io.permazen.kv.raft

Enum TxState

java.lang.Object

java.lang.Enum<TxState>

io.permazen.kv.raft.TxState

All Implemented Interfaces:

Serializable, Comparable<TxState>

public enum TxState
extends Enum<TxState>

RaftKVTransaction states.

Transactions always progress through these states in the forward direction (i.e., in their natural order).

Enum Constant Summary

Enum Constants

Enum Constant and Description
CLOSED The transaction is closed.
COMMIT_READY The transaction is ready for commit.
COMMIT_WAITING The transaction is waiting for the corresponding Raft log entry to be committed.
COMPLETED The transaction has committed successfully or failed, and is waiting to be cleaned up.
EXECUTING The transaction is open, executing locally, and neither RaftKVTransaction.commit() nor RaftKVTransaction.rollback() has been invoked yet.

Method Summary

Modifier and Type	Method and Description
static TxState	valueOf(String name) Returns the enum constant of this type with the specified name.
static TxState[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

EXECUTING

public static final TxState EXECUTING

The transaction is open, executing locally, and neither RaftKVTransaction.commit() nor RaftKVTransaction.rollback() has been invoked yet.

No network communication with any other node has occurred yet on behalf of the transaction.

COMMIT_READY

public static final TxState COMMIT_READY

The transaction is ready for commit.

RaftKVTransaction.commit() has been invoked, but the transaction has not otherwise been dealt with yet. If we are a follower, it will be transmitted to the leader once the leader is known and his output queue becomes empty; while we are waiting for the response from the leader, the transaction remains in this state. If we are the leader, it will be dealt with locally as soon as we can get to it.

COMMIT_WAITING

public static final TxState COMMIT_WAITING

The transaction is waiting for the corresponding Raft log entry to be committed.

The transaction has been assigned a commit term and index by the leader. We are waiting for the corresponding Raft log entry to be committed to the Raft log.

COMPLETED

public static final TxState COMPLETED

The transaction has committed successfully or failed, and is waiting to be cleaned up.

The thread that invoked RaftKVTransaction.commit() or RaftKVTransaction.rollback() has not yet woken up and returned from the invocation. The transaction's commitFuture has been completed one way or another.

CLOSED

public static final TxState CLOSED

The transaction is closed.

Method Detail

values

public static TxState[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (TxState c : TxState.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static TxState valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null