Cache remember

system/Cache/Handlers/BaseHandler.php

@@ -0,0 +1,44 @@
+<?php
+
+/**
+ * This file is part of the CodeIgniter 4 framework.
+ *
+ * (c) CodeIgniter Foundation <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace CodeIgniter\Cache\Handlers;
+
+use Closure;
+use CodeIgniter\Cache\CacheInterface;
+
+/**
+ * Base class for cache handling
+ */
+abstract class BaseHandler implements CacheInterface
+{
+	/**
+	 * Get an item from the cache, or execute the given Closure and store the result.
+	 *
+	 * @param string  $key      Cache item name
+	 * @param integer $ttl      Time to live
+	 * @param Closure $callback Callback return value
+	 *
+	 * @return mixed
+	 */
+	public function remember(string $key, int $ttl, Closure $callback)
+	{
+		$value = $this->get($key);
+
+		if (! is_null($value))
+		{
+			return $value;
+		}
+
+		$this->save($key, $value = $callback(), $ttl);
+
+		return $value;
+	}
+}

system/Cache/Handlers/DummyHandler.php

@@ -11,12 +11,12 @@
 
 namespace CodeIgniter\Cache\Handlers;
 
-use CodeIgniter\Cache\CacheInterface;
+use Closure;
 
 /**
  * Dummy cache handler
  */
-class DummyHandler implements CacheInterface
+class DummyHandler extends BaseHandler
 {
 	/**
 	 * Takes care of any handler-specific setup that must be done.
@@ -42,6 +42,22 @@ public function get(string $key)
 
 	//--------------------------------------------------------------------
 
+	/**
+	 * Get an item from the cache, or execute the given Closure and store the result.
+	 *
+	 * @param string  $key      Cache item name
+	 * @param integer $ttl      Time to live
+	 * @param Closure $callback Callback return value
+	 *
+	 * @return mixed
+	 */
+	public function remember(string $key, int $ttl, Closure $callback)
+	{
+		return null;
+	}
+
+	//--------------------------------------------------------------------
+
 	/**
 	 * Saves an item to the cache store.
 	 *

system/Cache/Handlers/FileHandler.php

@@ -11,14 +11,13 @@
 
 namespace CodeIgniter\Cache\Handlers;
 
-use CodeIgniter\Cache\CacheInterface;
 use CodeIgniter\Cache\Exceptions\CacheException;
 use Config\Cache;
 
 /**
  * File system cache handler
  */
-class FileHandler implements CacheInterface
+class FileHandler extends BaseHandler
 {
 	/**
 	 * Prefixed to all cache names.

system/Cache/Handlers/MemcachedHandler.php

@@ -11,7 +11,6 @@
 
 namespace CodeIgniter\Cache\Handlers;
 
-use CodeIgniter\Cache\CacheInterface;
 use CodeIgniter\Exceptions\CriticalError;
 use Config\Cache;
 use Exception;
@@ -21,7 +20,7 @@
 /**
  * Mamcached cache handler
  */
-class MemcachedHandler implements CacheInterface
+class MemcachedHandler extends BaseHandler
 {
 	/**
 	 * Prefixed to all cache names.

system/Cache/Handlers/PredisHandler.php

@@ -11,7 +11,6 @@
 
 namespace CodeIgniter\Cache\Handlers;
 
-use CodeIgniter\Cache\CacheInterface;
 use CodeIgniter\Exceptions\CriticalError;
 use Config\Cache;
 use Exception;
@@ -20,7 +19,7 @@
 /**
  * Predis cache handler
  */
-class PredisHandler implements CacheInterface
+class PredisHandler extends BaseHandler
 {
 	/**
 	 * Prefixed to all cache names.

system/Cache/Handlers/RedisHandler.php

@@ -11,7 +11,6 @@
 
 namespace CodeIgniter\Cache\Handlers;
 
-use CodeIgniter\Cache\CacheInterface;
 use CodeIgniter\Exceptions\CriticalError;
 use Config\Cache;
 use Redis;
@@ -20,7 +19,7 @@
 /**
  * Redis cache handler
  */
-class RedisHandler implements CacheInterface
+class RedisHandler extends BaseHandler
 {
 	/**
 	 * Prefixed to all cache names.

system/Cache/Handlers/WincacheHandler.php

@@ -11,15 +11,14 @@
 
 namespace CodeIgniter\Cache\Handlers;
 
-use CodeIgniter\Cache\CacheInterface;
 use Config\Cache;
 
 /**
  * Cache handler for WinCache from Microsoft & IIS.
  * Windows-only, so not testable on travis-ci.
  * Unusable methods flagged for code coverage ignoring.
  */
-class WincacheHandler implements CacheInterface
+class WincacheHandler extends BaseHandler
 {
 	/**
 	 * Prefixed to all cache names.

