Class Packed64

Space optimized random access capable array of values with a fixed number of bits/value. Values are packed contiguously.

The implementation strives to perform af fast as possible under the constraint of contiguous bits, by avoiding expensive operations. This comes at the cost of code clarity.

Technical details: this implementation is a refinement of a non-branching version. The non-branching get and set methods meant that 2 or 4 atomics in the underlying array were always accessed, even for the cases where only 1 or 2 were needed. Even with caching, this had a detrimental effect on performance. Related to this issue, the old implementation used lookup tables for shifts and masks, which also proved to be a bit slower than calculating the shifts and masks on the fly. See https://issues.apache.org/jira/browse/LUCENE-4062 for details.

Inheritance

object

NumericDocValues

PackedInt32s.Reader

PackedInt32s.Mutable

PackedInt32s.MutableImpl

Packed64

Inherited Members

PackedInt32s.MutableImpl.m_valueCount

PackedInt32s.MutableImpl.m_bitsPerValue

PackedInt32s.MutableImpl.BitsPerValue

PackedInt32s.MutableImpl.Count

PackedInt32s.Mutable.Save(DataOutput)

PackedInt32s.Reader.GetArray()

PackedInt32s.Reader.HasArray

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: Lucene.Net.Util.Packed

Assembly: Lucene.Net.dll

Syntax

public class Packed64 : PackedInt32s.MutableImpl

Constructors

Packed64(int, DataInput, int, int)

Creates an array with content retrieved from the given DataInput.

Declaration

public Packed64(int packedIntsVersion, DataInput @in, int valueCount, int bitsPerValue)

Parameters

Type	Name	Description
int	packedIntsVersion
DataInput	in	A DataInput, positioned at the start of Packed64-content.
int	valueCount	The number of elements.
int	bitsPerValue	The number of bits available for any given value.

Exceptions

Type	Condition
IOException	If the values for the backing array could not be retrieved.

Packed64(int, int)

Creates an array with the internal structures adjusted for the given limits and initialized to 0.

Declaration

public Packed64(int valueCount, int bitsPerValue)

Parameters

Type	Name	Description
int	valueCount	The number of elements.
int	bitsPerValue	The number of bits available for any given value.

Methods

Clear()

Sets all values to 0.

Declaration

public override void Clear()

Overrides

PackedInt32s.Mutable.Clear()

Fill(int, int, long)

Fill the mutable from fromIndex (inclusive) to toIndex (exclusive) with val.

Declaration

public override void Fill(int fromIndex, int toIndex, long val)

Parameters

Type	Name	Description
int	fromIndex
int	toIndex
long	val

Overrides

PackedInt32s.Mutable.Fill(int, int, long)

Get(int)

Space optimized random access capable array of values with a fixed number of bits/value. Values are packed contiguously.

The implementation strives to perform af fast as possible under the constraint of contiguous bits, by avoiding expensive operations. This comes at the cost of code clarity.

Technical details: this implementation is a refinement of a non-branching version. The non-branching get and set methods meant that 2 or 4 atomics in the underlying array were always accessed, even for the cases where only 1 or 2 were needed. Even with caching, this had a detrimental effect on performance. Related to this issue, the old implementation used lookup tables for shifts and masks, which also proved to be a bit slower than calculating the shifts and masks on the fly. See https://issues.apache.org/jira/browse/LUCENE-4062 for details.

Declaration

public override long Get(int index)

Parameters

Type	Name	Description
int	index	The position of the value.

Returns

Type	Description
long	The value at the given index.

Overrides

NumericDocValues.Get(int)

Get(int, long[], int, int)

Bulk get: read at least one and at most len longs starting from index into arr[off:off+len] and return the actual number of values that have been read.

Declaration

public override int Get(int index, long[] arr, int off, int len)

Parameters

Type	Name	Description
int	index
long[]	arr
int	off
int	len

Returns

Type	Description
int

Overrides

PackedInt32s.Reader.Get(int, long[], int, int)

RamBytesUsed()

Return the in-memory size in bytes.

Declaration

public override long RamBytesUsed()

Returns

Type	Description
long

Overrides

PackedInt32s.Reader.RamBytesUsed()

Set(int, long)

Set the value at the given index in the array.

Declaration

public override void Set(int index, long value)

Parameters

Type	Name	Description
int	index	Where the value should be positioned.
long	value	A value conforming to the constraints set by the array.

Overrides

PackedInt32s.Mutable.Set(int, long)

Set(int, long[], int, int)

Bulk set: set at least one and at most len longs starting at off in arr into this mutable, starting at index. Returns the actual number of values that have been set.

Declaration

public override int Set(int index, long[] arr, int off, int len)

Parameters

Type	Name	Description
int	index
long[]	arr
int	off
int	len

Returns

Type	Description
int

Overrides

PackedInt32s.Mutable.Set(int, long[], int, int)

ToString()

Returns a string that represents the current object.

Declaration

public override string ToString()

Returns

Type	Description
string	A string that represents the current object.

Overrides

object.ToString()