* not just purges, which can be useful for cache warming. Writes are eventually
* consistent via the Dynamo replication model. See https://github.com/Netflix/dynomite.
*
- * Broadcasted operations like delete() and touchCheckKey() are done asynchronously
- * in all datacenters this way, though the local one should likely be near immediate.
+ * Broadcasted operations like delete() and touchCheckKey() are intended to run
+ * immediately in the local datacenter and asynchronously in remote datacenters.
*
* This means that callers in all datacenters may see older values for however many
* milliseconds that the purge took to reach that datacenter. As with any cache, this
/** Tiny negative float to use when CTL comes up >= 0 due to clock skew */
const TINY_NEGATIVE = -0.000001;
+ /** Tiny positive float to use when using "minTime" to assert an inequality */
+ const TINY_POSTIVE = 0.000001;
/** Seconds of delay after get() where set() storms are a consideration with 'lockTSE' */
const SET_DELAY_HIGH_SEC = 0.1;
+ /** Min millisecond set() backoff for keys in hold-off (far less than INTERIM_KEY_TTL) */
+ const RECENT_SET_LOW_MS = 50;
+ /** Max millisecond set() backoff for keys in hold-off (far less than INTERIM_KEY_TTL) */
+ const RECENT_SET_HIGH_MS = 100;
+
+ /** Parameter to get()/getMulti() to return extra information by reference */
+ const PASS_BY_REF = -1;
/** Cache format version number */
const VERSION = 1;
* @return WANObjectCache
*/
public static function newEmpty() {
- return new static( [
- 'cache' => new EmptyBagOStuff()
- ] );
+ return new static( [ 'cache' => new EmptyBagOStuff() ] );
}
/**
* Consider using getWithSetCallback() instead of get() and set() cycles.
* That method has cache slam avoiding features for hot/expensive keys.
*
+ * Pass $info as WANObjectCache::PASS_BY_REF to transform it into a cache key info map.
+ * This map includes the following metadata:
+ * - asOf: UNIX timestamp of the value or null if the key is nonexistant
+ * - tombAsOf: UNIX timestamp of the tombstone or null if the key is not tombstoned
+ * - lastCKPurge: UNIX timestamp of the highest check key or null if none provided
+ *
+ * Othwerwise, $info will transform into the cached value timestamp.
+ *
* @param string $key Cache key made from makeKey() or makeGlobalKey()
* @param mixed|null &$curTTL Approximate TTL left on the key if present/tombstoned [returned]
* @param array $checkKeys List of "check" keys
- * @param float|null &$asOf UNIX timestamp of cached value; null on failure [returned]
+ * @param mixed|null &$info Key info if WANObjectCache::PASS_BY_REF [returned]
* @return mixed Value of cache key or false on failure
*/
- final public function get( $key, &$curTTL = null, array $checkKeys = [], &$asOf = null ) {
- $curTTLs = [];
- $asOfs = [];
- $values = $this->getMulti( [ $key ], $curTTLs, $checkKeys, $asOfs );
+ final public function get(
+ $key, &$curTTL = null, array $checkKeys = [], &$info = null
+ ) {
+ $curTTLs = self::PASS_BY_REF;
+ $infoByKey = self::PASS_BY_REF;
+ $values = $this->getMulti( [ $key ], $curTTLs, $checkKeys, $infoByKey );
$curTTL = $curTTLs[$key] ?? null;
- $asOf = $asOfs[$key] ?? null;
+ if ( $info === self::PASS_BY_REF ) {
+ $info = [
+ 'asOf' => $infoByKey[$key]['asOf'] ?? null,
+ 'tombAsOf' => $infoByKey[$key]['tombAsOf'] ?? null,
+ 'lastCKPurge' => $infoByKey[$key]['lastCKPurge'] ?? null
+ ];
+ } else {
+ $info = $infoByKey[$key]['asOf'] ?? null; // b/c
+ }
return $values[$key] ?? false;
}
/**
* Fetch the value of several keys from cache
*
+ * Pass $info as WANObjectCache::PASS_BY_REF to transform it into a map of cache keys
+ * to cache key info maps, each having the same style as those of WANObjectCache::get().
