Package me.ahoo.cosid.machine

Class AbstractMachineIdDistributor

java.lang.Object

me.ahoo.cosid.machine.AbstractMachineIdDistributor

All Implemented Interfaces:

MachineIdDistributor

Direct Known Subclasses:

JdbcMachineIdDistributor, ManualMachineIdDistributor, MongoMachineIdDistributor, ProxyMachineIdDistributor, SpringRedisMachineIdDistributor, StatefulSetMachineIdDistributor, ZookeeperMachineIdDistributor

public abstract class AbstractMachineIdDistributor
extends Object
implements MachineIdDistributor

Abstract MachineIdDistributor.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	NOT_FOUND_LAST_STAMP

Fields inherited from interface me.ahoo.cosid.machine.MachineIdDistributor

FOREVER_SAFE_GUARD_DURATION

Constructor Summary

Constructors

Constructor	Description
AbstractMachineIdDistributor(MachineStateStorage machineStateStorage, ClockBackwardsSynchronizer clockBackwardsSynchronizer)

Method Summary

Modifier and Type	Method	Description
MachineState	distribute(String namespace, int machineBit, InstanceId instanceId, Duration safeGuardDuration)	1.
protected abstract MachineState	distributeRemote(String namespace, int machineBit, InstanceId instanceId, Duration safeGuardDuration)
void	guard(String namespace, InstanceId instanceId, Duration safeGuardDuration)	Guard a machine ID with a heartbeat mechanism.
protected abstract void	guardRemote(String namespace, InstanceId instanceId, MachineState machineState, Duration safeGuardDuration)
void	revert(String namespace, InstanceId instanceId)	1.
protected abstract void	revertRemote(String namespace, InstanceId instanceId, MachineState machineState)

Methods inherited from class java.lang.Object

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

Field Details

NOT_FOUND_LAST_STAMP

public static final int NOT_FOUND_LAST_STAMP

See Also:

• Constant Field Values

Constructor Details

AbstractMachineIdDistributor

public AbstractMachineIdDistributor(MachineStateStorage machineStateStorage,
 ClockBackwardsSynchronizer clockBackwardsSynchronizer)

Method Details

distribute

@Nonnull
public MachineState distribute(String namespace,
 int machineBit,
 InstanceId instanceId,
 Duration safeGuardDuration)
                        throws MachineIdOverflowException

1. get from MachineStateStorage 2. when not found: distributeRemote(java.lang.String, int, me.ahoo.cosid.machine.InstanceId, java.time.Duration) 3. set MachineState to MachineStateStorage

Specified by:

distribute in interface MachineIdDistributor

Parameters:

namespace - The namespace for machine ID allocation

machineBit - The number of bits to use for machine IDs

instanceId - The instance identifier requesting the machine ID

safeGuardDuration - The duration for safe guarding the allocation

Returns:

The machine state containing the allocated machine ID

Throws:

MachineIdOverflowException - if no more machine IDs are available

distributeRemote

protected abstract MachineState distributeRemote(String namespace,
 int machineBit,
 InstanceId instanceId,
 Duration safeGuardDuration)

revert

public void revert(String namespace,
 InstanceId instanceId)

1. get from MachineStateStorage 2. when not found: distributeRemote(java.lang.String, int, me.ahoo.cosid.machine.InstanceId, java.time.Duration) , no need to revert 3. revert

Specified by:

revert in interface MachineIdDistributor

Parameters:

namespace - namespace

instanceId - instanceId

revertRemote

protected abstract void revertRemote(String namespace,
 InstanceId instanceId,
 MachineState machineState)

guard

public void guard(String namespace,
 InstanceId instanceId,
 Duration safeGuardDuration)
           throws NotFoundMachineStateException,
MachineIdLostException

Description copied from interface: MachineIdDistributor

Guard a machine ID with a heartbeat mechanism.

This method updates the heartbeat timestamp for a machine ID to prevent it from being considered stale and reallocated. It should be called periodically by instances to maintain their machine ID lease.

Specified by:

guard in interface MachineIdDistributor

Parameters:

namespace - The namespace of the machine ID

instanceId - The instance identifier whose machine ID should be guarded

safeGuardDuration - The duration for safe guarding the allocation

Throws:

NotFoundMachineStateException - if the machine ID was not found

MachineIdLostException - if the machine ID has been lost or reallocated

guardRemote

protected abstract void guardRemote(String namespace,
 InstanceId instanceId,
 MachineState machineState,
 Duration safeGuardDuration)