cmds/statsd/src/metrics/MetricProducer.h

/*
 * 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.
 */

#ifndef METRIC_PRODUCER_H
#define METRIC_PRODUCER_H

#include "condition/ConditionWizard.h"
#include "matchers/matcher_util.h"
#include "packages/PackageInfoListener.h"

#include <log/logprint.h>
#include <utils/RefBase.h>

namespace android {
namespace os {
namespace statsd {

// A MetricProducer is responsible for compute one single metrics, creating stats log report, and
// writing the report to dropbox. MetricProducers should respond to package changes as required in
// PackageInfoListener, but if none of the metrics are slicing by package name, then the update can
// be a no-op.
class MetricProducer : public virtual PackageInfoListener {
public:
    MetricProducer(const int64_t startTimeNs, const int conditionIndex,
                   const sp<ConditionWizard>& wizard)
        : mStartTimeNs(startTimeNs),
          mCurrentBucketStartTimeNs(startTimeNs),
          mCurrentBucketNum(0),
          mCondition(conditionIndex >= 0 ? false : true),
          mConditionSliced(false),
          mWizard(wizard),
          mConditionTrackerIndex(conditionIndex) {
        // reuse the same map for non-sliced metrics too. this way, we avoid too many if-else.
        mDimensionKeyMap[DEFAULT_DIMENSION_KEY] = std::vector<KeyValuePair>();
    };
    virtual ~MetricProducer(){};

    // Consume the parsed stats log entry that already matched the "what" of the metric.
    void onMatchedLogEvent(const size_t matcherIndex, const LogEvent& event, bool scheduledPull);

    virtual void onConditionChanged(const bool condition, const uint64_t eventTime) = 0;

    virtual void onSlicedConditionMayChange(const uint64_t eventTime) = 0;

    // This is called when the metric collecting is done, e.g., when there is a new configuration
    // coming. MetricProducer should do the clean up, and dump existing data to dropbox.
    virtual void finish() = 0;

    // TODO: Pass a timestamp as a parameter in onDumpReport and update all its
    // implementations.
    // onDumpReport returns the proto-serialized output and clears the previously stored contents.
    virtual std::unique_ptr<std::vector<uint8_t>> onDumpReport() = 0;

    virtual bool isConditionSliced() const {
        return mConditionSliced;
    };

    // Returns the memory in bytes currently used to store this metric's data. Does not change
    // state.
    virtual size_t byteSize() = 0;

protected:
    const uint64_t mStartTimeNs;

    uint64_t mCurrentBucketStartTimeNs;

    uint64_t mCurrentBucketNum;

    int64_t mBucketSizeNs;

    bool mCondition;

    bool mConditionSliced;

    sp<ConditionWizard> mWizard;

    int mConditionTrackerIndex;

    std::vector<KeyMatcher> mDimension;  // The dimension defined in statsd_config

    // Keep the map from the internal HashableDimensionKey to std::vector<KeyValuePair>
    // that StatsLogReport wants.
    std::unordered_map<HashableDimensionKey, std::vector<KeyValuePair>> mDimensionKeyMap;

    std::vector<EventConditionLink> mConditionLinks;

    /*
     * Individual metrics can implement their own business logic here. All pre-processing is done.
     *
     * [matcherIndex]: the index of the matcher which matched this event. This is interesting to
     *                 DurationMetric, because it has start/stop/stop_all 3 matchers.
     * [eventKey]: the extracted dimension key for the final output. if the metric doesn't have
     *             dimensions, it will be DEFAULT_DIMENSION_KEY
     * [conditionKey]: the keys of conditions which should be used to query the condition for this
     *                 target event (from EventConditionLink). This is passed to individual metrics
     *                 because DurationMetric needs it to be cached.
     * [condition]: whether condition is met. If condition is sliced, this is the result coming from
     *              query with ConditionWizard; If condition is not sliced, this is the
     *              nonSlicedCondition.
     * [event]: the log event, just in case the metric needs its data, e.g., EventMetric.
     */
    virtual void onMatchedLogEventInternal(
            const size_t matcherIndex, const HashableDimensionKey& eventKey,
            const std::map<std::string, HashableDimensionKey>& conditionKey, bool condition,
            const LogEvent& event, bool scheduledPull) = 0;

    std::unique_ptr<android::util::ProtoOutputStream> mProto;

    long long mProtoToken;

    virtual void startNewProtoOutputStream(long long timestamp) = 0;

    std::unique_ptr<std::vector<uint8_t>> serializeProto();
};

}  // namespace statsd
}  // namespace os
}  // namespace android
#endif  // METRIC_PRODUCER_H