adservices/service-core/java/com/android/adservices/service/measurement/TriggerSpecs.java - platform/packages/modules/AdServices - Git at Google

 /*
  * Copyright (C) 2023 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 com.android.adservices.service.measurement;

 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.util.Pair;

 import com.android.adservices.LoggerFactory;
 import com.android.adservices.service.measurement.noising.Combinatorics;
 import com.android.adservices.service.measurement.util.UnsignedLong;
 import com.android.internal.annotations.VisibleForTesting;

 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;

 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Comparator;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;

 /**
  * A class wrapper for the trigger specification from the input argument during source registration
  */
 public class TriggerSpecs {
     private final TriggerSpec[] mTriggerSpecs;
     private int mMaxEventLevelReports;
     private final PrivacyComputationParams mPrivacyParams;
     private final Map<UnsignedLong, Integer> mTriggerDataToTriggerSpecIndexMap = new HashMap<>();
     // Reference to a list that is a property of the Source object.
     private List<AttributedTrigger> mAttributedTriggersRef;

     /** The JSON keys for flexible event report API input */
     public interface FlexEventReportJsonKeys {
         String VALUE = "value";
         String PRIORITY = "priority";
         String TRIGGER_TIME = "trigger_time";
         String TRIGGER_DATA = "trigger_data";
         String FLIP_PROBABILITY = "flip_probability";
         String END_TIMES = "end_times";
         String START_TIME = "start_time";
         String SUMMARY_WINDOW_OPERATOR = "summary_window_operator";
         String EVENT_REPORT_WINDOWS = "event_report_windows";
         String SUMMARY_BUCKETS = "summary_buckets";
     }

     public TriggerSpecs(
             String triggerSpecsString,
             String maxEventLevelReports,
             Source source,
             String privacyParametersString)
             throws JSONException {
         this(
                 triggerSpecsString,
                 Integer.parseInt(maxEventLevelReports),
                 source,
                 privacyParametersString);
     }

     /**
      * This constructor is called during the attribution process. Current trigger status will be
      * read and process to determine the outcome of incoming trigger.
      *
      * @param triggerSpecsString input trigger specs from ad tech
      * @param maxEventLevelReports max event level reports from ad tech
      * @param source the source associated with this trigger specification
      * @param privacyParametersString computed privacy parameters
      * @throws JSONException JSON exception
      */
     public TriggerSpecs(
             String triggerSpecsString,
             int maxEventLevelReports,
             @Nullable Source source,
             String privacyParametersString)
             throws JSONException {
         if (triggerSpecsString == null || triggerSpecsString.isEmpty()) {
             throw new JSONException("the source is not registered as flexible event report API");
         }
         JSONArray triggerSpecs = new JSONArray(triggerSpecsString);
         mTriggerSpecs = new TriggerSpec[triggerSpecs.length()];
         for (int i = 0; i < triggerSpecs.length(); i++) {
             mTriggerSpecs[i] = new TriggerSpec.Builder(triggerSpecs.getJSONObject(i)).build();
             for (UnsignedLong triggerData : mTriggerSpecs[i].getTriggerData()) {
                 mTriggerDataToTriggerSpecIndexMap.put(triggerData, i);
             }
         }

         mMaxEventLevelReports = maxEventLevelReports;

         if (source != null) {
             mAttributedTriggersRef = source.getAttributedTriggers();
         }

         mPrivacyParams = new PrivacyComputationParams(privacyParametersString);
     }

     /**
      * This constructor is called during the source registration process.
      *
      * @param triggerSpecs trigger specs from ad tech
      * @param maxEventLevelReports max event level reports from ad tech
      * @param source the {@code Source} associated with this trigger specification
      */
     public TriggerSpecs(@NonNull TriggerSpec[] triggerSpecs, int maxEventLevelReports,
             Source source) {
         mTriggerSpecs = triggerSpecs;
         mMaxEventLevelReports = maxEventLevelReports;
         mPrivacyParams = new PrivacyComputationParams();
         if (source != null) {
             mAttributedTriggersRef = source.getAttributedTriggers();
         }
         for (int i = 0; i < triggerSpecs.length; i++) {
             for (UnsignedLong triggerData : triggerSpecs[i].getTriggerData()) {
                 mTriggerDataToTriggerSpecIndexMap.put(triggerData, i);
             }
         }
     }

