* @return WANObjectCache
*/
public static function newEmpty() {
- return new self( [
+ return new static( [
'cache' => new EmptyBagOStuff(),
'pool' => 'empty'
] );
$wrappedValues += $this->cache->getMulti( $keysGet );
}
// Time used to compare/init "check" keys (derived after getMulti() to be pessimistic)
- $now = microtime( true );
+ $now = $this->getCurrentTime();
// Collect timestamps from all "check" keys
$purgeValuesForAll = $this->processCheckKeys( $checkKeysForAll, $wrappedValues, $now );
* @return bool Success
*/
final public function set( $key, $value, $ttl = 0, array $opts = [] ) {
- $now = microtime( true );
+ $now = $this->getCurrentTime();
$lockTSE = isset( $opts['lockTSE'] ) ? $opts['lockTSE'] : self::TSE_NONE;
$staleTTL = isset( $opts['staleTTL'] ) ? $opts['staleTTL'] : self::STALE_TTL_NONE;
$age = isset( $opts['since'] ) ? max( 0, $now - $opts['since'] ) : 0;
$time = $purge[self::FLD_TIME];
} else {
// Casting assures identical floats for the next getCheckKeyTime() calls
- $now = (string)microtime( true );
+ $now = (string)$this->getCurrentTime();
$this->cache->add( $key,
$this->makePurgeValue( $now, self::HOLDOFF_TTL ),
self::CHECK_KEY_TTL
$cValue = $this->get( $key, $curTTL, $checkKeys, $asOf ); // current value
$value = $cValue; // return value
- $preCallbackTime = microtime( true );
+ $preCallbackTime = $this->getCurrentTime();
// Determine if a cached value regeneration is needed or desired
if ( $value !== false
&& $curTTL > 0
// so use a special INTERIM key to pass the new value around threads.
if ( ( $isTombstone && $lockTSE > 0 ) && $valueIsCacheable ) {
$tempTTL = max( 1, (int)$lockTSE ); // set() expects seconds
- $newAsOf = microtime( true );
+ $newAsOf = $this->getCurrentTime();
$wrapped = $this->wrap( $value, $tempTTL, $newAsOf );
// Avoid using set() to avoid pointless mcrouter broadcasting
$this->setInterimValue( $key, $wrapped, $tempTTL );
*/
protected function getInterimValue( $key, $versioned, $minTime, &$asOf ) {
$wrapped = $this->cache->get( self::INTERIM_KEY_PREFIX . $key );
- list( $value ) = $this->unwrap( $wrapped, microtime( true ) );
+ list( $value ) = $this->unwrap( $wrapped, $this->getCurrentTime() );
if ( $value !== false && $this->isValid( $value, $versioned, $asOf, $minTime ) ) {
$asOf = $wrapped[self::FLD_TIME];
if ( $this->purgeRelayer instanceof EventRelayerNull ) {
// This handles the mcrouter and the single-DC case
$ok = $this->cache->set( $key,
- $this->makePurgeValue( microtime( true ), self::HOLDOFF_NONE ),
+ $this->makePurgeValue( $this->getCurrentTime(), self::HOLDOFF_NONE ),
$ttl
);
} else {
* @return bool
*/
protected function worthRefreshExpiring( $curTTL, $lowTTL ) {
- if ( $curTTL >= $lowTTL ) {
+ if ( $lowTTL <= 0 ) {
+ return false;
+ } elseif ( $curTTL >= $lowTTL ) {
return false;
} elseif ( $curTTL <= 0 ) {
return true;
* @return bool
*/
protected function worthRefreshPopular( $asOf, $ageNew, $timeTillRefresh, $now ) {
+ if ( $ageNew < 0 || $timeTillRefresh <= 0 ) {
+ return false;
+ }
+
$age = $now - $asOf;
$timeOld = $age - $ageNew;
if ( $timeOld <= 0 ) {
return isset( $parts[1] ) ? $parts[1] : $parts[0]; // sanity
}
+ /**
+ * @return float UNIX timestamp
+ * @codeCoverageIgnore
+ */
+ protected function getCurrentTime() {
+ return microtime( true );
+ }
+
/**
* @param string $value Wrapped value like "PURGED:<timestamp>:<holdoff>"
