org.apache.ignite.internal.processors.cache.distributed.dht

Interface GridDhtTopologyFuture

All Superinterfaces:

IgniteInternalFuture<AffinityTopologyVersion>

All Known Implementing Classes:

GridDhtPartitionsExchangeFuture, GridDhtTopologyFutureAdapter

public interface GridDhtTopologyFuture
extends IgniteInternalFuture<AffinityTopologyVersion>

Future that implements a barrier after which dht topology is safe to use. Topology is considered to be safe to use when all transactions that involve moving primary partitions are completed and partition map exchange is also completed.

When new cache operation is started, it will wait for this future before acquiring new locks on particular topology version.

Method Summary

Modifier and Type	Method and Description
boolean	changedAffinity()
boolean	exchangeDone() Ready affinity future (GridCachePartitionExchangeManager.affinityReadyFuture(AffinityTopologyVersion) is completed before GridFutureAdapter.onDone(Object, Throwable) is called on GridDhtPartitionsExchangeFuture, it is guaranteed that this method will return true if affinity ready future is finished.
AffinityTopologyVersion	initialVersion() Returns topology version when exchange started.
AffinityTopologyVersion	topologyVersion() Gets result topology version of this future.
@Nullable CacheInvalidStateException	validateCache(GridCacheContext cctx, boolean recovery, boolean read, @Nullable Object key, @Nullable Collection<?> keys) Returns error is cache topology is not valid.

Methods inherited from interface org.apache.ignite.internal.IgniteInternalFuture

cancel, chain, chain, error, get, get, get, getUninterruptibly, isCancelled, isDone, listen, result

Method Detail

initialVersion

AffinityTopologyVersion initialVersion()

Returns topology version when exchange started. It can differ from result topology version if exchanges for multiple discovery events are merged. Initial version should not be used as version for cache operation since it is possible affinity for this version is never calculated.

Returns:

Topology version when exchange started.

topologyVersion

AffinityTopologyVersion topologyVersion()

Gets result topology version of this future. Result version can differ from initial exchange version if exchanges for multiple discovery events are merged, in this case result version is version of last discovery event.

This method should be called only for finished topology future since result version is not known before exchange finished.

Returns:

Result topology version.

exchangeDone

boolean exchangeDone()

Ready affinity future (GridCachePartitionExchangeManager.affinityReadyFuture(AffinityTopologyVersion) is completed before GridFutureAdapter.onDone(Object, Throwable) is called on GridDhtPartitionsExchangeFuture, it is guaranteed that this method will return true if affinity ready future is finished.

Also this method returns false for merged exchange futures.

Returns:

True if exchange is finished and result topology version can be used.

validateCache

@Nullable
@Nullable CacheInvalidStateException validateCache(GridCacheContext cctx,
                                                             boolean recovery,
                                                             boolean read,
                                                             @Nullable
                                                             @Nullable Object key,
                                                             @Nullable
                                                             @Nullable Collection<?> keys)

Returns error is cache topology is not valid.

Parameters:

cctx - Cache context.

recovery - True if cache operation is done in recovery mode. Then it will only check for cache active state and topology validator result.

read - True if validating read operation, false if validating write.

key - Key (optimization to avoid collection creation).

keys - Keys involved in a cache operation.

Returns:

Not null exception if a cache is in invalid state.

changedAffinity

boolean changedAffinity()

Returns:

True if this exchange changed affinity.