VarCloner.php 13 KB

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  1. <?php
  2. /*
  3. * This file is part of the Symfony package.
  4. *
  5. * (c) Fabien Potencier <fabien@symfony.com>
  6. *
  7. * For the full copyright and license information, please view the LICENSE
  8. * file that was distributed with this source code.
  9. */
  10. namespace Symfony\Component\VarDumper\Cloner;
  11. /**
  12. * @author Nicolas Grekas <p@tchwork.com>
  13. */
  14. class VarCloner extends AbstractCloner
  15. {
  16. private static $gid;
  17. private static $arrayCache = [];
  18. /**
  19. * {@inheritdoc}
  20. */
  21. protected function doClone($var)
  22. {
  23. $len = 1; // Length of $queue
  24. $pos = 0; // Number of cloned items past the minimum depth
  25. $refsCounter = 0; // Hard references counter
  26. $queue = [[$var]]; // This breadth-first queue is the return value
  27. $indexedArrays = []; // Map of queue indexes that hold numerically indexed arrays
  28. $hardRefs = []; // Map of original zval ids to stub objects
  29. $objRefs = []; // Map of original object handles to their stub object counterpart
  30. $objects = []; // Keep a ref to objects to ensure their handle cannot be reused while cloning
  31. $resRefs = []; // Map of original resource handles to their stub object counterpart
  32. $values = []; // Map of stub objects' ids to original values
  33. $maxItems = $this->maxItems;
  34. $maxString = $this->maxString;
  35. $minDepth = $this->minDepth;
  36. $currentDepth = 0; // Current tree depth
  37. $currentDepthFinalIndex = 0; // Final $queue index for current tree depth
  38. $minimumDepthReached = 0 === $minDepth; // Becomes true when minimum tree depth has been reached
  39. $cookie = (object) []; // Unique object used to detect hard references
  40. $a = null; // Array cast for nested structures
  41. $stub = null; // Stub capturing the main properties of an original item value
  42. // or null if the original value is used directly
  43. if (!$gid = self::$gid) {
  44. $gid = self::$gid = md5(random_bytes(6)); // Unique string used to detect the special $GLOBALS variable
  45. }
  46. $arrayStub = new Stub();
  47. $arrayStub->type = Stub::TYPE_ARRAY;
  48. $fromObjCast = false;
  49. for ($i = 0; $i < $len; ++$i) {
  50. // Detect when we move on to the next tree depth
  51. if ($i > $currentDepthFinalIndex) {
  52. ++$currentDepth;
  53. $currentDepthFinalIndex = $len - 1;
  54. if ($currentDepth >= $minDepth) {
  55. $minimumDepthReached = true;
  56. }
  57. }
  58. $refs = $vals = $queue[$i];
  59. if (\PHP_VERSION_ID < 70200 && empty($indexedArrays[$i])) {
  60. // see https://wiki.php.net/rfc/convert_numeric_keys_in_object_array_casts
  61. foreach ($vals as $k => $v) {
  62. if (\is_int($k)) {
  63. continue;
  64. }
  65. foreach ([$k => true] as $gk => $gv) {
  66. }
  67. if ($gk !== $k) {
  68. $fromObjCast = true;
  69. $refs = $vals = array_values($queue[$i]);
  70. break;
  71. }
  72. }
  73. }
  74. foreach ($vals as $k => $v) {
  75. // $v is the original value or a stub object in case of hard references
  76. if (\PHP_VERSION_ID >= 70400) {
