/**
* Removes expired elements.
* @return int number of removed elements
*/
protected function check_ttl()
{
if ($this->ttl === 0) {
return 0;
}
$maxtime = cache::now() - $this->ttl;
$count = 0;
for ($value = reset($this->store); $value !== false; $value = next($this->store)) {
if ($value[1] >= $maxtime) {
// We know that elements are sorted by ttl so no need to continue.
break;
}
$count++;
}
if ($count) {
// Remove first $count elements as they are expired.
$this->store = array_slice($this->store, $count, null, true);
if ($this->maxsize !== false) {
$this->storecount -= $count;
}
}
return $count;
}
/**
* Purges a cache of all information on a given event.
*
* @param string $event
*/
public static function purge_by_event($event)
{
$instance = cache_config::instance();
$invalidationeventset = false;
$factory = cache_factory::instance();
foreach ($instance->get_definitions() as $name => $definitionarr) {
$definition = cache_definition::load($name, $definitionarr);
if ($definition->invalidates_on_event($event)) {
// Create the cache.
$cache = $factory->create_cache($definition);
// Initialise, in case of a store.
if ($cache instanceof cache_store) {
$cache->initialise($definition);
}
// Purge the cache.
$cache->purge();
// We need to flag the event in the "Event invalidation" cache if it hasn't already happened.
if ($invalidationeventset === false) {
// Get the event invalidation cache.
$cache = cache::make('core', 'eventinvalidation');
// Create a key to invalidate all.
$data = array('purged' => cache::now());
// Set that data back to the cache.
$cache->set($event, $data);
// This only needs to occur once.
$invalidationeventset = true;
}
}
}
}
/**
* Override the cache::construct method.
*
* This function gets overriden so that we can process any invalidation events if need be.
* If the definition doesn't have any invalidation events then this occurs exactly as it would for the cache class.
* Otherwise we look at the last invalidation time and then check the invalidation data for events that have occured
* between then now.
*
* You should not call this method from your code, instead you should use the cache::make methods.
*
* @param cache_definition $definition
* @param cache_store $store
* @param cache_loader|cache_data_source $loader
*/
public function __construct(cache_definition $definition, cache_store $store, $loader = null)
{
// First up copy the loadeduserid to the current user id.
$this->currentuserid = self::$loadeduserid;
parent::__construct($definition, $store, $loader);
// This will trigger check tracked user. If this gets removed a call to that will need to be added here in its place.
$this->set(self::LASTACCESS, cache::now());
if ($definition->has_invalidation_events()) {
$lastinvalidation = $this->get('lastsessioninvalidation');
if ($lastinvalidation === false) {
// This is a new session, there won't be anything to invalidate. Set the time of the last invalidation and
// move on.
$this->set('lastsessioninvalidation', cache::now());
return;
} else {
if ($lastinvalidation == cache::now()) {
// We've already invalidated during this request.
return;
}
}
// Get the event invalidation cache.
$cache = cache::make('core', 'eventinvalidation');
$events = $cache->get_many($definition->get_invalidation_events());
$todelete = array();
$purgeall = false;
// Iterate the returned data for the events.
foreach ($events as $event => $keys) {
if ($keys === false) {
// No data to be invalidated yet.
continue;
}
// Look at each key and check the timestamp.
foreach ($keys as $key => $timestamp) {
// If the timestamp of the event is more than or equal to the last invalidation (happened between the last
// invalidation and now)then we need to invaliate the key.
if ($timestamp >= $lastinvalidation) {
if ($key === 'purged') {
$purgeall = true;
break;
} else {
$todelete[] = $key;
}
}
}
}
if ($purgeall) {
$this->purge();
} else {
if (!empty($todelete)) {
$todelete = array_unique($todelete);
$this->delete_many($todelete);
}
}
// Set the time of the last invalidation.
$this->set('lastsessioninvalidation', cache::now());
}
}
/**
* Returns true if the data has expired.
* @return int
*/
public function has_expired()
{
return $this->expires < cache::now();
}
/**
* Purges a cache of all information on a given event.
*
* @param string $event
*/
public static function purge_by_event($event)
{
$instance = cache_config::instance();
$invalidationeventset = false;
$factory = cache_factory::instance();
$inuse = $factory->get_caches_in_use();
foreach ($instance->get_definitions() as $name => $definitionarr) {
$definition = cache_definition::load($name, $definitionarr);
if ($definition->invalidates_on_event($event)) {
// First up check if there is a cache loader for this definition already.
// If there is we need to invalidate the keys from there.
$definitionkey = $definition->get_component() . '/' . $definition->get_area();
if (isset($inuse[$definitionkey])) {
$inuse[$definitionkey]->purge();
} else {
cache::make($definition->get_component(), $definition->get_area())->purge();
}
// We should only log events for application and session caches.
