Module org.apache.lucene.backward_codecs

Package org.apache.lucene.backward_codecs.lucene50

Class ForUtil

java.lang.Object

org.apache.lucene.backward_codecs.lucene50.ForUtil

final class ForUtil
extends Object

Encode all values in normal area with fixed bit width, which is determined by the max value in this block.

Field Summary

Fields

Modifier and Type	Field	Description
private static final int	ALL_VALUES_EQUAL	Special number of bits per value used whenever all values to encode are equal.
private final PackedInts.Decoder[]	decoders
private final int[]	encodedSizes
private final PackedInts.Encoder[]	encoders
private final int[]	iterations
(package private) static final int	MAX_DATA_SIZE	Upper limit of the number of values that might be decoded in a single call to readBlock(IndexInput, byte[], int[]).
(package private) static final int	MAX_ENCODED_SIZE	Upper limit of the number of bytes that might be required to stored BLOCK_SIZE encoded values.

Constructor Summary

Constructors

Constructor	Description
ForUtil(float acceptableOverheadRatio, DataOutput out)	Create a new ForUtil instance and save state into out.
ForUtil(DataInput in)	Restore a ForUtil from a DataInput.

Method Summary

Modifier and Type	Method	Description
private static int	bitsRequired(int[] data)	Compute the number of bits required to serialize any of the longs in data.
private static int	computeIterations(PackedInts.Decoder decoder)	Compute the number of iterations required to decode BLOCK_SIZE values with the provided PackedInts.Decoder.
private static int	encodedSize(PackedInts.Format format, int packedIntsVersion, int bitsPerValue)	Compute the number of bytes required to encode a block of values that require bitsPerValue bits per value with format format.
private static boolean	isAllEqual(int[] data)
(package private) void	readBlock(IndexInput in, byte[] encoded, int[] decoded)	Read the next block of data (For format).
(package private) void	skipBlock(IndexInput in)	Skip the next block of data.
(package private) void	writeBlock(int[] data, byte[] encoded, IndexOutput out)	Write a block of data (For format).

Methods inherited from class java.lang.Object

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

Field Details

ALL_VALUES_EQUAL

private static final int ALL_VALUES_EQUAL

Special number of bits per value used whenever all values to encode are equal.

See Also:

• Constant Field Values

MAX_ENCODED_SIZE

static final int MAX_ENCODED_SIZE

Upper limit of the number of bytes that might be required to stored BLOCK_SIZE encoded values.

See Also:

• Constant Field Values

MAX_DATA_SIZE

static final int MAX_DATA_SIZE

Upper limit of the number of values that might be decoded in a single call to readBlock(IndexInput, byte[], int[]). Although values after BLOCK_SIZE are garbage, it is necessary to allocate value buffers whose size is >= MAX_DATA_SIZE to avoid ArrayIndexOutOfBoundsExceptions.

encodedSizes

private final int[] encodedSizes

encoders

private final PackedInts.Encoder[] encoders

decoders

private final PackedInts.Decoder[] decoders

iterations

private final int[] iterations

Constructor Details

ForUtil

ForUtil(float acceptableOverheadRatio,
 DataOutput out)
 throws IOException

Create a new ForUtil instance and save state into out.

Throws:

IOException

ForUtil

ForUtil(DataInput in)
 throws IOException

Restore a ForUtil from a DataInput.

Throws:

IOException

Method Details

computeIterations

private static int computeIterations(PackedInts.Decoder decoder)

Compute the number of iterations required to decode BLOCK_SIZE values with the provided PackedInts.Decoder.

encodedSize

private static int encodedSize(PackedInts.Format format,
 int packedIntsVersion,
 int bitsPerValue)

Compute the number of bytes required to encode a block of values that require bitsPerValue bits per value with format format.

writeBlock

void writeBlock(int[] data,
 byte[] encoded,
 IndexOutput out)
         throws IOException

Write a block of data (For format).

Parameters:

data - the data to write

encoded - a buffer to use to encode data

out - the destination output

Throws:

IOException - If there is a low-level I/O error

readBlock

void readBlock(IndexInput in,
 byte[] encoded,
 int[] decoded)
        throws IOException

Read the next block of data (For format).

Parameters:

in - the input to use to read data

encoded - a buffer that can be used to store encoded data

decoded - where to write decoded data

Throws:

IOException - If there is a low-level I/O error

skipBlock

void skipBlock(IndexInput in)
        throws IOException

Skip the next block of data.

Parameters:

in - the input where to read data

Throws:

IOException - If there is a low-level I/O error

isAllEqual

private static boolean isAllEqual(int[] data)

bitsRequired

private static int bitsRequired(int[] data)

Compute the number of bits required to serialize any of the longs in data.