public class ProgressRowSplittable extends Object implements RowSplittable
Note that it is important to close instances of this splittable for correct progress reporting.
| Modifier and Type | Class and Description |
|---|---|
static interface |
ProgressRowSplittable.Target
Callback interface for objects that will be informed about iteration
progress, and also given the opportunity to terminate iteration.
|
| Constructor and Description |
|---|
ProgressRowSplittable(RowSplittable base,
ProgressRowSplittable.Target target)
Public constructor.
|
| Modifier and Type | Method and Description |
|---|---|
void |
close()
Indicates that this sequence will not be required any more.
|
Object |
getCell(int icol)
Returns the contents of a cell in the current row.
|
Object[] |
getRow()
Returns the contents of the current table row, as an array
with the same number of elements as there are columns in this
table.
|
boolean |
next()
Attempts to advance the current row to the next one.
|
java.util.function.LongSupplier |
rowIndex()
Returns a supplier for the index of the row currently being processed,
if possible.
|
ProgressRowSplittable |
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.
|
public ProgressRowSplittable(RowSplittable base, ProgressRowSplittable.Target target)
base - splittable which this one is to monitortarget - object to which progress events are reportedpublic boolean next()
throws IOException
RowSequencetrue is returned the attempt has been successful,
and if false is returned there are no more rows in this
sequence.
Since the initial position of a RowSequence is before the first row,
this method must be called before current row data
can be accessed using the
RowSequence.getCell(int) or RowSequence.getRow() methods.next in interface RowSequencenext in interface Sequencetrue iff this sequence has been advanced to the
next rowIOException - if there is some errorpublic ProgressRowSplittable split()
SplittableFollowing a successful call, the two parts may be processed in different threads.
split in interface Splittable<RowSplittable>Spliterator.trySplit()public Object getCell(int icol) throws IOException
RowSequencegetColumnInfo(icol).getContentClass().
An unchecked exception will be thrown if there is no current
row (next has not yet been called).getCell in interface RowDatagetCell in interface RowSequenceicol - column indexicol in the current rowIOException - if there is an error reading the datapublic Object[] getRow() throws IOException
RowSequencenext has not yet been called).getRow in interface RowDatagetRow in interface RowSequenceirowIOException - if there is an error reading the datapublic java.util.function.LongSupplier rowIndex()
RowSplittableTypically, the row index will start at 0 and increment for each row, but the numbering may be different depending on the requirements of the implementation or usage.
Before the RowSequence.next() method has been called,
the return value will be one less than the first row index.
After RowSequence.next has returned false,
the value is undefined.
Depending on the implementation, it may not be possible to determine the row index (for instance if the sequence is split into sub-splittables of unknown size). In such cases, this method returns null. The null-ness of the return value must be the same for all instances of the splittable hierarchy for a given sequence, so don't return a non-null value for the first splittable and then null values for some or all of its children.
rowIndex in interface RowSplittablepublic long splittableSize()
SplittableIf no estimate for the size is available, a negative value should be returned.
splittableSize in interface Splittable<RowSplittable>public void close()
throws IOException
RowSequenceclose is undefined.close in interface Closeableclose in interface AutoCloseableclose in interface RowSequenceIOExceptionCopyright © 2024 Central Laboratory of the Research Councils. All Rights Reserved.