org.apfloat.spi

Class ArrayAccess

java.lang.Object

org.apfloat.spi.ArrayAccess

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

DoubleMemoryArrayAccess, FloatMemoryArrayAccess, IntMemoryArrayAccess, LongMemoryArrayAccess

public abstract class ArrayAccess
extends Object
implements Serializable

The ArrayAccess class simulates a C language pointer. With one ArrayAccess object you can point to a location within an array. You can easily add or subtract a value to this "pointer", thus essentially emulating C pointer arithmetic. An ArrayAccess provides an array, the starting index within that array and the length of accessible data within the array, all in one convenient package.

Just like pointers in the C language, ArrayAccess objects are inherently unsafe and must be used cautiously. It is the responsibility of the user of an ArrayAccess object to make sure that he doesn't access the provided array outside the allowed range. The ArrayAccess object itself does nothing to enforce this, except of course the mandatory bounds check of Java, which can throw an ArrayIndexOutOfBoundsException.

Version:

1.6.3

Author:

Mikko Tommila

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ArrayAccess(int offset, int length) Create an array access.

Method Summary

Modifier and Type	Method and Description
abstract void	close() Close this array access and commit any changes to the underlying data storage if applicable.
abstract Object	getData() Returns the array of this array access.
double[]	getDoubleData() Returns the array of this array access as a double[].
float[]	getFloatData() Returns the array of this array access as a float[].
int[]	getIntData() Returns the array of this array access as an int[].
int	getLength() Returns the length of the access segment within the backing array.
long[]	getLongData() Returns the array of this array access as a long[].
int	getOffset() Returns the offset of the access segment within the backing array.
abstract ArrayAccess	subsequence(int offset, int length) Create a sub-sequence view of this array access.

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrayAccess

protected ArrayAccess(int offset,
                      int length)

Create an array access.

Parameters:

offset - The offset of the access segment within the array.

length - The access segment.

Method Detail

subsequence

public abstract ArrayAccess subsequence(int offset,
                                        int length)

Create a sub-sequence view of this array access.

Note that the changes done to the sub-sequence array are not necessarily committed to the underlying data storage when the sub-sequence is closed (with close()), but only when the "base" ArrayAccess is closed.

Parameters:

offset - The sub-sequence starting offset within this ArrayAccess.

length - The sub-sequence length.

Returns:

The sub-sequence array access.

getData

public abstract Object getData()
                        throws ApfloatRuntimeException

Returns the array of this array access. This is an array of a primitive type, depending on the implementation class.

Returns:

The backing array of this array access.

Throws:

ApfloatRuntimeException

getIntData

public int[] getIntData()
                 throws UnsupportedOperationException,
                        ApfloatRuntimeException

Returns the array of this array access as an int[].

Returns:

The backing array of this array access.

Throws:

UnsupportedOperationException - In case the backing array can't be presented as int[].

ApfloatRuntimeException

getLongData

public long[] getLongData()
                   throws UnsupportedOperationException,
                          ApfloatRuntimeException

Returns the array of this array access as a long[].

Returns:

The backing array of this array access.

Throws:

UnsupportedOperationException - In case the backing array can't be presented as long[].

ApfloatRuntimeException

getFloatData

public float[] getFloatData()
                     throws UnsupportedOperationException,
                            ApfloatRuntimeException

Returns the array of this array access as a float[].

Returns:

The backing array of this array access.

Throws:

UnsupportedOperationException - In case the backing array can't be presented as float[].

ApfloatRuntimeException

getDoubleData

public double[] getDoubleData()
                       throws UnsupportedOperationException,
                              ApfloatRuntimeException

Returns the array of this array access as a double[].

Returns:

The backing array of this array access.

Throws:

UnsupportedOperationException - In case the backing array can't be presented as double[].

ApfloatRuntimeException

getOffset

public int getOffset()

Returns the offset of the access segment within the backing array.

Returns:

The starting index within the backing array that is allowed to be accessed.

getLength

public int getLength()

Returns the length of the access segment within the backing array.

Returns:

The number of elements within the backing array that is allowed to be accessed.

close

public abstract void close()
                    throws ApfloatRuntimeException

Close this array access and commit any changes to the underlying data storage if applicable.

If the ArrayAccess was obtained in write mode, the changes are saved to the data storage. Note that even if the ArrayAccess was obtained for reading only, any changes made to the array data may still be committed to the data storage.

Note that changes done to a sub-sequence array are not necessarily committed to the underlying data storage when the sub-sequence is closed, but only when the "base" ArrayAccess is closed.

Throws:

ApfloatRuntimeException