DoublesUnion.java
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* distributed with this work for additional information
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* to you under the Apache License, Version 2.0 (the
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
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*/
package org.apache.datasketches.quantiles;
import org.apache.datasketches.memory.Memory;
import org.apache.datasketches.memory.WritableMemory;
/**
* The API for Union operations for quantiles DoublesSketches
*
* @author Lee Rhodes
*/
public abstract class DoublesUnion {
/**
* Returns a new UnionBuilder
* @return a new UnionBuilder
*/
public static DoublesUnionBuilder builder() {
return new DoublesUnionBuilder();
}
/**
* Returns a Heap Union object that has been initialized with the data from the given sketch.
* @param sketch A DoublesSketch to be used as a source of data only and will not be modified.
* @return a DoublesUnion object
*/
public static DoublesUnion heapify(final DoublesSketch sketch) {
return DoublesUnionImpl.heapifyInstance(sketch);
}
/**
* Returns a Heap Union object that has been initialized with the data from the given memory
* image of a sketch.
*
* @param srcMem A memory image of a DoublesSketch to be used as a source of data,
* but will not be modified.
* @return a Union object
*/
public static DoublesUnion heapify(final Memory srcMem) {
return DoublesUnionImpl.heapifyInstance(srcMem);
}
/**
* Returns a read-only Union object that wraps off-heap data of the given memory image of
* a sketch. The data structures of the Union remain off-heap.
*
* @param mem A memory region to be used as the data structure for the sketch
* and will be modified.
* @return a Union object
*/
public static DoublesUnion wrap(final Memory mem) {
return DoublesUnionImplR.wrapInstance(mem);
}
/**
* Returns an updatable Union object that wraps off-heap data of the given memory image of
* a sketch. The data structures of the Union remain off-heap.
*
* @param mem A memory region to be used as the data structure for the sketch
* and will be modified.
* @return a Union object
*/
public static DoublesUnion wrap(final WritableMemory mem) {
return DoublesUnionImpl.wrapInstance(mem);
}
/**
* Returns true if this union's data structure is backed by Memory or WritableMemory.
* @return true if this union's data structure is backed by Memory or WritableMemory.
*/
public abstract boolean hasMemory();
/**
* Returns true if this union is off-heap (direct)
* @return true if this union is off-heap (direct)
*/
public abstract boolean isDirect();
/**
* Returns true if this union is empty
* @return true if this union is empty
*/
public abstract boolean isEmpty();
/**
* Returns the configured <i>maxK</i> of this Union.
* @return the configured <i>maxK</i> of this Union.
*/
public abstract int getMaxK();
/**
* Returns the effective <i>k</i> of this Union.
* @return the effective <i>k</i> of this Union.
*/
public abstract int getEffectiveK();
/**
* Iterative union operation, which means this method can be repeatedly called.
* Merges the given sketch into this union object.
* The given sketch is not modified.
* It is required that the ratio of the two K's be a power of 2.
* This is easily satisfied if each of the K's are already a power of 2.
* If the given sketch is null or empty it is ignored.
*
* <p>It is required that the results of the union operation, which can be obtained at any time,
* is obtained from {@link #getResult() }.
*
* @param sketchIn the sketch to be merged into this one.
*/
public abstract void union(DoublesSketch sketchIn);
/**
* Iterative union operation, which means this method can be repeatedly called.
* Merges the given Memory image of a DoublesSketch into this union object.
* The given Memory object is not modified and a link to it is not retained.
* It is required that the ratio of the two K's be a power of 2.
* This is easily satisfied if each of the K's are already a power of 2.
* If the given sketch is null or empty it is ignored.
*
* <p>It is required that the results of the union operation, which can be obtained at any time,
* is obtained from {@link #getResult() }.
*
* @param mem Memory image of sketch to be merged
*/
public abstract void union(Memory mem);
/**
* Update this union with the given double (or float) data Item.
*
* @param dataItem The given double datum.
*/
public abstract void update(double dataItem);
/**
* Gets the result of this Union as an UpdateDoublesSketch, which enables further update
* operations on the resulting sketch. The Union state has not been changed, which allows
* further union operations.
*
* @return the result of this Union operation
*/
public abstract UpdateDoublesSketch getResult();
/**
* Places the result of this Union into the provided memory as an UpdateDoublesSketch,
* which enables further update operations on the resulting sketch. The Union state has not
* been changed, which allows further union operations.
*
* @param dstMem the destination memory for the result
* @return the result of this Union operation
*/
public abstract UpdateDoublesSketch getResult(WritableMemory dstMem);
/**
* Gets the result of this Union as an UpdateDoublesSketch, which enables further update
* operations on the resulting sketch. The Union is reset to the virgin state.
*
* @return the result of this Union operation and reset.
*/
public abstract UpdateDoublesSketch getResultAndReset();
/**
* Resets this Union to a virgin state.
*/
public abstract void reset();
/**
* Serialize this union to a byte array. Result is an UpdateDoublesSketch, serialized in an
* unordered, non-compact form. The resulting byte[] can be heapified or wrapped as either a
* sketch or a union.
*
* @return byte array of this union
*/
public abstract byte[] toByteArray();
/**
* Returns summary information about the backing sketch.
*/
@Override
public abstract String toString();
/**
* Returns summary information about the backing sketch. Used for debugging.
* @param sketchSummary if true includes sketch summary
* @param dataDetail if true includes data detail
* @return summary information about the sketch.
*/
public abstract String toString(boolean sketchSummary, boolean dataDetail);
/**
* Returns true if the backing resource of <i>this</i> is identical with the backing resource
* of <i>that</i>. The capacities must be the same. If <i>this</i> is a region,
* the region offset must also be the same.
* @param that A different non-null object
* @return true if the backing resource of <i>this</i> is the same as the backing resource
* of <i>that</i>.
*/
public abstract boolean isSameResource(final Memory that);
}