/*
 * Copyright (C) 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.
 */

#define DEBUG false

#include "Log.h"
#include "DurationMetricProducer.h"
#include "guardrail/StatsdStats.h"
#include "stats_util.h"
#include "stats_log_util.h"

#include <limits.h>
#include <stdlib.h>

using android::util::FIELD_COUNT_REPEATED;
using android::util::FIELD_TYPE_BOOL;
using android::util::FIELD_TYPE_FLOAT;
using android::util::FIELD_TYPE_INT32;
using android::util::FIELD_TYPE_INT64;
using android::util::FIELD_TYPE_MESSAGE;
using android::util::FIELD_TYPE_STRING;
using android::util::ProtoOutputStream;
using std::string;
using std::unordered_map;
using std::vector;
using std::shared_ptr;

namespace android {
namespace os {
namespace statsd {

// for StatsLogReport
const int FIELD_ID_ID = 1;
const int FIELD_ID_DURATION_METRICS = 6;
const int FIELD_ID_TIME_BASE = 9;
const int FIELD_ID_BUCKET_SIZE = 10;
const int FIELD_ID_DIMENSION_PATH_IN_WHAT = 11;
const int FIELD_ID_IS_ACTIVE = 14;
// for DurationMetricDataWrapper
const int FIELD_ID_DATA = 1;
// for DurationMetricData
const int FIELD_ID_DIMENSION_IN_WHAT = 1;
const int FIELD_ID_BUCKET_INFO = 3;
const int FIELD_ID_DIMENSION_LEAF_IN_WHAT = 4;
const int FIELD_ID_SLICE_BY_STATE = 6;
// for DurationBucketInfo
const int FIELD_ID_DURATION = 3;
const int FIELD_ID_BUCKET_NUM = 4;
const int FIELD_ID_START_BUCKET_ELAPSED_MILLIS = 5;
const int FIELD_ID_END_BUCKET_ELAPSED_MILLIS = 6;

DurationMetricProducer::DurationMetricProducer(
        const ConfigKey& key, const DurationMetric& metric, const int conditionIndex,
        const size_t startIndex, const size_t stopIndex, const size_t stopAllIndex,
        const bool nesting, const sp<ConditionWizard>& wizard,
        const FieldMatcher& internalDimensions, const int64_t timeBaseNs, const int64_t startTimeNs,
        const unordered_map<int, shared_ptr<Activation>>& eventActivationMap,
        const unordered_map<int, vector<shared_ptr<Activation>>>& eventDeactivationMap,
        const vector<int>& slicedStateAtoms,
        const unordered_map<int, unordered_map<int, int64_t>>& stateGroupMap)
    : MetricProducer(metric.id(), key, timeBaseNs, conditionIndex, wizard, eventActivationMap,
                     eventDeactivationMap, slicedStateAtoms, stateGroupMap),
      mAggregationType(metric.aggregation_type()),
      mStartIndex(startIndex),
      mStopIndex(stopIndex),
      mStopAllIndex(stopAllIndex),
      mNested(nesting),
      mContainANYPositionInInternalDimensions(false) {
    if (metric.has_bucket()) {
        mBucketSizeNs =
                TimeUnitToBucketSizeInMillisGuardrailed(key.GetUid(), metric.bucket()) * 1000000;
    } else {
        mBucketSizeNs = LLONG_MAX;
    }

    if (metric.has_dimensions_in_what()) {
        translateFieldMatcher(metric.dimensions_in_what(), &mDimensionsInWhat);
        mContainANYPositionInDimensionsInWhat = HasPositionANY(metric.dimensions_in_what());
    }

    if (internalDimensions.has_field()) {
        translateFieldMatcher(internalDimensions, &mInternalDimensions);
        mContainANYPositionInInternalDimensions = HasPositionANY(internalDimensions);
    }
    if (mContainANYPositionInInternalDimensions) {
        ALOGE("Position ANY in internal dimension not supported.");
    }
    if (mContainANYPositionInDimensionsInWhat) {
        ALOGE("Position ANY in dimension_in_what not supported.");
    }

    mSliceByPositionALL = HasPositionALL(metric.dimensions_in_what());

