org.apache.lucene.util.packed
Enum PackedInts.Format

java.lang.Object
  java.lang.Enum<PackedInts.Format>
      org.apache.lucene.util.packed.PackedInts.Format

All Implemented Interfaces:

Serializable, Comparable<PackedInts.Format>

Enclosing class:

PackedInts

public static enum PackedInts.Format
extends Enum<PackedInts.Format>

A format to write packed ints.

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

Enum Constant Summary

PACKED
Compact format, all bits are written contiguously.

PACKED_SINGLE_BLOCK
A format that may insert padding bits to improve encoding and decoding speed.

Field Summary

int

id

Method Summary

static PackedInts.Format	byId(int id) Get a format according to its ID.
long	byteCount(int packedIntsVersion, int valueCount, int bitsPerValue) Computes how many byte blocks are needed to store values values of size bitsPerValue.
int	getId() Returns the ID of the format.
boolean	isSupported(int bitsPerValue) Tests whether the provided number of bits per value is supported by the format.
int	longCount(int packedIntsVersion, int valueCount, int bitsPerValue) Computes how many long blocks are needed to store values values of size bitsPerValue.
float	overheadPerValue(int bitsPerValue) Returns the overhead per value, in bits.
float	overheadRatio(int bitsPerValue) Returns the overhead ratio (overhead per value / bits per value).
static PackedInts.Format	valueOf(String name) Returns the enum constant of this type with the specified name.
static PackedInts.Format[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

PACKED

public static final PackedInts.Format PACKED

Compact format, all bits are written contiguously.

PACKED_SINGLE_BLOCK

public static final PackedInts.Format PACKED_SINGLE_BLOCK

A format that may insert padding bits to improve encoding and decoding speed. Since this format doesn't support all possible bits per value, you should never use it directly, but rather use PackedInts.fastestFormatAndBits(int, int, float) to find the format that best suits your needs.

Field Detail

id

public int id

Method Detail

values

public static PackedInts.Format[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (PackedInts.Format c : PackedInts.Format.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static PackedInts.Format valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

byId

public static PackedInts.Format byId(int id)

Get a format according to its ID.

getId

public int getId()

Returns the ID of the format.

byteCount

public long byteCount(int packedIntsVersion,
                      int valueCount,
                      int bitsPerValue)

Computes how many byte blocks are needed to store values values of size bitsPerValue.

longCount

public int longCount(int packedIntsVersion,
                     int valueCount,
                     int bitsPerValue)

Computes how many long blocks are needed to store values values of size bitsPerValue.

isSupported

public boolean isSupported(int bitsPerValue)

Tests whether the provided number of bits per value is supported by the format.

overheadPerValue

public float overheadPerValue(int bitsPerValue)

Returns the overhead per value, in bits.

overheadRatio

public final float overheadRatio(int bitsPerValue)

Returns the overhead ratio (overhead per value / bits per value).