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