| /* |
| * Copyright 2017 The Android Open Source Project |
| * |
| * Licensed 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 android.privacy.internal.longitudinalreporting; |
| |
| import android.privacy.DifferentialPrivacyConfig; |
| import android.privacy.internal.rappor.RapporConfig; |
| import android.text.TextUtils; |
| |
| import com.android.internal.util.Preconditions; |
| |
| /** |
| * A class to store {@link LongitudinalReportingEncoder} configuration. |
| * |
| * <ul> |
| * <li> f is probability to flip input value, used in IRR. |
| * <li> p is probability to override input value, used in PRR1. |
| * <li> q is probability to set input value as 1 when result of PRR(p) is true, used in PRR2. |
| * </ul> |
| * |
| * @hide |
| */ |
| public class LongitudinalReportingConfig implements DifferentialPrivacyConfig { |
| |
| private static final String ALGORITHM_NAME = "LongitudinalReporting"; |
| |
| // Probability to flip input value. |
| private final double mProbabilityF; |
| |
| // Probability to override original value. |
| private final double mProbabilityP; |
| // Probability to override value with 1. |
| private final double mProbabilityQ; |
| |
| // IRR config to randomize original value |
| private final RapporConfig mIRRConfig; |
| |
| private final String mEncoderId; |
| |
| /** |
| * Constructor to create {@link LongitudinalReportingConfig} used for {@link |
| * LongitudinalReportingEncoder} |
| * |
| * @param encoderId Unique encoder id. |
| * @param probabilityF Probability F used in Longitudinal Reporting algorithm. |
| * @param probabilityP Probability P used in Longitudinal Reporting algorithm. This will be |
| * quantized to the nearest 1/256. |
| * @param probabilityQ Probability Q used in Longitudinal Reporting algorithm. This will be |
| * quantized to the nearest 1/256. |
| */ |
| public LongitudinalReportingConfig(String encoderId, double probabilityF, |
| double probabilityP, double probabilityQ) { |
| Preconditions.checkArgument(probabilityF >= 0 && probabilityF <= 1, |
| "probabilityF must be in range [0.0, 1.0]"); |
| this.mProbabilityF = probabilityF; |
| Preconditions.checkArgument(probabilityP >= 0 && probabilityP <= 1, |
| "probabilityP must be in range [0.0, 1.0]"); |
| this.mProbabilityP = probabilityP; |
| Preconditions.checkArgument(probabilityQ >= 0 && probabilityQ <= 1, |
| "probabilityQ must be in range [0.0, 1.0]"); |
| this.mProbabilityQ = probabilityQ; |
| Preconditions.checkArgument(!TextUtils.isEmpty(encoderId), "encoderId cannot be empty"); |
| mEncoderId = encoderId; |
| mIRRConfig = new RapporConfig(encoderId, 1, 0.0, probabilityF, 1 - probabilityF, 1, 1); |
| } |
| |
| @Override |
| public String getAlgorithm() { |
| return ALGORITHM_NAME; |
| } |
| |
| RapporConfig getIRRConfig() { |
| return mIRRConfig; |
| } |
| |
| double getProbabilityP() { |
| return mProbabilityP; |
| } |
| |
| double getProbabilityQ() { |
| return mProbabilityQ; |
| } |
| |
| String getEncoderId() { |
| return mEncoderId; |
| } |
| |
| @Override |
| public String toString() { |
| return String.format("EncoderId: %s, ProbabilityF: %.3f, ProbabilityP: %.3f" |
| + ", ProbabilityQ: %.3f", |
| mEncoderId, mProbabilityF, mProbabilityP, mProbabilityQ); |
| } |
| } |