some modify for collection

Author: inhere

src/FixedArray.php

@@ -0,0 +1,199 @@
+<?php
+/**
+ * Created by PhpStorm.
+ * User: inhere
+ * Date: 2017-04-26
+ * Time: 9:18
+ */
+
+namespace Toolkit\ArrUtil;
+
+/**
+ * Class FixedArray
+ *  fixed size array implements, and support string key.
+ *  `SplFixedArray` only allow int key.
+ * @package Toolkit\ArrUtil
+ */
+class FixedArray implements \ArrayAccess, \IteratorAggregate
+{
+    /**
+     * @var array
+     * [
+     *  'string:key' => 'int:value index'
+     * ]
+     */
+    protected $keys;
+
+    /**
+     * @var \SplFixedArray
+     */
+    protected $values;
+
+    /**
+     * FixedArray constructor.
+     * @param int $size
+     */
+    public function __construct(int $size = 0)
+    {
+        $this->keys = [];
+        $this->values = new \SplFixedArray($size);
+    }
+
+    /**
+     * reset
+     * @param int $size
+     */
+    public function reset(int $size = 0)
+    {
+        $this->keys = [];
+        $this->values = new \SplFixedArray($size);
+    }
+
+    /**
+     * @param string $key
+     * @return bool
+     */
+    public function __isset(string $key)
+    {
+        return $this->offsetExists($key);
+    }
+
+    /**
+     * @param string $key
+     * @param mixed $value
+     */
+    public function __set(string $key, $value)
+    {
+        $this->offsetSet($key, $value);
+    }
+
+    /**
+     * @param string $key
+     * @return mixed
+     */
+    public function __get(string $key)
+    {
+        return $this->offsetGet($key);
+    }
+
+    /**
+     * @return int
+     */
+    public function getSize(): int
+    {
+        return $this->values->getSize();
+    }
+
+    /**
+     * @param $key
+     * @return int
+     */
+    public function getKeyIndex($key): int
+    {
+        return $this->keys[$key] ?? -1;
+    }
+
+    /**
+     * @return array
+     */
+    public function getKeys(): array
+    {
+        return $this->keys;
+    }
+
+    /**
+     * @param array $keys
+     */
+    public function setKeys(array $keys)
+    {
+        $this->keys = $keys;
+    }
+
+    /**
+     * @return \SplFixedArray
+     */
+    public function getValues(): \SplFixedArray
+    {
+        return $this->values;
+    }
+
+    /**
+     * @param \SplFixedArray $values
+     */
+    public function setValues(\SplFixedArray $values)
+    {
+        $this->values = $values;
+    }
+
+    /**
+     * Defined by IteratorAggregate interface
+     * Returns an iterator for this object, for use with foreach
+     * @return \SplFixedArray
+     */
+    public function getIterator(): \SplFixedArray
+    {
+        return $this->values;
+    }
+
+    /**
+     * Checks whether an offset exists in the iterator.
+     * @param   mixed $offset The array offset.
+     * @return  boolean  True if the offset exists, false otherwise.
+     */
+    public function offsetExists($offset): bool
+    {
+        return isset($this->keys[$offset]);
+    }
+
+    /**
+     * Gets an offset in the iterator.
+     * @param   mixed $offset The array offset.
+     * @return  mixed  The array value if it exists, null otherwise.
+     */
+    public function offsetGet($offset)
+    {
+        $index = $this->getKeyIndex($offset);
+
+        if ($index >= 0) {
+            return $this->values[$index];
+        }
+
+        return null;
+    }
+
+    /**
+     * Sets an offset in the iterator.
+     * @param   mixed $offset The array offset.
+     * @param   mixed $value The array value.
+     * @return  void
+     */
+    public function offsetSet($offset, $value)
+    {
+        $index = $this->getSize();
+
+        // change size.
+        if ($index <= \count($this->keys)) {
+            $this->values->setSize($index + 10);
+        }
+
+        $this->values[$index] = $value;
+        $this->keys[$offset] = $index;
+    }
+
+    /**
+     * Unset an offset in the iterator.
+     * @param   mixed $offset The array offset.
+     * @return  void
+     */
+    public function offsetUnset($offset)
+    {
+        $index = $this->getKeyIndex($offset);
+
+        if ($index >= 0) {
+            // change size.
+            $this->values->setSize($index - 1);
+
+            unset($this->keys[$offset], $this->values[$index]);
+        }
+    }
+}