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 = uniqid(mt_rand(), true); // 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. $refs[$k] = $cookie;
  77. if ($zvalIsRef = $vals[$k] === $cookie) {
  78. $vals[$k] = &$stub; // Break hard references to make $queue completely
  79. unset($stub); // independent from the original structure
  80. if ($v instanceof Stub && isset($hardRefs[\spl_object_id($v)])) {
  81. $vals[$k] = $refs[$k] = $v;
  82. if ($v->value instanceof Stub && (Stub::TYPE_OBJECT === $v->value->type || Stub::TYPE_RESOURCE === $v->value->type)) {
  83. ++$v->value->refCount;
  84. }
  85. ++$v->refCount;
  86. continue;
  87. }
  88. $refs[$k] = $vals[$k] = new Stub();
  89. $refs[$k]->value = $v;
  90. $h = \spl_object_id($refs[$k]);
  91. $hardRefs[$h] = &$refs[$k];
  92. $values[$h] = $v;
  93. $vals[$k]->handle = ++$refsCounter;
  94. }
  95. // Create $stub when the original value $v can not be used directly
  96. // If $v is a nested structure, put that structure in array $a
  97. switch (true) {
  98. case null === $v:
  99. case \is_bool($v):
  100. case \is_int($v):
  101. case \is_float($v):
  102. continue 2;
  103. case \is_string($v):
  104. if ('' === $v) {
  105. continue 2;
  106. }
  107. if (!\preg_match('//u', $v)) {
  108. $stub = new Stub();
  109. $stub->type = Stub::TYPE_STRING;
  110. $stub->class = Stub::STRING_BINARY;
  111. if (0 <= $maxString && 0 < $cut = \strlen($v) - $maxString) {
  112. $stub->cut = $cut;
  113. $stub->value = \substr($v, 0, -$cut);
  114. } else {
  115. $stub->value = $v;
  116. }
  117. } elseif (0 <= $maxString && isset($v[1 + ($maxString >> 2)]) && 0 < $cut = \mb_strlen($v, 'UTF-8') - $maxString) {
  118. $stub = new Stub();
  119. $stub->type = Stub::TYPE_STRING;
  120. $stub->class = Stub::STRING_UTF8;
  121. $stub->cut = $cut;
  122. $stub->value = \mb_substr($v, 0, $maxString, 'UTF-8');
  123. } else {
  124. continue 2;
  125. }
  126. $a = null;
  127. break;
  128. case \is_array($v):
  129. if (!$v) {
  130. continue 2;
  131. }
  132. $stub = $arrayStub;
  133. $stub->class = Stub::ARRAY_INDEXED;
  134. $j = -1;
  135. foreach ($v as $gk => $gv) {
  136. if ($gk !== ++$j) {
  137. $stub->class = Stub::ARRAY_ASSOC;
  138. break;
  139. }
  140. }
  141. $a = $v;
  142. if (Stub::ARRAY_ASSOC === $stub->class) {
  143. // Copies of $GLOBALS have very strange behavior,
  144. // let's detect them with some black magic
  145. $a[$gid] = true;
  146. // Happens with copies of $GLOBALS
  147. if (isset($v[$gid])) {
  148. unset($v[$gid]);
  149. $a = [];
  150. foreach ($v as $gk => &$gv) {
  151. $a[$gk] = &$gv;
  152. }
  153. unset($gv);
  154. } else {
  155. $a = $v;
  156. }
  157. } elseif (\PHP_VERSION_ID < 70200) {
  158. $indexedArrays[$len] = true;
  159. }
  160. break;
  161. case \is_object($v):
  162. case $v instanceof \__PHP_Incomplete_Class:
  163. if (empty($objRefs[$h = \spl_object_id($v)])) {
  164. $stub = new Stub();
  165. $stub->type = Stub::TYPE_OBJECT;
  166. $stub->class = \get_class($v);
