org.rrd4j.core.RrdSafeFileBackendFactory

All Implemented Interfaces:: Closeable, AutoCloseable

@RrdBackendAnnotation(name="SAFE",
                      shouldValidateHeader=true,
                      cachingAllowed=false)
public class RrdSafeFileBackendFactory
extends RrdRandomAccessFileBackendFactory

Factory class which creates actual RrdSafeFileBackend objects.

Because of locking, each RrdDb can be open only once even from within the JVM. So usage of the RrdDbPool is mandatory with this backend.

Field Summary

Fields
Modifier and Type	Field	Description
`static long`	`LOCK_RETRY_PERIOD`	Default time between two consecutive file locking attempts.
`static long`	`LOCK_WAIT_TIME`	Default time (in milliseconds) this backend will wait for a file lock.

Fields inherited from class org.rrd4j.core.RrdBackendFactory

cachingAllowed, DEFAULTFACTORY, name, scheme, validateHeader

Constructor Summary

Constructors
Constructor	Description
`RrdSafeFileBackendFactory()`	Generate a factory using the default system wide lock settings
`RrdSafeFileBackendFactory(long lockWaitTime, long lockRetryPeriod)`	Generate a factory with custom lock settings

Method Summary

Modifier and Type	Method	Description
`static long`	`getLockRetryPeriod()`	Returns time between two consecutive file locking attempts.
`static long`	`getLockWaitTime()`	Returns time this backend will wait for a file lock.
`protected RrdBackend`	`open(String path, boolean readOnly)`	Creates RrdFileBackend object for the given file path.
`static void`	`setLockRetryPeriod(long lockRetryPeriod)`	Sets time between two consecutive file locking attempts.
`static void`	`setLockWaitTime(long lockWaitTime)`	Sets time this backend will wait for a file lock.

Methods inherited from class org.rrd4j.core.RrdFileBackendFactory

canStore, exists, getCanonicalUri, getPath, getUri

Methods inherited from class org.rrd4j.core.RrdBackendFactory

addActiveFactories, addFactories, buildGenericUri, checkClosing, close, exists, findFactory, getActiveFactories, getBackend, getBackend, getDefaultFactory, getFactory, getName, getRootUri, getScheme, registerAndSetAsDefaultFactory, registerFactory, resolve, setActiveFactories, setDefaultFactory, shouldValidateHeader, shouldValidateHeader

Methods inherited from class java.lang.Object

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

Field Details
- LOCK_WAIT_TIME
  
  public static final long LOCK_WAIT_TIME
  
  Default time (in milliseconds) this backend will wait for a file lock.
  
  See Also:
  
  Constant Field Values
- LOCK_RETRY_PERIOD
  
  public static final long LOCK_RETRY_PERIOD
  
  Default time between two consecutive file locking attempts.
  
  See Also:
  
  Constant Field Values
Constructor Details
- RrdSafeFileBackendFactory
  
  public RrdSafeFileBackendFactory()
  
  Generate a factory using the default system wide lock settings
- RrdSafeFileBackendFactory
  
  public RrdSafeFileBackendFactory(long lockWaitTime, long lockRetryPeriod)
  
  Generate a factory with custom lock settings
  
  Parameters:
  
  lockWaitTime - wait time in ms
  
  lockRetryPeriod - retry period in ms
Method Details
- open
  
  protected RrdBackend open(String path, boolean readOnly) throws IOException
  
  Creates RrdFileBackend object for the given file path. Creates RrdSafeFileBackend object for the given file path.
  
  Overrides:
  
  open in class RrdRandomAccessFileBackendFactory
  
  Throws:
  
  IOException
- getLockWaitTime
  
  public static long getLockWaitTime()
  
  Returns time this backend will wait for a file lock.
  
  Returns:
  
  Time (in milliseconds) this backend will wait for a file lock.
- setLockWaitTime
  
  public static void setLockWaitTime(long lockWaitTime)
  
  Sets time this backend will wait for a file lock.
  
  Parameters:
  
  lockWaitTime - Maximum lock wait time (in milliseconds)
- getLockRetryPeriod
  
  public static long getLockRetryPeriod()
  
  Returns time between two consecutive file locking attempts.
  
  Returns:
  
  Time (im milliseconds) between two consecutive file locking attempts.
- setLockRetryPeriod
  
  public static void setLockRetryPeriod(long lockRetryPeriod)
  
  Sets time between two consecutive file locking attempts.
  
  Parameters:
  
  lockRetryPeriod - time (in milliseconds) between two consecutive file locking attempts.

Class RrdSafeFileBackendFactory