  77. $zvalIsRef = null !== \ReflectionReference::fromArrayElement($vals, $k);
  78. } else {
  79. $refs[$k] = $cookie;
  80. $zvalIsRef = $vals[$k] === $cookie;
  81. }
  82. if ($zvalIsRef) {
  83. $vals[$k] = &$stub; // Break hard references to make $queue completely
  84. unset($stub); // independent from the original structure
  85. if ($v instanceof Stub && isset($hardRefs[spl_object_id($v)])) {
  86. $vals[$k] = $refs[$k] = $v;
  87. if ($v->value instanceof Stub && (Stub::TYPE_OBJECT === $v->value->type || Stub::TYPE_RESOURCE === $v->value->type)) {
  88. ++$v->value->refCount;
  89. }
  90. ++$v->refCount;
  91. continue;
  92. }
  93. $refs[$k] = $vals[$k] = new Stub();
  94. $refs[$k]->value = $v;
  95. $h = spl_object_id($refs[$k]);
  96. $hardRefs[$h] = &$refs[$k];
  97. $values[$h] = $v;
  98. $vals[$k]->handle = ++$refsCounter;
  99. }
  100. // Create $stub when the original value $v can not be used directly
  101. // If $v is a nested structure, put that structure in array $a
  102. switch (true) {
  103. case null === $v:
  104. case \is_bool($v):
  105. case \is_int($v):
  106. case \is_float($v):
  107. continue 2;
  108. case \is_string($v):
  109. if ('' === $v) {
  110. continue 2;
  111. }
  112. if (!preg_match('//u', $v)) {
  113. $stub = new Stub();
  114. $stub->type = Stub::TYPE_STRING;
  115. $stub->class = Stub::STRING_BINARY;
  116. if (0 <= $maxString && 0 < $cut = \strlen($v) - $maxString) {
  117. $stub->cut = $cut;
  118. $stub->value = substr($v, 0, -$cut);
  119. } else {
  120. $stub->value = $v;
  121. }
  122. } elseif (0 <= $maxString && isset($v[1 + ($maxString >> 2)]) && 0 < $cut = mb_strlen($v, 'UTF-8') - $maxString) {
  123. $stub = new Stub();
  124. $stub->type = Stub::TYPE_STRING;
  125. $stub->class = Stub::STRING_UTF8;
  126. $stub->cut = $cut;
  127. $stub->value = mb_substr($v, 0, $maxString, 'UTF-8');
  128. } else {
  129. continue 2;
  130. }
  131. $a = null;
  132. break;
  133. case \is_array($v):
  134. if (!$v) {
  135. continue 2;
  136. }
  137. $stub = $arrayStub;
  138. $stub->class = Stub::ARRAY_INDEXED;
  139. $j = -1;
  140. foreach ($v as $gk => $gv) {
  141. if ($gk !== ++$j) {
  142. $stub->class = Stub::ARRAY_ASSOC;
  143. break;
  144. }
  145. }
  146. $a = $v;
  147. if (Stub::ARRAY_ASSOC === $stub->class) {
  148. // Copies of $GLOBALS have very strange behavior,
  149. // let's detect them with some black magic
  150. if (\PHP_VERSION_ID < 80100 && ($a[$gid] = true) && isset($v[$gid])) {
  151. unset($v[$gid]);
  152. $a = [];
  153. foreach ($v as $gk => &$gv) {
  154. if ($v === $gv) {
  155. unset($v);
  156. $v = new Stub();
  157. $v->value = [$v->cut = \count($gv), Stub::TYPE_ARRAY => 0];
  158. $v->handle = -1;
  159. $gv = &$hardRefs[spl_object_id($v)];
  160. $gv = $v;
  161. }
  162. $a[$gk] = &$gv;
  163. }
  164. unset($gv);
  165. } else {
  166. $a = $v;
  167. }
  168. } elseif (\PHP_VERSION_ID < 70200) {
  169. $indexedArrays[$len] = true;
  170. }
  171. break;
  172. case \is_object($v):
  173. case $v instanceof \__PHP_Incomplete_Class:
  174. if (empty($objRefs[$h = spl_object_id($v)])) {
