Package org.apfloat.internal

Class DiskDataStorage

java.lang.Object

org.apfloat.spi.DataStorage

org.apfloat.internal.DiskDataStorage

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

DoubleDiskDataStorage, FloatDiskDataStorage, IntDiskDataStorage, LongDiskDataStorage

public abstract class DiskDataStorage
extends DataStorage

Abstract base class for disk-based data storage, containing the common functionality independent of the element type.

Version:

1.9.0

Author:

Mikko Tommila

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.apfloat.spi.DataStorage

DataStorage.AbstractIterator, DataStorage.Iterator

Field Summary

Fields inherited from class org.apfloat.spi.DataStorage

READ, READ_WRITE, WRITE

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	DiskDataStorage()	Default constructor.
protected	DiskDataStorage(DiskDataStorage diskDataStorage, long offset, long length)	Subsequence constructor.

Method Summary

Modifier and Type	Method	Description
protected abstract ArrayAccess	createArrayAccess(int mode, int startColumn, int columns, int rows)	Create an empty ArrayAccess.
protected abstract ArrayAccess	createTransposedArrayAccess(int mode, int startColumn, int columns, int rows)	Create an empty transposed ArrayAccess.
protected static int	getBlockSize()	Convenience method for getting the block size (in bytes) for the current ApfloatContext.
protected final FileChannel	getFileChannel()	The FileChannel of the underlying disk file.
protected final String	getFilename()	Filename of the underlying disk data storage.
protected abstract int	getUnitSize()	Size of the element type, in bytes.
protected void	implCopyFrom(DataStorage dataStorage, long size)	Copies the specified number of elements from another data storage to this data storage.
protected ArrayAccess	implGetArray(int mode, int startColumn, int columns, int rows)	Maps a block of data to a memory array when the data is treated as a matrix.
protected long	implGetSize()	Return the size of the whole data storage, not including sub-sequence settings.
protected ArrayAccess	implGetTransposedArray(int mode, int startColumn, int columns, int rows)	Maps a transposed block of data to a memory array when the data is treated as a matrix.
protected void	implSetSize(long size)	Sets the size of the data storage.
boolean	isCached()	Is this object cached in memory.
protected void	setArray(ArrayAccess arrayAccess, int startColumn, int columns, int rows)	Write the data back to the same location in the file that was retrieved with implGetArray(int,int,int,int).
protected void	setTransposedArray(ArrayAccess arrayAccess, int startColumn, int columns, int rows)	Write the data back to the same location in the file that was retrieved with implGetTransposedArray(int,int,int,int).
protected void	transferFrom(ReadableByteChannel in, long position, long size)	Transfer from a readable channel, possibly in multiple chunks.
protected void	transferTo(WritableByteChannel out, long position, long size)	Transfer to a writable channel, possibly in multiple chunks.

Methods inherited from class org.apfloat.spi.DataStorage

copyFrom, copyFrom, getArray, getArray, getOffset, getSize, getTransposedArray, implGetArray, implSubsequence, isReadOnly, isSubsequenced, iterator, setReadOnly, setSize, subsequence

Methods inherited from class java.lang.Object

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

Constructor Details

DiskDataStorage

protected DiskDataStorage()
                   throws ApfloatRuntimeException

Default constructor.

Throws:

ApfloatRuntimeException

DiskDataStorage

protected DiskDataStorage(DiskDataStorage diskDataStorage,
 long offset,
 long length)

Subsequence constructor.

Parameters:

diskDataStorage - The originating data storage.

offset - The subsequence starting position.

length - The subsequence length.

Method Details

isCached

public boolean isCached()

Description copied from class: DataStorage

Is this object cached in memory.

Specified by:

isCached in class DataStorage

Returns:

true if this object is cached in memory, false if not.

implCopyFrom

protected void implCopyFrom(DataStorage dataStorage,
 long size)
                     throws ApfloatRuntimeException

Description copied from class: DataStorage

Copies the specified number of elements from another data storage to this data storage. The validity of the arguments of this method do not need to be checked.

Specified by:

implCopyFrom in class DataStorage

Parameters:

dataStorage - The data storage where the data should be copied from.

size - The number of elements to be copied.

Throws:

ApfloatRuntimeException

implGetSize

protected long implGetSize()
                    throws ApfloatRuntimeException

Description copied from class: DataStorage

Return the size of the whole data storage, not including sub-sequence settings.

Specified by:

implGetSize in class DataStorage

Returns:

The size of the whole data storage, not including sub-sequence settings.

Throws:

ApfloatRuntimeException

implSetSize

protected void implSetSize(long size)
                    throws ApfloatRuntimeException

Description copied from class: DataStorage

Sets the size of the data storage. The validity of the arguments of this method do not need to be checked.

Specified by:

implSetSize in class DataStorage

Parameters:

size - The size of the data storage.

