From c602cf842203da95a6a1333e52813ae2e849dce4 Mon Sep 17 00:00:00 2001
From: Hugo Sales <hugo@fc.up.pt>
Date: Thu, 16 Jul 2020 00:01:00 +0000
Subject: [PATCH] [LIB][Util] Refactor and implement array indexing methods on
 RingBuffer

---
 src/Util/ds/RingBuffer.php | 55 ++++++++++++++++++++++++++++++--------
 1 file changed, 44 insertions(+), 11 deletions(-)

diff --git a/src/Util/ds/RingBuffer.php b/src/Util/ds/RingBuffer.php
index 99307bc5a7..4dedac8fd0 100644
--- a/src/Util/ds/RingBuffer.php
+++ b/src/Util/ds/RingBuffer.php
@@ -22,7 +22,7 @@ namespace App\Util\ds;
 use Ds\Deque;
 use Functional as F;
 
-class RingBuffer implements \Serializable
+class RingBuffer implements \Serializable, \ArrayAccess
 {
     private int $capacity;
     private Deque $elements;
@@ -33,16 +33,6 @@ class RingBuffer implements \Serializable
         $this->elements = new Deque();
     }
 
-    public function serialize()
-    {
-        return serialize($this->capacity) . serialize($this->elements);
-    }
-
-    public function unserialize($data)
-    {
-        list($this->capacity, $this->elements) = F\map(explode(';', $data), F\ary('unserialize', 1));
-    }
-
     public function add($e)
     {
         if ($this->capacity !== 0 && $this->elements->count() >= $this->capacity) {
@@ -55,4 +45,47 @@ class RingBuffer implements \Serializable
     {
         return $this->elements->remove($index);
     }
+
+    public function get(int $index)
+    {
+        return $this->elements->get($index);
+    }
+
+    // ------ Serialization
+    public function serialize()
+    {
+        return serialize($this->capacity) . serialize($this->elements);
+    }
+
+    public function unserialize($data)
+    {
+        list($this->capacity, $this->elements) = F\map(explode(';', $data), F\ary('unserialize', 1));
+    }
+    // ------ End Serialization
+
+    // ------ Array interface
+    public function offsetSet($index, $value)
+    {
+        if (is_null($index)) {
+            $this->add($value);
+        } else {
+            $this->elements->set($index, $value);
+        }
+    }
+
+    public function offsetExists($index)
+    {
+        return is_int($index) && $index >= 0 && $index < $this->elements->count();
+    }
+
+    public function offsetUnset($index)
+    {
+        $this->elements->remove($index);
+    }
+
+    public function offsetGet($index)
+    {
+        return $this->offsetExists($index) ? $this->get($index) : null;
+    }
+    // ------ End Array interface
 }