     /**
      * @return the information gain
      */
     public double getInformationGain() {
         return mPrivacyParams.getInformationGain();
     }

     /** @return the probability to use fake report */
     public double getFlipProbability() {
         return mPrivacyParams.getFlipProbability();
     }

     /**
      * Get the parameters for the privacy computation. 1st element: total report cap, an array with
      * 1 element is used to store the integer; 2nd element: number of windows per trigger data type;
      * 3rd element: number of report cap per trigger data type.
      *
      * @return the parameters to computer number of states and fake report
      */
     public int[][] getPrivacyParamsForComputation() {
         int[][] params = new int[3][];
         params[0] = new int[] {mMaxEventLevelReports};
         params[1] = mPrivacyParams.getPerTypeNumWindowList();
         params[2] = mPrivacyParams.getPerTypeCapList();
         return params;
     }

     /**
      * getter method for mTriggerSpecs
      *
      * @return the array of TriggerSpec
      */
     public TriggerSpec[] getTriggerSpecs() {
         return mTriggerSpecs;
     }

     /**
      * @return Max number of reports)
      */
     public int getMaxReports() {
         return mMaxEventLevelReports;
     }

     /**
      * Get the trigger datum given a trigger datum index. In the flexible event API, the trigger
      * data are distributed uniquely among the trigger spec objects.
      *
      * @param triggerDataIndex The index of the triggerData
      * @return the trigger data
      */
     public UnsignedLong getTriggerDataFromIndex(int triggerDataIndex) {
         for (TriggerSpec triggerSpec : mTriggerSpecs) {
             int prevTriggerDataIndex = triggerDataIndex;
             triggerDataIndex -= triggerSpec.getTriggerData().size();
             if (triggerDataIndex < 0) {
                 return triggerSpec.getTriggerData().get(prevTriggerDataIndex);
             }
         }
         // will not reach here
         return null;
     }

     /**
      * @param index the index of the summary bucket
      * @param summaryBuckets the summary bucket
      * @return return single summary bucket of the index
      */
     public static Pair<Long, Long> getSummaryBucketFromIndex(
             int index, @NonNull List<Long> summaryBuckets) {
         return new Pair<>(
                 summaryBuckets.get(index),
                 index < summaryBuckets.size() - 1
                         ? summaryBuckets.get(index + 1) - 1
                         : Integer.MAX_VALUE - 1);
     }

    /**
      * @param triggerData the trigger data
      * @return the summary bucket configured for the trigger data
      */
     public List<Long> getSummaryBucketsForTriggerData(UnsignedLong triggerData) {
         int index = mTriggerDataToTriggerSpecIndexMap.get(triggerData);
         return mTriggerSpecs[index].getSummaryBuckets();
     }

     /**
      * @param triggerData the trigger data
      * @return the summary operator type configured for the trigger data
      */
     public TriggerSpec.SummaryOperatorType getSummaryOperatorType(UnsignedLong triggerData) {
         int index = mTriggerDataToTriggerSpecIndexMap.get(triggerData);
         return mTriggerSpecs[index].getSummaryWindowOperator();
     }

     /**
      * @param triggerData the trigger data
      * @return the event report windows start time configured for the trigger data
      */
     public Long findReportingStartTimeForTriggerData(UnsignedLong triggerData) {
         int index = mTriggerDataToTriggerSpecIndexMap.get(triggerData);
         return mTriggerSpecs[index].getEventReportWindowsStart();
     }

     /**
      * @param triggerData the trigger data
      * @return the event report window ends configured for the trigger data
      */
     public List<Long> findReportingEndTimesForTriggerData(UnsignedLong triggerData) {
         int index = mTriggerDataToTriggerSpecIndexMap.get(triggerData);
         return mTriggerSpecs[index].getEventReportWindowsEnd();
     }

