Package net.algart.arrays

Class SignalMemoryModel

java.lang.Object

net.algart.arrays.AbstractMemoryModel

net.algart.arrays.SignalMemoryModel

All Implemented Interfaces:

MemoryModel

public class SignalMemoryModel
extends AbstractMemoryModel

The degenerate memory model that does not allow to create any AlgART arrays. Any attempt to create an array by methods of this class leads to UnsupportedElementTypeException (or, maybe, NullPointerException, IllegalArgumentException or ClassCastException, if the comments to the method require this).

This class may be useful to detect a bug, when some method have a MemoryModel argument, but you are sure that this argument must not be used for creating any AlgART arrays.

This class is immutable and thread-safe: there are no ways to modify settings of its instance returned by getInstance() method. Moreover, it is a singleton: getInstance() always returns the same object.

Author:

Daniel Alievsky

Method Summary

Modifier and Type	Method	Description
boolean	areAllElementTypesSupported()	This implementation always returns false.
boolean	areAllPrimitiveElementTypesSupported()	This implementation always returns false.
static SignalMemoryModel	getInstance()	Returns an instance of this memory model.
boolean	isCreatedBy(Array array)	This implementation always returns false.
boolean	isElementTypeSupported(Class<?> elementType)	This implementation always returns false.
long	maxSupportedLength(Class<?> elementType)	This implementation always returns -1.
MutableArray	newArray(Class<?> elementType, long initialLength)	Allocates a zero-filled resizable array with the specified element type and initial length.
MutableArray	newEmptyArray(Class<?> elementType)	Allocates an empty resizable array with the specified element type and a little initial capacity.
MutableArray	newEmptyArray(Class<?> elementType, long initialCapacity)	Allocates an empty resizable array with the specified element type and initial capacity.
UpdatableArray	newUnresizableArray(Class<?> elementType, long length)	Allocates a zero-filled unresizable array with the specified element type and length.

Methods inherited from class net.algart.arrays.AbstractMemoryModel

newArray, newBitArray, newBitMatrix, newByteArray, newByteMatrix, newCharArray, newCharMatrix, newDoubleArray, newDoubleMatrix, newEmptyBitArray, newEmptyBitArray, newEmptyByteArray, newEmptyByteArray, newEmptyCharArray, newEmptyCharArray, newEmptyDoubleArray, newEmptyDoubleArray, newEmptyFloatArray, newEmptyFloatArray, newEmptyIntArray, newEmptyIntArray, newEmptyLongArray, newEmptyLongArray, newEmptyObjectArray, newEmptyObjectArray, newEmptyShortArray, newEmptyShortArray, newFloatArray, newFloatMatrix, newIntArray, newIntMatrix, newLazyCopy, newLazyCopy, newLongArray, newLongMatrix, newMatrix, newMatrix, newMatrix, newObjectArray, newObjectMatrix, newShortArray, newShortMatrix, newStructuredMatrix, newUnresizableArray, newUnresizableBitArray, newUnresizableByteArray, newUnresizableCharArray, newUnresizableDoubleArray, newUnresizableFloatArray, newUnresizableIntArray, newUnresizableLazyCopy, newUnresizableLongArray, newUnresizableObjectArray, newUnresizableShortArray, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf, valueOf

Methods inherited from class java.lang.Object

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

Method Details

getInstance

public static SignalMemoryModel getInstance()

Returns an instance of this memory model.

Returns:

an instance of this memory model.

newEmptyArray

public MutableArray newEmptyArray(Class<?> elementType)

Description copied from interface: MemoryModel

Allocates an empty resizable array with the specified element type and a little initial capacity. It is equivalent to newEmptyArray(elementType, n), where n is some little value.

Example of usage:

     MutableFloatArray a = (MutableFloatArray)memoryModel.newEmptyArray(float.class);
 

Specified by:

newEmptyArray in interface MemoryModel

Specified by:

newEmptyArray in class AbstractMemoryModel

Parameters:

elementType - the type of array elements.

Returns:

created AlgART array.

See Also:

• MemoryModel.isElementTypeSupported(Class)
• MemoryModel.newArray(Class, long)

newEmptyArray

public MutableArray newEmptyArray(Class<?> elementType,
 long initialCapacity)

Description copied from interface: MemoryModel

Allocates an empty resizable array with the specified element type and initial capacity.

The element type can be either usual object class (as String.class), or one of the primitive types: boolean.class, byte.class, short.class, int.class, long.class, float.class, double.class, char.class. The element type cannot be void.class.

