Package org.jrobin.core

Class RrdNioByteBufferBackend

java.lang.Object

org.jrobin.core.RrdBackend

org.jrobin.core.RrdFileBackend

org.jrobin.core.RrdNioByteBufferBackend

public class RrdNioByteBufferBackend
extends RrdFileBackend

JRobin backend which is used to store RRD data to ordinary disk files by using fast java.nio.* package. This is the default backend engine since JRobin 1.4.0.

Field Summary

Fields inherited from class org.jrobin.core.RrdFileBackend

file

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	RrdNioByteBufferBackend(String path, boolean readOnly)	Creates RrdFileBackend object for the given file path, backed by java.nio.* classes.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the underlying RRD file.
protected void	read(long offset, byte[] b)	Reads a number of bytes from the RRD file on the disk
protected void	setLength(long newLength)	Sets length of the underlying RRD file.
protected void	write(long offset, byte[] b)	Writes bytes to the underlying RRD file on the disk

Methods inherited from class org.jrobin.core.RrdFileBackend

getCanonicalPath, getCanonicalPath, getLength

Methods inherited from class org.jrobin.core.RrdBackend

getPath, isCachingAllowed, isInstanceCreated, isReadOnly, readAll, readDouble, readDouble, readInt, readLong, readString, writeDouble, writeDouble, writeDouble, writeInt, writeLong, writeString

Methods inherited from class java.lang.Object

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

Constructor Detail

RrdNioByteBufferBackend

protected RrdNioByteBufferBackend(String path,
                                  boolean readOnly)
                           throws IOException,
                                  IllegalStateException

Creates RrdFileBackend object for the given file path, backed by java.nio.* classes.

Parameters:

path - Path to a file

readOnly - True, if file should be open in a read-only mode. False otherwise

Throws:

IOException - Thrown in case of I/O error

IllegalStateException

Method Detail

setLength

protected void setLength(long newLength)
                  throws IOException

Sets length of the underlying RRD file. This method is called only once, immediately after a new RRD file gets created.

Overrides:

setLength in class RrdFileBackend

Parameters:

newLength - Length of the RRD file

Throws:

IOException - Thrown in case of I/O error.

write

protected void write(long offset,
                     byte[] b)

Writes bytes to the underlying RRD file on the disk

Overrides:

write in class RrdFileBackend

Parameters:

offset - Starting file offset

b - Bytes to be written.

read

protected void read(long offset,
                    byte[] b)

Reads a number of bytes from the RRD file on the disk

Overrides:

read in class RrdFileBackend

Parameters:

offset - Starting file offset

b - Buffer which receives bytes read from the file.

close

public void close()
           throws IOException

Closes the underlying RRD file.

Overrides:

close in class RrdFileBackend

Throws:

IOException - Thrown in case of I/O error