     /**
      * Prepares structures for flex attribution handling.
      *
      * @param sourceEventReports delivered and pending reports for the source
      * @param triggerTime trigger time
      * @param reportsToDelete a list that the method will populate with reports to delete
      * @param triggerDataToBucketIndexMap a map that the method will populate with the current
      * bucket index per trigger data after considering delivered reports
      */
     public void prepareFlexAttribution(
             List<EventReport> sourceEventReports,
             long triggerTime,
             List<EventReport> reportsToDelete,
             Map<UnsignedLong, Integer> triggerDataToBucketIndexMap) {
         // Completed reports represent an ordered sequence of summary buckets.
         sourceEventReports.sort(
                 Comparator.comparing(EventReport::getTriggerData)
                         .thenComparing(Comparator.comparingLong(
                                 eventReport -> eventReport.getTriggerSummaryBucket().first)));

         // Iterate over completed reports and store for each attributed trigger its contribution.
         // Also record the list of pending reports to delete and recreate an updated sequence for.
         for (EventReport eventReport : sourceEventReports) {
             // Delete pending reports since we may have different ones based on new trigger priority
             // ordering.
             if (eventReport.getReportTime() >= triggerTime) {
                 reportsToDelete.add(eventReport);
                 continue;
             }

             UnsignedLong triggerData = eventReport.getTriggerData();

             // Event reports are sorted by summary bucket so this event report must be either for
             // the first or the next bucket. The index for the map is one higher, corresponding to
             // the current bucket we'll start with for attribution.
             triggerDataToBucketIndexMap.merge(triggerData, 1, (oldValue, value) -> oldValue + 1);

             List<Long> buckets = getSummaryBucketsForTriggerData(triggerData);
             int bucketIndex = triggerDataToBucketIndexMap.get(triggerData) - 1;
             long prevBucket = bucketIndex == 0 ? 0L : buckets.get(bucketIndex - 1);
             long bucketSize = buckets.get(bucketIndex) - prevBucket;

             for (AttributedTrigger attributedTrigger : mAttributedTriggersRef) {
                 bucketSize -= restoreTriggerContributionAndGetBucketDelta(
                         attributedTrigger, eventReport, bucketSize);
                 // We've covered the triggers that contributed to this report so we can exit the
                 // iteration.
                 if (bucketSize == 0L) {
                     break;
                 }
             }
         }
     }

     private long restoreTriggerContributionAndGetBucketDelta(
             AttributedTrigger attributedTrigger, EventReport eventReport, long bucketSize) {
         // Skip this trigger since if it did not contribute to completed reports or if trigger data
         // do not match.
         if (attributedTrigger.getTriggerTime() >= eventReport.getReportTime()
                 || !Objects.equals(attributedTrigger.getTriggerData(),
                         eventReport.getTriggerData())) {
             return 0L;
         }

         // Value sum operator.
         if (getSummaryOperatorType(eventReport.getTriggerData())
                 == TriggerSpec.SummaryOperatorType.VALUE_SUM) {
             // The trigger can cover the full bucket size of the completed report.
             if (attributedTrigger.remainingValue() >= bucketSize) {
                 attributedTrigger.addContribution(bucketSize);
                 return bucketSize;
             // The trigger only covers some of the report's bucket.
             } else {
                 long diff = attributedTrigger.remainingValue();
                 attributedTrigger.addContribution(diff);
                 return diff;
             }
         // Count operator for a trigger that we haven't counted yet.
         } else if (attributedTrigger.getContribution() == 0L) {
             attributedTrigger.addContribution(1L);
             return 1L;
         }

         return 0L;
     }

     private int[] computePerTypeNumWindowList() {
         List<Integer> list = new ArrayList<>();
         for (TriggerSpec triggerSpec : mTriggerSpecs) {
             for (UnsignedLong ignored : triggerSpec.getTriggerData()) {
                 list.add(triggerSpec.getEventReportWindowsEnd().size());
             }
         }
         return list.stream().mapToInt(Integer::intValue).toArray();
     }

     private int[] computePerTypeCapList() {
         List<Integer> list = new ArrayList<>();
         for (TriggerSpec triggerSpec : mTriggerSpecs) {
             for (UnsignedLong ignored : triggerSpec.getTriggerData()) {
                 list.add(triggerSpec.getSummaryBuckets().size());
             }
         }
         return list.stream().mapToInt(Integer::intValue).toArray();
     }

