Class ThresholdFuncBitmap
java.lang.Object
com.googlecode.javaewah.symmetric.UpdateableBitmapFunction
com.googlecode.javaewah.symmetric.ThresholdFuncBitmap
A threshold Boolean function returns true if the number of true values exceed
a threshold. It is a symmetric Boolean function.
This class implements an algorithm described in the following paper:
Owen Kaser and Daniel Lemire, Compressed bitmap indexes: beyond unions and intersections
http://arxiv.org/abs/1402.4466
It is not thread safe: you should use one object per thread.
- Since:
- 0.8.0
- See Also:
-
Field Summary
FieldsModifier and TypeFieldDescriptionprivate final int[]
private long[]
private int
private final int
private static final int[]
Fields inherited from class com.googlecode.javaewah.symmetric.UpdateableBitmapFunction
b, hammingWeight, litWeight, litwlist, rw
-
Constructor Summary
ConstructorsConstructorDescriptionThresholdFuncBitmap
(int min) Construction a threshold function with a given threshold -
Method Summary
Modifier and TypeMethodDescriptionprivate void
andLiterals
(BitmapStorage out, int runBegin, int runLength) void
dispatch
(BitmapStorage out, int runBegin, int runEnd) Writes out the answer.private void
generalLiterals
(int deficit, BitmapStorage out, int runBegin, int runLength) private void
orLiterals
(BitmapStorage out, int runBegin, int runLength) private long
threshold2buf
(int t, long[] buf, int bufUsed) private static long
threshold3
(int t, long[] buffers, int bufUsed) private long
threshold4
(int T, long[] buf, int bufUsed) Methods inherited from class com.googlecode.javaewah.symmetric.UpdateableBitmapFunction
clearLiteral, fillWithLiterals, getLiterals, getNumberOfLiterals, resize, setLiteral, setOne, setZero
-
Field Details
-
min
private final int min -
buffers
private long[] buffers -
bufferUsed
private int bufferUsed -
bufCounters
private final int[] bufCounters -
zeroes64
private static final int[] zeroes64
-
-
Constructor Details
-
ThresholdFuncBitmap
public ThresholdFuncBitmap(int min) Construction a threshold function with a given threshold- Parameters:
min
- threshold
-
-
Method Details
-
dispatch
Description copied from class:UpdateableBitmapFunction
Writes out the answer.- Specified by:
dispatch
in classUpdateableBitmapFunction
- Parameters:
out
- output bufferrunBegin
- beginning of the runrunEnd
- end of the run
-
threshold2buf
private long threshold2buf(int t, long[] buf, int bufUsed) -
threshold3
private static long threshold3(int t, long[] buffers, int bufUsed) -
threshold4
private long threshold4(int T, long[] buf, int bufUsed) -
orLiterals
-
andLiterals
-
generalLiterals
-