    if (metric.links().size() > 0) {
        for (const auto& link : metric.links()) {
            Metric2Condition mc;
            mc.conditionId = link.condition();
            translateFieldMatcher(link.fields_in_what(), &mc.metricFields);
            translateFieldMatcher(link.fields_in_condition(), &mc.conditionFields);
            mMetric2ConditionLinks.push_back(mc);
        }
        mConditionSliced = true;
    }
    mUnSlicedPartCondition = ConditionState::kUnknown;

    for (const auto& stateLink : metric.state_link()) {
        Metric2State ms;
        ms.stateAtomId = stateLink.state_atom_id();
        translateFieldMatcher(stateLink.fields_in_what(), &ms.metricFields);
        translateFieldMatcher(stateLink.fields_in_state(), &ms.stateFields);
        mMetric2StateLinks.push_back(ms);
    }

    mUseWhatDimensionAsInternalDimension = equalDimensions(mDimensionsInWhat, mInternalDimensions);
    if (mWizard != nullptr && mConditionTrackerIndex >= 0 &&
            mMetric2ConditionLinks.size() == 1) {
        mHasLinksToAllConditionDimensionsInTracker = mWizard->equalOutputDimensions(
                mConditionTrackerIndex, mMetric2ConditionLinks.begin()->conditionFields);
    }
    flushIfNeededLocked(startTimeNs);
    // Adjust start for partial bucket
    mCurrentBucketStartTimeNs = startTimeNs;
    VLOG("metric %lld created. bucket size %lld start_time: %lld", (long long)metric.id(),
         (long long)mBucketSizeNs, (long long)mTimeBaseNs);
}

DurationMetricProducer::~DurationMetricProducer() {
    VLOG("~DurationMetric() called");
}

sp<AnomalyTracker> DurationMetricProducer::addAnomalyTracker(
        const Alert &alert, const sp<AlarmMonitor>& anomalyAlarmMonitor) {
    std::lock_guard<std::mutex> lock(mMutex);
    if (mAggregationType == DurationMetric_AggregationType_SUM) {
        if (alert.trigger_if_sum_gt() > alert.num_buckets() * mBucketSizeNs) {
            ALOGW("invalid alert for SUM: threshold (%f) > possible recordable value (%d x %lld)",
                  alert.trigger_if_sum_gt(), alert.num_buckets(), (long long)mBucketSizeNs);
            return nullptr;
        }
    }
    sp<DurationAnomalyTracker> anomalyTracker =
        new DurationAnomalyTracker(alert, mConfigKey, anomalyAlarmMonitor);
    if (anomalyTracker != nullptr) {
        mAnomalyTrackers.push_back(anomalyTracker);
    }
    return anomalyTracker;
}

void DurationMetricProducer::onStateChanged(const int64_t eventTimeNs, const int32_t atomId,
                                            const HashableDimensionKey& primaryKey,
                                            const int32_t oldState, const int32_t newState) {
    // Create a FieldValue object to hold the new state.
    FieldValue value;
    value.mValue.setInt(newState);
    // Check if this metric has a StateMap. If so, map the new state value to
    // the correct state group id.
    mapStateValue(atomId, &value);

    flushIfNeededLocked(eventTimeNs);

    // Each duration tracker is mapped to a different whatKey (a set of values from the
    // dimensionsInWhat fields). We notify all trackers iff the primaryKey field values from the
    // state change event are a subset of the tracker's whatKey field values.
    //
    // Ex. For a duration metric dimensioned on uid and tag:
    // DurationTracker1 whatKey = uid: 1001, tag: 1
    // DurationTracker2 whatKey = uid: 1002, tag 1
    //
    // If the state change primaryKey = uid: 1001, we only notify DurationTracker1 of a state
    // change.
    for (auto& whatIt : mCurrentSlicedDurationTrackerMap) {
        if (!containsLinkedStateValues(whatIt.first, primaryKey, mMetric2StateLinks, atomId)) {
            continue;
        }
        whatIt.second->onStateChanged(eventTimeNs, atomId, value);
    }
}