+ * All the cache keys listed in $keys will have an entry.
+ *
+ * Othwerwise, $info will transform into a map of (cache key => cached value timestamp).
+ * Only the cache keys listed in $keys that exists or are tombstoned will have an entry.
+ *
* @see WANObjectCache::get()
*
* @param array $keys List of cache keys made from makeKey() or makeGlobalKey()
- * @param array &$curTTLs Map of (key => approximate TTL left) for existing keys [returned]
+ * @param mixed|null &$curTTLs Map of (key => TTL left) for existing/tombstoned keys [returned]
* @param array $checkKeys List of check keys to apply to all $keys. May also apply "check"
* keys to specific cache keys only by using cache keys as keys in the $checkKeys array.
- * @param float[] &$asOfs Map of (key => UNIX timestamp of cached value; null on failure)
+ * @param mixed|null &$info Map of (key => info) if WANObjectCache::PASS_BY_REF [returned]
* @return array Map of (key => value) for keys that exist and are not tombstoned
*/
final public function getMulti(
- array $keys, &$curTTLs = [], array $checkKeys = [], array &$asOfs = []
+ array $keys,
+ &$curTTLs = [],
+ array $checkKeys = [],
+ &$info = null
) {
$result = [];
$curTTLs = [];
- $asOfs = [];
+ $infoByKey = [];
$vPrefixLen = strlen( self::VALUE_KEY_PREFIX );
$valueKeys = self::prefixCacheKeys( $keys, self::VALUE_KEY_PREFIX );
foreach ( $checkKeys as $i => $checkKeyGroup ) {
$prefixed = self::prefixCacheKeys( (array)$checkKeyGroup, self::TIME_KEY_PREFIX );
$checkKeysFlat = array_merge( $checkKeysFlat, $prefixed );
- // Is this check keys for a specific cache key, or for all keys being fetched?
+ // Are these check keys for a specific cache key, or for all keys being fetched?
if ( is_int( $i ) ) {
$checkKeysForAll = array_merge( $checkKeysForAll, $prefixed );
} else {
- $checkKeysByKey[$i] = isset( $checkKeysByKey[$i] )
- ? array_merge( $checkKeysByKey[$i], $prefixed )
- : $prefixed;
+ $checkKeysByKey[$i] = $prefixed;
}
}
// Get the main cache value for each key and validate them
foreach ( $valueKeys as $vKey ) {
- if ( !isset( $wrappedValues[$vKey] ) ) {
- continue; // not found
+ $key = substr( $vKey, $vPrefixLen ); // unprefix
+ list( $value, $curTTL, $asOf, $tombAsOf ) = isset( $wrappedValues[$vKey] )
+ ? $this->unwrap( $wrappedValues[$vKey], $now )
+ : [ false, null, null, null ]; // not found
+ // Force dependent keys to be seen as stale for a while after purging
+ // to reduce race conditions involving stale data getting cached
+ $purgeValues = $purgeValuesForAll;
+ if ( isset( $purgeValuesByKey[$key] ) ) {
+ $purgeValues = array_merge( $purgeValues, $purgeValuesByKey[$key] );
}
- $key = substr( $vKey, $vPrefixLen ); // unprefix
+ $lastCKPurge = null; // timestamp of the highest check key
+ foreach ( $purgeValues as $purge ) {
+ $lastCKPurge = max( $purge[self::FLD_TIME], $lastCKPurge );
+ $safeTimestamp = $purge[self::FLD_TIME] + $purge[self::FLD_HOLDOFF];
+ if ( $value !== false && $safeTimestamp >= $asOf ) {
+ // How long ago this value was invalidated by *this* check key
+ $ago = min( $purge[self::FLD_TIME] - $now, self::TINY_NEGATIVE );
+ // How long ago this value was invalidated by *any* known check key
+ $curTTL = min( $curTTL, $ago );
+ }
+ }
- list( $value, $curTTL ) = $this->unwrap( $wrappedValues[$vKey], $now );
if ( $value !== false ) {
$result[$key] = $value;
