uk.ac.starlink.ttools.plot2.data

Class CachedTupleSequence

java.lang.Object

uk.ac.starlink.ttools.plot2.data.CachedTupleSequence

All Implemented Interfaces:

Tuple, TupleSequence, Sequence, Splittable<TupleSequence>

public class CachedTupleSequence
extends Object
implements TupleSequence

TupleSequence implementation based on CachedColumns.

Since:

3 Jan 2020

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
CachedTupleSequence(java.util.function.Supplier<CachedReader> maskSupplier, java.util.function.Supplier<CachedReader[]> colsSupplier, long nrow) Public constructor.

Method Summary

Modifier and Type	Method and Description
boolean	getBooleanValue(int icol) Returns the value of a given column as a boolean.
double	getDoubleValue(int icol) Returns the value of a given column as a double.
int	getIntValue(int icol) Returns the value of a given column as an integer.
long	getLongValue(int icol) Returns the value of a given column as a long.
Object	getObjectValue(int icol) Returns the value of a given column as an object.
long	getRowIndex() Returns the row index for the underlying data set.
boolean	next() Advances to the next entry.
TupleSequence	split() Attempts to partition this object into two halves, ideally of similar size.
long	splittableSize() Provides an estimate of the number of processable items in this object.

Methods inherited from class java.lang.Object

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

Constructor Detail

CachedTupleSequence

public CachedTupleSequence(java.util.function.Supplier<CachedReader> maskSupplier,
                           java.util.function.Supplier<CachedReader[]> colsSupplier,
                           long nrow)

Public constructor.

Parameters:

maskSupplier - supplier for boolean-typed column reader, providing inclusion flags per row; null means include all rows

colsSupplier - supplier for array of columns providing data cells per row

Method Detail

next

public boolean next()

Description copied from interface: TupleSequence

Advances to the next entry. No exception is thrown.

Specified by:

next in interface TupleSequence

Specified by:

next in interface Sequence

Returns:

true iff the current sequence element has data

split

public TupleSequence split()

Description copied from interface: Splittable

Attempts to partition this object into two halves, ideally of similar size. If a non-null value is returned, then the content previously contained by this object is now split between this object and the returned object. If for any reason a split is not carried out, null is returned.

Following a successful call, the two parts may be processed in different threads.

Specified by:

split in interface Splittable<TupleSequence>

Returns:

other half of this splittable, or null

See Also:

Spliterator.trySplit()

splittableSize

public long splittableSize()

Description copied from interface: Splittable

Provides an estimate of the number of processable items in this object. A processable item is not a well-defined quantity, but it should generally be something that can be processed fast. For instance, if this object represents a collection of collections, the value that should be returned is the total number of elements rather than the number of collections.

If no estimate for the size is available, a negative value should be returned.

Specified by:

splittableSize in interface Splittable<TupleSequence>

Returns:

approximate size, or negative value if not known

getRowIndex

public long getRowIndex()

Description copied from interface: Tuple

Returns the row index for the underlying data set. Note this value may not undergo a simple increment between steps (if rows are excluded from the underlying data set it may increase by more than one in some cases).

Specified by:

getRowIndex in interface Tuple

Returns:

row index of underlying table row

getObjectValue

public Object getObjectValue(int icol)

Description copied from interface: Tuple

Returns the value of a given column as an object. If that element of the tuple is not of object type, the result may not be useful.

If the result is a mutable object, its value may be overwritten by subsequent calls to this method (especially following calls to TupleSequence.next() if this object also implements TupleSequence).

Specified by:

getObjectValue in interface Tuple

Parameters:

icol - column index

Returns:

value of element icol, presumed of object type

getDoubleValue

public double getDoubleValue(int icol)

Description copied from interface: Tuple

Returns the value of a given column as a double. If that element of the tuple is not of numeric type, the result may not be useful.

Specified by:

getDoubleValue in interface Tuple

Parameters:

icol - column index

Returns:

value of element icol, presumed of numeric type

getIntValue

public int getIntValue(int icol)

Description copied from interface: Tuple

Returns the value of a given column as an integer. If that element of the tuple is not of numeric type, the result may not be useful.

Specified by:

getIntValue in interface Tuple

Parameters:

icol - column index

Returns:

value of element icol, presumed of numeric type

getLongValue

public long getLongValue(int icol)

Description copied from interface: Tuple

Returns the value of a given column as a long. If that element of the tuple is not of numeric type, the result may not be useful.

Specified by:

getLongValue in interface Tuple

Parameters:

icol - column index

Returns:

value of element icol, presumed of numeric type

getBooleanValue

public boolean getBooleanValue(int icol)

Description copied from interface: Tuple

Returns the value of a given column as a boolean. If that element of the table is not of boolean type, the result may not be useful.

Specified by:

getBooleanValue in interface Tuple

Parameters:

icol - column index

Returns:

value of element icol, presumed of boolean type