     @Override
     public boolean equals(Object obj) {
         if (!(obj instanceof TriggerSpecs)) {
             return false;
         }
         TriggerSpecs t = (TriggerSpecs) obj;

         return mMaxEventLevelReports == t.mMaxEventLevelReports
                 && Objects.equals(mAttributedTriggersRef, t.mAttributedTriggersRef)
                 && Arrays.equals(mTriggerSpecs, t.mTriggerSpecs);
     }

     @Override
     public int hashCode() {
         return Objects.hash(
                 Arrays.hashCode(mTriggerSpecs),
                 mMaxEventLevelReports,
                 mAttributedTriggersRef);
     }

     /**
      * Encode the privacy reporting parameters to JSON
      *
      * @return json object encode this class
      */
     public String encodeToJson() {
         return encodeToJson(mTriggerSpecs);
     }

     /**
      * Encodes provided {@link TriggerSpec} into {@link JSONArray} string.
      *
      * @param triggerSpecs triggerSpec array to be encoded
      * @return JSON encoded String
      */
     public static String encodeToJson(TriggerSpec[] triggerSpecs) {
         try {
             JSONObject[] triggerSpecsArray = new JSONObject[triggerSpecs.length];
             for (int i = 0; i < triggerSpecs.length; i++) {
                 triggerSpecsArray[i] = triggerSpecs[i].encodeJSON();
             }
             return new JSONArray(triggerSpecsArray).toString();
         } catch (JSONException e) {
             LoggerFactory.getMeasurementLogger()
                     .e("TriggerSpecs::encodeToJson is unable to encode TriggerSpecs");
             return null;
         }
     }

     /**
      * Encode the result of privacy parameters computed based on input parameters to JSON
      *
      * @return String encoded the privacy parameters
      */
     public String encodePrivacyParametersToJSONString() {
         JSONObject json = new JSONObject();
         try {
             json.put(
                     FlexEventReportJsonKeys.FLIP_PROBABILITY,
                     mPrivacyParams.mFlipProbability);
         } catch (JSONException e) {
             LoggerFactory.getMeasurementLogger()
                     .e(
                             "TriggerSpecs::encodePrivacyParametersToJSONString is unable to encode"
                                     + " PrivacyParams to JSON");
             return null;
         }
         return json.toString();
     }

     /**
      * @param triggerData the triggerData to be checked
      * @return whether the triggerData is registered
      */
     public boolean containsTriggerData(UnsignedLong triggerData) {
         return mTriggerDataToTriggerSpecIndexMap.containsKey(triggerData);
     }

     @VisibleForTesting
     public List<AttributedTrigger> getAttributedTriggers() {
         return mAttributedTriggersRef;
     }

     private class PrivacyComputationParams {
         private final int[] mPerTypeNumWindowList;
         private final int[] mPerTypeCapList;
         private final long mNumStates;
         private final double mFlipProbability;
         private final double mInformationGain;

         PrivacyComputationParams() {
             mPerTypeNumWindowList = computePerTypeNumWindowList();
             mPerTypeCapList = computePerTypeCapList();

             // compute number of state and other privacy parameters
             mNumStates =
                     Combinatorics.getNumStatesFlexApi(
                             mMaxEventLevelReports, mPerTypeNumWindowList, mPerTypeCapList);
             mFlipProbability = Combinatorics.getFlipProbability(mNumStates);
             mInformationGain = Combinatorics.getInformationGain(mNumStates, mFlipProbability);
         }

         PrivacyComputationParams(String inputLine) throws JSONException {
             JSONObject json = new JSONObject(inputLine);
             mFlipProbability =
                     json.getDouble(FlexEventReportJsonKeys.FLIP_PROBABILITY);
             mPerTypeNumWindowList = null;
             mPerTypeCapList = null;
             mNumStates = -1;
             mInformationGain = -1.0;
         }

         private double getFlipProbability() {
             return mFlipProbability;
         }

         private double getInformationGain() {
             return mInformationGain;
         }

         private int[] getPerTypeNumWindowList() {
             return mPerTypeNumWindowList;
         }

         private int[] getPerTypeCapList() {
             return mPerTypeCapList;
         }
     }
 }
	/*
	* Copyright (C) 2023 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 com.android.adservices.service.measurement;

	import android.annotation.NonNull;
	import android.annotation.Nullable;
	import android.util.Pair;

	import com.android.adservices.LoggerFactory;
	import com.android.adservices.service.measurement.noising.Combinatorics;
	import com.android.adservices.service.measurement.util.UnsignedLong;
	import com.android.internal.annotations.VisibleForTesting;

	import org.json.JSONArray;
	import org.json.JSONException;
	import org.json.JSONObject;

