org.apache.lucene.util.packed

Class DirectMonotonicWriter

java.lang.Object

org.apache.lucene.util.packed.DirectMonotonicWriter

public final class DirectMonotonicWriter
extends Object

Write monotonically-increasing sequences of integers. This writer splits data into blocks and then for each block, computes the average slope, the minimum value and only encode the delta from the expected value using a DirectWriter.

See Also:

DirectMonotonicReader

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Field Summary

Fields

Modifier and Type	Field and Description
static int	MAX_BLOCK_SHIFT
static int	MIN_BLOCK_SHIFT

Method Summary

Modifier and Type	Method and Description
void	add(long v) Write a new value.
void	finish() This must be called exactly once after all values have been added.
static DirectMonotonicWriter	getInstance(IndexOutput metaOut, IndexOutput dataOut, long numValues, int blockShift) Returns an instance suitable for encoding numValues into monotonic blocks of 2blockShift values.

Methods inherited from class java.lang.Object

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

Field Detail

MIN_BLOCK_SHIFT

public static final int MIN_BLOCK_SHIFT

See Also:

Constant Field Values

MAX_BLOCK_SHIFT

public static final int MAX_BLOCK_SHIFT

See Also:

Constant Field Values

Method Detail

add

public void add(long v)
         throws IOException

Write a new value. Note that data might not make it to storage until finish() is called.

Throws:

IllegalArgumentException - if values don't come in order

IOException

finish

public void finish()
            throws IOException

This must be called exactly once after all values have been added.

Throws:

IOException

getInstance

public static DirectMonotonicWriter getInstance(IndexOutput metaOut,
                                                IndexOutput dataOut,
                                                long numValues,
                                                int blockShift)

Returns an instance suitable for encoding numValues into monotonic blocks of 2^blockShift values. Metadata will be written to metaOut and actual data to dataOut.