/** @var int[] Map of (ATTR_* class constant => QOS_* class constant) */
protected $attrMap = [];
- /** Bitfield constants for get()/getMulti() */
- const READ_LATEST = 1; // use latest data for replicated stores
- const READ_VERIFIED = 2; // promise that caller can tell when keys are stale
- /** Bitfield constants for set()/merge() */
- const WRITE_SYNC = 4; // synchronously write to all locations for replicated stores
- const WRITE_CACHE_ONLY = 8; // Only change state of the in-memory cache
- const WRITE_ALLOW_SEGMENTS = 16; // Allow partitioning of the value if it is large
- const WRITE_PRUNE_SEGMENTS = 32; // Delete all partition segments of the value
+ /** Bitfield constants for get()/getMulti(); these are only advisory */
+ const READ_LATEST = 1; // if supported, avoid reading stale data due to replication
+ const READ_VERIFIED = 2; // promise that the caller handles detection of staleness
+ /** Bitfield constants for set()/merge(); these are only advisory */
+ const WRITE_SYNC = 4; // if supported, block until the write is fully replicated
+ const WRITE_CACHE_ONLY = 8; // only change state of the in-memory cache
+ const WRITE_ALLOW_SEGMENTS = 16; // allow partitioning of the value if it is large
+ const WRITE_PRUNE_SEGMENTS = 32; // delete all the segments if the value is partitioned
+ const WRITE_BACKGROUND = 64; // if supported,
/** @var string Component to use for key construction of blob segment keys */
const SEGMENT_COMPONENT = 'segment';
*
* This does not support WRITE_ALLOW_SEGMENTS to avoid excessive read I/O
*
+ * WRITE_BACKGROUND can be used for bulk insertion where the response is not vital
+ *
* @param mixed[] $data Map of (key => value)
* @param int $exptime Either an interval in seconds or a unix timestamp for expiry
* @param int $flags Bitfield of BagOStuff::WRITE_* constants (since 1.33)
*
* This does not support WRITE_ALLOW_SEGMENTS to avoid excessive read I/O
*
+ * WRITE_BACKGROUND can be used for bulk deletion where the response is not vital
+ *
* @param string[] $keys List of keys
* @param int $flags Bitfield of BagOStuff::WRITE_* constants
* @return bool Success