| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF 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 org.apache.datasketches.cpc; |
| |
| import static org.apache.datasketches.cpc.CpcConfidence.getHipConfidenceLB; |
| import static org.apache.datasketches.cpc.CpcConfidence.getHipConfidenceUB; |
| import static org.apache.datasketches.cpc.CpcConfidence.getIconConfidenceLB; |
| import static org.apache.datasketches.cpc.CpcConfidence.getIconConfidenceUB; |
| import static org.apache.datasketches.cpc.IconEstimator.getIconEstimate; |
| import static org.apache.datasketches.cpc.PreambleUtil.checkLoPreamble; |
| import static org.apache.datasketches.cpc.PreambleUtil.getHipAccum; |
| import static org.apache.datasketches.cpc.PreambleUtil.getNumCoupons; |
| import static org.apache.datasketches.cpc.PreambleUtil.hasHip; |
| import static org.apache.datasketches.cpc.PreambleUtil.isCompressed; |
| import static org.apache.datasketches.cpc.RuntimeAsserts.rtAssert; |
| |
| import org.apache.datasketches.Family; |
| import org.apache.datasketches.memory.Memory; |
| |
| /** |
| * This provides a read-only view of a serialized image of a CpcSketch, which can be |
| * on-heap or off-heap represented as a Memory object, or on-heap represented as a byte array. |
| * @author Lee Rhodes |
| * @author Kevin Lang |
| */ |
| public final class CpcWrapper { |
| Memory mem; |
| |
| /** |
| * Construct a read-only view of the given Memory that contains a CpcSketch |
| * @param mem the given Memory |
| */ |
| public CpcWrapper(final Memory mem) { |
| this.mem = mem; |
| checkLoPreamble(mem); |
| rtAssert(isCompressed(mem)); |
| |
| } |
| |
| /** |
| * Construct a read-only view of the given byte array that contains a CpcSketch. |
| * @param byteArray the given byte array |
| */ |
| public CpcWrapper(final byte[] byteArray) { |
| this(Memory.wrap(byteArray)); |
| } |
| |
| /** |
| * Returns the best estimate of the cardinality of the sketch. |
| * @return the best estimate of the cardinality of the sketch. |
| */ |
| public double getEstimate() { |
| if (!hasHip(mem)) { |
| return getIconEstimate(PreambleUtil.getLgK(mem), getNumCoupons(mem)); |
| } |
| return getHipAccum(mem); |
| } |
| |
| /** |
| * Return the DataSketches identifier for this CPC family of sketches. |
| * @return the DataSketches identifier for this CPC family of sketches. |
| */ |
| public static Family getFamily() { |
| return Family.CPC; |
| } |
| |
| /** |
| * Returns the configured Log_base2 of K of this sketch. |
| * @return the configured Log_base2 of K of this sketch. |
| */ |
| public int getLgK() { |
| return PreambleUtil.getLgK(mem); |
| } |
| |
| /** |
| * Returns the best estimate of the lower bound of the confidence interval given <i>kappa</i>, |
| * the number of standard deviations from the mean. |
| * @param kappa the given number of standard deviations from the mean: 1, 2 or 3. |
| * @return the best estimate of the lower bound of the confidence interval given <i>kappa</i>. |
| */ |
| public double getLowerBound(final int kappa) { |
| if (!hasHip(mem)) { |
| return getIconConfidenceLB(PreambleUtil.getLgK(mem), getNumCoupons(mem), kappa); |
| } |
| return getHipConfidenceLB(PreambleUtil.getLgK(mem), getNumCoupons(mem), getHipAccum(mem), kappa); |
| } |
| |
| /** |
| * Returns the best estimate of the upper bound of the confidence interval given <i>kappa</i>, |
| * the number of standard deviations from the mean. |
| * @param kappa the given number of standard deviations from the mean: 1, 2 or 3. |
| * @return the best estimate of the upper bound of the confidence interval given <i>kappa</i>. |
| */ |
| public double getUpperBound(final int kappa) { |
| if (!hasHip(mem)) { |
| return getIconConfidenceUB(PreambleUtil.getLgK(mem), getNumCoupons(mem), kappa); |
| } |
| return getHipConfidenceUB(PreambleUtil.getLgK(mem), getNumCoupons(mem), getHipAccum(mem), kappa); |
| } |
| |
| } |