unique_ptr<DurationTracker> DurationMetricProducer::createDurationTracker(
        const MetricDimensionKey& eventKey) const {
    switch (mAggregationType) {
        case DurationMetric_AggregationType_SUM:
            return make_unique<OringDurationTracker>(
                    mConfigKey, mMetricId, eventKey, mWizard, mConditionTrackerIndex, mNested,
                    mCurrentBucketStartTimeNs, mCurrentBucketNum, mTimeBaseNs, mBucketSizeNs,
                    mConditionSliced, mHasLinksToAllConditionDimensionsInTracker, mAnomalyTrackers);
        case DurationMetric_AggregationType_MAX_SPARSE:
            return make_unique<MaxDurationTracker>(
                    mConfigKey, mMetricId, eventKey, mWizard, mConditionTrackerIndex, mNested,
                    mCurrentBucketStartTimeNs, mCurrentBucketNum, mTimeBaseNs, mBucketSizeNs,
                    mConditionSliced, mHasLinksToAllConditionDimensionsInTracker, mAnomalyTrackers);
    }
}

// SlicedConditionChange optimization case 1:
// 1. If combination condition, logical operation is AND, only one sliced child predicate.
// 2. The links covers all dimension fields in the sliced child condition predicate.
void DurationMetricProducer::onSlicedConditionMayChangeLocked_opt1(bool condition,
                                                                   const int64_t eventTime) {
    if (mMetric2ConditionLinks.size() != 1 ||
        !mHasLinksToAllConditionDimensionsInTracker) {
        return;
    }

    bool  currentUnSlicedPartCondition = true;
    if (!mWizard->IsSimpleCondition(mConditionTrackerIndex)) {
        ConditionState unslicedPartState =
            mWizard->getUnSlicedPartConditionState(mConditionTrackerIndex);
        // When the unsliced part is still false, return directly.
        if (mUnSlicedPartCondition == ConditionState::kFalse &&
            unslicedPartState == ConditionState::kFalse) {
            return;
        }
        mUnSlicedPartCondition = unslicedPartState;
        currentUnSlicedPartCondition = mUnSlicedPartCondition > 0;
    }

    auto dimensionsChangedToTrue = mWizard->getChangedToTrueDimensions(mConditionTrackerIndex);
    auto dimensionsChangedToFalse = mWizard->getChangedToFalseDimensions(mConditionTrackerIndex);

    // The condition change is from the unsliced predicates.
    // We need to find out the true dimensions from the sliced predicate and flip their condition
    // state based on the new unsliced condition state.
    if (dimensionsChangedToTrue == nullptr || dimensionsChangedToFalse == nullptr ||
        (dimensionsChangedToTrue->empty() && dimensionsChangedToFalse->empty())) {
        std::set<HashableDimensionKey> trueConditionDimensions;
        mWizard->getTrueSlicedDimensions(mConditionTrackerIndex, &trueConditionDimensions);
        for (auto& whatIt : mCurrentSlicedDurationTrackerMap) {
            HashableDimensionKey linkedConditionDimensionKey;
            getDimensionForCondition(whatIt.first.getValues(), mMetric2ConditionLinks[0],
                                     &linkedConditionDimensionKey);
            if (trueConditionDimensions.find(linkedConditionDimensionKey) !=
                    trueConditionDimensions.end()) {
                whatIt.second->onConditionChanged(currentUnSlicedPartCondition, eventTime);
            }
        }
    } else {
        // Handle the condition change from the sliced predicate.
        if (currentUnSlicedPartCondition) {
            for (auto& whatIt : mCurrentSlicedDurationTrackerMap) {
                HashableDimensionKey linkedConditionDimensionKey;
                getDimensionForCondition(whatIt.first.getValues(), mMetric2ConditionLinks[0],
                                         &linkedConditionDimensionKey);
                if (dimensionsChangedToTrue->find(linkedConditionDimensionKey) !=
                        dimensionsChangedToTrue->end()) {
                    whatIt.second->onConditionChanged(true, eventTime);
                }
                if (dimensionsChangedToFalse->find(linkedConditionDimensionKey) !=
                        dimensionsChangedToFalse->end()) {
                    whatIt.second->onConditionChanged(false, eventTime);
                }
            }
        }
    }
}

void DurationMetricProducer::onSlicedConditionMayChangeInternalLocked(bool overallCondition,
        const int64_t eventTimeNs) {
    bool changeDimTrackable = mWizard->IsChangedDimensionTrackable(mConditionTrackerIndex);
    if (changeDimTrackable && mHasLinksToAllConditionDimensionsInTracker) {
        onSlicedConditionMayChangeLocked_opt1(overallCondition, eventTimeNs);
        return;
    }

