pt.unl.fct.di.novasys.babel.crdts.delta.implementations

Class DeltaLWWCRDTMap

java.lang.Object

pt.unl.fct.di.novasys.babel.crdts.generic.CRDT

pt.unl.fct.di.novasys.babel.crdts.delta.generic.DeltaBasedCRDT

pt.unl.fct.di.novasys.babel.crdts.delta.implementations.DeltaLWWCRDTMap

All Implemented Interfaces:

DeltaCRDT, GenericCRDT

public class DeltaLWWCRDTMap
extends DeltaBasedCRDT

A delta-based map with a last-writer-wins policy (LWW) for storing generic CRDTS. The key represents a pair (crdtType,String) and the value as a CRDT of that type. This map is also implemented as a generic CRDT, thus enabling a map of maps of CRDTs (and so forth). The generateDelta method contains the following semantics: all of the entries of the map that correspond to a delta-based CRDT are included in the delta, while the others are excluded. This implementation doesn't support deletes (an alternative that implements this can be found in DeltaORMap) but enables a longer ranger of datatypes embedded into the CRDT. It provides methods to put, delete and get for elements. Additionally, it is possible to iterate over the different elements of the map.

Field Summary

Fields

Modifier and Type	Field and Description
static pt.unl.fct.di.novasys.network.ISerializer<DeltaLWWCRDTMap>	serializer A serializer that serializes the CRDT into (and from) a ByteBuf.

Fields inherited from class pt.unl.fct.di.novasys.babel.crdts.delta.generic.DeltaBasedCRDT

state

Fields inherited from class pt.unl.fct.di.novasys.babel.crdts.generic.CRDT

type

Constructor Summary

Constructors

Constructor and Description
DeltaLWWCRDTMap(ReplicaID replicaID)
DeltaLWWCRDTMap(VVState state)

Method Summary

Modifier and Type	Method and Description
GenericCRDT	copy() Creates a copy of the CRDT.
DeltaLWWCRDTMap	generateDelta(VersionVector vv) Calculates a delta from a given version for the current state
DeltaLWWCRDTMap	generateDelta(VersionVector vv, CRDTsTypes.FLAVOR flavor)
GenericCRDT	get(CRDTTypeKeyPair key)
Iterator<Map.Entry<CRDTTypeKeyPair,GenericCRDT>>	iterator()
DeltaLWWCRDTMap	mergeDelta(DeltaBasedCRDT crdt) Applies a delta to the current state.
DeltaLWWCRDTMap	put(CRDTTypeKeyPair key, GenericCRDT crdt)
void	serialize(io.netty.buffer.ByteBuf in) Serializes the CRDT into a ByteBuf

Methods inherited from class pt.unl.fct.di.novasys.babel.crdts.delta.generic.DeltaBasedCRDT

getReplicaID, getReplicaState

Methods inherited from class pt.unl.fct.di.novasys.babel.crdts.generic.CRDT

getType

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface pt.unl.fct.di.novasys.babel.crdts.generic.GenericCRDT

deserializeDataType, getType

Field Detail

serializer

public static pt.unl.fct.di.novasys.network.ISerializer<DeltaLWWCRDTMap> serializer

A serializer that serializes the CRDT into (and from) a ByteBuf.

Constructor Detail

DeltaLWWCRDTMap

public DeltaLWWCRDTMap(ReplicaID replicaID)

DeltaLWWCRDTMap

public DeltaLWWCRDTMap(VVState state)

Method Detail

put

public DeltaLWWCRDTMap put(CRDTTypeKeyPair key,
                           GenericCRDT crdt)

get

public GenericCRDT get(CRDTTypeKeyPair key)

iterator

public Iterator<Map.Entry<CRDTTypeKeyPair,GenericCRDT>> iterator()

copy

public GenericCRDT copy()

Description copied from interface: GenericCRDT

Creates a copy of the CRDT. Modifications on the copy don't modify the original.

Returns:

a copy of the CRDT

serialize

public void serialize(io.netty.buffer.ByteBuf in)
               throws IOException

Description copied from interface: GenericCRDT

Serializes the CRDT into a ByteBuf

Parameters:

in - ByteBuf to serialize the CRDT to

Throws:

IOException - if an error occurs while serializing

generateDelta

public DeltaLWWCRDTMap generateDelta(VersionVector vv)

Description copied from interface: DeltaCRDT

Calculates a delta from a given version for the current state

Specified by:

generateDelta in interface DeltaCRDT

Specified by:

generateDelta in class DeltaBasedCRDT

Parameters:

vv - a version version to calculate the delta from

Returns:

a delta for the current state

generateDelta

public DeltaLWWCRDTMap generateDelta(VersionVector vv,
                                     CRDTsTypes.FLAVOR flavor)

mergeDelta

public DeltaLWWCRDTMap mergeDelta(DeltaBasedCRDT crdt)

Description copied from interface: DeltaCRDT

Applies a delta to the current state. This method is analogous to a merge of states

Specified by:

mergeDelta in interface DeltaCRDT

Specified by:

mergeDelta in class DeltaBasedCRDT

Parameters:

crdt - a crdt representing the delta

Returns:

the current state