- // Force dependent keys to be seen as stale for a while after purging
- // to reduce race conditions involving stale data getting cached
- $purgeValues = $purgeValuesForAll;
- if ( isset( $purgeValuesByKey[$key] ) ) {
- $purgeValues = array_merge( $purgeValues, $purgeValuesByKey[$key] );
- }
- foreach ( $purgeValues as $purge ) {
- $safeTimestamp = $purge[self::FLD_TIME] + $purge[self::FLD_HOLDOFF];
- if ( $safeTimestamp >= $wrappedValues[$vKey][self::FLD_TIME] ) {
- // How long ago this value was invalidated by *this* check key
- $ago = min( $purge[self::FLD_TIME] - $now, self::TINY_NEGATIVE );
- // How long ago this value was invalidated by *any* known check key
- $curTTL = min( $curTTL, $ago );
- }
- }
}
- $curTTLs[$key] = $curTTL;
- $asOfs[$key] = ( $value !== false ) ? $wrappedValues[$vKey][self::FLD_TIME] : null;
+ if ( $curTTL !== null ) {
+ $curTTLs[$key] = $curTTL;
+ }
+
+ $infoByKey[$key] = ( $info === self::PASS_BY_REF )
+ ? [ 'asOf' => $asOf, 'tombAsOf' => $tombAsOf, 'lastCKPurge' => $lastCKPurge ]
+ : $asOf; // b/c
}
+ $info = $infoByKey;
+
return $result;
}
$popWindow = $opts['hotTTR'] ?? self::HOT_TTR;
$ageNew = $opts['ageNew'] ?? self::AGE_NEW;
$minTime = $opts['minAsOf'] ?? self::MIN_TIMESTAMP_NONE;
- $versioned = isset( $opts['version'] );
- $touchedCallback = $opts['touchedCallback'] ?? null;
+ $needsVersion = isset( $opts['version'] );
+ $touchedCb = $opts['touchedCallback'] ?? null;
$initialTime = $this->getCurrentTime();
// Get a collection name to describe this class of key
$kClass = $this->determineKeyClass( $key );
- // Get the current key value and populate $curTTL and $asOf accordingly
- $curTTL = null;
- $cValue = $this->get( $key, $curTTL, $checkKeys, $asOf ); // current value
- $value = $cValue; // return value
- // Apply additional dynamic expiration logic if supplied
- $curTTL = $this->applyTouchedCallback( $value, $asOf, $curTTL, $touchedCallback );
+ // Get the current key value
+ $curTTL = self::PASS_BY_REF;
+ $curInfo = self::PASS_BY_REF; /** @var array $curInfo */
+ $curValue = $this->get( $key, $curTTL, $checkKeys, $curInfo );
+ // Apply any $touchedCb invalidation timestamp to get the "last purge timestamp"
+ list( $curTTL, $LPT ) = $this->resolveCTL( $curValue, $curTTL, $curInfo, $touchedCb );
+ // Keep track of the best candidate value and its timestamp
+ $value = $curValue; // return value
+ $asOf = $curInfo['asOf']; // return value timestamp
// Determine if a cached value regeneration is needed or desired
if (
- $this->isValid( $value, $versioned, $asOf, $minTime ) &&
+ $this->isValid( $value, $needsVersion, $asOf, $minTime ) &&
$this->isAliveOrInGracePeriod( $curTTL, $graceTTL )
) {
$preemptiveRefresh = (
}
}
- // Only a tombstoned key yields no value yet has a (negative) "current time left"
- $isKeyTombstoned = ( $curTTL !== null && $value === false );
+ $isKeyTombstoned = ( $curInfo['tombAsOf'] !== null );
+ if ( $isKeyTombstoned ) {
+ // Get the interim key value since the key is tombstoned (write-holed)
+ list( $value, $asOf ) = $this->getInterimValue( $key, $needsVersion, $minTime );
+ // Update the "last purge time" since the $touchedCb timestamp depends on $value
+ $LPT = $this->resolveTouched( $value, $LPT, $touchedCb );
+ }
+
+ // Reduce mutex and cache set spam while keys are in the tombstone/holdoff period by
+ // checking if $value was genereated by a recent thread much less than a second ago.