    // Now for each of the on-going event, check if the condition has changed for them.
    for (auto& whatIt : mCurrentSlicedDurationTrackerMap) {
        whatIt.second->onSlicedConditionMayChange(overallCondition, eventTimeNs);
    }
}

void DurationMetricProducer::onSlicedConditionMayChangeLocked(bool overallCondition,
                                                              const int64_t eventTime) {
    VLOG("Metric %lld onSlicedConditionMayChange", (long long)mMetricId);

    if (!mIsActive) {
        return;
    }

    flushIfNeededLocked(eventTime);

    if (!mConditionSliced) {
        return;
    }

    onSlicedConditionMayChangeInternalLocked(overallCondition, eventTime);
}

void DurationMetricProducer::onActiveStateChangedLocked(const int64_t& eventTimeNs) {
    MetricProducer::onActiveStateChangedLocked(eventTimeNs);

    if (!mConditionSliced) {
        if (ConditionState::kTrue != mCondition) {
            return;
        }

        if (mIsActive) {
            flushIfNeededLocked(eventTimeNs);
        }

        for (auto& whatIt : mCurrentSlicedDurationTrackerMap) {
            whatIt.second->onConditionChanged(mIsActive, eventTimeNs);
        }
    } else if (mIsActive) {
        flushIfNeededLocked(eventTimeNs);
        onSlicedConditionMayChangeInternalLocked(mIsActive, eventTimeNs);
    } else { // mConditionSliced == true && !mIsActive
        for (auto& whatIt : mCurrentSlicedDurationTrackerMap) {
            whatIt.second->onConditionChanged(mIsActive, eventTimeNs);
        }
    }
}

void DurationMetricProducer::onConditionChangedLocked(const bool conditionMet,
                                                      const int64_t eventTime) {
    VLOG("Metric %lld onConditionChanged", (long long)mMetricId);
    mCondition = conditionMet ? ConditionState::kTrue : ConditionState::kFalse;

    if (!mIsActive) {
        return;
    }

    flushIfNeededLocked(eventTime);
    for (auto& whatIt : mCurrentSlicedDurationTrackerMap) {
        whatIt.second->onConditionChanged(conditionMet, eventTime);
    }
}

void DurationMetricProducer::dropDataLocked(const int64_t dropTimeNs) {
    flushIfNeededLocked(dropTimeNs);
    StatsdStats::getInstance().noteBucketDropped(mMetricId);
    mPastBuckets.clear();
}

void DurationMetricProducer::clearPastBucketsLocked(const int64_t dumpTimeNs) {
    flushIfNeededLocked(dumpTimeNs);
    mPastBuckets.clear();
}

void DurationMetricProducer::onDumpReportLocked(const int64_t dumpTimeNs,
                                                const bool include_current_partial_bucket,
                                                const bool erase_data,
                                                const DumpLatency dumpLatency,
                                                std::set<string> *str_set,
                                                ProtoOutputStream* protoOutput) {
    if (include_current_partial_bucket) {
        flushLocked(dumpTimeNs);
    } else {
        flushIfNeededLocked(dumpTimeNs);
    }
    protoOutput->write(FIELD_TYPE_INT64 | FIELD_ID_ID, (long long)mMetricId);
    protoOutput->write(FIELD_TYPE_BOOL | FIELD_ID_IS_ACTIVE, isActiveLocked());

    if (mPastBuckets.empty()) {
        VLOG(" Duration metric, empty return");
        return;
    }

    protoOutput->write(FIELD_TYPE_INT64 | FIELD_ID_TIME_BASE, (long long)mTimeBaseNs);
    protoOutput->write(FIELD_TYPE_INT64 | FIELD_ID_BUCKET_SIZE, (long long)mBucketSizeNs);

    if (!mSliceByPositionALL) {
        if (!mDimensionsInWhat.empty()) {
            uint64_t dimenPathToken = protoOutput->start(
                    FIELD_TYPE_MESSAGE | FIELD_ID_DIMENSION_PATH_IN_WHAT);
            writeDimensionPathToProto(mDimensionsInWhat, protoOutput);
            protoOutput->end(dimenPathToken);
        }
    }

    uint64_t protoToken = protoOutput->start(FIELD_TYPE_MESSAGE | FIELD_ID_DURATION_METRICS);

