*
* @file
* @ingroup Cache
- * @author Aaron Schulz
*/
use Psr\Log\LoggerAwareInterface;
private $callbackDepth = 0;
/** @var mixed[] Temporary warm-up cache */
private $warmupCache = [];
+ /** @var integer Key fetched */
+ private $warmupKeyMisses = 0;
/** Max time expected to pass between delete() and DB commit finishing */
const MAX_COMMIT_DELAY = 3;
public static function newEmpty() {
return new self( [
'cache' => new EmptyBagOStuff(),
- 'pool' => 'empty',
- 'relayer' => new EventRelayerNull( [] )
+ 'pool' => 'empty'
] );
}
* @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)
- * @return array Map of (key => value) for keys that exist
+ * @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 = []
if ( $this->warmupCache ) {
$wrappedValues = array_intersect_key( $this->warmupCache, array_flip( $keysGet ) );
$keysGet = array_diff( $keysGet, array_keys( $wrappedValues ) ); // keys left to fetch
+ $this->warmupKeyMisses += count( $keysGet );
} else {
$wrappedValues = [];
}
- $wrappedValues += $this->cache->getMulti( $keysGet );
+ if ( $keysGet ) {
+ $wrappedValues += $this->cache->getMulti( $keysGet );
+ }
// Time used to compare/init "check" keys (derived after getMulti() to be pessimistic)
$now = microtime( true );
}
/**
- * Method to fetch/regenerate multiple cache keys at once
+ * Method to fetch multiple cache keys at once with regeneration
*
* This works the same as getWithSetCallback() except:
* - a) The $keys argument expects the result of WANObjectCache::makeMultiKeys()
* - c) The return value is a map of (cache key => value) in the order of $keyedIds
*
* @see WANObjectCache::getWithSetCallback()
+ * @see WANObjectCache::getMultiWithUnionSetCallback()
*
* Example usage:
* @code
final public function getMultiWithSetCallback(
ArrayIterator $keyedIds, $ttl, callable $callback, array $opts = []
) {
- $keysWarmUp = iterator_to_array( $keyedIds, true );
+ $valueKeys = array_keys( $keyedIds->getArrayCopy() );
$checkKeys = isset( $opts['checkKeys'] ) ? $opts['checkKeys'] : [];
- foreach ( $checkKeys as $i => $checkKeyOrKeys ) {
- if ( is_int( $i ) ) {
- $keysWarmUp[] = $checkKeyOrKeys;
- } else {
- $keysWarmUp = array_merge( $keysWarmUp, $checkKeyOrKeys );
+
+ // Load required keys into process cache in one go
+ $this->warmupCache = $this->getRawKeysForWarmup(
+ $this->getNonProcessCachedKeys( $valueKeys, $opts ),
+ $checkKeys
+ );
+ $this->warmupKeyMisses = 0;
+
+ // Wrap $callback to match the getWithSetCallback() format while passing $id to $callback
+ $id = null; // current entity ID
+ $func = function ( $oldValue, &$ttl, &$setOpts, $oldAsOf ) use ( $callback, &$id ) {
+ return $callback( $id, $oldValue, $ttl, $setOpts, $oldAsOf );
+ };
+
+ $values = [];
+ foreach ( $keyedIds as $key => $id ) { // preserve order
+ $values[$key] = $this->getWithSetCallback( $key, $ttl, $func, $opts );
+ }
+
+ $this->warmupCache = [];
+
+ return $values;
+ }
+
+ /**
+ * Method to fetch/regenerate multiple cache keys at once
+ *
+ * This works the same as getWithSetCallback() except:
+ * - a) The $keys argument expects the result of WANObjectCache::makeMultiKeys()
+ * - b) The $callback argument expects a callback returning a map of (ID => new value)
+ * for all entity IDs in $regenById and it takes the following arguments:
+ * - $ids: a list of entity IDs to regenerate
+ * - &$ttls: a reference to the (entity ID => new TTL) map
+ * - &$setOpts: a reference to options for set() which can be altered
+ * - c) The return value is a map of (cache key => value) in the order of $keyedIds
+ * - d) The "lockTSE" and "busyValue" options are ignored
+ *
