/
VarCloner.php
324 lines (302 loc) · 14.1 KB
/
VarCloner.php
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<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\VarDumper\Cloner;
/**
* @author Nicolas Grekas <p@tchwork.com>
*/
class VarCloner extends AbstractCloner
{
private static $hashMask = 0;
private static $hashOffset = 0;
/**
* {@inheritdoc}
*/
protected function doClone($var)
{
$useExt = $this->useExt;
$i = 0; // Current iteration position in $queue
$len = 1; // Length of $queue
$pos = 0; // Number of cloned items past the first level
$refsCounter = 0; // Hard references counter
$queue = array(array($var)); // This breadth-first queue is the return value
$arrayRefs = array(); // Map of queue indexes to stub array objects
$hardRefs = array(); // Map of original zval hashes to stub objects
$objRefs = array(); // Map of original object handles to their stub object couterpart
$resRefs = array(); // Map of original resource handles to their stub object couterpart
$values = array(); // Map of stub objects' hashes to original values
$maxItems = $this->maxItems;
$maxString = $this->maxString;
$cookie = (object) array(); // Unique object used to detect hard references
$gid = uniqid(mt_rand(), true); // Unique string used to detect the special $GLOBALS variable
$a = null; // Array cast for nested structures
$stub = null; // Stub capturing the main properties of an original item value
// or null if the original value is used directly
$zval = array( // Main properties of the current value
'type' => null,
'zval_isref' => null,
'zval_hash' => null,
'array_count' => null,
'object_class' => null,
'object_handle' => null,
'resource_type' => null,
);
if (!self::$hashMask) {
self::initHashMask();
}
$hashMask = self::$hashMask;
$hashOffset = self::$hashOffset;
for ($i = 0; $i < $len; ++$i) {
$indexed = true; // Whether the currently iterated array is numerically indexed or not
$j = -1; // Position in the currently iterated array
$fromObjCast = array_keys($queue[$i]);
$fromObjCast = array_keys(array_flip($fromObjCast)) !== $fromObjCast;
$refs = $vals = $fromObjCast ? array_values($queue[$i]) : $queue[$i];
foreach ($queue[$i] as $k => $v) {
// $k is the original key
// $v is the original value or a stub object in case of hard references
if ($k !== ++$j) {
$indexed = false;
}
if ($fromObjCast) {
$k = $j;
}
if ($useExt) {
$zval = symfony_zval_info($k, $refs);
} else {
$refs[$k] = $cookie;
if ($zval['zval_isref'] = $vals[$k] === $cookie) {
$zval['zval_hash'] = $v instanceof Stub ? spl_object_hash($v) : null;
}
$zval['type'] = gettype($v);
}
if ($zval['zval_isref']) {
$vals[$k] = &$stub; // Break hard references to make $queue completely
unset($stub); // independent from the original structure
if (isset($hardRefs[$zval['zval_hash']])) {
$vals[$k] = $useExt ? ($v = $hardRefs[$zval['zval_hash']]) : ($refs[$k] = $v);
if ($v->value instanceof Stub && (Stub::TYPE_OBJECT === $v->value->type || Stub::TYPE_RESOURCE === $v->value->type)) {
++$v->value->refCount;
}
++$v->refCount;
continue;
}
}
// Create $stub when the original value $v can not be used directly
// If $v is a nested structure, put that structure in array $a
switch ($zval['type']) {
case 'string':
if (isset($v[0]) && !preg_match('//u', $v)) {
$stub = new Stub();
$stub->type = Stub::TYPE_STRING;
$stub->class = Stub::STRING_BINARY;
if (0 <= $maxString && 0 < $cut = strlen($v) - $maxString) {
$stub->cut = $cut;
$stub->value = substr($v, 0, -$cut);
} else {
$stub->value = $v;
}
} elseif (0 <= $maxString && isset($v[1 + ($maxString >> 2)]) && 0 < $cut = mb_strlen($v, 'UTF-8') - $maxString) {
$stub = new Stub();
$stub->type = Stub::TYPE_STRING;
$stub->class = Stub::STRING_UTF8;
$stub->cut = $cut;
$stub->value = mb_substr($v, 0, $maxString, 'UTF-8');
}
break;
case 'integer':
break;
case 'array':
if ($v) {
$stub = $arrayRefs[$len] = new Stub();
$stub->type = Stub::TYPE_ARRAY;
$stub->class = Stub::ARRAY_ASSOC;
// Copies of $GLOBALS have very strange behavior,
// let's detect them with some black magic
$a = $v;
$a[$gid] = true;
