ByteBufferBackend (Javadocs [I2P+ 2.13.0+]

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.

Field Summary
- Fields inherited from class org.rrd4j.core.RrdBackend
  BYTEORDER

Constructor Summary
Constructors
Modifier Constructor and Description
protected ByteBufferBackend(String path)
Constructs a ByteBufferBackend with the given file path.

Constructors
Modifier	Constructor and Description
`protected`	`ByteBufferBackend(String path)` Constructs a ByteBufferBackend with the given file path.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and 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()` Check whether the buffer has been modified since the last sync.
`protected void`	`read(long offset, byte[] b)` Reads a number of bytes from the RRD file on the disk
`double`	`readDouble(long offset)` Reads a double value from the underlying storage at the given offset.
`double[]`	`readDouble(long offset, int count)` Reads an array of double values from the underlying storage at the given offset.
`protected int`	`readInt(long offset)` Reads an integer value from the underlying storage at the given offset.
`protected long`	`readLong(long offset)` Reads a long value from the underlying storage at the given offset.
`protected short`	`readShort(long offset)` Reads a short value from the underlying storage at the given offset.
`protected void`	`rrdClose()` Closes the underlying backend.
`protected void`	`setByteBuffer(ByteBuffer byteBuffer)` Set the byte buffer to use for backing storage.
`protected void`	`write(long offset, byte[] b)` Writes bytes to the underlying RRD file on the disk
`protected void`	`writeDouble(long offset, double value)` Writes a double value to the underlying storage at the given offset.
`protected void`	`writeDouble(long offset, double[] values)` Writes an array of double values to the underlying storage at the given offset.
`protected void`	`writeDouble(long offset, double value, int count)` Writes multiple copies of a double value to the underlying storage at the given offset.
`protected void`	`writeInt(long offset, int value)` Writes an integer value to the underlying storage at the given offset.
`protected void`	`writeLong(long offset, long value)` Writes a long value to the underlying storage at the given offset.
`protected void`	`writeShort(long offset, short value)` Writes a short value to the underlying storage at the given offset.
`protected void`	`writeString(long offset, String value, int length)` Writes a string to the underlying storage at the given offset with a fixed 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 Detail
  - ByteBufferBackend
```
protected ByteBufferBackend(String path)
```
    Constructs a ByteBufferBackend with the given file path.
    Parameters:
    path - the file path
- Method Detail
  - 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
  - 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
  - isDirty
```
protected boolean isDirty()
```
    Check whether the buffer has been modified since the last sync.
    Returns:
    true if the buffer has been modified since last sync
  - 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).
  - readDouble
```
public double readDouble(long offset)
                  throws IOException
```
    Description copied from class: RrdBackend
    Reads a double value from the underlying storage at the given offset.
    Overrides:
    readDouble in class RrdBackend
    Parameters:
    offset - Storage offset.
    Returns:
    The double value read from storage.
    Throws:
    IOException - Thrown in case of I/O error.
  - readDouble
```
public double[] readDouble(long offset,
                           int count)
                    throws IOException
```
    Description copied from class: RrdBackend
    Reads an array of double values from the underlying storage at the given offset.
    Overrides:
    readDouble in class RrdBackend
    Parameters:
    offset - Storage offset.
    count - Number of double values to read.
    Returns:
    Array of double values read from storage.
    Throws:
    IOException - Thrown in case of I/O error.
  - readInt
```
protected int readInt(long offset)
               throws IOException
```
    Description copied from class: RrdBackend
    Reads an integer value from the underlying storage at the given offset.
    Overrides:
    readInt in class RrdBackend
    Parameters:
    offset - Storage offset.
    Returns:
    The integer value read from storage.
    Throws:
    IOException - Thrown in case of I/O error.
  - readLong
```
protected long readLong(long offset)
                 throws IOException
```
    Description copied from class: RrdBackend
    Reads a long value from the underlying storage at the given offset.
    Overrides:
    readLong in class RrdBackend
    Parameters:
    offset - Storage offset.
    Returns:
    The long value read from storage.
    Throws:
    IOException - Thrown in case of I/O error.
  - readShort
```
protected short readShort(long offset)
                   throws IOException
```
    Description copied from class: RrdBackend
    Reads a short value from the underlying storage at the given offset.
    Overrides:
    readShort in class RrdBackend
    Parameters:
    offset - Storage offset.
    Returns:
    The short value read from storage.
    Throws:
    IOException - Thrown in case of I/O error.
  - 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
  - setByteBuffer
```
protected void setByteBuffer(ByteBuffer byteBuffer)
```
    Set the byte buffer to use for backing storage.
    Parameters:
    byteBuffer - the byte buffer to set
  - 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).
  - writeDouble
```
protected void writeDouble(long offset,
                           double value)
                    throws IOException
```
    Description copied from class: RrdBackend
    Writes a double value to the underlying storage at the given offset.
    Overrides:
    writeDouble in class RrdBackend
    Parameters:
    offset - Storage offset.
    value - Double value to write.
    Throws:
    IOException - Thrown in case of I/O error.
  - writeDouble
```
protected void writeDouble(long offset,
                           double[] values)
                    throws IOException
```
    Description copied from class: RrdBackend
    Writes an array of double values to the underlying storage at the given offset.
    Overrides:
    writeDouble in class RrdBackend
    Parameters:
    offset - Storage offset.
    values - Array of double values to write.
    Throws:
    IOException - Thrown in case of I/O error.
  - writeDouble
```
protected void writeDouble(long offset,
                           double value,
                           int count)
                    throws IOException
```
    Description copied from class: RrdBackend
    Writes multiple copies of a double value to the underlying storage at the given offset.
    Overrides:
    writeDouble in class RrdBackend
    Parameters:
    offset - Storage offset.
    value - Double value to write.
    count - Number of times to write the value.
    Throws:
    IOException - Thrown in case of I/O error.
  - writeInt
```
protected void writeInt(long offset,
                        int value)
                 throws IOException
```
    Description copied from class: RrdBackend
    Writes an integer value to the underlying storage at the given offset.
    Overrides:
    writeInt in class RrdBackend
    Parameters:
    offset - Storage offset.
    value - Integer value to write.
    Throws:
    IOException - Thrown in case of I/O error.
  - writeLong
```
protected void writeLong(long offset,
                         long value)
                  throws IOException
```
    Description copied from class: RrdBackend
    Writes a long value to the underlying storage at the given offset.
    Overrides:
    writeLong in class RrdBackend
    Parameters:
    offset - Storage offset.
    value - Long value to write.
    Throws:
    IOException - Thrown in case of I/O error.
  - writeShort
```
protected void writeShort(long offset,
                          short value)
                   throws IOException
```
    Description copied from class: RrdBackend
    Writes a short value to the underlying storage at the given offset.
    Overrides:
    writeShort in class RrdBackend
    Parameters:
    offset - Storage offset.
    value - Short value to write.
    Throws:
    IOException - Thrown in case of I/O error.
  - writeString
```
protected void writeString(long offset,
                           String value,
                           int length)
                    throws IOException
```
    Description copied from class: RrdBackend
    Writes a string to the underlying storage at the given offset with a fixed length.
    Overrides:
    writeString in class RrdBackend
    Parameters:
    offset - Storage offset.
    value - String value to write.
    length - Fixed length for the string storage.
    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 Detail

ByteBufferBackend

Method Detail

close

getCharBuffer

isDirty

read

readDouble

readDouble

readInt

readLong

readShort

rrdClose

setByteBuffer

write

writeDouble

writeDouble

writeDouble

writeInt

writeLong

writeShort

writeString