical to the keys returned from PHP's |
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294 | * stream_get_meta_data() function. |
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295 | * |
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296 | * @link http://php.net/manual/en/function.stream-get-meta-data.php |
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297 | * @param string $key Specific metadata to retrieve. |
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298 | * @return array|mixed|null Returns an associative array if no key is |
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299 | * provided. Returns a specific key value if a key is provided and the |
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300 | * value is found, or null if the key is not found. |
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301 | */ |
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302 | public function getMetadata($key = null) |
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313 | |||
314 | /** |
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315 | * Closes the stream on destroy |
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316 | */ |
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317 | public function __destruct() |
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321 | } |