Package org.roaringbitmap.buffer

Class BufferFastAggregation

  • public final class BufferFastAggregation
extends java.lang.Object
    Fast algorithms to aggregate many bitmaps.

    • Method Detail

      • and

        public static MutableRoaringBitmap and​(long[] aggregationBuffer,
                                       ImmutableRoaringBitmap... bitmaps)
        Compute the AND aggregate.
        Parameters:
        aggregationBuffer - a memory buffer for use in the aggregation. Will be cleared after use.
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap

      • and

        public static MutableRoaringBitmap and​(java.util.Iterator<? extends ImmutableRoaringBitmap> bitmaps)
        Compute the AND aggregate. In practice, calls {#link workShyAnd}
        Parameters:
        bitmaps - input bitmaps (ImmutableRoaringBitmap or MutableRoaringBitmap)
        Returns:
        aggregated bitmap

      • and

        public static MutableRoaringBitmap and​(long[] aggregationBuffer,
                                       java.util.Iterator<? extends ImmutableRoaringBitmap> bitmaps)
        Compute the AND aggregate. In practice, calls {#link workShyAnd}
        Parameters:
        bitmaps - input bitmaps (ImmutableRoaringBitmap or MutableRoaringBitmap)
        Returns:
        aggregated bitmap

      • and

        public static MutableRoaringBitmap and​(MutableRoaringBitmap... bitmaps)
        Compute the AND aggregate. In practice, calls {#link naive_and}
        Parameters:
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap

      • convertToImmutable

        public static java.util.Iterator<ImmutableRoaringBitmap> convertToImmutable​(java.util.Iterator<MutableRoaringBitmap> i)
        Convenience method converting one type of iterator into another, to avoid unnecessary warnings.
        Parameters:
        i - input bitmaps
        Returns:
        an iterator over the provided iterator, with a different type

      • horizontal_or

        public static MutableRoaringBitmap horizontal_or​(ImmutableRoaringBitmap... bitmaps)
        Minimizes memory usage while computing the or aggregate on a moderate number of bitmaps. This function runs in linearithmic (O(n log n)) time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap
        See Also:
        or(ImmutableRoaringBitmap...)

      • horizontal_or

        @Deprecated
public static MutableRoaringBitmap horizontal_or​(java.util.Iterator bitmaps)
        Deprecated.
        Calls naive_or.
        Parameters:
        bitmaps - input bitmaps (ImmutableRoaringBitmap or MutableRoaringBitmap)
        Returns:
        aggregated bitmap

      • horizontal_or

        public static MutableRoaringBitmap horizontal_or​(MutableRoaringBitmap... bitmaps)
        Minimizes memory usage while computing the or aggregate on a moderate number of bitmaps. This function runs in linearithmic (O(n log n)) time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap
        See Also:
        or(ImmutableRoaringBitmap...)

      • horizontal_xor

        public static MutableRoaringBitmap horizontal_xor​(ImmutableRoaringBitmap... bitmaps)
        Minimizes memory usage while computing the xor aggregate on a moderate number of bitmaps. This function runs in linearithmic (O(n log n)) time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap
        See Also:
        xor(ImmutableRoaringBitmap...)

      • horizontal_xor

        public static MutableRoaringBitmap horizontal_xor​(MutableRoaringBitmap... bitmaps)
        Minimizes memory usage while computing the xor aggregate on a moderate number of bitmaps. This function runs in linearithmic (O(n log n)) time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap
        See Also:
        xor(ImmutableRoaringBitmap...)

      • naive_and

        public static MutableRoaringBitmap naive_and​(ImmutableRoaringBitmap... bitmaps)
        Compute overall AND between bitmaps two-by-two. This function runs in linear time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap

      • naive_and

        public static MutableRoaringBitmap naive_and​(java.util.Iterator bitmaps)
        Compute overall AND between bitmaps two-by-two. This function runs in linear time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps (ImmutableRoaringBitmap or MutableRoaringBitmap)
        Returns:
        aggregated bitmap

      • naive_and

        public static MutableRoaringBitmap naive_and​(MutableRoaringBitmap... bitmaps)
        Compute overall AND between bitmaps two-by-two. This function runs in linear time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap

      • workAndMemoryShyAnd

        public static MutableRoaringBitmap workAndMemoryShyAnd​(long[] buffer,
                                                       ImmutableRoaringBitmap... bitmaps)
        Computes the intersection by first intersecting the keys, avoids materialising containers, limits memory usage. You must provide a long[] array of length at least 1024, initialized with zeroes. We do not check whether the array is initialized with zeros: it is the caller's responsability. You should expect this function to be slower than workShyAnd and the reduction in memory usage might be small.
        Parameters:
        buffer - should be a 1024-long array
        bitmaps - the inputs
        Returns:
        the intersection of the bitmaps

      • naive_or

        public static MutableRoaringBitmap naive_or​(ImmutableRoaringBitmap... bitmaps)
        Compute overall OR between bitmaps two-by-two. This function runs in linear time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap

      • naive_or

        public static MutableRoaringBitmap naive_or​(java.util.Iterator bitmaps)
        Compute overall OR between bitmaps two-by-two. This function runs in linear time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps (ImmutableRoaringBitmap or MutableRoaringBitmap)
        Returns:
        aggregated bitmap

      • naive_or

        public static MutableRoaringBitmap naive_or​(MutableRoaringBitmap... bitmaps)
        Compute overall OR between bitmaps two-by-two. This function runs in linear time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap

      • naive_xor

        public static MutableRoaringBitmap naive_xor​(ImmutableRoaringBitmap... bitmaps)
        Compute overall XOR between bitmaps two-by-two. This function runs in linear time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap

      • naive_xor

        public static MutableRoaringBitmap naive_xor​(java.util.Iterator bitmaps)
        Compute overall XOR between bitmaps two-by-two. This function runs in linear time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps (ImmutableRoaringBitmap or MutableRoaringBitmap)
        Returns:
        aggregated bitmap

      • naive_xor

        public static MutableRoaringBitmap naive_xor​(MutableRoaringBitmap... bitmaps)
        Compute overall XOR between bitmaps two-by-two. This function runs in linear time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap

      • or

        public static MutableRoaringBitmap or​(java.util.Iterator bitmaps)
        Compute overall OR between bitmaps.
        Parameters:
        bitmaps - input bitmaps (ImmutableRoaringBitmap or MutableRoaringBitmap)
        Returns:
        aggregated bitmap

      • priorityqueue_or

        public static MutableRoaringBitmap priorityqueue_or​(java.util.Iterator bitmaps)
        Uses a priority queue to compute the or aggregate. This function runs in linearithmic (O(n log n)) time with respect to the number of bitmaps.
        Parameters:
        bitmaps - input bitmaps
        Returns:
        aggregated bitmap
        See Also:
        horizontal_or(ImmutableRoaringBitmap...)

      • xor

        public static MutableRoaringBitmap xor​(java.util.Iterator bitmaps)
        Compute overall XOR between bitmaps.
        Parameters:
        bitmaps - input bitmaps (ImmutableRoaringBitmap or MutableRoaringBitmap)
        Returns:
        aggregated bitmap