// Happens with copies of $GLOBALS
if (isset($v[$gid])) {
unset($v[$gid]);
$a = array();
foreach ($v as $gk => &$gv) {
$a[$gk] = &$gv;
}
} else {
$a = $v;
}
$stub->value = $zval['array_count'] ?: count($a);
}
break;
case 'object':
if (empty($objRefs[$h = $zval['object_handle'] ?: ($hashMask ^ hexdec(substr(spl_object_hash($v), $hashOffset, PHP_INT_SIZE)))])) {
$stub = new Stub();
$stub->type = Stub::TYPE_OBJECT;
$stub->class = $zval['object_class'] ?: get_class($v);
$stub->value = $v;
$stub->handle = $h;
$a = $this->castObject($stub, 0 < $i);
if ($v !== $stub->value) {
if (Stub::TYPE_OBJECT !== $stub->type || null === $stub->value) {
break;
}
if ($useExt) {
$zval['type'] = $stub->value;
$zval = symfony_zval_info('type', $zval);
$h = $zval['object_handle'];
} else {
$h = $hashMask ^ hexdec(substr(spl_object_hash($stub->value), $hashOffset, PHP_INT_SIZE));
}
$stub->handle = $h;
}
$stub->value = null;
if (0 <= $maxItems && $maxItems <= $pos) {
$stub->cut = count($a);
$a = null;
}
}
if (empty($objRefs[$h])) {
$objRefs[$h] = $stub;
} else {
$stub = $objRefs[$h];
++$stub->refCount;
$a = null;
}
break;
case 'resource':
case 'unknown type':
if (empty($resRefs[$h = (int) $v])) {
$stub = new Stub();
$stub->type = Stub::TYPE_RESOURCE;
$stub->class = $zval['resource_type'] ?: get_resource_type($v);
$stub->value = $v;
$stub->handle = $h;
$a = $this->castResource($stub, 0 < $i);
$stub->value = null;
if (0 <= $maxItems && $maxItems <= $pos) {
$stub->cut = count($a);
$a = null;
}
}
if (empty($resRefs[$h])) {
$resRefs[$h] = $stub;
} else {
$stub = $resRefs[$h];
++$stub->refCount;
$a = null;
}
break;
}
if (isset($stub)) {
if ($zval['zval_isref']) {
if ($useExt) {
$vals[$k] = $hardRefs[$zval['zval_hash']] = $v = new Stub();
$v->value = $stub;
} else {
$refs[$k] = new Stub();
$refs[$k]->value = $stub;
$h = spl_object_hash($refs[$k]);
$vals[$k] = $hardRefs[$h] = &$refs[$k];
$values[$h] = $v;
}
$vals[$k]->handle = ++$refsCounter;
} else {
$vals[$k] = $stub;
}
if ($a) {
if ($i && 0 <= $maxItems) {
$k = count($a);
if ($pos < $maxItems) {
if ($maxItems < $pos += $k) {
$a = array_slice($a, 0, $maxItems - $pos);
if ($stub->cut >= 0) {
$stub->cut += $pos - $maxItems;
}
}
} else {
if ($stub->cut >= 0) {
$stub->cut += $k;
}
$stub = $a = null;
unset($arrayRefs[$len]);
continue;
}
}
$queue[$len] = $a;
$stub->position = $len++;
}
$stub = $a = null;
} elseif ($zval['zval_isref']) {
if ($useExt) {
$vals[$k] = $hardRefs[$zval['zval_hash']] = new Stub();
$vals[$k]->value = $v;
} else {
$refs[$k] = $vals[$k] = new Stub();
$refs[$k]->value = $v;
$h = spl_object_hash($refs[$k]);
$hardRefs[$h] = &$refs[$k];
$values[$h] = $v;
}
$vals[$k]->handle = ++$refsCounter;
}
}
if ($fromObjCast) {
$refs = $vals;
$vals = array();
$j = -1;
foreach ($queue[$i] as $k => $v) {
foreach (array($k => $v) as $a => $v) {
}
if ($a !== $k) {
$vals = (object) $vals;
$vals->{$k} = $refs[++$j];
$vals = (array) $vals;
} else {
$vals[$k] = $refs[++$j];
}
}
}
$queue[$i] = $vals;
if (isset($arrayRefs[$i])) {
if ($indexed) {
$arrayRefs[$i]->class = Stub::ARRAY_INDEXED;
}
unset($arrayRefs[$i]);
}
}
foreach ($values as $h => $v) {
$hardRefs[$h] = $v;
}
return $queue;
}
private static function initHashMask()
{
$obj = (object) array();
self::$hashOffset = 16 - PHP_INT_SIZE;
self::$hashMask = -1;
if (defined('HHVM_VERSION')) {
self::$hashOffset += 16;
} else {
// check if we are nested in an output buffering handler to prevent a fatal error with ob_start() below
$obFuncs = array('ob_clean', 'ob_end_clean', 'ob_flush', 'ob_end_flush', 'ob_get_contents', 'ob_get_flush');
foreach (debug_backtrace(PHP_VERSION_ID >= 50400 ? DEBUG_BACKTRACE_IGNORE_ARGS : false) as $frame) {
if (isset($frame['function'][0]) && !isset($frame['class']) && 'o' === $frame['function'][0] && in_array($frame['function'], $obFuncs)) {
$frame['line'] = 0;
break;
}
}
if (!empty($frame['line'])) {
ob_start();
debug_zval_dump($obj);
self::$hashMask = (int) substr(ob_get_clean(), 17);
}
}
self::$hashMask ^= hexdec(substr(spl_object_hash($obj), self::$hashOffset, PHP_INT_SIZE));
}
}