+ * @see WANObjectCache::getWithSetCallback()
+ * @see WANObjectCache::getMultiWithSetCallback()
+ *
+ * Example usage:
+ * @code
+ * $rows = $cache->getMultiWithUnionSetCallback(
+ * // Map of cache keys to entity IDs
+ * $cache->makeMultiKeys(
+ * $this->fileVersionIds(),
+ * function ( $id, WANObjectCache $cache ) {
+ * return $cache->makeKey( 'file-version', $id );
+ * }
+ * ),
+ * // Time-to-live (in seconds)
+ * $cache::TTL_DAY,
+ * // Function that derives the new key value
+ * function ( array $ids, array &$ttls, array &$setOpts ) {
+ * $dbr = wfGetDB( DB_REPLICA );
+ * // Account for any snapshot/replica DB lag
+ * $setOpts += Database::getCacheSetOptions( $dbr );
+ *
+ * // Load the rows for these files
+ * $rows = [];
+ * $res = $dbr->select( 'file', '*', [ 'id' => $ids ], __METHOD__ );
+ * foreach ( $res as $row ) {
+ * $rows[$row->id] = $row;
+ * $mtime = wfTimestamp( TS_UNIX, $row->timestamp );
+ * $ttls[$row->id] = $this->adaptiveTTL( $mtime, $ttls[$row->id] );
+ * }
+ *
+ * return $rows;
+ * },
+ * ]
+ * );
+ * $files = array_map( [ __CLASS__, 'newFromRow' ], $rows );
+ * @endcode
+ *
+ * @param ArrayIterator $keyedIds Result of WANObjectCache::makeMultiKeys()
+ * @param integer $ttl Seconds to live for key updates
+ * @param callable $callback Callback the yields entity regeneration callbacks
+ * @param array $opts Options map
+ * @return array Map of (cache key => value) in the same order as $keyedIds
+ * @since 1.30
+ */
+ final public function getMultiWithUnionSetCallback(
+ ArrayIterator $keyedIds, $ttl, callable $callback, array $opts = []
+ ) {
+ $idsByValueKey = $keyedIds->getArrayCopy();
+ $valueKeys = array_keys( $idsByValueKey );
+ $checkKeys = isset( $opts['checkKeys'] ) ? $opts['checkKeys'] : [];
+ unset( $opts['lockTSE'] ); // incompatible
+ unset( $opts['busyValue'] ); // incompatible
+
+ // Load required keys into process cache in one go
+ $keysGet = $this->getNonProcessCachedKeys( $valueKeys, $opts );
+ $this->warmupCache = $this->getRawKeysForWarmup( $keysGet, $checkKeys );
+ $this->warmupKeyMisses = 0;
+
+ // IDs of entities known to be in need of regeneration
+ $idsRegen = [];
+
+ // Find out which keys are missing/deleted/stale
+ $curTTLs = [];
+ $asOfs = [];
+ $curByKey = $this->getMulti( $keysGet, $curTTLs, $checkKeys, $asOfs );
+ foreach ( $keysGet as $key ) {
+ if ( !array_key_exists( $key, $curByKey ) || $curTTLs[$key] < 0 ) {
+ $idsRegen[] = $idsByValueKey[$key];
}
}
- $this->warmupCache = $this->cache->getMulti( $keysWarmUp );
- $this->warmupCache += array_fill_keys( $keysWarmUp, false );
+ // Run the callback to populate the regeneration value map for all required IDs
+ $newSetOpts = [];
+ $newTTLsById = array_fill_keys( $idsRegen, $ttl );
+ $newValsById = $idsRegen ? $callback( $idsRegen, $newTTLsById, $newSetOpts ) : [];
// Wrap $callback to match the getWithSetCallback() format while passing $id to $callback
- $id = null;
- $func = function ( $oldValue, &$ttl, array &$setOpts, $oldAsOf ) use ( $callback, &$id ) {
- return $callback( $id, $oldValue, $ttl, $setOpts, $oldAsOf );
+ $id = null; // current entity ID
+ $func = function ( $oldValue, &$ttl, &$setOpts, $oldAsOf )
+ use ( $callback, &$id, $newValsById, $newTTLsById, $newSetOpts )
+ {
+ if ( array_key_exists( $id, $newValsById ) ) {
+ // Value was already regerated as expected, so use the value in $newValsById
+ $newValue = $newValsById[$id];
+ $ttl = $newTTLsById[$id];
+ $setOpts = $newSetOpts;
+ } else {
+ // Pre-emptive/popularity refresh and version mismatch cases are not detected
+ // above and thus $newValsById has no entry. Run $callback on this single entity.
