Package com.github.ddth.dlock.impl

Class AbstractDLock

java.lang.Object

com.github.ddth.dlock.impl.AbstractDLock

All Implemented Interfaces:

IDLock, AutoCloseable

Direct Known Subclasses:

BaseRedisDLock, InmemDLock

public abstract class AbstractDLock
extends Object
implements IDLock, AutoCloseable

Abstract implementation of IDLock.

Since:

0.1.0

Author:

Thanh Ba Nguyen

Field Summary

Fields inherited from interface com.github.ddth.dlock.IDLock

DEFAULT_LOCK_DURATION_MS

Constructor Summary

Constructors

Constructor	Description
AbstractDLock(String name)

Method Summary

Modifier and Type	Method	Description
void	close()
void	destroy()	Cleanup method.
protected String	getClientId()	Get client-id who is currently holding the lock.
protected Properties	getLockProperties()	Get lock's custom properties.
protected String	getLockProperty(String key)	Get lock's custom property.
String	getName()	Get lock's name(space).
protected long	getTimestampExpiry()	Get timestamp (in milliseconds) when the lock-acquisition expires.
AbstractDLock	init()	Init method.
LockResult	lock(int waitWeight, String clientId)	Acquire the lock for clientId with default duration.
LockResult	lock(String clientId)	Acquire the lock for clientId with default duration.
LockResult	lock(String clientId, long lockDurationMs)	Acquire the lock for clientId for a duration of lockDurationMs.
protected AbstractDLock	setClientId(String clientId)	Get client-id who is currently holding the lock.
AbstractDLock	setLockProperties(Properties lockProps)	Lock's custom properties.
AbstractDLock	setName(String name)
protected AbstractDLock	setTimestampExpiry(long timestampExpiry)	Get timestamp (in milliseconds) when the lock-acquisition expires.
String	toString()
protected void	updateLockHolder(String clientId, long lockDurationMs)	Update current lock's holder info.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.github.ddth.dlock.IDLock

lock, unlock

Constructor Detail

AbstractDLock

public AbstractDLock(String name)

Method Detail

getName

public String getName()

Get lock's name(space).

Specified by:

getName in interface IDLock

Returns:

setName

public AbstractDLock setName(String name)

updateLockHolder

protected void updateLockHolder(String clientId,
                                long lockDurationMs)

Update current lock's holder info.

Parameters:

clientId -

lockDurationMs -

Since:

0.1.1

getClientId

protected String getClientId()

Get client-id who is currently holding the lock.

Note: value returned from this method is "estimated".

Returns:

Since:

0.1.1

setClientId

protected AbstractDLock setClientId(String clientId)

Get client-id who is currently holding the lock.

Parameters:

clientId -

Returns:

Since:

0.1.1

getTimestampExpiry

protected long getTimestampExpiry()

Get timestamp (in milliseconds) when the lock-acquisition expires.

Note: value returned from this method is "estimated".

Returns:

Since:

0.1.1

setTimestampExpiry

protected AbstractDLock setTimestampExpiry(long timestampExpiry)

Get timestamp (in milliseconds) when the lock-acquisition expires.

Parameters:

timestampExpiry -

Returns:

Since:

0.1.1

setLockProperties

public AbstractDLock setLockProperties(Properties lockProps)

Lock's custom properties.

Parameters:

lockProps -

Returns:

getLockProperties

protected Properties getLockProperties()

Get lock's custom properties.

Returns:

getLockProperty

protected String getLockProperty(String key)

Get lock's custom property.

Parameters:

key -

Returns:

init

public AbstractDLock init()

Init method.

Returns:

destroy

public void destroy()

Cleanup method.

close

public void close()

Specified by:

close in interface AutoCloseable

lock

public LockResult lock(String clientId)

Acquire the lock for clientId with default duration.

Reentrant: lock can be acquired multiple times by the same clientId. Lock's expiry will be extended accordingly.

Specified by:

lock in interface IDLock

Parameters:

clientId - within a namespace, only one client is allowed to hold lock as a given time

Returns:

LockResult.SUCCESSFUL if successful, LockResult.HOLD_BY_ANOTHER_CLIENT if lock is currently hold by another client

lock

public LockResult lock(int waitWeight,
                       String clientId)

Acquire the lock for clientId with default duration.

Reentrant: lock can be acquired multiple times by the same clientId. Lock's expiry will be extended accordingly.

Specified by:

lock in interface IDLock

Parameters:

waitWeight - "fairness": clientId with higher waitWeight value might have higher chance to acquire the lock, negative value means "no fairness"

clientId - within a namespace, only one client is allowed to hold the lock as a given time

Returns:

LockResult.SUCCESSFUL if successful, LockResult.HOLD_BY_ANOTHER_CLIENT if lock is currently hold by another client

Since:

0.1.2

lock

public LockResult lock(String clientId,
                       long lockDurationMs)

Acquire the lock for clientId for a duration of lockDurationMs.

Reentrant: lock can be acquired multiple times by the same clientId. Lock's expiry will be extended accordingly.

Specified by:

lock in interface IDLock

Parameters:

clientId - within a namespace, only one client is allowed to hold the lock as a given time

Returns:

LockResult.SUCCESSFUL if successful, LockResult.HOLD_BY_ANOTHER_CLIENT if lock is currently hold by another client

Since:

0.1.2

toString

public String toString()

Overrides:

toString in class Object

Since:

0.1.1