// Request caches shouldn't have events as all data is lost at the end of the request.
// Events should only be logged once of course and likely several definitions are watching so we
// track its logging with $invalidationeventset.
$logevent = $invalidationeventset === false && $definition->get_mode() !== cache_store::MODE_REQUEST;
// We need to flag the event in the "Event invalidation" cache if it hasn't already happened.
if ($logevent && $invalidationeventset === false) {
// Get the event invalidation cache.
$cache = cache::make('core', 'eventinvalidation');
// Create a key to invalidate all.
$data = array('purged' => cache::now());
// Set that data back to the cache.
$cache->set($event, $data);
// This only needs to occur once.
$invalidationeventset = true;
}
}
}
}
/**
* Tests application cache event invalidation over a distributed setup.
*/
public function test_distributed_application_event_invalidation()
{
global $CFG;
// This is going to be an intense wee test.
// We need to add data the to cache, invalidate it by event, manually force it back without MUC knowing to simulate a
// disconnected/distributed setup (think load balanced server using local cache), instantiate the cache again and finally
// check that it is not picked up.
$instance = cache_config_phpunittest::instance();
$instance->phpunit_add_definition('phpunit/eventinvalidationtest', array('mode' => cache_store::MODE_APPLICATION, 'component' => 'phpunit', 'area' => 'eventinvalidationtest', 'simplekeys' => true, 'simpledata' => true, 'invalidationevents' => array('crazyevent')));
$cache = cache::make('phpunit', 'eventinvalidationtest');
$this->assertTrue($cache->set('testkey1', 'test data 1'));
$this->assertEquals('test data 1', $cache->get('testkey1'));
cache_helper::invalidate_by_event('crazyevent', array('testkey1'));
$this->assertFalse($cache->get('testkey1'));
// OK data added, data invalidated, and invalidation time has been set.
// Now we need to manually add back the data and adjust the invalidation time.
$hash = md5(cache_store::MODE_APPLICATION . '/phpunit/eventinvalidationtest/' . $CFG->wwwroot . 'phpunit');
$timefile = $CFG->dataroot . "/cache/cachestore_file/default_application/phpunit_eventinvalidationtest/las/lastinvalidation-{$hash}.cache";
// Make sure the file is correct.
$this->assertTrue(file_exists($timefile));
$timecont = serialize(cache::now() - 60);
// Back 60sec in the past to force it to re-invalidate.
make_writable_directory(dirname($timefile));
file_put_contents($timefile, $timecont);
$this->assertTrue(file_exists($timefile));
$datafile = $CFG->dataroot . "/cache/cachestore_file/default_application/phpunit_eventinvalidationtest/tes/testkey1-{$hash}.cache";
$datacont = serialize("test data 1");
make_writable_directory(dirname($datafile));
file_put_contents($datafile, $datacont);
$this->assertTrue(file_exists($datafile));
// Test 1: Rebuild without the event and test its there.
cache_factory::reset();
$instance = cache_config_phpunittest::instance();
$instance->phpunit_add_definition('phpunit/eventinvalidationtest', array('mode' => cache_store::MODE_APPLICATION, 'component' => 'phpunit', 'area' => 'eventinvalidationtest', 'simplekeys' => true, 'simpledata' => true));
$cache = cache::make('phpunit', 'eventinvalidationtest');
$this->assertEquals('test data 1', $cache->get('testkey1'));
// Test 2: Rebuild and test the invalidation of the event via the invalidation cache.
cache_factory::reset();
$instance = cache_config_phpunittest::instance();
$instance->phpunit_add_definition('phpunit/eventinvalidationtest', array('mode' => cache_store::MODE_APPLICATION, 'component' => 'phpunit', 'area' => 'eventinvalidationtest', 'simplekeys' => true, 'simpledata' => true, 'invalidationevents' => array('crazyevent')));
$cache = cache::make('phpunit', 'eventinvalidationtest');
$this->assertFalse($cache->get('testkey1'));
}
/**
* Checks if the store has a record for the given key and returns true if so.
*
* @param string $key
* @return bool
*/
public function has($key)
{
$filename = $key . '.cache';
$maxtime = cache::now() - $this->definition->get_ttl();
if ($this->prescan) {
return array_key_exists($filename, $this->keys) && $this->keys[$filename] >= $maxtime;
}
$file = $this->file_path_for_key($key);
return file_exists($file) && ($this->definition->get_ttl() == 0 || filemtime($file) >= $maxtime);
}
/**
* Override the cache::construct method.
*
* This function gets overriden so that we can process any invalidation events if need be.