	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Comparator;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Objects;

	/**
	* A class wrapper for the trigger specification from the input argument during source registration
	*/
	public class TriggerSpecs {
	private final TriggerSpec[] mTriggerSpecs;
	private int mMaxEventLevelReports;
	private final PrivacyComputationParams mPrivacyParams;
	private final Map<UnsignedLong, Integer> mTriggerDataToTriggerSpecIndexMap = new HashMap<>();
	// Reference to a list that is a property of the Source object.
	private List<AttributedTrigger> mAttributedTriggersRef;

	/** The JSON keys for flexible event report API input */
	public interface FlexEventReportJsonKeys {
	String VALUE = "value";
	String PRIORITY = "priority";
	String TRIGGER_TIME = "trigger_time";
	String TRIGGER_DATA = "trigger_data";
	String FLIP_PROBABILITY = "flip_probability";
	String END_TIMES = "end_times";
	String START_TIME = "start_time";
	String SUMMARY_WINDOW_OPERATOR = "summary_window_operator";
	String EVENT_REPORT_WINDOWS = "event_report_windows";
	String SUMMARY_BUCKETS = "summary_buckets";
	}

	public TriggerSpecs(
	String triggerSpecsString,
	String maxEventLevelReports,
	Source source,
	String privacyParametersString)
	throws JSONException {
	this(
	triggerSpecsString,
	Integer.parseInt(maxEventLevelReports),
	source,
	privacyParametersString);
	}

	/**
	* This constructor is called during the attribution process. Current trigger status will be
	* read and process to determine the outcome of incoming trigger.
	*
	* @param triggerSpecsString input trigger specs from ad tech
	* @param maxEventLevelReports max event level reports from ad tech
	* @param source the source associated with this trigger specification
	* @param privacyParametersString computed privacy parameters
	* @throws JSONException JSON exception
	*/
	public TriggerSpecs(
	String triggerSpecsString,
	int maxEventLevelReports,
	@Nullable Source source,
	String privacyParametersString)
	throws JSONException {
	if (triggerSpecsString == null \|\| triggerSpecsString.isEmpty()) {
	throw new JSONException("the source is not registered as flexible event report API");
	}
	JSONArray triggerSpecs = new JSONArray(triggerSpecsString);
	mTriggerSpecs = new TriggerSpec[triggerSpecs.length()];
	for (int i = 0; i < triggerSpecs.length(); i++) {
	mTriggerSpecs[i] = new TriggerSpec.Builder(triggerSpecs.getJSONObject(i)).build();
	for (UnsignedLong triggerData : mTriggerSpecs[i].getTriggerData()) {
	mTriggerDataToTriggerSpecIndexMap.put(triggerData, i);
	}
	}

	mMaxEventLevelReports = maxEventLevelReports;

	if (source != null) {
	mAttributedTriggersRef = source.getAttributedTriggers();
	}

	mPrivacyParams = new PrivacyComputationParams(privacyParametersString);
	}

	/**
	* This constructor is called during the source registration process.
	*
	* @param triggerSpecs trigger specs from ad tech
	* @param maxEventLevelReports max event level reports from ad tech
	* @param source the {@code Source} associated with this trigger specification
	*/
	public TriggerSpecs(@NonNull TriggerSpec[] triggerSpecs, int maxEventLevelReports,
	Source source) {
	mTriggerSpecs = triggerSpecs;
	mMaxEventLevelReports = maxEventLevelReports;
	mPrivacyParams = new PrivacyComputationParams();
	if (source != null) {
	mAttributedTriggersRef = source.getAttributedTriggers();
	}
	for (int i = 0; i < triggerSpecs.length; i++) {
	for (UnsignedLong triggerData : triggerSpecs[i].getTriggerData()) {
	mTriggerDataToTriggerSpecIndexMap.put(triggerData, i);
	}
	}
	}

