edu.umass.cs.txn.txpackets

Class TXPacket

java.lang.Object

edu.umass.cs.nio.JSONPacket

edu.umass.cs.txn.txpackets.TXPacket

All Implemented Interfaces:

ClientRequest, Request, RequestIdentifier, ReplicableRequest, Summarizable

Direct Known Subclasses:

AbortRequest, CommitRequest, LockRequest, TxOpRequest, TxStateRequest, UnlockRequest

public abstract class TXPacket
extends JSONPacket
implements ReplicableRequest, ClientRequest

Author:

arun All transaction processing related packets inherit from this class.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	TXPacket.PacketType Transaction packet types.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.String	txid

Fields inherited from class edu.umass.cs.nio.JSONPacket

PACKET_TYPE, type

Fields inherited from interface edu.umass.cs.gigapaxos.interfaces.Request

NO_OP

Constructor Summary

Constructors

Constructor and Description
TXPacket(IntegerPacketType t, java.lang.String txid)
TXPacket(org.json.JSONObject json)

Method Summary

Modifier and Type	Method and Description
long	getRequestID() The uniqueness of this identifier across all requests to a replica group is important for safety when PaxosConfig.PC.PREVENT_DOUBLE_EXECUTION is enabled as gigapaxos may otherwise assume that the duplicate request identifier corresponds to a retransmission and will send back the response if any corresponding to the first execution.
IntegerPacketType	getRequestType()
ClientRequest	getResponse()
ResponseCode	getResponseCode()
java.lang.String	getServiceName()
java.lang.String	getTXID()
TXPacket.PacketType	getTXPacketType()
boolean	isFailed()
boolean	needsCoordination()
protected TXPacket	setFailed()
void	setResponseCode(ResponseCode code)
protected org.json.JSONObject	toJSONObjectImpl()

Methods inherited from class edu.umass.cs.nio.JSONPacket

couldBeJSON, couldBeJSON, couldBeJSON, couldBeJSONArray, couldBeJSONObject, getPacketType, putPacketType, putPacketType, toJSONObject, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.umass.cs.reconfiguration.interfaces.ReplicableRequest

setNeedsCoordination

Methods inherited from interface edu.umass.cs.gigapaxos.interfaces.ClientRequest

getClientAddress

Methods inherited from interface edu.umass.cs.gigapaxos.interfaces.Request

getSummary, toBytes, toString

Methods inherited from interface edu.umass.cs.utils.Summarizable

getSummary

Field Detail

txid

protected final java.lang.String txid

Constructor Detail

TXPacket

public TXPacket(IntegerPacketType t,
                java.lang.String txid)

Parameters:

t -

txid -

TXPacket

public TXPacket(org.json.JSONObject json)
         throws org.json.JSONException

Parameters:

json -

Throws:

org.json.JSONException

Method Detail

getRequestType

public IntegerPacketType getRequestType()

Specified by:

getRequestType in interface Request

Returns:

The IntegerPacketType type corresponding to this request.

getTXPacketType

public TXPacket.PacketType getTXPacketType()

Returns:

TXPacket.PacketType

getServiceName

public java.lang.String getServiceName()

Specified by:

getServiceName in interface Request

Returns:

Returns the unique app-level replica-group ID.

getRequestID

public long getRequestID()

Description copied from interface: RequestIdentifier

The uniqueness of this identifier across all requests to a replica group is important for safety when PaxosConfig.PC.PREVENT_DOUBLE_EXECUTION is enabled as gigapaxos may otherwise assume that the duplicate request identifier corresponds to a retransmission and will send back the response if any corresponding to the first execution. With PaxosConfig.PC.PREVENT_DOUBLE_EXECUTION disabled, the uniqueness is important for liveness as duplicate request identifiers may result in the client not receiving a response for the latter request; this is because gigapaxos stores request execution callbacks indexed by the request identifier, so there must be at most one outstanding request with a given identifier for a given replica group.

Specified by:

getRequestID in interface RequestIdentifier

Returns:

A unique request identifier for this request.

getResponse

public ClientRequest getResponse()

Specified by:

getResponse in interface ClientRequest

Returns:

The response to be sent back to the client that issued this request. AbstractReplicaCoordinator, e.g., PaxosManager, will invoke this method immediately after Application.execute(Request) and, if the returned response is non-null, will send it back to the client that issued that request. Applications are expected to internally implement logic that sets the response at the end of Application.execute(Request) as follows:

public boolean Replicable.execute(Request request)} {
// execute request to obtain response
request.setResponse(response);
}

needsCoordination

public boolean needsCoordination()

Specified by:

needsCoordination in interface ReplicableRequest

Returns:

True if this request needs to be coordinated, false otherwise.

toJSONObjectImpl

protected org.json.JSONObject toJSONObjectImpl()
                                        throws org.json.JSONException

Specified by:

toJSONObjectImpl in class JSONPacket

Returns:

JSONObject corresponding to fields in classes extending this class.

Throws:

org.json.JSONException

isFailed

public boolean isFailed()

Returns:

True if this request failed; false otherwise.

setFailed

protected TXPacket setFailed()

getResponseCode

public ResponseCode getResponseCode()

Returns:

Response code.

setResponseCode

public void setResponseCode(ResponseCode code)

Parameters:

code -

getTXID

public java.lang.String getTXID()

Returns:

The ID of the transaction to which this packet corresponds. The initiator is set only after a transaction request has been received by the entry server, so until then, the ID only has the transaction number.