+ if (
+ $this->isValid( $value, $needsVersion, $asOf, $minTime, $LPT ) &&
+ $this->isVolatileValueAgeNegligible( $initialTime - $asOf )
+ ) {
+ $this->stats->increment( "wanobjectcache.$kClass.hit.volatile" );
+
+ return $value;
+ }
+
// Decide if only one thread should handle regeneration at a time
$useMutex =
// Note that since tombstones no-op set(), $lockTSE and $curTTL cannot be used to
// the risk of high regeneration load after the delete() method is called.
$isKeyTombstoned ||
// Assume a key is hot if requested soon ($lockTSE seconds) after invalidation.
- // This avoids stampedes when timestamps from $checkKeys/$touchedCallback bump.
+ // This avoids stampedes when timestamps from $checkKeys/$touchedCb bump.
( $curTTL !== null && $curTTL <= 0 && abs( $curTTL ) <= $lockTSE ) ||
// Assume a key is hot if there is no value and a busy fallback is given.
// This avoids stampedes on eviction or preemptive regeneration taking too long.
if ( $this->cache->add( self::MUTEX_KEY_PREFIX . $key, 1, self::LOCK_TTL ) ) {
// Lock acquired; this thread will recompute the value and update cache
$hasLock = true;
- } elseif ( $this->isValid( $value, $versioned, $asOf, $minTime ) ) {
+ } elseif ( $this->isValid( $value, $needsVersion, $asOf, $minTime ) ) {
// Lock not acquired and a stale value exists; use the stale value
$this->stats->increment( "wanobjectcache.$kClass.hit.stale" );
return $value;
} else {
// Lock not acquired and no stale value exists
- if ( $isKeyTombstoned ) {
- // Use the INTERIM value from the last thread that regenerated it if possible
- $value = $this->getInterimValue( $key, $versioned, $minTime, $asOf );
- if ( $value !== false ) {
- $this->stats->increment( "wanobjectcache.$kClass.hit.volatile" );
-
- return $value;
- }
- }
-
if ( $busyValue !== null ) {
// Use the busy fallback value if nothing else
$miss = is_infinite( $minTime ) ? 'renew' : 'miss';
$setOpts = [];
++$this->callbackDepth;
try {
- $value = call_user_func_array( $callback, [ $cValue, &$ttl, &$setOpts, $asOf ] );
+ $value = call_user_func_array( $callback, [ $curValue, &$ttl, &$setOpts, $asOf ] );
} finally {
--$this->callbackDepth;
}
if ( $isKeyTombstoned ) {
if ( $this->checkAndSetCooloff( $key, $kClass, $ago, $lockTSE, $hasLock ) ) {
- // When delete() is called, writes are write-holed by the tombstone,
- // so use a special INTERIM key to pass the new value among threads.
