org.apache.lucene.util
Class BitVector
public final
class
BitVector
extends Object
Optimized implementation of a vector of bits. This is more-or-less like
java.util.BitSet, but also includes the following:
- a count() method, which efficiently computes the number of one bits;
- optimized read from and write to disk;
- inlinable get() method;
- store and load, as bit set or d-gaps, depending on sparseness;
Version: $Id: BitVector.java 494136 2007-01-08 18:11:08Z mikemccand $
Author: Doug Cutting
Method Summary |
void | clear(int bit) Sets the value of bit to zero. |
int | count() Returns the total number of one bits in this vector. |
boolean | get(int bit) Returns true if bit is one and
false if it is zero. |
void | set(int bit) Sets the value of bit to one. |
int | size() Returns the number of bits in this vector. |
void | write(Directory d, String name) Writes this vector to the file name in Directory
d , in a format that can be read by the constructor BitVector. |
public BitVector(int n)
Constructs a vector capable of holding n
bits.
Constructs a bit vector from the file
name
in Directory
d
, as written by the
BitVector method.
public final void clear(int bit)
Sets the value of bit
to zero.
public final int count()
Returns the total number of one bits in this vector. This is efficiently
computed and cached, so that, if the vector is not changed, no
recomputation is done for repeated calls.
public final boolean get(int bit)
Returns true
if bit
is one and
false
if it is zero.
public final void set(int bit)
Sets the value of bit
to one.
public final int size()
Returns the number of bits in this vector. This is also one greater than
the number of the largest valid bit number.
public final void write(
Directory d, String name)
Writes this vector to the file
name
in Directory
d
, in a format that can be read by the constructor
BitVector.
Copyright © 2000-2007 Apache Software Foundation. All Rights Reserved.