    VLOG("Duration metric %lld dump report now...", (long long)mMetricId);

    for (const auto& pair : mPastBuckets) {
        const MetricDimensionKey& dimensionKey = pair.first;
        VLOG("  dimension key %s", dimensionKey.toString().c_str());

        uint64_t wrapperToken =
                protoOutput->start(FIELD_TYPE_MESSAGE | FIELD_COUNT_REPEATED | FIELD_ID_DATA);

        // First fill dimension.
        if (mSliceByPositionALL) {
            uint64_t dimensionToken = protoOutput->start(
                    FIELD_TYPE_MESSAGE | FIELD_ID_DIMENSION_IN_WHAT);
            writeDimensionToProto(dimensionKey.getDimensionKeyInWhat(), str_set, protoOutput);
            protoOutput->end(dimensionToken);
        } else {
            writeDimensionLeafNodesToProto(dimensionKey.getDimensionKeyInWhat(),
                                           FIELD_ID_DIMENSION_LEAF_IN_WHAT, str_set, protoOutput);
        }
        // Then fill slice_by_state.
        for (auto state : dimensionKey.getStateValuesKey().getValues()) {
            uint64_t stateToken = protoOutput->start(FIELD_TYPE_MESSAGE | FIELD_COUNT_REPEATED |
                                                     FIELD_ID_SLICE_BY_STATE);
            writeStateToProto(state, protoOutput);
            protoOutput->end(stateToken);
        }
        // Then fill bucket_info (DurationBucketInfo).
        for (const auto& bucket : pair.second) {
            uint64_t bucketInfoToken = protoOutput->start(
                    FIELD_TYPE_MESSAGE | FIELD_COUNT_REPEATED | FIELD_ID_BUCKET_INFO);
            if (bucket.mBucketEndNs - bucket.mBucketStartNs != mBucketSizeNs) {
                protoOutput->write(FIELD_TYPE_INT64 | FIELD_ID_START_BUCKET_ELAPSED_MILLIS,
                                   (long long)NanoToMillis(bucket.mBucketStartNs));
                protoOutput->write(FIELD_TYPE_INT64 | FIELD_ID_END_BUCKET_ELAPSED_MILLIS,
                                   (long long)NanoToMillis(bucket.mBucketEndNs));
            } else {
                protoOutput->write(FIELD_TYPE_INT64 | FIELD_ID_BUCKET_NUM,
                                   (long long)(getBucketNumFromEndTimeNs(bucket.mBucketEndNs)));
            }
            protoOutput->write(FIELD_TYPE_INT64 | FIELD_ID_DURATION, (long long)bucket.mDuration);
            protoOutput->end(bucketInfoToken);
            VLOG("\t bucket [%lld - %lld] duration: %lld", (long long)bucket.mBucketStartNs,
                 (long long)bucket.mBucketEndNs, (long long)bucket.mDuration);
        }

        protoOutput->end(wrapperToken);
    }

    protoOutput->end(protoToken);
    if (erase_data) {
        mPastBuckets.clear();
    }
}

void DurationMetricProducer::flushIfNeededLocked(const int64_t& eventTimeNs) {
    int64_t currentBucketEndTimeNs = getCurrentBucketEndTimeNs();

    if (currentBucketEndTimeNs > eventTimeNs) {
        return;
    }
    VLOG("flushing...........");
    int numBucketsForward = 1 + (eventTimeNs - currentBucketEndTimeNs) / mBucketSizeNs;
    int64_t nextBucketNs = currentBucketEndTimeNs + (numBucketsForward - 1) * mBucketSizeNs;
    flushCurrentBucketLocked(eventTimeNs, nextBucketNs);

    mCurrentBucketNum += numBucketsForward;
}

void DurationMetricProducer::flushCurrentBucketLocked(const int64_t& eventTimeNs,
                                                      const int64_t& nextBucketStartTimeNs) {
    for (auto whatIt = mCurrentSlicedDurationTrackerMap.begin();
            whatIt != mCurrentSlicedDurationTrackerMap.end();) {
        if (whatIt->second->flushCurrentBucket(eventTimeNs, &mPastBuckets)) {
            VLOG("erase bucket for key %s", whatIt->first.toString().c_str());
            whatIt = mCurrentSlicedDurationTrackerMap.erase(whatIt);
        } else {
            ++whatIt;
        }
    }
    StatsdStats::getInstance().noteBucketCount(mMetricId);
    mCurrentBucketStartTimeNs = nextBucketStartTimeNs;
}