- $tempTTL = max( self::INTERIM_KEY_TTL, (int)$lockTSE ); // set() expects seconds
- $newAsOf = $this->getCurrentTime();
- $wrapped = $this->wrap( $value, $tempTTL, $newAsOf );
- // Avoid using set() to avoid pointless mcrouter broadcasting
- $this->setInterimValue( $key, $wrapped, $tempTTL );
+ // Use the interim key value since the key is tombstoned (write-holed)
+ $tempTTL = max( self::INTERIM_KEY_TTL, (int)$lockTSE );
+ $this->setInterimValue( $key, $value, $tempTTL, $this->getCurrentTime() );
}
} elseif ( !$useMutex || $hasLock ) {
if ( $this->checkAndSetCooloff( $key, $kClass, $ago, $lockTSE, $hasLock ) ) {
}
if ( $hasLock ) {
- // Avoid using delete() to avoid pointless mcrouter broadcasting
$this->cache->changeTTL( self::MUTEX_KEY_PREFIX . $key, (int)$initialTime - 60 );
}
return $value;
}
+ /**
+ * @param float $age Age of volatile/interim key in seconds
+ * @return bool Whether the age of a volatile value is negligible
+ */
+ private function isVolatileValueAgeNegligible( $age ) {
+ return ( $age < mt_rand( self::RECENT_SET_LOW_MS, self::RECENT_SET_HIGH_MS ) / 1e3 );
+ }
+
/**
* @param string $key
* @param string $kClass
/**
* @param mixed $value
- * @param float $asOf
- * @param float $curTTL
- * @param callable|null $callback
- * @return float
+ * @param float|null $curTTL
+ * @param array $curInfo
+ * @param callable|null $touchedCallback
+ * @return array (current time left or null, UNIX timestamp of last purge or null)
+ * @note Callable type hints are not used to avoid class-autoloading
*/
- protected function applyTouchedCallback( $value, $asOf, $curTTL, $callback ) {
- if ( $callback === null ) {
- return $curTTL;
+ protected function resolveCTL( $value, $curTTL, $curInfo, $touchedCallback ) {
+ if ( $touchedCallback === null || $value === false ) {
+ return [ $curTTL, max( $curInfo['tombAsOf'], $curInfo['lastCKPurge'] ) ];
}
- if ( !is_callable( $callback ) ) {
+ if ( !is_callable( $touchedCallback ) ) {
throw new InvalidArgumentException( "Invalid expiration callback provided." );
}
- if ( $value !== false ) {
- $touched = $callback( $value );
- if ( $touched !== null && $touched >= $asOf ) {
- $curTTL = min( $curTTL, self::TINY_NEGATIVE, $asOf - $touched );
- }
+ $touched = $touchedCallback( $value );
+ if ( $touched !== null && $touched >= $curInfo['asOf'] ) {
+ $curTTL = min( $curTTL, self::TINY_NEGATIVE, $curInfo['asOf'] - $touched );
+ }
+
+ return [ $curTTL, max( $curInfo['tombAsOf'], $curInfo['lastCKPurge'], $touched ) ];
+ }
+
+ /**
+ * @param mixed $value
+ * @param float|null $lastPurge
+ * @param callable|null $touchedCallback
+ * @return float|null UNIX timestamp of last purge or null
+ * @note Callable type hints are not used to avoid class-autoloading
+ */
+ protected function resolveTouched( $value, $lastPurge, $touchedCallback ) {
+ if ( $touchedCallback === null || $value === false ) {
+ return $lastPurge;
}
- return $curTTL;
+ if ( !is_callable( $touchedCallback ) ) {
+ throw new InvalidArgumentException( "Invalid expiration callback provided." );
+ }
+
+ return max( $touchedCallback( $value ), $lastPurge );
}
/**
* @param string $key
* @param bool $versioned
* @param float $minTime
- * @param mixed &$asOf
- * @return mixed
+ * @return array (cached value or false, cached value timestamp or null)
*/
- protected function getInterimValue( $key, $versioned, $minTime, &$asOf ) {
+ protected function getInterimValue( $key, $versioned, $minTime ) {