system/Test/Mock/MockCache.php

@@ -12,6 +12,7 @@
 namespace CodeIgniter\Test\Mock;
 
 use CodeIgniter\Cache\CacheInterface;
+use Closure;
 
 class MockCache implements CacheInterface
 {
@@ -59,6 +60,31 @@ public function get(string $key)
 
 	//--------------------------------------------------------------------
 
+	/**
+	 * Get an item from the cache, or execute the given Closure and store the result.
+	 *
+	 * @param string  $key      Cache item name
+	 * @param integer $ttl      Time to live
+	 * @param Closure $callback Callback return value
+	 *
+	 * @return mixed
+	 */
+	public function remember(string $key, int $ttl, Closure $callback)
+	{
+		$value = $this->get($key);
+
+		if (! is_null($value))
+		{
+			return $value;
+		}
+
+		$this->save($key, $value = $callback(), $ttl);
+
+		return $value;
+	}
+
+	//--------------------------------------------------------------------
+
 	/**
 	 * Saves an item to the cache store.
 	 *

tests/system/Cache/Handlers/DummyHandlerTest.php

@@ -20,6 +20,15 @@ public function testGet()
 		$this->assertNull($this->dummyHandler->get('key'));
 	}
 
+	public function testRemember()
+	{
+		$dummyHandler = $this->dummyHandler->remember('key', 2, function () {
+			return 'value';
+		});
+
+		$this->assertNull($dummyHandler);
+	}
+
 	public function testSave()
 	{
 		$this->assertTrue($this->dummyHandler->save('key', 'value'));

tests/system/Cache/Handlers/FileHandlerTest.php

@@ -94,6 +94,19 @@ public function testGet()
 		$this->assertNull($this->fileHandler->get(self::$key1));
 	}
 
+	public function testRemember()
+	{
+		$this->fileHandler->remember(self::$key1, 2, function () {
+			return 'value';
+		});
+
+		$this->assertSame('value', $this->fileHandler->get(self::$key1));
+		$this->assertNull($this->fileHandler->get(self::$dummy));
+
+		\CodeIgniter\CLI\CLI::wait(3);
+		$this->assertNull($this->fileHandler->get(self::$key1));
+	}
+
 	public function testSave()
 	{
 		$this->assertTrue($this->fileHandler->save(self::$key1, 'value'));

tests/system/Cache/Handlers/MemcachedHandlerTest.php

@@ -57,6 +57,19 @@ public function testGet()
 		$this->assertNull($this->memcachedHandler->get(self::$key1));
 	}
 
+	public function testRemember()
+	{
+		$this->memcachedHandler->remember(self::$key1, 2, function () {
+			return 'value';
+		});
+
+		$this->assertSame('value', $this->memcachedHandler->get(self::$key1));
+		$this->assertNull($this->memcachedHandler->get(self::$dummy));
+
+		\CodeIgniter\CLI\CLI::wait(3);
+		$this->assertNull($this->memcachedHandler->get(self::$key1));
+	}
+
 	public function testSave()
 	{
 		$this->assertTrue($this->memcachedHandler->save(self::$key1, 'value'));

tests/system/Cache/Handlers/PredisHandlerTest.php

@@ -65,6 +65,19 @@ public function testGet()
 		$this->assertNull($this->PredisHandler->get(self::$key1));
 	}
 
+	public function testRemember()
+	{
+		$this->PredisHandler->remember(self::$key1, 2, function () {
+			return 'value';
+		});
+
+		$this->assertSame('value', $this->PredisHandler->get(self::$key1));
+		$this->assertNull($this->PredisHandler->get(self::$dummy));
+
+		\CodeIgniter\CLI\CLI::wait(3);
+		$this->assertNull($this->PredisHandler->get(self::$key1));
+	}
+
 	public function testSave()
 	{
 		$this->assertTrue($this->PredisHandler->save(self::$key1, 'value'));

tests/system/Cache/Handlers/RedisHandlerTest.php

@@ -101,6 +101,19 @@ public function testGet()
 		$this->assertNull($this->redisHandler->get(self::$key1));
 	}
 
+	public function testRemember()
+	{
+		$this->redisHandler->remember(self::$key1, 2, function () {
+			return 'value';
+		});
+
+		$this->assertSame('value', $this->redisHandler->get(self::$key1));
+		$this->assertNull($this->redisHandler->get(self::$dummy));
+
+		\CodeIgniter\CLI\CLI::wait(3);
+		$this->assertNull($this->redisHandler->get(self::$key1));
+	}
+
 	public function testSave()
 	{
 		$this->assertTrue($this->redisHandler->save(self::$key1, 'value'));