org.apache.lucene.util.packed

Class DirectMonotonicWriter

java.lang.Object

org.apache.lucene.util.packed.DirectMonotonicWriter

public final class DirectMonotonicWriter
extends java.lang.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

Field Summary

Fields

Modifier and Type	Field and Description
(package private) long	baseDataPointer
(package private) long[]	buffer
(package private) int	bufferSize
(package private) long	count
(package private) IndexOutput	data
(package private) boolean	finished
static int	MAX_BLOCK_SHIFT
(package private) IndexOutput	meta
static int	MIN_BLOCK_SHIFT
(package private) long	numValues
(package private) long	previous

Constructor Summary

Constructors

Constructor and Description
DirectMonotonicWriter(IndexOutput metaOut, IndexOutput dataOut, long numValues, int blockShift)

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.
private void	flush()
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

meta

final IndexOutput meta

data

final IndexOutput data

numValues

final long numValues

baseDataPointer

final long baseDataPointer

buffer

final long[] buffer

bufferSize

int bufferSize

count

long count

finished

boolean finished

previous

long previous

Constructor Detail

DirectMonotonicWriter

DirectMonotonicWriter(IndexOutput metaOut,
                      IndexOutput dataOut,
                      long numValues,
                      int blockShift)

Method Detail

flush

private void flush()
            throws java.io.IOException

Throws:

java.io.IOException

add

public void add(long v)
         throws java.io.IOException

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

Throws:

java.lang.IllegalArgumentException - if values don't come in order

java.io.IOException

finish

public void finish()
            throws java.io.IOException

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

Throws:

java.io.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.