if ( !$this->useInterimHoldOffCaching ) {
- return false; // disabled
+ return [ false, null ]; // disabled
}
$wrapped = $this->cache->get( self::INTERIM_KEY_PREFIX . $key );
list( $value ) = $this->unwrap( $wrapped, $this->getCurrentTime() );
- if ( $this->isValid( $value, $versioned, $asOf, $minTime ) ) {
- $asOf = $wrapped[self::FLD_TIME];
-
- return $value;
+ $valueAsOf = $wrapped[self::FLD_TIME] ?? null;
+ if ( $this->isValid( $value, $versioned, $valueAsOf, $minTime ) ) {
+ return [ $value, $valueAsOf ];
}
- return false;
+ return [ false, null ];
}
/**
* @param string $key
- * @param array $wrapped
+ * @param mixed $value
* @param int $tempTTL
+ * @param float $newAsOf
*/
- protected function setInterimValue( $key, $wrapped, $tempTTL ) {
+ protected function setInterimValue( $key, $value, $tempTTL, $newAsOf ) {
+ $wrapped = $this->wrap( $value, $tempTTL, $newAsOf );
+
$this->cache->merge(
self::INTERIM_KEY_PREFIX . $key,
function () use ( $wrapped ) {
* @param bool $versioned
* @param float $asOf The time $value was generated
* @param float $minTime The last time the main value was generated (0.0 if unknown)
+ * @param float|null $purgeTime The last time the value was invalidated
* @return bool
*/
- protected function isValid( $value, $versioned, $asOf, $minTime ) {
+ protected function isValid( $value, $versioned, $asOf, $minTime, $purgeTime = null ) {
+ // Avoid reading any key not generated after the latest delete() or touch
+ $safeMinTime = max( $minTime, $purgeTime + self::TINY_POSTIVE );
+
if ( $value === false ) {
return false;
} elseif ( $versioned && !isset( $value[self::VFLD_VERSION] ) ) {
return false;
- } elseif ( $minTime > 0 && $asOf < $minTime ) {
+ } elseif ( $safeMinTime > 0 && $asOf < $minTime ) {
return false;
}
/**
* Do not use this method outside WANObjectCache
*
+ * The cached value will be false if absent/tombstoned/malformed
+ *
* @param array|string|bool $wrapped
* @param float $now Unix Current timestamp (preferrably pre-query)
- * @return array (mixed; false if absent/tombstoned/malformed, current time left)
+ * @return array (cached value or false, current TTL, value timestamp, tombstone timestamp)
*/
protected function unwrap( $wrapped, $now ) {
// Check if the value is a tombstone
if ( $purge !== false ) {
// Purged values should always have a negative current $ttl
$curTTL = min( $purge[self::FLD_TIME] - $now, self::TINY_NEGATIVE );
- return [ false, $curTTL ];
+ return [ false, $curTTL, null, $purge[self::FLD_TIME] ];
}
if ( !is_array( $wrapped ) // not found
|| !isset( $wrapped[self::FLD_VERSION] ) // wrong format
|| $wrapped[self::FLD_VERSION] !== self::VERSION // wrong version
) {
- return [ false, null ];
+ return [ false, null, null, null ];
}
if ( $wrapped[self::FLD_TTL] > 0 ) {
if ( $wrapped[self::FLD_TIME] < $this->epoch ) {
// Values this old are ignored
- return [ false, null ];
+ return [ false, null, null, null ];
}
- return [ $wrapped[self::FLD_VALUE], $curTTL ];
+ return [ $wrapped[self::FLD_VALUE], $curTTL, $wrapped[self::FLD_TIME], null ];
}
/**
}
public function testProcessCache() {
+ $mockWallClock = 1549343530.2053;
+ $this->cache->setMockTime( $mockWallClock );
+
$hit = 0;
$callback = function () use ( &$hit ) {
++$hit;
$this->assertEquals( 6, $hit, "New values cached" );
foreach ( $keys as $i => $key ) {
+ // Should evict from process cache
$this->cache->delete( $key );
+ $mockWallClock += 0.001; // cached values will be newer than tombstone
