Chris@0: <?php
Chris@0: /*
Chris@0:  * This file is part of the Recursion Context package.
Chris@0:  *
Chris@0:  * (c) Sebastian Bergmann <sebastian@phpunit.de>
Chris@0:  *
Chris@0:  * For the full copyright and license information, please view the LICENSE
Chris@0:  * file that was distributed with this source code.
Chris@0:  */
Chris@0: 
Chris@0: namespace SebastianBergmann\RecursionContext;
Chris@0: 
Chris@0: /**
Chris@0:  * A context containing previously processed arrays and objects
Chris@0:  * when recursively processing a value.
Chris@0:  */
Chris@0: final class Context
Chris@0: {
Chris@0:     /**
Chris@0:      * @var array[]
Chris@0:      */
Chris@0:     private $arrays;
Chris@0: 
Chris@0:     /**
Chris@0:      * @var \SplObjectStorage
Chris@0:      */
Chris@0:     private $objects;
Chris@0: 
Chris@0:     /**
Chris@0:      * Initialises the context
Chris@0:      */
Chris@0:     public function __construct()
Chris@0:     {
Chris@0:         $this->arrays  = array();
Chris@0:         $this->objects = new \SplObjectStorage;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Adds a value to the context.
Chris@0:      *
Chris@0:      * @param array|object $value The value to add.
Chris@0:      *
Chris@0:      * @return int|string The ID of the stored value, either as a string or integer.
Chris@0:      *
Chris@0:      * @throws InvalidArgumentException Thrown if $value is not an array or object
Chris@0:      */
Chris@0:     public function add(&$value)
Chris@0:     {
Chris@0:         if (is_array($value)) {
Chris@0:             return $this->addArray($value);
Chris@0:         } elseif (is_object($value)) {
Chris@0:             return $this->addObject($value);
Chris@0:         }
Chris@0: 
Chris@0:         throw new InvalidArgumentException(
Chris@0:             'Only arrays and objects are supported'
Chris@0:         );
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Checks if the given value exists within the context.
Chris@0:      *
Chris@0:      * @param array|object $value The value to check.
Chris@0:      *
Chris@0:      * @return int|string|false The string or integer ID of the stored value if it has already been seen, or false if the value is not stored.
Chris@0:      *
Chris@0:      * @throws InvalidArgumentException Thrown if $value is not an array or object
Chris@0:      */
Chris@0:     public function contains(&$value)
Chris@0:     {
Chris@0:         if (is_array($value)) {
Chris@0:             return $this->containsArray($value);
Chris@0:         } elseif (is_object($value)) {
Chris@0:             return $this->containsObject($value);
Chris@0:         }
Chris@0: 
Chris@0:         throw new InvalidArgumentException(
Chris@0:             'Only arrays and objects are supported'
Chris@0:         );
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @param array $array
Chris@0:      *
Chris@0:      * @return bool|int
Chris@0:      */
Chris@0:     private function addArray(array &$array)
Chris@0:     {
Chris@0:         $key = $this->containsArray($array);
Chris@0: 
Chris@0:         if ($key !== false) {
Chris@0:             return $key;
Chris@0:         }
Chris@0: 
Chris@14:         $key            = count($this->arrays);
Chris@0:         $this->arrays[] = &$array;
Chris@0: 
Chris@14:         if (!isset($array[PHP_INT_MAX]) && !isset($array[PHP_INT_MAX - 1])) {
Chris@14:             $array[] = $key;
Chris@14:             $array[] = $this->objects;
Chris@14:         } else { /* cover the improbable case too */
Chris@14:             do {
Chris@14:                 $key = random_int(PHP_INT_MIN, PHP_INT_MAX);
Chris@14:             } while (isset($array[$key]));
Chris@14: 
Chris@14:             $array[$key] = $key;
Chris@14: 
Chris@14:             do {
Chris@14:                 $key = random_int(PHP_INT_MIN, PHP_INT_MAX);
Chris@14:             } while (isset($array[$key]));
Chris@14: 
Chris@14:             $array[$key] = $this->objects;
Chris@14:         }
Chris@14: 
Chris@14:         return $key;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @param object $object
Chris@0:      *
Chris@0:      * @return string
Chris@0:      */
Chris@0:     private function addObject($object)
Chris@0:     {
Chris@0:         if (!$this->objects->contains($object)) {
Chris@0:             $this->objects->attach($object);
Chris@0:         }
Chris@0: 
Chris@0:         return spl_object_hash($object);
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @param array $array
Chris@0:      *
Chris@0:      * @return int|false
Chris@0:      */
Chris@0:     private function containsArray(array &$array)
Chris@0:     {
Chris@14:         $end = array_slice($array, -2);
Chris@0: 
Chris@14:         return isset($end[1]) && $end[1] === $this->objects ? $end[0] : false;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @param object $value
Chris@0:      *
Chris@0:      * @return string|false
Chris@0:      */
Chris@0:     private function containsObject($value)
Chris@0:     {
Chris@0:         if ($this->objects->contains($value)) {
Chris@0:             return spl_object_hash($value);
Chris@0:         }
Chris@0: 
Chris@0:         return false;
Chris@0:     }
Chris@14: 
Chris@14:     public function __destruct()
Chris@14:     {
Chris@14:         foreach ($this->arrays as &$array) {
Chris@14:             if (is_array($array)) {
Chris@14:                 array_pop($array);
Chris@14:                 array_pop($array);
Chris@14:             }
Chris@14:         }
Chris@14:     }
Chris@0: }