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

Class DeltaLWWRegister

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.DeltaLWWRegister

All Implemented Interfaces:

DeltaCRDT, GenericCRDT

public class DeltaLWWRegister
extends DeltaBasedCRDT

A delta-based register with a last-writer-wins policy (LWW). It allows the assignment of the register and obtaining its value.

Field Summary

Fields

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

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
DeltaLWWRegister(ReplicaID replicaID) Creates a delta-based register by passing the replica identifier.
DeltaLWWRegister(ReplicaID replicaID, String value) Creates a delta-based register with a default value, by passing the replica identifier.
DeltaLWWRegister(VVState state) Creates a delta-based register by passing the replica current state.
DeltaLWWRegister(VVState state, String value) Creates a delta-based register by passing the replica current state.

Method Summary

Modifier and Type	Method and Description
DeltaLWWRegister	assign(String value) Assigns a new value to the register
GenericCRDT	copy() Creates a copy of the CRDT.
DeltaLWWRegister	generateDelta(VersionVector vv) Calculates a delta from a given version for the current state
String	get() Obtains the value of the register
DeltaLWWRegister	mergeDelta(DeltaBasedCRDT crdt) Applies a delta to the current state.
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

TYPE

public static final CRDTsTypes TYPE

serializer

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

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

Constructor Detail

DeltaLWWRegister

public DeltaLWWRegister(ReplicaID replicaID)

Creates a delta-based register by passing the replica identifier. The register is initialized as an empty string.

Parameters:

replicaID - replica identifier

DeltaLWWRegister

public DeltaLWWRegister(ReplicaID replicaID,
                        String value)

Creates a delta-based register with a default value, by passing the replica identifier. The register is initialized as an empty string.

Parameters:

replicaID - replica identifier

value - the initial value of the register

DeltaLWWRegister

public DeltaLWWRegister(VVState state)

Creates a delta-based register by passing the replica current state. The register is initialized as an empty string.

Parameters:

state - replica current state

DeltaLWWRegister

public DeltaLWWRegister(VVState state,
                        String value)

Creates a delta-based register by passing the replica current state. The register is initialized with an initial value.

Parameters:

state - replica current state

value - the initial value of the register

Method Detail

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

get

public String get()

Obtains the value of the register

Returns:

the value of the register

assign

public DeltaLWWRegister assign(String value)

Assigns a new value to the register

Parameters:

value - value to assign

Returns:

a delta with the operation

mergeDelta

public DeltaLWWRegister mergeDelta(DeltaBasedCRDT crdt)
                            throws CRDTNotValidException

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

Throws:

CRDTNotValidException - if the crdt passed as argument is invalid

generateDelta

public DeltaLWWRegister 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

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