Package org.rrd4j.core

Class RrdMemoryBackendFactory

java.lang.Object

org.rrd4j.core.RrdBackendFactory

org.rrd4j.core.RrdMemoryBackendFactory

All Implemented Interfaces:

Closeable, AutoCloseable

@RrdBackendAnnotation(name="MEMORY",
                      shouldValidateHeader=false)
public class RrdMemoryBackendFactory
extends RrdBackendFactory

Factory class which creates actual RrdMemoryBackend objects. Rrd4j's support for in-memory RRDs is still experimental. You should know that all active RrdMemoryBackend objects are held in memory, each backend object stores RRD data in one big byte array. This implementation is therefore quite basic and memory hungry but runs very fast.

Calling close() on RrdDb objects does not release any memory at all (RRD data must be available for the next new RrdDb(path) call. To release allocated memory, you'll have to call delete(path) method of this class.

Field Summary

Fields

Modifier and Type	Field	Description
protected Map<String,AtomicReference<ByteBuffer>>	backends

Fields inherited from class org.rrd4j.core.RrdBackendFactory

cachingAllowed, DEFAULTFACTORY, name, scheme, validateHeader

Constructor Summary

Constructors

Constructor	Description
RrdMemoryBackendFactory()

Method Summary

Modifier and Type	Method	Description
boolean	canStore(URI uri)
boolean	delete(String id)	Removes the storage with the given ID from the memory.
protected boolean	exists(String id)	Determines if a storage with the given path already exists.
protected RrdBackend	open(String id, boolean readOnly)	Creates RrdMemoryBackend object.

Methods inherited from class org.rrd4j.core.RrdBackendFactory

addActiveFactories, addFactories, buildGenericUri, checkClosing, close, exists, findFactory, getActiveFactories, getBackend, getBackend, getCanonicalUri, getDefaultFactory, getFactory, getName, getPath, getRootUri, getScheme, getUri, 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 Detail

backends

protected final Map<String,AtomicReference<ByteBuffer>> backends

Constructor Detail

RrdMemoryBackendFactory

public RrdMemoryBackendFactory()

Method Detail

open

protected RrdBackend open(String id,
                          boolean readOnly)
                   throws IOException

Creates RrdMemoryBackend object.

Specified by:

open in class RrdBackendFactory

Throws:

IOException

canStore

public boolean canStore(URI uri)

Overrides:

canStore in class RrdBackendFactory

exists

protected boolean exists(String id)

Determines if a storage with the given path already exists. Method to determine if a memory storage with the given ID already exists.

Specified by:

exists in class RrdBackendFactory

Parameters:

id - Storage path

Returns:

a boolean.

delete

public boolean delete(String id)

Removes the storage with the given ID from the memory.

Parameters:

id - Storage ID

Returns:

a boolean.