Complex classes like Profile 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 Profile, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 15 | class Profile |
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| 16 | { |
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| 17 | /** |
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| 18 | * @const Key used for methods with no parent |
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| 19 | */ |
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| 20 | private const NO_PARENT = '__xhgui_top__'; |
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| 21 | |||
| 22 | private $data; |
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| 23 | private $collapsed; |
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| 24 | private $indexed; |
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| 25 | private $visited; |
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| 26 | private $links; |
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| 27 | private $nodes; |
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| 28 | |||
| 29 | private $keys = ['ct', 'wt', 'cpu', 'mu', 'pmu']; |
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| 30 | private $exclusiveKeys = ['ewt', 'ecpu', 'emu', 'epmu']; |
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| 31 | private $functionCount; |
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| 32 | |||
| 33 | public function __construct(array $profile, $convert = true) |
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| 46 | |||
| 47 | /** |
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| 48 | * Convert the raw data into a flatter list that is easier to use. |
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| 49 | * |
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| 50 | * This removes some of the parentage detail as all calls of a given |
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| 51 | * method are aggregated. We are not able to maintain a full tree structure |
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| 52 | * in any case, as xhprof only keeps one level of detail. |
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| 53 | */ |
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| 54 | private function process(): void |
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| 55 | { |
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| 56 | $result = []; |
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| 57 | foreach ($this->data['profile'] as $name => $values) { |
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| 58 | [$parent, $func] = $this->splitName($name); |
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| 59 | // normalize, fill all missing keys |
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| 60 | $values += [ |
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| 61 | 'ct' => 0, |
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| 62 | 'wt' => 0, |
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| 63 | 'cpu' => 0, |
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| 64 | 'mu' => 0, |
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| 65 | 'pmu' => 0, |
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| 66 | ]; |
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| 67 | |||
| 68 | // Generate collapsed data. |
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| 69 | if (isset($result[$func])) { |
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| 70 | $result[$func] = $this->_sumKeys($result[$func], $values); |
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| 71 | $result[$func]['parents'][] = $parent; |
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| 72 | } else { |
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| 73 | $result[$func] = $values; |
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| 74 | $result[$func]['parents'] = [$parent]; |
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| 75 | } |
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| 76 | |||
| 77 | // Build the indexed data. |
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| 78 | if ($parent === null) { |
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| 79 | $parent = self::NO_PARENT; |
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| 80 | } |
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| 81 | if (!isset($this->indexed[$parent])) { |
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| 82 | $this->indexed[$parent] = []; |
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| 83 | } |
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| 84 | $this->indexed[$parent][$func] = $values; |
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| 85 | } |
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| 86 | $this->collapsed = $result; |
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| 87 | } |
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| 88 | |||
| 89 | /** |
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| 90 | * Sum up the values in $this->_keys; |
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| 91 | * |
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| 92 | * @param array $a The first set of profile data |
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| 93 | * @param array $b the second set of profile data |
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| 94 | * @return array merged profile data |
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| 95 | */ |
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| 96 | protected function _sumKeys($a, $b) |
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| 107 | |||
| 108 | protected function _diffKeys($a, $b, $includeSelf = true) |
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| 120 | |||
| 121 | protected function _diffPercentKeys($a, $b, $includeSelf = true) |
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| 138 | |||
| 139 | /** |
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| 140 | * Get the profile run data. |
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| 141 | * |
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| 142 | * TODO remove this and move all the features using it into this/ |
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| 143 | * other classes. |
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| 144 | * |
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| 145 | * @return array |
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| 146 | */ |
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| 147 | public function getProfile() |
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| 151 | |||
| 152 | public function getId() |
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| 156 | |||
| 157 | public function getDate() |
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| 166 | |||
| 167 | /** |
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| 168 | * Get meta data about the profile. Read's a . split path |
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| 169 | * out of the meta data in a profile. For example `SERVER.REQUEST_TIME` |
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| 170 | * |
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| 171 | * @param string $key the dotted key to read |
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| 172 | * @return mixed|null null on failure, otherwise the stored value |
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| 173 | */ |
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| 174 | public function getMeta($key = null) |
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| 191 | |||
| 192 | /** |
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| 193 | * Read data from the profile run. |
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| 194 | * |
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| 195 | * @param string $key the function key name to read |
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| 196 | * @param string $metric the metric to read |
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| 197 | * @return float|null |
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| 198 | */ |
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| 199 | public function get($key, $metric = null) |
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| 213 | |||
| 214 | /** |
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| 215 | * Find a function matching a watched function. |
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| 216 | * |
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| 217 | * @param string $pattern the pattern to look for |
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| 218 | * @return array|null an list of matching functions |
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| 219 | * or null |
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| 220 | */ |
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| 221 | public function getWatched($pattern) |
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| 241 | |||
| 242 | /** |
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| 243 | * Find the parent and children method/functions for a given |
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| 244 | * symbol. |
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| 245 | * |
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| 246 | * The parent/children arrays will contain all the callers + callees |
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| 247 | * of the symbol given. The current index will give the total |
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| 248 | * inclusive values for all properties. |
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| 249 | * |
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| 250 | * @param string $symbol the name of the function/method to find |
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| 251 | * relatives for |
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| 252 | * @param string $metric the metric to compare $threshold with |
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| 253 | * @param float $threshold The threshold to exclude child functions at. Any |
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| 254 | * function that represents less than this percentage of the current metric |
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| 255 | * will be filtered out. |
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| 256 | * @return array List of (parent, current, children) |
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| 257 | */ |
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| 258 | public function getRelatives($symbol, $metric = null, $threshold = 0) |
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| 278 | |||
| 279 | /** |
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| 280 | * Get the parent methods for a given symbol. |