Throws:

ApfloatRuntimeException

implGetArray

protected ArrayAccess implGetArray(int mode,
 int startColumn,
 int columns,
 int rows)
                            throws ApfloatRuntimeException

Description copied from class: DataStorage

Maps a block of data to a memory array when the data is treated as a matrix. The validity of the arguments of this method do not need to be checked.

Specified by:

implGetArray in class DataStorage

Parameters:

mode - Whether the array is prepared for reading, writing or both. The value should be DataStorage.READ, DataStorage.WRITE or a combination of these.

startColumn - The starting column where data is read.

columns - The number of columns of data to read.

rows - The number of rows of data to read. This should be equivalent to n₁, number of rows in the matrix.

Returns:

Access to an array of size columns x rows containing the data.

Throws:

ApfloatRuntimeException

implGetTransposedArray

protected ArrayAccess implGetTransposedArray(int mode,
 int startColumn,
 int columns,
 int rows)
                                      throws ApfloatRuntimeException

Description copied from class: DataStorage

Maps a transposed block of data to a memory array when the data is treated as a matrix. The validity of the arguments of this method do not need to be checked.

Specified by:

implGetTransposedArray in class DataStorage

Parameters:

mode - Whether the array is prepared for reading, writing or both. The value should be DataStorage.READ, DataStorage.WRITE or a combination of these.

startColumn - The starting column where data is read.

columns - The number of columns of data to read.

rows - The number of rows of data to read. This should be equivalent to n₁, number of rows in the matrix.

Returns:

Access to an array of size columns x rows containing the transposed data.

Throws:

ApfloatRuntimeException

setArray

protected void setArray(ArrayAccess arrayAccess,
 int startColumn,
 int columns,
 int rows)
                 throws ApfloatRuntimeException

Write the data back to the same location in the file that was retrieved with implGetArray(int,int,int,int).

Parameters:

arrayAccess - The transposed array access.

startColumn - The starting column where data is stored.

columns - The number of columns of data.

rows - The number of rows of data.

Throws:

ApfloatRuntimeException

Since:

1.7.0

setTransposedArray

protected void setTransposedArray(ArrayAccess arrayAccess,
 int startColumn,
 int columns,
 int rows)
                           throws ApfloatRuntimeException

Write the data back to the same location in the file that was retrieved with implGetTransposedArray(int,int,int,int).

Parameters:

arrayAccess - The transposed array access.

startColumn - The starting column where data is stored.

columns - The number of columns of data.

rows - The number of rows of data.

Throws:

ApfloatRuntimeException

Since:

1.7.0

createArrayAccess

protected abstract ArrayAccess createArrayAccess(int mode,
 int startColumn,
 int columns,
 int rows)

Create an empty ArrayAccess.

Parameters:

mode - Whether the array is prepared for reading, writing or both. The value should be DataStorage.READ, DataStorage.WRITE or a combination of these.

startColumn - The starting column where data is stored.

columns - The number of columns of data.

rows - The number of rows of data.

Returns:

Access to an empty array of the specified size and position.

Since:

1.7.0

createTransposedArrayAccess

protected abstract ArrayAccess createTransposedArrayAccess(int mode,
 int startColumn,
 int columns,
 int rows)

Create an empty transposed ArrayAccess.

Parameters:

mode - Whether the array is prepared for reading, writing or both. The value should be DataStorage.READ, DataStorage.WRITE or a combination of these.

startColumn - The starting column where data is stored.

columns - The number of columns of data.

rows - The number of rows of data.

Returns:

Access to an empty array of the specified size and position.

Since:

1.7.0

transferFrom

protected void transferFrom(ReadableByteChannel in,
 long position,
 long size)
                     throws ApfloatRuntimeException

Transfer from a readable channel, possibly in multiple chunks.

Parameters:

in - Input channel.

position - Start position of transfer.

size - Total number of bytes to transfer.

Throws:

ApfloatRuntimeException

transferTo

protected void transferTo(WritableByteChannel out,
 long position,
 long size)
                   throws ApfloatRuntimeException

Transfer to a writable channel, possibly in multiple chunks.

Parameters:

out - Output channel.

position - Start position of transfer.

size - Total number of bytes to transfer.

Throws:

ApfloatRuntimeException

getBlockSize

protected static int getBlockSize()

Convenience method for getting the block size (in bytes) for the current ApfloatContext.

Returns:

I/O block size, in bytes.

getUnitSize

protected abstract int getUnitSize()

Size of the element type, in bytes.

Returns:

Size of the element type, in bytes.

getFilename

protected final String getFilename()

Filename of the underlying disk data storage.

Returns:

Filename of the underlying disk data storage.

getFileChannel

protected final FileChannel getFileChannel()

The FileChannel of the underlying disk file.

Returns:

The FileChannel of the underlying disk file.