Package org.apache.lucene.document.column

Class LongValuesCursor

java.lang.Object

org.apache.lucene.document.column.LongValuesCursor

public abstract class LongValuesCursor
extends Object

A values cursor over a dense LongColumn. The cursor produces exactly size() values for consecutive batch-local doc-ids starting at 0, one per call to nextLong().

Implementations must throw an exception if nextLong() is called more than size() times.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	LongValuesCursor(int size)	Creates a cursor that will produce exactly size values, one per batch-local doc-id in [0, size).

Method Summary

Modifier and Type	Method	Description
void	fillDocValues(long[] dst, int offset, int length)	Bulk-fill length values into dst starting at offset, advancing the cursor by length.
void	fillIntPoints(byte[] dst, int offset, int length)	Bulk-encode length values as 4-byte big-endian sortable int points (sign-flipped so negatives sort before positives) into dst starting at byte offset, advancing the cursor by length.
void	fillLongPoints(byte[] dst, int offset, int length)	Bulk-encode length values as 8-byte big-endian sortable long points (sign-flipped so negatives sort before positives) into dst starting at byte offset, advancing the cursor by length.
abstract long	nextLong()	Returns the next long value.
final int	size()	Total number of values this cursor will produce.

Methods inherited from class java.lang.Object

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

Constructor Details

LongValuesCursor

protected LongValuesCursor(int size)

Creates a cursor that will produce exactly size values, one per batch-local doc-id in [0, size). size is fixed for the cursor's lifetime and must equal the dense column's numDocs.

Lucene's internal indexing paths will not consume past size across nextLong(), fillDocValues(long[], int, int), and the fillPoints variants. Defensive throws on overrun are still encouraged to catch misuse from external callers.

Method Details

size

public final int size()

Total number of values this cursor will produce.

nextLong

public abstract long nextLong()

Returns the next long value. Must not be called more than size() times.

fillDocValues

public void fillDocValues(long[] dst,
 int offset,
 int length)

Bulk-fill length values into dst starting at offset, advancing the cursor by length. Combined nextLong() and fill calls must not consume more than size() values; implementations must throw if they do.

The default implementation calls nextLong() in a loop. Override to provide a more efficient bulk fill (for example a System.arraycopy(java.lang.Object, int, java.lang.Object, int, int) from a backing array).

fillLongPoints

public void fillLongPoints(byte[] dst,
 int offset,
 int length)

Bulk-encode length values as 8-byte big-endian sortable long points (sign-flipped so negatives sort before positives) into dst starting at byte offset, advancing the cursor by length. Combined consumption across nextLong(), fillDocValues(long[], int, int), and the fillPoints variants must not exceed size().

Values are read in doc-values orientation: callers using this for DOUBLE columns are responsible for ensuring the cursor's longs are already sortable-long encoded, which is the documented LongColumn contract.

The default implementation calls nextLong() per value. Override for a tight indexable loop over a backing array.

fillIntPoints

public void fillIntPoints(byte[] dst,
 int offset,
 int length)

Bulk-encode length values as 4-byte big-endian sortable int points (sign-flipped so negatives sort before positives) into dst starting at byte offset, advancing the cursor by length. Each value is narrowed via (int) nextLong(). Combined consumption across nextLong(), fillDocValues(long[], int, int), and the fillPoints variants must not exceed size().

Values are read in doc-values orientation: callers using this for FLOAT columns are responsible for ensuring the cursor's longs are already sortable-int encoded (in the low 32 bits), which is the documented LongColumn contract.

The default implementation calls nextLong() per value. Override for a tight indexable loop over a backing array.