	/**
	* @return the information gain
	*/
	public double getInformationGain() {
	return mPrivacyParams.getInformationGain();
	}

	/** @return the probability to use fake report */
	public double getFlipProbability() {
	return mPrivacyParams.getFlipProbability();
	}

	/**
	* Get the parameters for the privacy computation. 1st element: total report cap, an array with
	* 1 element is used to store the integer; 2nd element: number of windows per trigger data type;
	* 3rd element: number of report cap per trigger data type.
	*
	* @return the parameters to computer number of states and fake report
	*/
	public int[][] getPrivacyParamsForComputation() {
	int[][] params = new int[3][];
	params[0] = new int[] {mMaxEventLevelReports};
	params[1] = mPrivacyParams.getPerTypeNumWindowList();
	params[2] = mPrivacyParams.getPerTypeCapList();
	return params;
	}

	/**
	* getter method for mTriggerSpecs
	*
	* @return the array of TriggerSpec
	*/
	public TriggerSpec[] getTriggerSpecs() {
	return mTriggerSpecs;
	}

	/**
	* @return Max number of reports)
	*/
	public int getMaxReports() {
	return mMaxEventLevelReports;
	}

	/**
	* Get the trigger datum given a trigger datum index. In the flexible event API, the trigger
	* data are distributed uniquely among the trigger spec objects.
	*
	* @param triggerDataIndex The index of the triggerData
	* @return the trigger data
	*/
	public UnsignedLong getTriggerDataFromIndex(int triggerDataIndex) {
	for (TriggerSpec triggerSpec : mTriggerSpecs) {
	int prevTriggerDataIndex = triggerDataIndex;
	triggerDataIndex -= triggerSpec.getTriggerData().size();
	if (triggerDataIndex < 0) {
	return triggerSpec.getTriggerData().get(prevTriggerDataIndex);
	}
	}
	// will not reach here
	return null;
	}

	/**
	* @param index the index of the summary bucket
	* @param summaryBuckets the summary bucket
	* @return return single summary bucket of the index
	*/
	public static Pair<Long, Long> getSummaryBucketFromIndex(
	int index, @NonNull List<Long> summaryBuckets) {
	return new Pair<>(
	summaryBuckets.get(index),
	index < summaryBuckets.size() - 1
	? summaryBuckets.get(index + 1) - 1
	: Integer.MAX_VALUE - 1);
	}

	/**
	* @param triggerData the trigger data
	* @return the summary bucket configured for the trigger data
	*/
	public List<Long> getSummaryBucketsForTriggerData(UnsignedLong triggerData) {
	int index = mTriggerDataToTriggerSpecIndexMap.get(triggerData);
	return mTriggerSpecs[index].getSummaryBuckets();
	}

	/**
	* @param triggerData the trigger data
	* @return the summary operator type configured for the trigger data
	*/
	public TriggerSpec.SummaryOperatorType getSummaryOperatorType(UnsignedLong triggerData) {
	int index = mTriggerDataToTriggerSpecIndexMap.get(triggerData);
	return mTriggerSpecs[index].getSummaryWindowOperator();
	}

	/**
	* @param triggerData the trigger data
	* @return the event report windows start time configured for the trigger data
	*/
	public Long findReportingStartTimeForTriggerData(UnsignedLong triggerData) {
	int index = mTriggerDataToTriggerSpecIndexMap.get(triggerData);
	return mTriggerSpecs[index].getEventReportWindowsStart();
	}

	/**
	* @param triggerData the trigger data
	* @return the event report window ends configured for the trigger data
	*/
	public List<Long> findReportingEndTimesForTriggerData(UnsignedLong triggerData) {
	int index = mTriggerDataToTriggerSpecIndexMap.get(triggerData);
	return mTriggerSpecs[index].getEventReportWindowsEnd();
	}