+ // Get into cache (specific process cache group)
$this->cache->getWithSetCallback(
$key, 100, $callback, [ 'pcTTL' => 5, 'pcGroup' => $groups[$i] ] );
}
- $this->assertEquals( 9, $hit, "Values evicted" );
+ $this->assertEquals( 9, $hit, "Values evicted by delete()" );
- $key = reset( $keys );
// Get into cache (default process cache group)
+ $key = reset( $keys );
$this->cache->getWithSetCallback( $key, 100, $callback, [ 'pcTTL' => 5 ] );
- $this->assertEquals( 10, $hit, "Value calculated" );
+ $this->assertEquals( 9, $hit, "Value recently interim-cached" );
+
+ $mockWallClock += 0.2; // interim key not brand new
+ $this->cache->clearProcessCache();
+ $this->cache->getWithSetCallback( $key, 100, $callback, [ 'pcTTL' => 5 ] );
+ $this->assertEquals( 10, $hit, "Value calculated (interim key not recent and reset)" );
$this->cache->getWithSetCallback( $key, 100, $callback, [ 'pcTTL' => 5 ] );
- $this->assertEquals( 10, $hit, "Value cached" );
+ $this->assertEquals( 10, $hit, "Value process cached" );
+
+ $mockWallClock += 0.2; // interim key not brand new
$outerCallback = function () use ( &$callback, $key ) {
$v = $this->cache->getWithSetCallback( $key, 100, $callback, [ 'pcTTL' => 5 ] );
$t2 = $cache->getCheckKeyTime( $cKey2 );
$this->assertGreaterThanOrEqual( $priorTime, $t2, 'Check keys generated on miss' );
- $mockWallClock += 0.01;
+ $mockWallClock += 0.2; // interim key is not brand new and check keys have past values
$priorTime = $mockWallClock; // reference time
$wasSet = 0;
$v = $cache->getWithSetCallback(
return $value;
};
- $cache = new NearExpiringWANObjectCache( [
- 'cache' => new HashBagOStuff()
- ] );
+ $cache = new NearExpiringWANObjectCache( [ 'cache' => new HashBagOStuff() ] );
+ $mockWallClock = 1549343530.2053;
+ $cache->setMockTime( $mockWallClock );
$wasSet = 0;
$key = wfRandomString();
$v = $cache->getWithSetCallback( $key, 20, $func, $opts );
$this->assertEquals( $value, $v, "Value returned" );
$this->assertEquals( 1, $wasSet, "Value calculated" );
+
+ $mockWallClock += 0.2; // interim key is not brand new
$v = $cache->getWithSetCallback( $key, 20, $func, $opts );
$this->assertEquals( 2, $wasSet, "Value re-calculated" );
$key = wfRandomString();
$value = wfRandomString();
+ $mockWallClock = 1549343530.2053;
+ $cache->setMockTime( $mockWallClock );
+
$calls = 0;
$func = function () use ( &$calls, $value, $cache, $key ) {
++$calls;
$this->assertEquals( 1, $calls, 'Callback was not used' );
$cache->delete( $key );
+ $mockWallClock += 0.001; // cached values will be newer than tombstone
$ret = $cache->getWithSetCallback( $key, 30, $func,
[ 'lockTSE' => 5, 'checkKeys' => $checkKeys ] );
$this->assertEquals( $value, $ret, 'Callback was used; interim saved' );
$value = wfRandomString();
$mockWallClock = 1549343530.2053;
- $priorTime = $mockWallClock;
$cache->setMockTime( $mockWallClock );
$calls = 0;
- $func = function ( $oldValue, &$ttl, &$setOpts ) use ( &$calls, $value, $priorTime ) {
+ $func = function ( $oldValue, &$ttl, &$setOpts ) use ( &$calls, $value, &$mockWallClock ) {
++$calls;
- $setOpts['since'] = $priorTime - 10;
+ $setOpts['since'] = $mockWallClock - 10;
return $value;
};
$this->assertEquals( 1, $curTTL, 'Value has reduced logical TTL', 0.01 );
$this->assertEquals( 1, $calls, 'Value was generated' );
- $mockWallClock += 2;
+ $mockWallClock += 2; // low logical TTL expired
$ret = $cache->getWithSetCallback( $key, 300, $func, [ 'lockTSE' => 5 ] );
