// makeKey encodes the range ID and client command ID into a key
// for storage in the underlying engine. Note that the prefix for
// response cache keys sorts them at the very top of the engine's
// keyspace.
func (rc *ResponseCache) makeKey(cmdID proto.ClientCmdID) engine.Key {
// Key specifics: range ID & HLC timestamp.
b := append([]byte{}, engine.KeyLocalRangeResponseCachePrefix...)
b = encoding.EncodeInt(b, rc.rangeID)
b = encoding.EncodeInt(b, cmdID.WallTime) // wall time helps sort for locality
b = encoding.EncodeInt(b, cmdID.Random) // TODO(spencer): encode as Fixed64
return b
}
// makeKey encodes the range ID and client command ID into a key
// for storage in the underlying engine. Note that the prefix for
// response cache keys sorts them at the very top of the engine's
// keyspace.
// TODO(spencer): going to need to encode the server timestamp
// for when the value was written for GC.
func (rc *ResponseCache) makeKey(cmdID ClientCmdID) engine.Key {
// The max length of encoded int is 12.
b := make([]byte, 0, len(engine.KeyLocalRangeResponseCachePrefix)+3*12)
b = append(b, engine.KeyLocalRangeResponseCachePrefix...)
b = encoding.EncodeInt(b, rc.rangeID)
b = encoding.EncodeInt(b, cmdID.WallTime) // wall time helps sort for locality
b = encoding.EncodeInt(b, cmdID.Random) // TODO(spencer): encode as Fixed64
return b
}