cmds/statsd/src/StatsLogProcessor.cpp

/*
 * 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.
 */

#include "Log.h"

#include "StatsLogProcessor.h"
#include "frameworks/base/cmds/statsd/src/stats_log.pb.h"
#include "metrics/CountMetricProducer.h"
#include "stats_util.h"

#include <log/log_event_list.h>
#include <utils/Errors.h>

using namespace android;
using std::make_unique;
using std::unique_ptr;
using std::vector;

namespace android {
namespace os {
namespace statsd {

StatsLogProcessor::StatsLogProcessor(const sp<UidMap>& uidMap,
                                     const std::function<void(const vector<uint8_t>&)>& pushLog)
    : mUidMap(uidMap), mPushLog(pushLog) {
}

StatsLogProcessor::~StatsLogProcessor() {
}

// TODO: what if statsd service restarts? How do we know what logs are already processed before?
void StatsLogProcessor::OnLogEvent(const LogEvent& msg) {
    // pass the event to metrics managers.
    for (auto& pair : mMetricsManagers) {
        pair.second->onLogEvent(msg);
        flushIfNecessary(msg.GetTimestampNs(), pair.first, pair.second);
    }
}

void StatsLogProcessor::OnConfigUpdated(const ConfigKey& key, const StatsdConfig& config) {
    auto it = mMetricsManagers.find(key);
    if (it != mMetricsManagers.end()) {
        it->second->finish();
    }

    ALOGD("Updated configuration for key %s", key.ToString().c_str());

    unique_ptr<MetricsManager> newMetricsManager = std::make_unique<MetricsManager>(config);
    if (newMetricsManager->isConfigValid()) {
        mUidMap->OnConfigUpdated(key);
        mMetricsManagers[key] = std::move(newMetricsManager);
        // Why doesn't this work? mMetricsManagers.insert({key, std::move(newMetricsManager)});
        ALOGD("StatsdConfig valid");
    } else {
        // If there is any error in the config, don't use it.
        ALOGD("StatsdConfig NOT valid");
    }
}

ConfigMetricsReport StatsLogProcessor::onDumpReport(const ConfigKey& key) {
    ConfigMetricsReport report;

    auto it = mMetricsManagers.find(key);
    if (it == mMetricsManagers.end()) {
        ALOGW("Config source %s does not exist", key.ToString().c_str());
        return report;
    }

    auto set_key = report.mutable_config_key();
    set_key->set_uid(key.GetUid());
    set_key->set_name(key.GetName());
    for (auto m : it->second->onDumpReport()) {
        // Transfer the vector of StatsLogReport into a field
        // TODO: perhaps we just have bytes being returned from onDumpReport and transfer bytes
        auto dest = report.add_metrics();
        *dest = m;
    }
    auto temp = mUidMap->getOutput(key);
    report.mutable_uid_map()->Swap(&temp);
    return report;
}

void StatsLogProcessor::OnConfigRemoved(const ConfigKey& key) {
    auto it = mMetricsManagers.find(key);
    if (it != mMetricsManagers.end()) {
        it->second->finish();
        mMetricsManagers.erase(it);
        mUidMap->OnConfigRemoved(key);
    }
    auto flushTime = mLastFlushTimes.find(key);
    if (flushTime != mLastFlushTimes.end()) {
        mLastFlushTimes.erase(flushTime);
    }
}

void StatsLogProcessor::flushIfNecessary(uint64_t timestampNs,
                                         const ConfigKey& key,
                                         const unique_ptr<MetricsManager>& metricsManager) {
    auto lastFlushNs = mLastFlushTimes.find(key);
    if (lastFlushNs != mLastFlushTimes.end()) {
        if (timestampNs - lastFlushNs->second < kMinFlushPeriod) {
            return;
        }
    }

    size_t totalBytes = metricsManager->byteSize();
    if (totalBytes > kMaxSerializedBytes) {
        flush();
        mLastFlushTimes[key] = std::move(timestampNs);
    }
}

void StatsLogProcessor::flush() {
    // TODO: Take ConfigKey as an argument and flush metrics related to the
    // ConfigKey. Also, create a wrapper that holds a repeated field of
    // StatsLogReport's.
    /*
    StatsLogReport logReport;
    const int numBytes = logReport.ByteSize();
    vector<uint8_t> logReportBuffer(numBytes);
    logReport.SerializeToArray(&logReportBuffer[0], numBytes);
    mPushLog(logReportBuffer);
    */
}

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