Yuta HIGUCHI | 598e57e | 2014-06-16 21:19:01 -0700 | [diff] [blame] | 1 | package net.onrc.onos.core.datastore.ramcloud; |
| 2 | |
| 3 | import org.slf4j.Logger; |
| 4 | import org.slf4j.LoggerFactory; |
| 5 | |
| 6 | import net.onrc.onos.core.datastore.IKVTable; |
| 7 | import net.onrc.onos.core.datastore.IKVTableID; |
| 8 | import net.onrc.onos.core.datastore.ObjectDoesntExistException; |
| 9 | import net.onrc.onos.core.datastore.ObjectExistsException; |
| 10 | import net.onrc.onos.core.datastore.IKVTable.IKVEntry; |
| 11 | import net.onrc.onos.core.datastore.utils.ByteArrayUtil; |
| 12 | import net.onrc.onos.core.util.distributed.DistributedAtomicLong; |
| 13 | |
| 14 | /** |
| 15 | * RAMCloudImplementation of DistributedAtomicLong. |
| 16 | */ |
| 17 | public class RCDistributedAtomicLong implements DistributedAtomicLong { |
| 18 | private static final String PREFIX = "DAL:"; |
| 19 | private static final byte[] KEY = {0}; |
| 20 | private static final byte[] ZERO = ByteArrayUtil.toLEBytes(0L); |
| 21 | |
| 22 | private static final Logger log = LoggerFactory.getLogger(RCDistributedAtomicLong.class); |
| 23 | |
| 24 | |
| 25 | private final RCClient client; |
| 26 | private final String name; |
| 27 | private final IKVTableID tableID; |
| 28 | |
| 29 | |
| 30 | /** |
| 31 | * Creates or Gets the DistributedAtomicLong instance. |
| 32 | * |
| 33 | * @param client client to use. |
| 34 | * @param name name of the DistributedAtomicLong instance. |
| 35 | */ |
| 36 | public RCDistributedAtomicLong(final RCClient client, final String name) { |
| 37 | |
| 38 | this.client = client; |
| 39 | this.name = name; |
| 40 | IKVTable table = client.getTable(PREFIX + name); |
| 41 | this.tableID = table.getTableId(); |
| 42 | |
| 43 | try { |
| 44 | table.create(KEY, ZERO); |
| 45 | } catch (ObjectExistsException e) { |
| 46 | log.trace("RCDistributedAtomicLong {} already exists", name); |
| 47 | } |
| 48 | } |
| 49 | |
| 50 | @Override |
| 51 | public long get() { |
| 52 | try { |
| 53 | IKVEntry entry = client.read(tableID, KEY); |
| 54 | return ByteArrayUtil.fromLEBytes(entry.getValue()); |
| 55 | } catch (ObjectDoesntExistException e) { |
| 56 | log.error("RCDistributedAtomicLong {} does not exist", name); |
| 57 | throw new IllegalStateException(name + " does not exist", e); |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | @Override |
| 62 | public long addAndGet(long delta) { |
| 63 | return client.incrementCounter(tableID, KEY, delta); |
| 64 | } |
| 65 | |
| 66 | @Override |
| 67 | public void set(long newValue) { |
| 68 | client.setCounter(tableID, KEY, newValue); |
| 69 | } |
| 70 | |
| 71 | @Override |
| 72 | public long incrementAndGet() { |
| 73 | return addAndGet(1L); |
| 74 | } |
| 75 | |
| 76 | } |