SimpleNioBuf

java.lang.Object
- uk.ac.bristol.star.cdf.record.SimpleNioBuf

All Implemented Interfaces:

Buf
```
public class SimpleNioBuf
extends java.lang.Object
implements Buf
```
Buf implementation based on a single NIO ByteBuffer. This works fine as long as it doesn't need to be more than 2^31 bytes (2Gb), which is the maximum length of a ByteBuffer.

Since:

18 Jun 2013

See Also:

ByteBuffer

Constructor Summary

Constructors
Constructor and Description

SimpleNioBuf(java.nio.ByteBuffer byteBuf, boolean isBit64, boolean isBigendian)
Constructor.

Constructors
Constructor and Description
`SimpleNioBuf(java.nio.ByteBuffer byteBuf, boolean isBit64, boolean isBigendian)` Constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`java.io.InputStream`	`createInputStream(long offset)` Returns an input stream consisting of all the bytes in this buf starting from the given offset.
`Buf`	`fillNewBuf(long count, java.io.InputStream in)` Creates a new Buf of a given length populated from a given input stream.
`long`	`getLength()` Returns the extent of this buf in bytes.
`boolean`	`isBigendian()` Determines the data encoding of this buf.
`boolean`	`isBit64()` Determines the 64bit-ness of this buf.
`java.lang.String`	`readAsciiString(Pointer ptr, int nbyte)` Reads a fixed number of bytes interpreting them as ASCII characters and returns the result as a string.
`void`	`readDataBytes(long offset, int count, byte[] array)` Reads a sequence of byte values from this buf into an array.
`void`	`readDataDoubles(long offset, int count, double[] array)` Reads a sequence of double values from this buf into an array.
`void`	`readDataFloats(long offset, int count, float[] array)` Reads a sequence of float values from this buf into an array.
`void`	`readDataInts(long offset, int count, int[] array)` Reads a sequence of int values from this buf into an array.
`void`	`readDataLongs(long offset, int count, long[] array)` Reads a sequence of long integer values from this buf into an array.
`void`	`readDataShorts(long offset, int count, short[] array)` Reads a sequence of short values from this buf into an array.
`int`	`readInt(Pointer ptr)` Reads a signed big-endian 4-byte integer from the pointer position.
`long`	`readOffset(Pointer ptr)` Reads a file offset or size from the pointer position.
`int`	`readUnsignedByte(Pointer ptr)` Reads a single byte from the pointer position, returning a value in the range 0..255.
`void`	`setBit64(boolean isBit64)` Sets the 64bit-ness of this buf.
`void`	`setEncoding(boolean bigend)` Sets the encoding for reading numeric values as performed by the `readData*` methods.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - SimpleNioBuf
```
public SimpleNioBuf(java.nio.ByteBuffer byteBuf,
                    boolean isBit64,
                    boolean isBigendian)
```
    Constructor.
    
    Parameters:
    
    byteBuf - NIO byte buffer containing the byte data
    
    isBit64 - 64bit-ness of this buf
    
    isBigendian - true for big-endian, false for little-endian
- Method Detail
  - getLength
```
public long getLength()
```
    Description copied from interface: Buf
    
    Returns the extent of this buf in bytes.
    
    Specified by:
    
    getLength in interface Buf
    
    Returns:
    
    buffer length
  - readUnsignedByte
```
public int readUnsignedByte(Pointer ptr)
```
    Description copied from interface: Buf
    
    Reads a single byte from the pointer position, returning a value in the range 0..255. Pointer position is moved on appropriately.
    
    Specified by:
    
    readUnsignedByte in interface Buf
    
    Parameters:
    
    ptr - pointer
    
    Returns:
    
    byte value
  - readInt
```
public int readInt(Pointer ptr)
```
    Description copied from interface: Buf
    
    Reads a signed big-endian 4-byte integer from the pointer position. Pointer position is moved on appropriately.
    
    Specified by:
    
    readInt in interface Buf
    
    Parameters:
    
    ptr - pointer
    
    Returns:
    
    integer value
  - readOffset
```
public long readOffset(Pointer ptr)
```
    Description copied from interface: Buf
    
    Reads a file offset or size from the pointer position. This is a signed big-endian integer, occupying either 4 or 8 bytes according to the return value of Buf.isBit64(). Pointer position is moved on appropriately.
    
    Specified by:
    
    readOffset in interface Buf
    
    Returns:
    
    buffer size or offset value
  - readAsciiString
```
public java.lang.String readAsciiString(Pointer ptr,
                                        int nbyte)
```
    Description copied from interface: Buf
    
    Reads a fixed number of bytes interpreting them as ASCII characters and returns the result as a string. If a character 0x00 appears before nbyte bytes have been read, it is taken as the end of the string. Pointer position is moved on appropriately.
    
    Specified by:
    
    readAsciiString in interface Buf
    
    Parameters:
    
    ptr - pointer
    
    nbyte - maximum number of bytes in string
    
    Returns:
    
    ASCII string
  - setBit64
```
public void setBit64(boolean isBit64)
```
    Description copied from interface: Buf
    
    Sets the 64bit-ness of this buf. This determines whether readOffset reads 4- or 8-byte values.
    This method should be called before the readOffset method is invoked.
    