In a case of primitive types, the created array will implement the corresponding interface BitArray, ByteArray, ShortArray, IntArray, LongArray, FloatArray, DoubleArray or CharArray. In this case, the created array (unlike standard ArrayList) will occupy the same amount of memory as the Java array boolean[initialCapacity], byte[initialCapacity], etc.

In a case of non-primitive types (Object inheritors), the created array will implement the MutableObjectArray interface.

Some element type may be not supported by this memory model. For example, some memory models may support only primitive types, or only one concrete type. In such a case, UnsupportedElementTypeException will be thrown.

Some too large array capacities may be not supported by this memory model. For example, SimpleMemoryModel does not support arrays larger than 0x7FFFFFFF (Integer.MAX_VALUE) elements.

Example of usage:

     MutableFloatArray a = (MutableFloatArray)memoryModel.newEmptyArray(float.class, 10000);
 

Specified by:

newEmptyArray in interface MemoryModel

Specified by:

newEmptyArray in class AbstractMemoryModel

Parameters:

elementType - the type of array elements.

initialCapacity - the initial capacity of the array.

Returns:

created AlgART array.

See Also:

• MemoryModel.isElementTypeSupported(Class)
• MemoryModel.newArray(Class, long)

newArray

public MutableArray newArray(Class<?> elementType,
 long initialLength)

Description copied from interface: MemoryModel

Allocates a zero-filled resizable array with the specified element type and initial length. The capacity of new array will be equal to its length.

This method is equivalent to the following call: newEmptyArray(elementType, initialLength).length(initialLength).trim().

Specified by:

newArray in interface MemoryModel

Specified by:

newArray in class AbstractMemoryModel

Parameters:

elementType - the type of array elements.

initialLength - the initial length and capacity of the array.

Returns:

created AlgART array.

See Also:

• MemoryModel.isElementTypeSupported(Class)
• MemoryModel.newEmptyArray(Class, long)
• MemoryModel.newUnresizableArray(Class, long)

newUnresizableArray

public UpdatableArray newUnresizableArray(Class<?> elementType,
 long length)

Description copied from interface: MemoryModel

Allocates a zero-filled unresizable array with the specified element type and length. The capacity of new array will be equal to its length.

The analogous result may be obtained the following call: newArray(elementType, length).asUnresizable(). However, we don't recommend to use such code. If you are sure that you will not need to change the array length, please always use this method (or newUnresizableBitArray, newUnresizableBteArray, etc.). In some memory models, creating resizable array with the given length may require much more resources that creating unresizable one. For example, in the large memory model every resizable array is stored in the file consisting of integer number of blocks per DataFileModel.recommendedBankSize(true) bytes.

Specified by:

newUnresizableArray in interface MemoryModel

Specified by:

newUnresizableArray in class AbstractMemoryModel

Parameters:

elementType - the type of array elements.

length - the length and capacity of the array.

Returns:

created unresizable AlgART array.

See Also:

• MemoryModel.isElementTypeSupported(Class)
• MemoryModel.newArray(Class, long)

isElementTypeSupported

public boolean isElementTypeSupported(Class<?> elementType)

This implementation always returns false.

Specified by:

isElementTypeSupported in interface MemoryModel

Specified by:

isElementTypeSupported in class AbstractMemoryModel

Parameters:

elementType - the type of array elements.

Returns:

false always.

Throws:

NullPointerException - if elementType is null.

areAllPrimitiveElementTypesSupported

public boolean areAllPrimitiveElementTypesSupported()

This implementation always returns false.

Specified by:

areAllPrimitiveElementTypesSupported in interface MemoryModel

Specified by:

areAllPrimitiveElementTypesSupported in class AbstractMemoryModel

Returns:

false always.

See Also:

• MemoryModel.isElementTypeSupported(Class)

areAllElementTypesSupported

public boolean areAllElementTypesSupported()

This implementation always returns false.

Specified by:

areAllElementTypesSupported in interface MemoryModel

Specified by:

areAllElementTypesSupported in class AbstractMemoryModel

Returns:

false always.

See Also:

• MemoryModel.isElementTypeSupported(Class)

maxSupportedLength

public long maxSupportedLength(Class<?> elementType)

This implementation always returns -1.

Specified by:

maxSupportedLength in interface MemoryModel

Specified by:

maxSupportedLength in class AbstractMemoryModel

Parameters:

elementType - the type of array elements.

Returns:

-1 always.

Throws:

NullPointerException - if elementType is null.

isCreatedBy

public boolean isCreatedBy(Array array)

This implementation always returns false.

Specified by:

isCreatedBy in interface MemoryModel

Specified by:

isCreatedBy in class AbstractMemoryModel

Parameters:

array - the AlgART array (may be null, than the method returns false).

Returns:

false always.