	/**
	* Prepares structures for flex attribution handling.
	*
	* @param sourceEventReports delivered and pending reports for the source
	* @param triggerTime trigger time
	* @param reportsToDelete a list that the method will populate with reports to delete
	* @param triggerDataToBucketIndexMap a map that the method will populate with the current
	* bucket index per trigger data after considering delivered reports
	*/
	public void prepareFlexAttribution(
	List<EventReport> sourceEventReports,
	long triggerTime,
	List<EventReport> reportsToDelete,
	Map<UnsignedLong, Integer> triggerDataToBucketIndexMap) {
	// Completed reports represent an ordered sequence of summary buckets.
	sourceEventReports.sort(
	Comparator.comparing(EventReport::getTriggerData)
	.thenComparing(Comparator.comparingLong(
	eventReport -> eventReport.getTriggerSummaryBucket().first)));

	// Iterate over completed reports and store for each attributed trigger its contribution.
	// Also record the list of pending reports to delete and recreate an updated sequence for.
	for (EventReport eventReport : sourceEventReports) {
	// Delete pending reports since we may have different ones based on new trigger priority
	// ordering.
	if (eventReport.getReportTime() >= triggerTime) {
	reportsToDelete.add(eventReport);
	continue;
	}

	UnsignedLong triggerData = eventReport.getTriggerData();

	// Event reports are sorted by summary bucket so this event report must be either for
	// the first or the next bucket. The index for the map is one higher, corresponding to
	// the current bucket we'll start with for attribution.
	triggerDataToBucketIndexMap.merge(triggerData, 1, (oldValue, value) -> oldValue + 1);

	List<Long> buckets = getSummaryBucketsForTriggerData(triggerData);
	int bucketIndex = triggerDataToBucketIndexMap.get(triggerData) - 1;
	long prevBucket = bucketIndex == 0 ? 0L : buckets.get(bucketIndex - 1);
	long bucketSize = buckets.get(bucketIndex) - prevBucket;

	for (AttributedTrigger attributedTrigger : mAttributedTriggersRef) {
	bucketSize -= restoreTriggerContributionAndGetBucketDelta(
	attributedTrigger, eventReport, bucketSize);
	// We've covered the triggers that contributed to this report so we can exit the
	// iteration.
	if (bucketSize == 0L) {
	break;
	}
	}
	}
	}

	private long restoreTriggerContributionAndGetBucketDelta(
	AttributedTrigger attributedTrigger, EventReport eventReport, long bucketSize) {
	// Skip this trigger since if it did not contribute to completed reports or if trigger data
	// do not match.
	if (attributedTrigger.getTriggerTime() >= eventReport.getReportTime()
	\|\| !Objects.equals(attributedTrigger.getTriggerData(),
	eventReport.getTriggerData())) {
	return 0L;
	}

	// Value sum operator.
	if (getSummaryOperatorType(eventReport.getTriggerData())
	== TriggerSpec.SummaryOperatorType.VALUE_SUM) {
	// The trigger can cover the full bucket size of the completed report.
	if (attributedTrigger.remainingValue() >= bucketSize) {
	attributedTrigger.addContribution(bucketSize);
	return bucketSize;
	// The trigger only covers some of the report's bucket.
	} else {
	long diff = attributedTrigger.remainingValue();
	attributedTrigger.addContribution(diff);
	return diff;
	}
	// Count operator for a trigger that we haven't counted yet.
	} else if (attributedTrigger.getContribution() == 0L) {
	attributedTrigger.addContribution(1L);
	return 1L;
	}

	return 0L;
	}

	private int[] computePerTypeNumWindowList() {
	List<Integer> list = new ArrayList<>();
	for (TriggerSpec triggerSpec : mTriggerSpecs) {
	for (UnsignedLong ignored : triggerSpec.getTriggerData()) {
	list.add(triggerSpec.getEventReportWindowsEnd().size());
	}
	}
	return list.stream().mapToInt(Integer::intValue).toArray();
	}

	private int[] computePerTypeCapList() {
	List<Integer> list = new ArrayList<>();
	for (TriggerSpec triggerSpec : mTriggerSpecs) {
	for (UnsignedLong ignored : triggerSpec.getTriggerData()) {
	list.add(triggerSpec.getSummaryBuckets().size());
	}
	}
	return list.stream().mapToInt(Integer::intValue).toArray();
	}