    Specified by:
    
    setBit64 in interface Buf
    
    Parameters:
    
    isBit64 - true for 8-byte offsets, false for 4-byte offsets
  - setEncoding
```
public void setEncoding(boolean bigend)
```
    Description copied from interface: Buf
    
    Sets the encoding for reading numeric values as performed by the readData* methods.
    As currently specified, there are only two possibiliies, Big-Endian and Little-Endian. Interface and implementation would need to be reworked somewhat to accommodate the (presumably, rarely seen in this day and age) D_FLOAT and G_FLOAT encodings supported by the CDF standard.
    This method should be called before any of the readData* methods are invoked.
    
    Specified by:
    
    setEncoding in interface Buf
    
    Parameters:
    
    bigend - true for big-endian, false for little-endian
  - isBigendian
```
public boolean isBigendian()
```
    Description copied from interface: Buf
    
    Determines the data encoding of this buf.
    
    Specified by:
    
    isBigendian in interface Buf
    
    Returns:
    
    true for big-endian, false for little-endian
  - isBit64
```
public boolean isBit64()
```
    Description copied from interface: Buf
    
    Determines the 64bit-ness of this buf. This determines whether readOffset reads 4- or 8-byte values.
    
    Specified by:
    
    isBit64 in interface Buf
    
    Returns:
    
    true for 8-byte offsets, false for 4-byte offsets
  - readDataBytes
```
public void readDataBytes(long offset,
                          int count,
                          byte[] array)
```
    Description copied from interface: Buf
    
    Reads a sequence of byte values from this buf into an array.
    
    Specified by:
    
    readDataBytes in interface Buf
    
    Parameters:
    
    offset - position sequence start in this buffer in bytes
    
    count - number of byte values to read
    
    array - array to receive values, starting at array element 0
  - readDataShorts
```
public void readDataShorts(long offset,
                           int count,
                           short[] array)
```
    Description copied from interface: Buf
    
    Reads a sequence of short values from this buf into an array.
    
    Specified by:
    
    readDataShorts in interface Buf
    
    Parameters:
    
    offset - position sequence start in this buffer in bytes
    
    count - number of short values to read
    
    array - array to receive values, starting at array element 0
  - readDataInts
```
public void readDataInts(long offset,
                         int count,
                         int[] array)
```
    Description copied from interface: Buf
    
    Reads a sequence of int values from this buf into an array.
    
    Specified by:
    
    readDataInts in interface Buf
    
    Parameters:
    
    offset - position sequence start in this buffer in bytes
    
    count - number of int values to read
    
    array - array to receive values, starting at array element 0
  - readDataLongs
```
public void readDataLongs(long offset,
                          int count,
                          long[] array)
```
    Description copied from interface: Buf
    
    Reads a sequence of long integer values from this buf into an array.
    
    Specified by:
    
    readDataLongs in interface Buf
    
    Parameters:
    
    offset - position sequence start in this buffer in bytes
    
    count - number of long values to read
    
    array - array to receive values, starting at array element 0
  - readDataFloats
```
public void readDataFloats(long offset,
                           int count,
                           float[] array)
```
    Description copied from interface: Buf
    
    Reads a sequence of float values from this buf into an array.
    
    Specified by:
    
    readDataFloats in interface Buf
    
    Parameters:
    
    offset - position sequence start in this buffer in bytes
    
    count - number of float values to read
    
    array - array to receive values, starting at array element 0
  - readDataDoubles
```
public void readDataDoubles(long offset,
                            int count,
                            double[] array)
```
    Description copied from interface: Buf
    
    Reads a sequence of double values from this buf into an array.
    
    Specified by:
    
    readDataDoubles in interface Buf
    
    Parameters:
    
    offset - position sequence start in this buffer in bytes
    
    count - number of double values to read
    
    array - array to receive values, starting at array element 0
  - createInputStream
```
public java.io.InputStream createInputStream(long offset)
```
    Description copied from interface: Buf
    
    Returns an input stream consisting of all the bytes in this buf starting from the given offset.
    
    Specified by:
    
    createInputStream in interface Buf
    
    Parameters:
    
    offset - position of first byte in buf that will appear in the returned stream
    
    Returns:
    
    input stream
  - fillNewBuf
```
public Buf fillNewBuf(long count,
                      java.io.InputStream in)
               throws java.io.IOException
```
    Description copied from interface: Buf
    
    Creates a new Buf of a given length populated from a given input stream. The new buf object must have the same data encoding and 64bit-ness as this one.
    
    Specified by:
    
    fillNewBuf in interface Buf
    
    Parameters:
    
    count - size of new buffer in bytes
    
    in - input stream capable of supplying (at least) count bytes
    
    Returns:
    
    new buffer of length count filled with bytes from in
    
    Throws:
    
    java.io.IOException

Class SimpleNioBuf

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

SimpleNioBuf

Method Detail

getLength

readUnsignedByte

readInt

readOffset

readAsciiString

setBit64

setEncoding

isBigendian

isBit64

readDataBytes

readDataShorts

readDataInts

readDataLongs

readDataFloats

readDataDoubles

createInputStream

fillNewBuf