* @return array|bool Array containing a UNIX timestamp (float) and holdoff period (integer),
];
}
+ public function testPreemtiveRefresh() {
+ $value = 'KatCafe';
+ $wasSet = 0;
+ $func = function ( $old, &$ttl, &$opts, $asOf ) use ( &$wasSet, $value )
+ {
+ ++$wasSet;
+ return $value;
+ };
+
+ $cache = new NearExpiringWANObjectCache( [
+ 'cache' => new HashBagOStuff(),
+ 'pool' => 'empty'
+ ] );
+
+ $wasSet = 0;
+ $key = wfRandomString();
+ $opts = [ 'lowTTL' => 30 ];
+ $v = $cache->getWithSetCallback( $key, 20, $func, $opts );
+ $this->assertEquals( $value, $v, "Value returned" );
+ $this->assertEquals( 1, $wasSet, "Value calculated" );
+ $v = $cache->getWithSetCallback( $key, 20, $func, $opts );
+ $this->assertEquals( 2, $wasSet, "Value re-calculated" );
+
+ $wasSet = 0;
+ $key = wfRandomString();
+ $opts = [ 'lowTTL' => 1 ];
+ $v = $cache->getWithSetCallback( $key, 30, $func, $opts );
+ $this->assertEquals( $value, $v, "Value returned" );
+ $this->assertEquals( 1, $wasSet, "Value calculated" );
+ $v = $cache->getWithSetCallback( $key, 30, $func, $opts );
+ $this->assertEquals( 1, $wasSet, "Value cached" );
+
+ $cache = new PopularityRefreshingWANObjectCache( [
+ 'cache' => new HashBagOStuff(),
+ 'pool' => 'empty'
+ ] );
+
+ $now = microtime( true ); // reference time
+ $wasSet = 0;
+ $key = wfRandomString();
+ $opts = [ 'hotTTR' => 900 ];
+ $v = $cache->getWithSetCallback( $key, 60, $func, $opts );
+ $this->assertEquals( $value, $v, "Value returned" );
+ $this->assertEquals( 1, $wasSet, "Value calculated" );
+ $cache->setTime( $now + 30 );
+ $v = $cache->getWithSetCallback( $key, 60, $func, $opts );
+ $this->assertEquals( 1, $wasSet, "Value cached" );
+
+ $wasSet = 0;
+ $key = wfRandomString();
+ $opts = [ 'hotTTR' => 10 ];
+ $cache->setTime( $now );
+ $v = $cache->getWithSetCallback( $key, 60, $func, $opts );
+ $this->assertEquals( $value, $v, "Value returned" );
+ $this->assertEquals( 1, $wasSet, "Value calculated" );
+ $cache->setTime( $now + 30 );
+ $v = $cache->getWithSetCallback( $key, 60, $func, $opts );
+ $this->assertEquals( 2, $wasSet, "Value re-calculated" );
+ }
+
/**
* @covers WANObjectCache::getWithSetCallback()
* @covers WANObjectCache::doGetWithSetCallback()
$this->assertEquals( $class, $wanCache->determineKeyClass( $key ) );
}
}
+
+class TimeAdjustableHashBagOStuff extends HashBagOStuff {
+ private $timeOverride = 0;
+
+ public function setTime( $time ) {
+ $this->timeOverride = $time;
+ }
+
+ protected function getCurrentTime() {
+ return $this->timeOverride ?: parent::getCurrentTime();
+ }
+}
+
+class TimeAdjustableWANObjectCache extends WANObjectCache {
+ private $timeOverride = 0;
+
+ public function setTime( $time ) {
+ $this->timeOverride = $time;
+ if ( $this->cache instanceof TimeAdjustableHashBagOStuff ) {
+ $this->cache->setTime( $time );
+ }
+ }
+
+ protected function getCurrentTime() {
+ return $this->timeOverride ?: parent::getCurrentTime();
+ }
+}
+
+class NearExpiringWANObjectCache extends TimeAdjustableWANObjectCache {
+ const CLOCK_SKEW = 1;
+
+ protected function worthRefreshExpiring( $curTTL, $lowTTL ) {
+ return ( ( $curTTL + self::CLOCK_SKEW ) < $lowTTL );
+ }
+}
+
+class PopularityRefreshingWANObjectCache extends TimeAdjustableWANObjectCache {
+ protected function worthRefreshPopular( $asOf, $ageNew, $timeTillRefresh, $now ) {
+ return ( ( $now - $asOf ) > $timeTillRefresh );
+ }
+}