$this->assertEquals( $value, $ret );
$this->assertEquals( 2, $calls, 'Callback used (mutex acquired)' );
+ $ret = $cache->getWithSetCallback( $key, 300, $func, [ 'lockTSE' => 5 ] );
+ $this->assertEquals( $value, $ret );
+ $this->assertEquals( 2, $calls, 'Callback was not used (interim value used)' );
+
+ $mockWallClock += 2; // low logical TTL expired
// Acquire a lock to verify that getWithSetCallback uses lockTSE properly
$this->internalCache->add( $cache::MUTEX_KEY_PREFIX . $key, 1, 0 );
$ret = $cache->getWithSetCallback( $key, 300, $func, [ 'lockTSE' => 5 ] );
$this->assertEquals( $value, $ret );
- $this->assertEquals( 3, $calls, 'Callback was not used (mutex not acquired)' );
+ $this->assertEquals( 2, $calls, 'Callback was not used (mutex not acquired)' );
+
+ $mockWallClock += 301; // physical TTL expired
+ // Acquire a lock to verify that getWithSetCallback uses lockTSE properly
+ $this->internalCache->add( $cache::MUTEX_KEY_PREFIX . $key, 1, 0 );
+
+ $ret = $cache->getWithSetCallback( $key, 300, $func, [ 'lockTSE' => 5 ] );
+ $this->assertEquals( $value, $ret );
+ $this->assertEquals( 3, $calls, 'Callback was used (mutex not acquired, not in cache)' );
$calls = 0;
- $func2 = function ( $oldValue, &$ttl, &$setOpts ) use ( &$calls, $value, $priorTime ) {
+ $func2 = function ( $oldValue, &$ttl, &$setOpts ) use ( &$calls, $value ) {
++$calls;
$setOpts['lag'] = 15;
return $value;
$value = wfRandomString();
$busyValue = wfRandomString();
+ $mockWallClock = 1549343530.2053;
+ $cache->setMockTime( $mockWallClock );
+
$calls = 0;
$func = function () use ( &$calls, $value, $cache, $key ) {
++$calls;
$this->assertEquals( $value, $ret );
$this->assertEquals( 1, $calls, 'Value was populated' );
+ $mockWallClock += 0.2; // interim keys not brand new
+
// Acquire a lock to verify that getWithSetCallback uses busyValue properly
$this->internalCache->add( $cache::MUTEX_KEY_PREFIX . $key, 1, 0 );
$this->assertEquals( 2, $calls, 'Callback was not used; used busy value' );
$this->internalCache->delete( $cache::MUTEX_KEY_PREFIX . $key );
+ $mockWallClock += 0.001; // cached values will be newer than tombstone
$ret = $cache->getWithSetCallback( $key, 30, $func,
[ 'lockTSE' => 30, 'busyValue' => $busyValue, 'checkKeys' => $checkKeys ] );
$this->assertEquals( $value, $ret, 'Callback was used; saved interim' );
public function testInterimHoldOffCaching() {
$cache = $this->cache;
+ $mockWallClock = 1549343530.2053;
+ $cache->setMockTime( $mockWallClock );
+
$value = 'CRL-40-940';
$wasCalled = 0;
$func = function () use ( &$wasCalled, $value ) {
$v = $cache->getWithSetCallback( $key, 60, $func );
$v = $cache->getWithSetCallback( $key, 60, $func );
$this->assertEquals( 1, $wasCalled, 'Value cached' );
+
$cache->delete( $key );
+ $mockWallClock += 0.001; // cached values will be newer than tombstone
$v = $cache->getWithSetCallback( $key, 60, $func );
$this->assertEquals( 2, $wasCalled, 'Value regenerated (got mutex)' ); // sets interim
$v = $cache->getWithSetCallback( $key, 60, $func );
+ $this->assertEquals( 2, $wasCalled, 'Value interim cached' ); // reuses interim
+
+ $mockWallClock += 0.2; // interim key not brand new
+ $v = $cache->getWithSetCallback( $key, 60, $func );
$this->assertEquals( 3, $wasCalled, 'Value regenerated (got mutex)' ); // sets interim
// Lock up the mutex so interim cache is used
$this->internalCache->add( $cache::MUTEX_KEY_PREFIX . $key, 1, 0 );
dépôts / lhc / web / wiklou.git / commitdiff