  175. $stub = new Stub();
  176. $stub->type = Stub::TYPE_OBJECT;
  177. $stub->class = \get_class($v);
  178. $stub->value = $v;
  179. $stub->handle = $h;
  180. $a = $this->castObject($stub, 0 < $i);
  181. if ($v !== $stub->value) {
  182. if (Stub::TYPE_OBJECT !== $stub->type || null === $stub->value) {
  183. break;
  184. }
  185. $stub->handle = $h = spl_object_id($stub->value);
  186. }
  187. $stub->value = null;
  188. if (0 <= $maxItems && $maxItems <= $pos && $minimumDepthReached) {
  189. $stub->cut = \count($a);
  190. $a = null;
  191. }
  192. }
  193. if (empty($objRefs[$h])) {
  194. $objRefs[$h] = $stub;
  195. $objects[] = $v;
  196. } else {
  197. $stub = $objRefs[$h];
  198. ++$stub->refCount;
  199. $a = null;
  200. }
  201. break;
  202. default: // resource
  203. if (empty($resRefs[$h = (int) $v])) {
  204. $stub = new Stub();
  205. $stub->type = Stub::TYPE_RESOURCE;
  206. if ('Unknown' === $stub->class = @get_resource_type($v)) {
  207. $stub->class = 'Closed';
  208. }
  209. $stub->value = $v;
  210. $stub->handle = $h;
  211. $a = $this->castResource($stub, 0 < $i);
  212. $stub->value = null;
  213. if (0 <= $maxItems && $maxItems <= $pos && $minimumDepthReached) {
  214. $stub->cut = \count($a);
  215. $a = null;
  216. }
  217. }
  218. if (empty($resRefs[$h])) {
  219. $resRefs[$h] = $stub;
  220. } else {
  221. $stub = $resRefs[$h];
  222. ++$stub->refCount;
  223. $a = null;
  224. }
  225. break;
  226. }
  227. if ($a) {
  228. if (!$minimumDepthReached || 0 > $maxItems) {
  229. $queue[$len] = $a;
  230. $stub->position = $len++;
  231. } elseif ($pos < $maxItems) {
  232. if ($maxItems < $pos += \count($a)) {
  233. $a = \array_slice($a, 0, $maxItems - $pos, true);
  234. if ($stub->cut >= 0) {
  235. $stub->cut += $pos - $maxItems;
  236. }
  237. }
  238. $queue[$len] = $a;
  239. $stub->position = $len++;
  240. } elseif ($stub->cut >= 0) {
  241. $stub->cut += \count($a);
  242. $stub->position = 0;
  243. }
  244. }
  245. if ($arrayStub === $stub) {
  246. if ($arrayStub->cut) {
  247. $stub = [$arrayStub->cut, $arrayStub->class => $arrayStub->position];
  248. $arrayStub->cut = 0;
  249. } elseif (isset(self::$arrayCache[$arrayStub->class][$arrayStub->position])) {
  250. $stub = self::$arrayCache[$arrayStub->class][$arrayStub->position];
  251. } else {
  252. self::$arrayCache[$arrayStub->class][$arrayStub->position] = $stub = [$arrayStub->class => $arrayStub->position];
  253. }
  254. }
  255. if ($zvalIsRef) {
  256. $refs[$k]->value = $stub;
  257. } else {
  258. $vals[$k] = $stub;
  259. }
  260. }
  261. if ($fromObjCast) {
  262. $fromObjCast = false;
  263. $refs = $vals;
  264. $vals = [];
  265. $j = -1;
  266. foreach ($queue[$i] as $k => $v) {
  267. foreach ([$k => true] as $gk => $gv) {
  268. }
  269. if ($gk !== $k) {
  270. $vals = (object) $vals;
  271. $vals->{$k} = $refs[++$j];
  272. $vals = (array) $vals;
  273. } else {
  274. $vals[$k] = $refs[++$j];
  275. }
  276. }
  277. }
  278. $queue[$i] = $vals;
  279. }
  280. foreach ($values as $h => $v) {
  281. $hardRefs[$h] = $v;
  282. }
  283. return $queue;
  284. }
  285. }