StorageBasedLockProvider (shedlock-core 4.7.0 API)

java.lang.Object
- net.javacrumbs.shedlock.support.StorageBasedLockProvider

All Implemented Interfaces:

LockProvider
```
public class StorageBasedLockProvider
extends Object
implements LockProvider
```
Distributed lock using abstract storage
It uses a table/collection that contains ID = lock name and a field locked_until.
1. Attempts to insert a new lock record. As an optimization, we keep in-memory track of created lock records. If the record has been inserted, returns lock.
2. We will try to update lock record using filter ID == name AND lock_until <= now
3. If the update succeeded (1 updated row/document), we have the lock. If the update failed (0 updated documents) somebody else holds the lock
4. When unlocking, lock_until is set to now.

Constructor Summary

Constructors
Modifier Constructor Description

protected StorageBasedLockProvider(@NotNull StorageAccessor storageAccessor)

Method Summary

Modifier and Type	Method	Description
`void`	`clearCache()`	Clears cache of existing lock records.
`protected boolean`	`doLock(LockConfiguration lockConfiguration)`	Sets lockUntil according to LockConfiguration if current lockUntil <= now
`@NotNull Optional<SimpleLock>`	`lock(@NotNull LockConfiguration lockConfiguration)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StorageBasedLockProvider

protected StorageBasedLockProvider(@NotNull
                                   @NotNull StorageAccessor storageAccessor)

Method Detail
- clearCache
```
public void clearCache()
```
  Clears cache of existing lock records.
- lock
```
@NotNull
public @NotNull Optional<SimpleLock> lock(@NotNull
                                          @NotNull LockConfiguration lockConfiguration)
```
  Specified by:
  
  lock in interface LockProvider
  
  Returns:
  
  If empty optional has been returned, lock could not be acquired. The lock has to be released by the callee.
- doLock
```
protected boolean doLock(LockConfiguration lockConfiguration)
```
  Sets lockUntil according to LockConfiguration if current lockUntil <= now