org.apache.lucene.util.packed
Class GrowableWriter

java.lang.Object
  org.apache.lucene.index.NumericDocValues
      org.apache.lucene.util.packed.PackedInts.Reader
          org.apache.lucene.util.packed.PackedInts.Mutable
              org.apache.lucene.util.packed.GrowableWriter

public class GrowableWriter
extends PackedInts.Mutable

Implements PackedInts.Mutable, but grows the bit count of the underlying packed ints on-demand.

Beware that this class will accept to set negative values but in order to do this, it will grow the number of bits per value to 64.

@lucene.internal

Field Summary

Fields inherited from class org.apache.lucene.index.NumericDocValues

EMPTY

Constructor Summary

GrowableWriter(int startBitsPerValue, int valueCount, float acceptableOverheadRatio)

Method Summary

void	clear() Sets all values to 0.
void	fill(int fromIndex, int toIndex, long val) Fill the mutable from fromIndex (inclusive) to toIndex (exclusive) with val.
long	get(int index) Returns the numeric value for the specified document ID.
int	get(int index, long[] arr, int off, int len) 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.
Object	getArray() Expert: if the bit-width of this reader matches one of java's native types, returns the underlying array (ie, byte[], short[], int[], long[]); else, returns null.
int	getBitsPerValue()
PackedInts.Mutable	getMutable()
boolean	hasArray() Returns true if this implementation is backed by a native java array.
long	ramBytesUsed() Return the in-memory size in bytes.
GrowableWriter	resize(int newSize)
void	save(DataOutput out) Save this mutable into out.
void	set(int index, long value) Set the value at the given index in the array.
int	set(int index, long[] arr, int off, int len) Bulk set: set at least one and at most len longs starting at off in arr into this mutable, starting at index.
int	size()

Methods inherited from class java.lang.Object

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

Constructor Detail

GrowableWriter

public GrowableWriter(int startBitsPerValue,
                      int valueCount,
                      float acceptableOverheadRatio)

Parameters:

startBitsPerValue - the initial number of bits per value, may grow depending on the data

valueCount - the number of values

acceptableOverheadRatio - an acceptable overhead ratio

Method Detail

get

public long get(int index)

Description copied from class: NumericDocValues

Returns the numeric value for the specified document ID.

Specified by:

get in class NumericDocValues

Parameters:

index - document ID to lookup

Returns:

numeric value

size

public int size()

Specified by:

size in class PackedInts.Reader

Returns:

the number of values.

getBitsPerValue

public int getBitsPerValue()

Specified by:

getBitsPerValue in class PackedInts.Reader

Returns:

the number of bits used to store any given value. Note: This does not imply that memory usage is bitsPerValue * #values as implementations are free to use non-space-optimal packing of bits.

getMutable

public PackedInts.Mutable getMutable()

getArray

public Object getArray()

Description copied from class: PackedInts.Reader

Expert: if the bit-width of this reader matches one of java's native types, returns the underlying array (ie, byte[], short[], int[], long[]); else, returns null. Note that when accessing the array you must upgrade the type (bitwise AND with all ones), to interpret the full value as unsigned. Ie, bytes[idx]&0xFF, shorts[idx]&0xFFFF, etc.

Overrides:

getArray in class PackedInts.Reader

hasArray

public boolean hasArray()

Description copied from class: PackedInts.Reader

Returns true if this implementation is backed by a native java array.

Overrides:

hasArray in class PackedInts.Reader

See Also:

PackedInts.Reader.getArray()

set

public void set(int index,
                long value)

Description copied from class: PackedInts.Mutable

Set the value at the given index in the array.

Specified by:

set in class PackedInts.Mutable

Parameters:

index - where the value should be positioned.

value - a value conforming to the constraints set by the array.

clear

public void clear()

Description copied from class: PackedInts.Mutable

Sets all values to 0.

Overrides:

clear in class PackedInts.Mutable

resize

public GrowableWriter resize(int newSize)

get

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

Description copied from class: PackedInts.Reader

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.

Overrides:

get in class PackedInts.Reader

set

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

Description copied from class: PackedInts.Mutable

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.

Overrides:

set in class PackedInts.Mutable

fill

public void fill(int fromIndex,
                 int toIndex,
                 long val)

Description copied from class: PackedInts.Mutable

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

Overrides:

fill in class PackedInts.Mutable

ramBytesUsed

public long ramBytesUsed()

Description copied from class: PackedInts.Reader

Return the in-memory size in bytes.

Specified by:

ramBytesUsed in class PackedInts.Reader

save

public void save(DataOutput out)
          throws IOException

Description copied from class: PackedInts.Mutable

Save this mutable into out. Instantiating a reader from the generated data will return a reader with the same number of bits per value.

Overrides:

save in class PackedInts.Mutable

Throws:

IOException