SwissQR: add Sprain\SwissQrBill and dependencies

htdocs/includes/symfony/intl/Data/Util/RingBuffer.php

@@ -0,0 +1,79 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Intl\Data\Util;
+
+use Symfony\Component\Intl\Exception\OutOfBoundsException;
+
+/**
+ * Implements a ring buffer.
+ *
+ * A ring buffer is an array-like structure with a fixed size. If the buffer
+ * is full, the next written element overwrites the first bucket in the buffer,
+ * then the second and so on.
+ *
+ * @author Bernhard Schussek <bschussek@gmail.com>
+ *
+ * @template TKey of array-key
+ * @template TValue
+ *
+ * @implements \ArrayAccess<TKey, TValue>
+ *
+ * @internal
+ */
+class RingBuffer implements \ArrayAccess
+{
+    /** @var array<int, TValue> */
+    private array $values = [];
+    /** @var array<TKey, int> */
+    private array $indices = [];
+    private int $cursor = 0;
+    private int $size;
+
+    public function __construct(int $size)
+    {
+        $this->size = $size;
+    }
+
+    public function offsetExists(mixed $key): bool
+    {
+        return isset($this->indices[$key]);
+    }
+
+    public function offsetGet(mixed $key): mixed
+    {
+        if (!isset($this->indices[$key])) {
+            throw new OutOfBoundsException(sprintf('The index "%s" does not exist.', $key));
+        }
+
+        return $this->values[$this->indices[$key]];
+    }
+
+    public function offsetSet(mixed $key, mixed $value): void
+    {
+        if (false !== ($keyToRemove = array_search($this->cursor, $this->indices))) {
+            unset($this->indices[$keyToRemove]);
+        }
+
+        $this->values[$this->cursor] = $value;
+        $this->indices[$key] = $this->cursor;
+
+        $this->cursor = ($this->cursor + 1) % $this->size;
+    }
+
+    public function offsetUnset(mixed $key): void
+    {
+        if (isset($this->indices[$key])) {
+            $this->values[$this->indices[$key]] = null;
+            unset($this->indices[$key]);
+        }
+    }
+}