void DurationMetricProducer::dumpStatesLocked(FILE* out, bool verbose) const {
    if (mCurrentSlicedDurationTrackerMap.size() == 0) {
        return;
    }

    fprintf(out, "DurationMetric %lld dimension size %lu\n", (long long)mMetricId,
            (unsigned long)mCurrentSlicedDurationTrackerMap.size());
    if (verbose) {
        for (const auto& whatIt : mCurrentSlicedDurationTrackerMap) {
            fprintf(out, "\t(what)%s\n", whatIt.first.toString().c_str());
            whatIt.second->dumpStates(out, verbose);
        }
    }
}

bool DurationMetricProducer::hitGuardRailLocked(const MetricDimensionKey& newKey) {
    auto whatIt = mCurrentSlicedDurationTrackerMap.find(newKey.getDimensionKeyInWhat());
    if (whatIt == mCurrentSlicedDurationTrackerMap.end()) {
        // 1. Report the tuple count if the tuple count > soft limit
        if (mCurrentSlicedDurationTrackerMap.size() > StatsdStats::kDimensionKeySizeSoftLimit - 1) {
            size_t newTupleCount = mCurrentSlicedDurationTrackerMap.size() + 1;
            StatsdStats::getInstance().noteMetricDimensionSize(
                    mConfigKey, mMetricId, newTupleCount);
            // 2. Don't add more tuples, we are above the allowed threshold. Drop the data.
            if (newTupleCount > StatsdStats::kDimensionKeySizeHardLimit) {
                ALOGE("DurationMetric %lld dropping data for what dimension key %s",
                    (long long)mMetricId, newKey.getDimensionKeyInWhat().toString().c_str());
                StatsdStats::getInstance().noteHardDimensionLimitReached(mMetricId);
                return true;
            }
        }
    }
    return false;
}

void DurationMetricProducer::handleStartEvent(const MetricDimensionKey& eventKey,
                                              const ConditionKey& conditionKeys,
                                              bool condition, const LogEvent& event) {
    const auto& whatKey = eventKey.getDimensionKeyInWhat();
    auto whatIt = mCurrentSlicedDurationTrackerMap.find(whatKey);
    if (whatIt == mCurrentSlicedDurationTrackerMap.end()) {
        if (hitGuardRailLocked(eventKey)) {
            return;
        }
        mCurrentSlicedDurationTrackerMap[whatKey] = createDurationTracker(eventKey);
    }

    auto it = mCurrentSlicedDurationTrackerMap.find(whatKey);
    if (mUseWhatDimensionAsInternalDimension) {
        it->second->noteStart(whatKey, condition, event.GetElapsedTimestampNs(), conditionKeys);
        return;
    }

    if (mInternalDimensions.empty()) {
        it->second->noteStart(DEFAULT_DIMENSION_KEY, condition, event.GetElapsedTimestampNs(),
                              conditionKeys);
    } else {
        HashableDimensionKey dimensionKey = DEFAULT_DIMENSION_KEY;
        filterValues(mInternalDimensions, event.getValues(), &dimensionKey);
        it->second->noteStart(dimensionKey, condition, event.GetElapsedTimestampNs(),
                              conditionKeys);
    }

}

void DurationMetricProducer::onMatchedLogEventInternalLocked(
        const size_t matcherIndex, const MetricDimensionKey& eventKey,
        const ConditionKey& conditionKeys, bool condition, const LogEvent& event,
        const map<int, HashableDimensionKey>& statePrimaryKeys) {
    ALOGW("Not used in duration tracker.");
}

void DurationMetricProducer::onMatchedLogEventLocked(const size_t matcherIndex,
                                                     const LogEvent& event) {
    int64_t eventTimeNs = event.GetElapsedTimestampNs();
    if (eventTimeNs < mTimeBaseNs) {
        return;
    }

    if (mIsActive) {
        flushIfNeededLocked(event.GetElapsedTimestampNs());
    }

