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