* If the definition doesn't have any invalidation events then this occurs exactly as it would for the cache class.
* Otherwise we look at the last invalidation time and then check the invalidation data for events that have occured
* between then now.
*
* You should not call this method from your code, instead you should use the cache::make methods.
*
* @param cache_definition $definition
* @param cache_store $store
* @param cache_loader|cache_data_source $loader
* @return void
*/
public function __construct(cache_definition $definition, cache_store $store, $loader = null)
{
parent::__construct($definition, $store, $loader);
if ($definition->has_invalidation_events()) {
$lastinvalidation = $this->get('lastsessioninvalidation');
if ($lastinvalidation === false) {
// This is a new session, there won't be anything to invalidate. Set the time of the last invalidation and
// move on.
$this->set('lastsessioninvalidation', cache::now());
return;
} else {
if ($lastinvalidation == cache::now()) {
// We've already invalidated during this request.
return;
}
}
// Get the event invalidation cache.
$cache = cache::make('core', 'eventinvalidation');
$events = $cache->get_many($definition->get_invalidation_events());
$todelete = array();
// Iterate the returned data for the events.
foreach ($events as $event => $keys) {
if ($keys === false) {
// No data to be invalidated yet.
continue;
}
// Look at each key and check the timestamp.
foreach ($keys as $key => $timestamp) {
// If the timestamp of the event is more than or equal to the last invalidation (happened between the last
// invalidation and now)then we need to invaliate the key.
if ($timestamp >= $lastinvalidation) {
$todelete[] = $key;
}
}
}
if (!empty($todelete)) {
$todelete = array_unique($todelete);
$this->delete_many($todelete);
}
// Set the time of the last invalidation.
$this->set('lastsessioninvalidation', cache::now());
}
}
/**
* Tests application cache event invalidation over a distributed setup.
*/
public function test_distributed_application_event_invalidation()
{
global $CFG;
// This is going to be an intense wee test.
// We need to add data the to cache, invalidate it by event, manually force it back without MUC knowing to simulate a
// disconnected/distributed setup (think load balanced server using local cache), instantiate the cache again and finally
// check that it is not picked up.
$instance = cache_config_testing::instance();
$instance->phpunit_add_definition('phpunit/eventinvalidationtest', array('mode' => cache_store::MODE_APPLICATION, 'component' => 'phpunit', 'area' => 'eventinvalidationtest', 'simplekeys' => true, 'simpledata' => true, 'invalidationevents' => array('crazyevent')));
$cache = cache::make('phpunit', 'eventinvalidationtest');
$this->assertTrue($cache->set('testkey1', 'test data 1'));
$this->assertEquals('test data 1', $cache->get('testkey1'));
cache_helper::invalidate_by_event('crazyevent', array('testkey1'));
$this->assertFalse($cache->get('testkey1'));
// OK data added, data invalidated, and invalidation time has been set.
// Now we need to manually add back the data and adjust the invalidation time.
$hash = md5(cache_store::MODE_APPLICATION . '/phpunit/eventinvalidationtest/' . $CFG->wwwroot . 'phpunit');
$timefile = $CFG->dataroot . "/cache/cachestore_file/default_application/phpunit_eventinvalidationtest/las-cache/lastinvalidation-{$hash}.cache";
// Make sure the file is correct.
$this->assertTrue(file_exists($timefile));
$timecont = serialize(cache::now() - 60);
// Back 60sec in the past to force it to re-invalidate.
make_writable_directory(dirname($timefile));
file_put_contents($timefile, $timecont);
$this->assertTrue(file_exists($timefile));
$datafile = $CFG->dataroot . "/cache/cachestore_file/default_application/phpunit_eventinvalidationtest/tes-cache/testkey1-{$hash}.cache";
$datacont = serialize("test data 1");
make_writable_directory(dirname($datafile));
file_put_contents($datafile, $datacont);
$this->assertTrue(file_exists($datafile));
// Test 1: Rebuild without the event and test its there.
cache_factory::reset();
$instance = cache_config_testing::instance();
$instance->phpunit_add_definition('phpunit/eventinvalidationtest', array('mode' => cache_store::MODE_APPLICATION, 'component' => 'phpunit', 'area' => 'eventinvalidationtest', 'simplekeys' => true, 'simpledata' => true));
$cache = cache::make('phpunit', 'eventinvalidationtest');
$this->assertEquals('test data 1', $cache->get('testkey1'));
// Test 2: Rebuild and test the invalidation of the event via the invalidation cache.
cache_factory::reset();
$instance = cache_config_testing::instance();
$instance->phpunit_add_definition('phpunit/eventinvalidationtest', array('mode' => cache_store::MODE_APPLICATION, 'component' => 'phpunit', 'area' => 'eventinvalidationtest', 'simplekeys' => true, 'simpledata' => true, 'invalidationevents' => array('crazyevent')));
$cache = cache::make('phpunit', 'eventinvalidationtest');
$this->assertFalse($cache->get('testkey1'));
// Test 3: Verify that an existing lastinvalidation cache file is updated when needed.
