# Package org.rrd4j.core

core RRD4J implementation.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  DataHolder | Interface for holding data sources.
  Robin | Class to represent archive values for a single datasource.
  RrdFileBackend | An abstract backend which is used to store RRD data to ordinary files on the disk.
  RrdUpdater<T extends RrdUpdater<T>> | Interface for RRD components that can update their state.
  XmlWriter.DoubleFormater | Functional interface for formatting double values in XML output.

- Class Summary
  Class | Description
  --- | ---
  ArcDef | Class to represent single archive definition within the RRD.
  Archive | Class to represent single RRD archive in a RRD with its internal state.
  ArcState | Class to represent internal RRD archive state for a single datasource.
  ByteBufferBackend | A backend that store and provides access to data using a `ByteBuffer`, using java internal methods for long, integer and others types.
  DataImporter | An abstract class to import data from external source.
  Datasource | Class to represent single datasource within RRD.
  DsDef | Class to represent single data source definition within the RRD.
  FetchData | Class used to represent data fetched from the RRD.
  FetchRequest | Class to represent fetch request.
  Header | Class to represent RRD header.
  RobinArray | Class to represent archive values for a single datasource.
  RobinMatrix | Class to represent archive values for a single datasource.
  RrdAllocator | An internal usage class.
  RrdBackend | Base implementation class for all backend classes.
  RrdBackendFactory | Base (abstract) backend factory class which holds references to all concrete backend factories and defines abstract methods which must be implemented in all concrete factory implementations.
  RrdByteArrayBackend | Abstract byte array based backend.
  RrdDb | Main class used to create and manipulate round robin databases (RRDs).
  RrdDb.Builder | Builder for `RrdDb` instances.
  RrdDbPool | This class should be used to synchronize access to RRD files in a multithreaded environment.
  RrdDef | Class to represent definition of new Round Robin Database (RRD).
  RrdDefTemplate | Class used to create an arbitrary number of `RrdDef` (RRD definition) objects from a single XML template.
  RrdDouble<U extends RrdUpdater<U>> | RRD double primitive type.
  RrdDoubleArray<U extends RrdUpdater<U>> | RRD primitive type for handling arrays of double values.
  RrdDoubleMatrix<U extends RrdUpdater<U>> | RRD primitive type for handling matrices of double values.
  RrdEnum<U extends RrdUpdater<U>,E extends Enum<E>> | RRD primitive type for handling enum values.
  RrdFileBackendFactory | An abstract backend factory which is used to store RRD data to ordinary files on the disk.
  RrdInt<U extends RrdUpdater<U>> | RRD integer primitive type.
  RrdLong<U extends RrdUpdater<U>> | RRD primitive type for handling long integer values.
  RrdMemoryBackend | Backend to be used to store all RRD bytes in memory.
  RrdMemoryBackendFactory | Factory class which creates actual `RrdMemoryBackend` objects.
  RrdNioBackend | Backend which is used to store RRD data to ordinary disk files using java.nio.* package.
  RrdNioBackendFactory | Factory class which creates actual `RrdNioBackend` objects.
  RrdPrimitive<U extends RrdUpdater<U>> | Abstract base class for all RRD primitive data types.
  RrdRandomAccessFileBackend | Backend which is used to store RRD data to ordinary files on the disk.
  RrdRandomAccessFileBackendFactory | Factory class which creates actual `RrdRandomAccessFileBackend` objects.
  RrdSafeFileBackend | Backend which is used to store RRD data to ordinary files on the disk, using locking.
  RrdSafeFileBackend.Counters | Internal counters for tracking file locking operations.
  RrdSafeFileBackendFactory | Factory class which creates actual `RrdSafeFileBackend` objects.
  RrdString<U extends RrdUpdater<U>> | RRD primitive type for handling string values.
  RrdSyncThreadPool | Thread pool used by `RrdNioBackend` instances to periodically sync the mapped file to disk.
  RrdSyncThreadPool.DaemonThreadFactory | Daemon thread factory used by the monitor executors.
  RrdToolkit | Class used to perform various complex operations on RRD files.
  RrdToolReader | Reader for RRDTool format RRD files.
  Sample | Class to represent data source values for the given timestamp.
  Util | Class defines various utility functions used in Rrd4j.
  Util.Xml | Various DOM utility functions.
  XmlReader | Reader for importing RRD data from XML format.
  XmlTemplate | Class used as a base class for various XML template related classes.
  XmlWriter | Extremely simple utility class used to create XML documents.

- Exception Summary
  Exception | Description
  --- | ---
  InvalidRrdException | An exception indicating a corrupted RRD.
  RrdBackendException | Wrap a exception generated by the backend store
  RrdException | A general purpose RRD4J exception.

- Annotation Types Summary
  Annotation Type | Description
  --- | ---
  RrdBackendAnnotation | Description of a `RrdBackendFactory`

## Package org.rrd4j.core Description

core RRD4J implementation.