Package org.apache.lucene.util

Class GroupVIntUtil

java.lang.Object

org.apache.lucene.util.GroupVIntUtil

public final class GroupVIntUtil
extends Object

This class contains utility methods and constants for group varint

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

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	GroupVIntUtil.IntReader	Provides an abstraction for read int values, so that decoding logic can be reused in different DataInput.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	MAX_LENGTH_PER_GROUP

Constructor Summary

Constructors

Constructor	Description
GroupVIntUtil()

Method Summary

Modifier and Type	Method	Description
static void	readGroupVInt(DataInput in, int[] dst, int offset)	Default implementation of read single group, for optimal performance, you should use readGroupVInts(DataInput, int[], int) instead.
static void	readGroupVInt(DataInput in, long[] dst, int offset)	Default implementation of read single group, for optimal performance, you should use readGroupVInts(DataInput, long[], int) instead.
static int	readGroupVInt(DataInput in, long remaining, GroupVIntUtil.IntReader reader, long pos, int[] dst, int offset)	Faster implementation of read single group, It read values from the buffer that would not cross boundaries.
static int	readGroupVInt(DataInput in, long remaining, GroupVIntUtil.IntReader reader, long pos, long[] dst, int offset)	Faster implementation of read single group, It read values from the buffer that would not cross boundaries.
static void	readGroupVInts(DataInput in, int[] dst, int limit)	Read all the group varints, including the tail vints.
static void	readGroupVInts(DataInput in, long[] dst, int limit)	Read all the group varints, including the tail vints.
static void	writeGroupVInts(DataOutput out, byte[] scratch, int[] values, int limit)	The implementation for group-varint encoding, It uses a maximum of MAX_LENGTH_PER_GROUP bytes scratch buffer.
static void	writeGroupVInts(DataOutput out, byte[] scratch, long[] values, int limit)	The implementation for group-varint encoding, It uses a maximum of MAX_LENGTH_PER_GROUP bytes scratch buffer.

Methods inherited from class java.lang.Object

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

Field Details

MAX_LENGTH_PER_GROUP

public static final int MAX_LENGTH_PER_GROUP

See Also:

• Constant Field Values

Constructor Details

GroupVIntUtil

public GroupVIntUtil()

Method Details

readGroupVInts

public static void readGroupVInts(DataInput in,
 long[] dst,
 int limit)
                           throws IOException

Read all the group varints, including the tail vints. we need a long[] because this is what postings are using, all longs are actually required to be integers.

Parameters:

dst - the array to read ints into.

limit - the number of int values to read.

Throws:

IOException

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

readGroupVInts

public static void readGroupVInts(DataInput in,
 int[] dst,
 int limit)
                           throws IOException

Read all the group varints, including the tail vints.

Parameters:

dst - the array to read ints into.

limit - the number of int values to read.

Throws:

IOException

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

readGroupVInt

public static void readGroupVInt(DataInput in,
 long[] dst,
 int offset)
                          throws IOException

Default implementation of read single group, for optimal performance, you should use readGroupVInts(DataInput, long[], int) instead.

Parameters:

in - the input to use to read data.

dst - the array to read ints into.

offset - the offset in the array to start storing ints.

Throws:

IOException

readGroupVInt

public static void readGroupVInt(DataInput in,
 int[] dst,
 int offset)
                          throws IOException

Default implementation of read single group, for optimal performance, you should use readGroupVInts(DataInput, int[], int) instead.

Parameters:

in - the input to use to read data.

dst - the array to read ints into.

offset - the offset in the array to start storing ints.

Throws:

IOException

readGroupVInt

public static int readGroupVInt(DataInput in,
 long remaining,
 GroupVIntUtil.IntReader reader,
 long pos,
 long[] dst,
 int offset)
                         throws IOException

Faster implementation of read single group, It read values from the buffer that would not cross boundaries.

Parameters:

in - the input to use to read data.

remaining - the number of remaining bytes allowed to read for current block/segment.

reader - the supplier of read int.

pos - the start pos to read from the reader.

dst - the array to read ints into.

offset - the offset in the array to start storing ints.

Returns:

the number of bytes read excluding the flag. this indicates the number of positions should to be increased for caller, it is 0 or positive number and less than MAX_LENGTH_PER_GROUP

Throws:

IOException

readGroupVInt

public static int readGroupVInt(DataInput in,
 long remaining,
 GroupVIntUtil.IntReader reader,
 long pos,
 int[] dst,
 int offset)
                         throws IOException

Faster implementation of read single group, It read values from the buffer that would not cross boundaries.

Parameters:

in - the input to use to read data.

remaining - the number of remaining bytes allowed to read for current block/segment.

reader - the supplier of read int.

pos - the start pos to read from the reader.

dst - the array to read ints into.

offset - the offset in the array to start storing ints.

Returns:

the number of bytes read excluding the flag. this indicates the number of positions should to be increased for caller, it is 0 or positive number and less than MAX_LENGTH_PER_GROUP

Throws:

IOException

writeGroupVInts

public static void writeGroupVInts(DataOutput out,
 byte[] scratch,
 long[] values,
 int limit)
                            throws IOException

The implementation for group-varint encoding, It uses a maximum of MAX_LENGTH_PER_GROUP bytes scratch buffer.

Throws:

IOException

writeGroupVInts

public static void writeGroupVInts(DataOutput out,
 byte[] scratch,
 int[] values,
 int limit)
                            throws IOException

The implementation for group-varint encoding, It uses a maximum of MAX_LENGTH_PER_GROUP bytes scratch buffer.

Throws:

IOException