// Make a new cache class. This should should invalidate testkey2.
$cache = cache::make('phpunit', 'eventinvalidationtest');
// Timestamp should have updated to cache::now().
$this->assertEquals(cache::now(), $cache->get('lastinvalidation'));
// Set testkey2 data.
$cache->set('testkey2', 'test data 2');
// Backdate the event invalidation time by 30 seconds.
$invalidationcache = cache::make('core', 'eventinvalidation');
$invalidationcache->set('crazyevent', array('testkey2' => cache::now() - 30));
// Lastinvalidation should already be cache::now().
$this->assertEquals(cache::now(), $cache->get('lastinvalidation'));
// Set it to 15 seconds ago so that we know if it changes.
$cache->set('lastinvalidation', cache::now() - 15);
// Make a new cache class. This should not invalidate anything.
cache_factory::instance()->reset_cache_instances();
$cache = cache::make('phpunit', 'eventinvalidationtest');
// Lastinvalidation shouldn't change since it was already newer than invalidation event.
$this->assertEquals(cache::now() - 15, $cache->get('lastinvalidation'));
// Now set the event invalidation to newer than the lastinvalidation time.
$invalidationcache->set('crazyevent', array('testkey2' => cache::now() - 5));
// Make a new cache class. This should should invalidate testkey2.
cache_factory::instance()->reset_cache_instances();
$cache = cache::make('phpunit', 'eventinvalidationtest');
// Lastinvalidation timestamp should have updated to cache::now().
$this->assertEquals(cache::now(), $cache->get('lastinvalidation'));
// Now simulate a purge_by_event 5 seconds ago.
$invalidationcache = cache::make('core', 'eventinvalidation');
$invalidationcache->set('crazyevent', array('purged' => cache::now() - 5));
// Set our lastinvalidation timestamp to 15 seconds ago.
$cache->set('lastinvalidation', cache::now() - 15);
// Make a new cache class. This should invalidate the cache.
cache_factory::instance()->reset_cache_instances();
$cache = cache::make('phpunit', 'eventinvalidationtest');
// Lastinvalidation timestamp should have updated to cache::now().
$this->assertEquals(cache::now(), $cache->get('lastinvalidation'));
}
/**
* Purges a cache of all information on a given event.
*
* @param string $event
*/
public static function purge_by_event($event)
{
$instance = cache_config::instance();
$invalidationeventset = false;
$factory = cache_factory::instance();
foreach ($instance->get_definitions() as $name => $definitionarr) {
$definition = cache_definition::load($name, $definitionarr);
if ($definition->invalidates_on_event($event)) {
// Check if this definition would result in a persistent loader being in use.
if ($definition->should_be_persistent()) {
// There may be a persistent cache loader. Lets purge that first so that any persistent data is removed.
$cache = $factory->create_cache_from_definition($definition->get_component(), $definition->get_area());
$cache->purge();
}
// Get all of the store instances that are in use for this store.
$stores = $factory->get_store_instances_in_use($definition);
foreach ($stores as $store) {
// Purge each store individually.
$store->purge();
}
// We need to flag the event in the "Event invalidation" cache if it hasn't already happened.
if ($invalidationeventset === false) {
// Get the event invalidation cache.
$cache = cache::make('core', 'eventinvalidation');
// Create a key to invalidate all.
$data = array('purged' => cache::now());
// Set that data back to the cache.
$cache->set($event, $data);
// This only needs to occur once.
$invalidationeventset = true;
}
}
}
}
/**
* Returns true if the store contains records for any of the given keys.
*
* @param array $keys
* @return bool
*/
public function has_any(array $keys)
{
$maxtime = cache::now() - $this->ttl;
foreach ($keys as $key) {
if (array_key_exists($key, $this->store) && ($this->ttl == 0 || $this->store[$key][1] >= $maxtime)) {
return true;
}
}
return false;
}
/**
* Returns true if the store contains records for any of the given keys.
*
* @param array $keys
* @return bool
*/
public function has_any(array $keys)
{
if ($this->ttl != 0) {
$maxtime = cache::now() - $this->ttl;
}
foreach ($keys as $key) {
if (isset($this->store[$key]) && ($this->ttl == 0 || $this->store[$key][1] >= $maxtime)) {
return true;
}
}
return false;
}