+ $ttls = [ $id => $ttl ];
+ $newValue = $callback( [ $id ], $ttls, $setOpts )[$id];
+ $ttl = $ttls[$id];
+ }
+
+ return $newValue;
};
+ // Run the cache-aside logic using warmupCache instead of persistent cache queries
$values = [];
- foreach ( $keyedIds as $key => $id ) {
+ foreach ( $idsByValueKey as $key => $id ) { // preserve order
$values[$key] = $this->getWithSetCallback( $key, $ttl, $func, $opts );
}
return (int)min( $maxTTL, max( $minTTL, $factor * $age ) );
}
+ /**
+ * @return integer Number of warmup key cache misses last round
+ * @since 1.30
+ */
+ public function getWarmupKeyMisses() {
+ return $this->warmupKeyMisses;
+ }
+
/**
* Do the actual async bus purge of a key
*
*
* @param array|string|bool $wrapped
* @param float $now Unix Current timestamp (preferrably pre-query)
- * @return array (mixed; false if absent/invalid, current time left)
+ * @return array (mixed; false if absent/tombstoned/invalid, current time left)
*/
protected function unwrap( $wrapped, $now ) {
// Check if the value is a tombstone
return $this->processCaches[$group];
}
+
+ /**
+ * @param array $keys
+ * @param array $opts
+ * @return array List of keys
+ */
+ private function getNonProcessCachedKeys( array $keys, array $opts ) {
+ $keysFound = [];
+ if ( isset( $opts['pcTTL'] ) && $opts['pcTTL'] > 0 && $this->callbackDepth == 0 ) {
+ $pcGroup = isset( $opts['pcGroup'] ) ? $opts['pcGroup'] : self::PC_PRIMARY;
+ $procCache = $this->getProcessCache( $pcGroup );
+ foreach ( $keys as $key ) {
+ if ( $procCache->get( $key ) !== false ) {
+ $keysFound[] = $key;
+ }
+ }
+ }
+
+ return array_diff( $keys, $keysFound );
+ }
+
+ /**
+ * @param array $keys
+ * @param array $checkKeys
+ * @return array Map of (cache key => mixed)
+ */
+ private function getRawKeysForWarmup( array $keys, array $checkKeys ) {
+ if ( !$keys ) {
+ return [];
+ }
+
+ $keysWarmUp = [];
+ // Get all the value keys to fetch...
+ foreach ( $keys as $key ) {
+ $keysWarmUp[] = self::VALUE_KEY_PREFIX . $key;
+ }
+ // Get all the check keys to fetch...
+ foreach ( $checkKeys as $i => $checkKeyOrKeys ) {
+ if ( is_int( $i ) ) {
+ // Single check key that applies to all value keys
+ $keysWarmUp[] = self::TIME_KEY_PREFIX . $checkKeyOrKeys;
+ } else {
+ // List of check keys that apply to value key $i
+ $keysWarmUp = array_merge(
+ $keysWarmUp,
+ self::prefixCacheKeys( $checkKeyOrKeys, self::TIME_KEY_PREFIX )
+ );
+ }
+ }
+
+ $warmupCache = $this->cache->getMulti( $keysWarmUp );
+ $warmupCache += array_fill_keys( $keysWarmUp, false );
+
+ return $warmupCache;
+ }
}
dépôts / lhc / web / wiklou.git / blobdiff