Initial commit

kirby/src/Cache/Value.php

@@ -0,0 +1,152 @@
+<?php
+
+namespace Kirby\Cache;
+
+use Throwable;
+
+/**
+ * Cache Value
+ * Stores the value, creation timestamp and expiration timestamp
+ * and makes it possible to store all three with a single cache key
+ *
+ * @package   Kirby Cache
+ * @author    Bastian Allgeier <bastian@getkirby.com>
+ * @link      https://getkirby.com
+ * @copyright Bastian Allgeier
+ * @license   https://opensource.org/licenses/MIT
+ */
+class Value
+{
+    /**
+     * Cached value
+     * @var mixed
+     */
+    protected $value;
+
+    /**
+     * the number of minutes until the value expires
+     * @todo Rename this property to $expiry to reflect
+     *       both minutes and absolute timestamps
+     * @var int
+     */
+    protected $minutes;
+
+    /**
+     * Creation timestamp
+     * @var int
+     */
+    protected $created;
+
+    /**
+     * Constructor
+     *
+     * @param mixed $value
+     * @param int $minutes the number of minutes until the value expires
+     *                     or an absolute UNIX timestamp
+     * @param int $created the UNIX timestamp when the value has been created
+     */
+    public function __construct($value, int $minutes = 0, int $created = null)
+    {
+        $this->value   = $value;
+        $this->minutes = $minutes ?? 0;
+        $this->created = $created ?? time();
+    }
+
+    /**
+     * Returns the creation date as UNIX timestamp
+     *
+     * @return int
+     */
+    public function created(): int
+    {
+        return $this->created;
+    }
+
+    /**
+     * Returns the expiration date as UNIX timestamp or
+     * null if the value never expires
+     *
+     * @return int|null
+     */
+    public function expires(): ?int
+    {
+        // 0 = keep forever
+        if ($this->minutes === 0) {
+            return null;
+        }
+
+        if ($this->minutes > 1000000000) {
+            // absolute timestamp
+            return $this->minutes;
+        }
+
+        return $this->created + ($this->minutes * 60);
+    }
+
+    /**
+     * Creates a value object from an array
+     *
+     * @param array $array
+     * @return static
+     */
+    public static function fromArray(array $array)
+    {
+        return new static($array['value'] ?? null, $array['minutes'] ?? 0, $array['created'] ?? null);
+    }
+
+    /**
+     * Creates a value object from a JSON string;
+     * returns null on error
+     *
+     * @param string $json
+     * @return static|null
+     */
+    public static function fromJson(string $json)
+    {
+        try {
+            $array = json_decode($json, true);
+
+            if (is_array($array)) {
+                return static::fromArray($array);
+            } else {
+                return null;
+            }
+        } catch (Throwable $e) {
+            return null;
+        }
+    }
+
+    /**
+     * Converts the object to a JSON string
+     *
+     * @return string
+     */
+    public function toJson(): string
+    {
+        return json_encode($this->toArray());
+    }
+
+    /**
+     * Converts the object to an array
+     *
+     * @return array
+     */
+    public function toArray(): array
+    {
+        return [
+            'created' => $this->created,
+            'minutes' => $this->minutes,
+            'value'   => $this->value,
+        ];
+    }
+
+    /**
+     * Returns the pure value
+     *
+     * @return mixed
+     */
+    public function value()
+    {
+        return $this->value;
+    }
+}