com.couchbase.client.dcp.state

Class SessionState

java.lang.Object

com.couchbase.client.dcp.state.SessionState

public class SessionState
extends Object

Holds the state information for the current session (all partitions involved).

Since:

1.0.0

Author:

Michael Nitschinger

Field Summary

Fields

Modifier and Type	Field and Description
static int	CURRENT_VERSION The current version format used on export, respected on import to aid backwards compatibility.
static long	NO_END_SEQNO The highest possible sequence number, (2^64)-1.

Constructor Summary

Constructors

Constructor and Description
SessionState() Initializes with an empty partition state for 1024 partitions.

Method Summary

Modifier and Type	Method and Description
byte[]	export(StateFormat format) Export the PartitionState into the desired format.
void	foreachPartition(BiConsumer<Integer,PartitionState> consumer)
void	foreachPartition(Consumer<PartitionState> action) Provides an iterator over all partitions, calling the callback for each one.
PartitionState	get(int partition) Accessor into the partition state, only use this if really needed.
boolean	isAtEnd() Check if the current sequence numbers for all partitions are >= the ones set as end.
void	rollbackToPosition(int partition, long seqno) Helper method to rollback the given partition to the given sequence number.
void	set(int partition, PartitionState partitionState) Accessor to set/override the current partition state, only use this if really needed.
void	setFromJson(byte[] persisted) Recovers the session state from persisted JSON.
void	setToBeginningWithNoEnd(int numPartitions) Initializes all partition states to start at the beginning (0) with no end.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

NO_END_SEQNO

public static final long NO_END_SEQNO

The highest possible sequence number, (2^64)-1. Sequence numbers must be interpreted as unsigned values. When comparing two sequence numbers to see which is greater, use Long.compareUnsigned.

See Also:

Constant Field Values

CURRENT_VERSION

public static final int CURRENT_VERSION

The current version format used on export, respected on import to aid backwards compatibility.

See Also:

Constant Field Values

Constructor Detail

SessionState

public SessionState()

Initializes with an empty partition state for 1024 partitions.

Method Detail

setToBeginningWithNoEnd

public void setToBeginningWithNoEnd(int numPartitions)

Initializes all partition states to start at the beginning (0) with no end.

Parameters:

numPartitions - the actual number of partitions used.

setFromJson

public void setFromJson(byte[] persisted)

Recovers the session state from persisted JSON.

Parameters:

persisted - the persisted JSON format.

get

public PartitionState get(int partition)

Accessor into the partition state, only use this if really needed.

If you want to avoid going out of bounds, use the simpler iterator way on foreachPartition(Consumer).

Parameters:

partition - the index of the partition.

Returns:

the partition state for the given partition id.

set

public void set(int partition,
                PartitionState partitionState)

Accessor to set/override the current partition state, only use this if really needed.

Parameters:

partition - the index of the partition.

partitionState - the partition state to override.

isAtEnd

public boolean isAtEnd()

Check if the current sequence numbers for all partitions are >= the ones set as end.

Returns:

true if all are at the end, false otherwise.

rollbackToPosition

public void rollbackToPosition(int partition,
                               long seqno)

Helper method to rollback the given partition to the given sequence number.

This will set the seqno AND REMOVE ALL ENTRIES from the failover log that are higher than the given sequence number!

Parameters:

partition - the partition to rollback

seqno - the sequence number where to roll it back to.

foreachPartition

public void foreachPartition(Consumer<PartitionState> action)

Provides an iterator over all partitions, calling the callback for each one.

Parameters:

action - the action to be called with the state for every partition.

foreachPartition

public void foreachPartition(BiConsumer<Integer,PartitionState> consumer)

export

public byte[] export(StateFormat format)

Export the PartitionState into the desired format.

Parameters:

format - the format in which the state should be exposed, always uses the current version.

Returns:

the exported format, depending on the type can be converted into a string by the user.

toString

public String toString()

Overrides:

toString in class Object