java.lang.Object

org.rrd4j.core.RrdBackend

org.rrd4j.core.ByteBufferBackend

Direct Known Subclasses:: RrdByteArrayBackend, RrdMemoryBackend, RrdNioBackend

public abstract class ByteBufferBackend
extends RrdBackend

A backend that store and provides access to data using a ByteBuffer, using java internal methods for long, integer and others types.

Since:: 3.4
Author:: Fabrice Bacchella

Field Summary

Fields inherited from class org.rrd4j.core.RrdBackend
BYTEORDER
Constructor Summary

Constructors

Modifier Constructor Description

protected ByteBufferBackend(String path)

Method Summary

Modifier and Type	Method	Description
`protected void`	`close()`	Closes the underlying backend.
`protected CharBuffer`	`getCharBuffer(long offset, int size)`	Extract a CharBuffer from the backend, used by readString
`protected boolean`	`isDirty()`
`protected void`	`read(long offset, byte[] b)`	Reads a number of bytes from the RRD file on the disk
`double`	`readDouble(long offset)`
`double[]`	`readDouble(long offset, int count)`
`protected int`	`readInt(long offset)`
`protected long`	`readLong(long offset)`
`protected short`	`readShort(long offset)`
`protected void`	`rrdClose()`	Closes the underlying backend.
`protected void`	`setByteBuffer(ByteBuffer byteBuffer)`
`protected void`	`write(long offset, byte[] b)`	Writes bytes to the underlying RRD file on the disk
`protected void`	`writeDouble(long offset, double value)`
`protected void`	`writeDouble(long offset, double[] values)`
`protected void`	`writeDouble(long offset, double value, int count)`
`protected void`	`writeInt(long offset, int value)`
`protected void`	`writeLong(long offset, long value)`
`protected void`	`writeShort(long offset, short value)`
`protected void`	`writeString(long offset, String value, int length)`

Methods inherited from class org.rrd4j.core.RrdBackend

done, getFactory, getLength, getPath, getUri, isCachingAllowed, isInstanceCreated, readAll, readString, setLength, writeString

Methods inherited from class java.lang.Object

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

Constructor Details
- ByteBufferBackend
  
  protected ByteBufferBackend(String path)
Method Details
- setByteBuffer
  
  protected void setByteBuffer(ByteBuffer byteBuffer)
- write
  
  protected void write(long offset, byte[] b) throws IOException
  
  Writes bytes to the underlying RRD file on the disk
  
  Specified by:
  
  write in class RrdBackend
  
  Parameters:
  
  offset - Starting file offset
  
  b - Bytes to be written.
  
  Throws:
  
  IOException - if any.
  
  IllegalArgumentException - if offset is bigger that the possible mapping position (2GiB).
- writeShort
  
  protected void writeShort(long offset, short value) throws IOException
  
  Overrides:
  
  writeShort in class RrdBackend
  
  Throws:
  
  IOException
- writeInt
  
  protected void writeInt(long offset, int value) throws IOException
  
  Overrides:
  
  writeInt in class RrdBackend
  
  Throws:
  
  IOException
- writeLong
  
  protected void writeLong(long offset, long value) throws IOException
  
  Overrides:
  
  writeLong in class RrdBackend
  
  Throws:
  
  IOException
- writeDouble
  
  protected void writeDouble(long offset, double value) throws IOException
  
  Overrides:
  
  writeDouble in class RrdBackend
  
  Throws:
  
  IOException
- writeDouble
  
  protected void writeDouble(long offset, double value, int count) throws IOException
  
  Overrides:
  
  writeDouble in class RrdBackend
  
  Throws:
  
  IOException
- writeDouble
  
  protected void writeDouble(long offset, double[] values) throws IOException
  
  Overrides:
  
  writeDouble in class RrdBackend
  
  Throws:
  
  IOException
- writeString
  
  protected void writeString(long offset, String value, int length) throws IOException
  
  Overrides:
  
  writeString in class RrdBackend
  
  Throws:
  
  IOException
- read
  
  protected void read(long offset, byte[] b) throws IOException
  
  Reads a number of bytes from the RRD file on the disk
  
  Specified by:
  
  read in class RrdBackend
  
  Parameters:
  
  offset - Starting file offset
  
  b - Buffer which receives bytes read from the file.
  
  Throws:
  
  IOException - Thrown in case of I/O error.
  
  IllegalArgumentException - if offset is bigger that the possible mapping position (2GiB).
- readShort
  
  protected short readShort(long offset) throws IOException
  
  Overrides:
  
  readShort in class RrdBackend
  
  Throws:
  
  IOException
- readInt
  
  protected int readInt(long offset) throws IOException
  
  Overrides:
  
  readInt in class RrdBackend
  
  Throws:
  
  IOException
- readLong
  
  protected long readLong(long offset) throws IOException
  
  Overrides:
  
  readLong in class RrdBackend
  
  Throws:
  
  IOException
- readDouble
  
  public double readDouble(long offset) throws IOException
  
  Overrides:
  
  readDouble in class RrdBackend
  
  Throws:
  
  IOException
- readDouble
  
  public double[] readDouble(long offset, int count) throws IOException
  
  Overrides:
  
  readDouble in class RrdBackend
  
  Throws:
  
  IOException
- getCharBuffer
  
  protected CharBuffer getCharBuffer(long offset, int size) throws RrdException
  
  Description copied from class: RrdBackend
  
  Extract a CharBuffer from the backend, used by readString
  
  Overrides:
  
  getCharBuffer in class RrdBackend
  
  Parameters:
  
  offset - the offset in the rrd
  
  size - the size of the buffer, in character
  
  Returns:
  
  a new CharBuffer
  
  Throws:
  
  RrdException
- close
  
  protected void close() throws IOException
  
  Description copied from class: RrdBackend
  
  Closes the underlying backend. Used internally, should not be called from external code.
  
  Specified by:
  
  close in class RrdBackend
  
  Throws:
  
  IOException - Thrown in case of I/O error
- isDirty
  
  protected boolean isDirty()
- rrdClose
  
  protected void rrdClose() throws IOException
  
  Description copied from class: RrdBackend
  
  Closes the underlying backend. Call by RrdDb#close() when it's closed. All subclass must keep calling it.
  
  Overrides:
  
  rrdClose in class RrdBackend
  
  Throws:
  
  IOException - Thrown in case of I/O error

Class ByteBufferBackend

Field Summary

Fields inherited from class org.rrd4j.core.RrdBackend

Constructor Summary

Method Summary

Methods inherited from class org.rrd4j.core.RrdBackend

Methods inherited from class java.lang.Object

Constructor Details

Method Details