  167. $stub->value = $v;
  168. $stub->handle = $h;
  169. $a = $this->castObject($stub, 0 < $i);
  170. if ($v !== $stub->value) {
  171. if (Stub::TYPE_OBJECT !== $stub->type || null === $stub->value) {
  172. break;
  173. }
  174. $stub->handle = $h = \spl_object_id($stub->value);
  175. }
  176. $stub->value = null;
  177. if (0 <= $maxItems && $maxItems <= $pos && $minimumDepthReached) {
  178. $stub->cut = \count($a);
  179. $a = null;
  180. }
  181. }
  182. if (empty($objRefs[$h])) {
  183. $objRefs[$h] = $stub;
  184. $objects[] = $v;
  185. } else {
  186. $stub = $objRefs[$h];
  187. ++$stub->refCount;
  188. $a = null;
  189. }
  190. break;
  191. default: // resource
  192. if (empty($resRefs[$h = (int) $v])) {
  193. $stub = new Stub();
  194. $stub->type = Stub::TYPE_RESOURCE;
  195. if ('Unknown' === $stub->class = @\get_resource_type($v)) {
  196. $stub->class = 'Closed';
  197. }
  198. $stub->value = $v;
  199. $stub->handle = $h;
  200. $a = $this->castResource($stub, 0 < $i);
  201. $stub->value = null;
  202. if (0 <= $maxItems && $maxItems <= $pos && $minimumDepthReached) {
  203. $stub->cut = \count($a);
  204. $a = null;
  205. }
  206. }
  207. if (empty($resRefs[$h])) {
  208. $resRefs[$h] = $stub;
  209. } else {
  210. $stub = $resRefs[$h];
  211. ++$stub->refCount;
  212. $a = null;
  213. }
  214. break;
  215. }
  216. if ($a) {
  217. if (!$minimumDepthReached || 0 > $maxItems) {
  218. $queue[$len] = $a;
  219. $stub->position = $len++;
  220. } elseif ($pos < $maxItems) {
  221. if ($maxItems < $pos += \count($a)) {
  222. $a = \array_slice($a, 0, $maxItems - $pos);
  223. if ($stub->cut >= 0) {
  224. $stub->cut += $pos - $maxItems;
  225. }
  226. }
  227. $queue[$len] = $a;
  228. $stub->position = $len++;
  229. } elseif ($stub->cut >= 0) {
  230. $stub->cut += \count($a);
  231. $stub->position = 0;
  232. }
  233. }
  234. if ($arrayStub === $stub) {
  235. if ($arrayStub->cut) {
  236. $stub = [$arrayStub->cut, $arrayStub->class => $arrayStub->position];
  237. $arrayStub->cut = 0;
  238. } elseif (isset(self::$arrayCache[$arrayStub->class][$arrayStub->position])) {
  239. $stub = self::$arrayCache[$arrayStub->class][$arrayStub->position];
  240. } else {
  241. self::$arrayCache[$arrayStub->class][$arrayStub->position] = $stub = [$arrayStub->class => $arrayStub->position];
  242. }
  243. }
  244. if ($zvalIsRef) {
  245. $refs[$k]->value = $stub;
  246. } else {
  247. $vals[$k] = $stub;
  248. }
  249. }
  250. if ($fromObjCast) {
  251. $fromObjCast = false;
  252. $refs = $vals;
  253. $vals = [];
  254. $j = -1;
  255. foreach ($queue[$i] as $k => $v) {
  256. foreach ([$k => true] as $gk => $gv) {
  257. }
  258. if ($gk !== $k) {
  259. $vals = (object) $vals;
  260. $vals->{$k} = $refs[++$j];
  261. $vals = (array) $vals;
  262. } else {
  263. $vals[$k] = $refs[++$j];
  264. }
  265. }
  266. }
  267. $queue[$i] = $vals;
  268. }
  269. foreach ($values as $h => $v) {
  270. $hardRefs[$h] = $v;
  271. }
  272. return $queue;
  273. }
  274. }