	@Override
	public boolean equals(Object obj) {
	if (!(obj instanceof TriggerSpecs)) {
	return false;
	}
	TriggerSpecs t = (TriggerSpecs) obj;

	return mMaxEventLevelReports == t.mMaxEventLevelReports
	&& Objects.equals(mAttributedTriggersRef, t.mAttributedTriggersRef)
	&& Arrays.equals(mTriggerSpecs, t.mTriggerSpecs);
	}

	@Override
	public int hashCode() {
	return Objects.hash(
	Arrays.hashCode(mTriggerSpecs),
	mMaxEventLevelReports,
	mAttributedTriggersRef);
	}

	/**
	* Encode the privacy reporting parameters to JSON
	*
	* @return json object encode this class
	*/
	public String encodeToJson() {
	return encodeToJson(mTriggerSpecs);
	}

	/**
	* Encodes provided {@link TriggerSpec} into {@link JSONArray} string.
	*
	* @param triggerSpecs triggerSpec array to be encoded
	* @return JSON encoded String
	*/
	public static String encodeToJson(TriggerSpec[] triggerSpecs) {
	try {
	JSONObject[] triggerSpecsArray = new JSONObject[triggerSpecs.length];
	for (int i = 0; i < triggerSpecs.length; i++) {
	triggerSpecsArray[i] = triggerSpecs[i].encodeJSON();
	}
	return new JSONArray(triggerSpecsArray).toString();
	} catch (JSONException e) {
	LoggerFactory.getMeasurementLogger()
	.e("TriggerSpecs::encodeToJson is unable to encode TriggerSpecs");
	return null;
	}
	}

	/**
	* Encode the result of privacy parameters computed based on input parameters to JSON
	*
	* @return String encoded the privacy parameters
	*/
	public String encodePrivacyParametersToJSONString() {
	JSONObject json = new JSONObject();
	try {
	json.put(
	FlexEventReportJsonKeys.FLIP_PROBABILITY,
	mPrivacyParams.mFlipProbability);
	} catch (JSONException e) {
	LoggerFactory.getMeasurementLogger()
	.e(
	"TriggerSpecs::encodePrivacyParametersToJSONString is unable to encode"
	+ " PrivacyParams to JSON");
	return null;
	}
	return json.toString();
	}

	/**
	* @param triggerData the triggerData to be checked
	* @return whether the triggerData is registered
	*/
	public boolean containsTriggerData(UnsignedLong triggerData) {
	return mTriggerDataToTriggerSpecIndexMap.containsKey(triggerData);
	}

	@VisibleForTesting
	public List<AttributedTrigger> getAttributedTriggers() {
	return mAttributedTriggersRef;
	}

	private class PrivacyComputationParams {
	private final int[] mPerTypeNumWindowList;
	private final int[] mPerTypeCapList;
	private final long mNumStates;
	private final double mFlipProbability;
	private final double mInformationGain;

	PrivacyComputationParams() {
	mPerTypeNumWindowList = computePerTypeNumWindowList();
	mPerTypeCapList = computePerTypeCapList();

	// compute number of state and other privacy parameters
	mNumStates =
	Combinatorics.getNumStatesFlexApi(
	mMaxEventLevelReports, mPerTypeNumWindowList, mPerTypeCapList);
	mFlipProbability = Combinatorics.getFlipProbability(mNumStates);
	mInformationGain = Combinatorics.getInformationGain(mNumStates, mFlipProbability);
	}

	PrivacyComputationParams(String inputLine) throws JSONException {
	JSONObject json = new JSONObject(inputLine);
	mFlipProbability =
	json.getDouble(FlexEventReportJsonKeys.FLIP_PROBABILITY);
	mPerTypeNumWindowList = null;
	mPerTypeCapList = null;
	mNumStates = -1;
	mInformationGain = -1.0;
	}

	private double getFlipProbability() {
	return mFlipProbability;
	}

	private double getInformationGain() {
	return mInformationGain;
	}

	private int[] getPerTypeNumWindowList() {
	return mPerTypeNumWindowList;
	}

	private int[] getPerTypeCapList() {
	return mPerTypeCapList;
	}
	}
	}