    // Handles Stopall events.
    if (matcherIndex == mStopAllIndex) {
        for (auto& whatIt : mCurrentSlicedDurationTrackerMap) {
            whatIt.second->noteStopAll(event.GetElapsedTimestampNs());
        }
        return;
    }

    HashableDimensionKey dimensionInWhat = DEFAULT_DIMENSION_KEY;
    if (!mDimensionsInWhat.empty()) {
        filterValues(mDimensionsInWhat, event.getValues(), &dimensionInWhat);
    }

    // Stores atom id to primary key pairs for each state atom that the metric is
    // sliced by.
    std::map<int, HashableDimensionKey> statePrimaryKeys;

    // For states with primary fields, use MetricStateLinks to get the primary
    // field values from the log event. These values will form a primary key
    // that will be used to query StateTracker for the correct state value.
    for (const auto& stateLink : mMetric2StateLinks) {
        getDimensionForState(event.getValues(), stateLink,
                             &statePrimaryKeys[stateLink.stateAtomId]);
    }

    // For each sliced state, query StateTracker for the state value using
    // either the primary key from the previous step or the DEFAULT_DIMENSION_KEY.
    //
    // Expected functionality: for any case where the MetricStateLinks are
    // initialized incorrectly (ex. # of state links != # of primary fields, no
    // links are provided for a state with primary fields, links are provided
    // in the wrong order, etc.), StateTracker will simply return kStateUnknown
    // when queried using an incorrect key.
    HashableDimensionKey stateValuesKey = DEFAULT_DIMENSION_KEY;
    for (auto atomId : mSlicedStateAtoms) {
        FieldValue value;
        if (statePrimaryKeys.find(atomId) != statePrimaryKeys.end()) {
            // found a primary key for this state, query using the key
            queryStateValue(atomId, statePrimaryKeys[atomId], &value);
        } else {
            // if no MetricStateLinks exist for this state atom,
            // query using the default dimension key (empty HashableDimensionKey)
            queryStateValue(atomId, DEFAULT_DIMENSION_KEY, &value);
        }
        mapStateValue(atomId, &value);
        stateValuesKey.addValue(value);
    }

    // Handles Stop events.
    if (matcherIndex == mStopIndex) {
        if (mUseWhatDimensionAsInternalDimension) {
            auto whatIt = mCurrentSlicedDurationTrackerMap.find(dimensionInWhat);
            if (whatIt != mCurrentSlicedDurationTrackerMap.end()) {
                whatIt->second->noteStop(dimensionInWhat, event.GetElapsedTimestampNs(), false);
            }
            return;
        }

        HashableDimensionKey internalDimensionKey = DEFAULT_DIMENSION_KEY;
        if (!mInternalDimensions.empty()) {
            filterValues(mInternalDimensions, event.getValues(), &internalDimensionKey);
        }

        auto whatIt = mCurrentSlicedDurationTrackerMap.find(dimensionInWhat);
        if (whatIt != mCurrentSlicedDurationTrackerMap.end()) {
            whatIt->second->noteStop(internalDimensionKey, event.GetElapsedTimestampNs(), false);
        }
        return;
    }

    bool condition;
    ConditionKey conditionKey;
    if (mConditionSliced) {
        for (const auto& link : mMetric2ConditionLinks) {
            getDimensionForCondition(event.getValues(), link, &conditionKey[link.conditionId]);
        }

        auto conditionState =
            mWizard->query(mConditionTrackerIndex, conditionKey,
                           !mHasLinksToAllConditionDimensionsInTracker);
        condition = conditionState == ConditionState::kTrue;
    } else {
        // TODO: The unknown condition state is not handled here, we should fix it.
        condition = mCondition == ConditionState::kTrue;
    }

    condition = condition && mIsActive;

    handleStartEvent(MetricDimensionKey(dimensionInWhat, stateValuesKey), conditionKey, condition,
                     event);
}

size_t DurationMetricProducer::byteSizeLocked() const {
    size_t totalSize = 0;
    for (const auto& pair : mPastBuckets) {
        totalSize += pair.second.size() * kBucketSize;
    }
    return totalSize;
}

}  // namespace statsd
}  // namespace os
}  // namespace android