io.druid.query.aggregation.datasketches.tuple.doublearray.SketchOperations.java Source code

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Here is the source code for io.druid.query.aggregation.datasketches.tuple.doublearray.SketchOperations.java

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/*
 * Licensed to Metamarkets Group Inc. (Metamarkets) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. Metamarkets licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package io.druid.query.aggregation.datasketches.tuple.doublearray;

import org.apache.commons.codec.binary.Base64;

import com.google.common.base.Charsets;
import com.yahoo.sketches.ResizeFactor;
import com.yahoo.memory.Memory;
import com.yahoo.memory.NativeMemory;
import com.yahoo.sketches.theta.Sketch;
import com.yahoo.sketches.tuple.ArrayOfDoublesSketch;
import com.yahoo.sketches.tuple.ArrayOfDoublesSketches;
import com.yahoo.sketches.tuple.ArrayOfDoublesUpdatableSketch;
import com.yahoo.sketches.tuple.ArrayOfDoublesUpdatableSketchBuilder;

/**
 * 
 * @author sunxin@rongcapital.cn
 *
 */
public class SketchOperations {

    public static final ArrayOfDoublesSketch EMPTY_SKETCH = new ArrayOfDoublesUpdatableSketchBuilder()
            .setNominalEntries(16384).setResizeFactor(ResizeFactor.X2).setNumberOfValues(1).build();

    public static ArrayOfDoublesUpdatableSketch createSketch(int size, int valuesCount, Object key, Object values) {
        ArrayOfDoublesUpdatableSketch sketch = new ArrayOfDoublesUpdatableSketchBuilder().setNominalEntries(size)
                .setResizeFactor(ResizeFactor.X2).setNumberOfValues(valuesCount).build();
        String KeyStr = (String) key;
        double[] valuesAry = (double[]) values;
        double[] finalValuesAry = new double[valuesCount];
        System.arraycopy(valuesAry, 0, finalValuesAry, 0, valuesAry.length);
        sketch.update(KeyStr, finalValuesAry);
        return sketch;
    }

    public static ArrayOfDoublesSketch deserialize(Object serializedSketch) {
        if (serializedSketch instanceof String) {
            return deserializeFromBase64EncodedString((String) serializedSketch);
        } else if (serializedSketch instanceof byte[]) {
            return deserializeFromByteArray((byte[]) serializedSketch);
        } else if (serializedSketch instanceof ArrayOfDoublesSketch) {
            return (ArrayOfDoublesSketch) serializedSketch;
        }

        throw new IllegalStateException(
                "Object is not of a type that can deserialize to sketch: " + serializedSketch.getClass());
    }

    public static ArrayOfDoublesSketch deserializeFromBase64EncodedString(String str) {
        return deserializeFromByteArray(Base64.decodeBase64(str.getBytes(Charsets.UTF_8)));
    }

    public static ArrayOfDoublesSketch deserializeFromByteArray(byte[] data) {
        return deserializeFromMemory(new NativeMemory(data));
    }

    public static ArrayOfDoublesSketch deserializeFromMemory(Memory mem) {
        if (Sketch.getSerializationVersion(mem) < 3) {
            return ArrayOfDoublesSketches.heapifySketch(mem);
        } else {
            return ArrayOfDoublesSketches.wrapSketch(mem);
        }
    }

}