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| 281 | * |
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| 282 | * @param string $symbol the name of the function/method to find |
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| 283 | * parents for |
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| 284 | * @return array List of parents |
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| 285 | */ |
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| 286 | protected function _getParents($symbol) |
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| 298 | |||
| 299 | /** |
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| 300 | * Find symbols that are the children of the given name. |
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| 301 | * |
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| 302 | * @param string $symbol the name of the function to find children of |
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| 303 | * @param string $metric the metric to compare $threshold with |
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| 304 | * @param float $threshold The threshold to exclude functions at. Any |
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| 305 | * function that represents less than |
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| 306 | * @return array an array of child methods |
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| 307 | */ |
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| 308 | protected function _getChildren($symbol, $metric = null, $threshold = 0) |
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| 335 | |||
| 336 | /** |
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| 337 | * Extracts a single dimension of data |
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| 338 | * from a profile run. |
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| 339 | * |
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| 340 | * Useful for creating bar/column graphs. |
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| 341 | * The profile data will be sorted by the column |
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| 342 | * and then the $limit records will be extracted. |
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| 343 | * |
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| 344 | * @param string $dimension The dimension to extract |
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| 345 | * @param int $limit Number of elements to pull |
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| 346 | * @return array array of data with name = function name and |
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| 347 | * value = the dimension |
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| 348 | */ |
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| 349 | public function extractDimension($dimension, $limit) |
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| 363 | |||
| 364 | /** |
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| 365 | * Generate the approximate exclusive values for each metric. |
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| 366 | * |
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| 367 | * We get a==>b as the name, we need a key for a and b in the array |
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| 368 | * to get exclusive values for A we need to subtract the values of B (and any other children); |
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| 369 | * call passing in the entire profile only, should return an array of |
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| 370 | * functions with their regular timing, and exclusive numbers inside ['exclusive'] |
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| 371 | * |
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| 372 | * Consider: |
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| 373 | * /---c---d---e |
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| 374 | * a -/----b---d---e |
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| 375 | * |
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| 376 | * We have c==>d and b==>d, and in both instances d invokes e, yet we will |
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| 377 | * have but a single d==>e result. This is a known and documented limitation of XHProf |
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| 378 | * |
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| 379 | * We have one d==>e entry, with some values, including ct=2 |
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| 380 | * We also have c==>d and b==>d |
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| 381 | * |
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| 382 | * We should determine how many ==>d options there are, and equally |
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| 383 | * split the cost of d==>e across them since d==>e represents the sum total of all calls. |
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| 384 | * |
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| 385 | * Notes: |
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| 386 | * Function names are not unique, but we're merging them |
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| 387 | * |
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| 388 | * @return Profile a new instance with exclusive data set |
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| 389 | */ |
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| 390 | public function calculateSelf() |
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| 417 | |||
| 418 | /** |
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| 419 | * Sort data by a dimension. |
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| 420 | * |
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| 421 | * @param string $dimension the dimension to sort by |
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| 422 | * @param array $data the data to sort |
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| 423 | * @return array the sorted data |
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| 424 | */ |
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| 425 | public function sort($dimension, $data) |
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| 438 | |||
| 439 | /** |
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| 440 | * @param array $profileData |
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| 441 | * @param array $filters |
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| 442 | * |
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| 443 | * @return array |
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| 444 | */ |
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| 445 | public function filter($profileData, $filters = []) |
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| 457 | |||
| 458 | /** |
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| 459 | * Split a key name into the parent==>child format. |
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| 460 | * |
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| 461 | * @param string $name the name to split |
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| 462 | * @return array An array of parent, child. parent will be null if there |
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| 463 | * is no parent. |
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| 464 | */ |
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| 465 | public function splitName($name) |
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| 474 | |||
| 475 | /** |
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| 476 | * Get the total number of tracked function calls in this run. |
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| 477 | * |
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| 478 | * @return int |
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| 479 | */ |
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| 480 | public function getFunctionCount() |
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| 493 | |||
| 494 | /** |
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| 495 | * Compare this run to another run. |
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| 496 | * |
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| 497 | * @param Profile $head The other run to compare with |
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| 498 | * @return array an array of comparison data |
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| 499 | */ |
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| 500 | public function compare(self $head) |
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| 533 | |||
| 534 | /** |
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| 535 | * Get the max value for any give metric. |
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| 536 | * |
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| 537 | * @param string $metric the metric to get a max value for |
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| 538 | */ |
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| 539 | protected function _maxValue($metric) |
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| 553 | |||
| 554 | /** |
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| 555 | * Return a structured array suitable for generating callgraph visualizations. |
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| 556 | * |
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| 557 | * Functions whose inclusive time is less than 2% of the total time will |
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| 558 | * be excluded from the callgraph data. |
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| 559 | * |
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| 560 | * @return array |
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| 561 | */ |
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| 562 | public function getCallgraph($metric = 'wt', $threshold = 0.01) |
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| 589 | |||
| 590 | protected function _callgraphData($parentName, $main, $metric, $threshold, $parentIndex = null): void |
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| 636 | |||
| 637 | public function toArray() |
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| 641 | } |
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| 642 |
If you define a variable conditionally, it can happen that it is not defined for all execution paths.
Let’s take a look at an example:
In the above example, the variable $x is defined if you pass “foo” or “bar” as argument for $a. However, since the switch statement has no default case statement, if you pass any other value, the variable $x would be undefined.
Available Fixes
Check for existence of the variable explicitly:
Define a default value for the variable:
Add a value for the missing path: