Making memcache cache adapter, set the expiry time of any value great…

…er than 30 days to never expire. This works around the 30 day limitation of the PHP extension. Test case added. Fixes #1451

cake/libs/cache/memcache.php

@@ -119,8 +119,7 @@ function _parseServerString($server) {
 /**
  * Write data for key into cache.  When using memcache as your cache engine
  * remember that the Memcache pecl extension does not support cache expiry times greater 
- * than 30 days in the future. If you wish to create cache entries that do not expire, set the duration
- * to `0` in your cache configuration.
+ * than 30 days in the future. Any duration greater than 30 days will be treated as never expiring.
  *
  * @param string $key Identifier for the data
  * @param mixed $value Data to be cached
@@ -130,6 +129,9 @@ function _parseServerString($server) {
  * @access public
  */
 	function write($key, &$value, $duration) {
+		if ($duration > 30 * DAY) {
+			$duration = 0;
+		}
 		return $this->__Memcache->set($key, $value, $this->settings['compress'], $duration);
 	}
 

cake/tests/cases/libs/cache/memcache.test.php

@@ -33,8 +33,14 @@ class TestMemcacheEngine extends MemcacheEngine {
 	function parseServerString($server) {
 		return $this->_parseServerString($server);
 	}
+
+	function setMemcache(&$memcache) {
+		$this->__Memcache = $memcache;
+	}
 }
 
+Mock::generate('Memcache', 'MemcacheMockMemcache');
+
 /**
  * MemcacheEngineTest class
  *
@@ -361,7 +367,23 @@ function testZeroDuration() {
 		$this->assertTrue($result, 'Could not write with duration 0');
 		$result = Cache::read('test_key', 'memcache');
 		$this->assertEqual($result, 'written!');
-
+	}
+
+/**
+ * test that durations greater than 30 days never expire
+ *
+ * @return void
+ */
+	function testLongDurationEqualToZero() {
+		$memcache =& new TestMemcacheEngine();
+		$memcache->settings['compress'] = false;
+
+		$mock = new MemcacheMockMemcache();
+		$memcache->setMemcache($mock);
+		$mock->expectAt(0, 'set', array('key', 'value', false, 0));
+
+		$value = 'value';
+		$memcache->write('key', $value, 50 * DAY);
 	}
 
 }