Test for ways of storing node types

NodeTypeTest.php

<?php

class Tree {
    public $left = null;
    public $right = null;
}

class Type {
    /** @var int */
    public $i = 0;
}

class Context {
    private $cache = [];
    
    public function getType(int $node_id) : ?Type
    {
        return $this->cache[$node_id] ?? null;
    }
    
    public function setType(int $node_id, Type $type) : void
    {
        $this->cache[$node_id] = $type;
    }
}

$tree1 = new Tree();
$tree2 = new Tree();
$tree3 = new Tree();

function branchTree(Tree $tree, int $i) : void {
    if (--$i < 0) {
        return;
    }
    
    $tree->left = new Tree;
    $tree->right = new Tree;
    
    branchTree($tree->left, $i);
    branchTree($tree->right, $i);
}

branchTree($tree1, 12);
branchTree($tree2, 12);
branchTree($tree3, 12);

function crawlTreeAddingProperty(Tree $tree) : void {
    if ($tree->left) {
        if (rand(0, 1)) $tree->left->type = new Type(rand(0, 100));
        crawlTreeAddingProperty($tree->left);
    }
    
    if ($tree->right) {
        if (rand(0, 1)) $tree->right->type = new Type(rand(0, 100));
        crawlTreeAddingProperty($tree->right);
    }
}

function crawlTreeCheckingProperty(Tree $tree) : void {
    if ($tree->left) {
        if (isset($tree->left->type) && $tree->left->type->i < 0) {
            echo 'never happens';
        }
        
        crawlTreeCheckingProperty($tree->left);
    }
    
    if ($tree->right) {
        if (isset($tree->right->type) && $tree->right->type->i < 0) {
            echo 'never happens';
        }
        
        crawlTreeCheckingProperty($tree->right);
    }
}

function crawlTreeSettingObjectStorage(Tree $tree, SplObjectStorage $types) : void {
    if ($tree->left) {
        if (rand(0, 1)) $types[$tree->left] = new Type(rand(0, 100));
        crawlTreeSettingObjectStorage($tree->left, $types);
    }
    
    if ($tree->right) {
        if (rand(0, 1)) $types[$tree->right] = new Type(rand(0, 100));
        crawlTreeSettingObjectStorage($tree->right, $types);
    }
}

function crawlTreeGettingObjectStorage(Tree $tree, SplObjectStorage $types) : void {
    if ($tree->left) {
        if (isset($types[$tree->left]) && $types[$tree->left]->i < 0) {
            echo 'never happens';
        }
        crawlTreeGettingObjectStorage($tree->left, $types);
    }
    
    if ($tree->right) {
        if (isset($types[$tree->right]) && $types[$tree->right]->i < 0) {
            echo 'never happens';
        }
        
        crawlTreeGettingObjectStorage($tree->right, $types);
    }
}

function crawlTreeSettingContext(Tree $tree, Context $context) : void {
    if ($tree->left) {
        if (rand(0, 1)) $context->setType(spl_object_id($tree->left), new Type(rand(0, 100)));
        crawlTreeSettingContext($tree->left, $context);
    }
    
    if ($tree->right) {
        if (rand(0, 1)) $context->setType(spl_object_id($tree->right), new Type(rand(0, 100)));
        crawlTreeSettingContext($tree->right, $context);
    }
}

function crawlTreeGettingContext(Tree $tree, Context $context) : void {
    if ($tree->left) {
        $type = $context->getType(spl_object_id($tree->left));
        if ($type !== null && $type->i < 0) {
            echo 'never happens';
        }
        crawlTreeGettingContext($tree->left, $context);
    }
    
    if ($tree->right) {
        $type = $context->getType(spl_object_id($tree->right));
        if ($type !== null && $type->i < 0) {
            echo 'never happens';
        }
        
        crawlTreeGettingContext($tree->right, $context);
    }
}

$time = microtime(true);
crawlTreeAddingProperty($tree1);
crawlTreeCheckingProperty($tree1);
echo 1000 * (microtime(true) - $time) . PHP_EOL;

$time = microtime(true);
$types = new SplObjectStorage();
crawlTreeSettingObjectStorage($tree2, $types);
crawlTreeGettingObjectStorage($tree2, $types);
echo 1000 * (microtime(true) - $time) . PHP_EOL;

$time = microtime(true);
$context = new Context();
crawlTreeSettingContext($tree3, $context);
crawlTreeGettingContext($tree3, $context);
echo 1000 * (microtime(true) - $time) . PHP_EOL;