xref: /frameworks/base/apex/jobscheduler/service/java/com/android/server/job/JobStore.java

/*
 * Copyright (C) 2014 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.server.job;

import static android.net.NetworkCapabilities.NET_CAPABILITY_TEMPORARILY_NOT_METERED;
import static android.net.NetworkCapabilities.TRANSPORT_TEST;

import static com.android.server.job.JobSchedulerService.sElapsedRealtimeClock;
import static com.android.server.job.JobSchedulerService.sSystemClock;

import android.annotation.NonNull;
import android.annotation.Nullable;
import android.app.job.JobInfo;
import android.app.job.JobWorkItem;
import android.content.ComponentName;
import android.content.Context;
import android.net.NetworkRequest;
import android.os.Environment;
import android.os.Handler;
import android.os.PersistableBundle;
import android.os.Process;
import android.os.SystemClock;
import android.text.TextUtils;
import android.text.format.DateUtils;
import android.util.ArraySet;
import android.util.AtomicFile;
import android.util.Pair;
import android.util.Slog;
import android.util.SparseArray;
import android.util.SparseBooleanArray;
import android.util.SystemConfigFileCommitEventLogger;
import android.util.Xml;

import com.android.internal.annotations.GuardedBy;
import com.android.internal.annotations.VisibleForTesting;
import com.android.internal.util.ArrayUtils;
import com.android.internal.util.BitUtils;
import com.android.modules.expresslog.Histogram;
import com.android.modules.utils.TypedXmlPullParser;
import com.android.modules.utils.TypedXmlSerializer;
import com.android.server.AppSchedulingModuleThread;
import com.android.server.IoThread;
import com.android.server.job.JobSchedulerInternal.JobStorePersistStats;
import com.android.server.job.controllers.JobStatus;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlSerializer;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.Set;
import java.util.StringJoiner;
import java.util.concurrent.CountDownLatch;
import java.util.function.Consumer;
import java.util.function.Predicate;
import java.util.regex.Pattern;

/**
 * Maintains the master list of jobs that the job scheduler is tracking. These jobs are compared by
 * reference, so none of the functions in this class should make a copy.
 * Also handles read/write of persisted jobs.
 *
 * Note on locking:
 *      All callers to this class must <strong>lock on the class object they are calling</strong>.
 *      This is important b/c {@link com.android.server.job.JobStore.WriteJobsMapToDiskRunnable}
 *      and {@link com.android.server.job.JobStore.ReadJobMapFromDiskRunnable} lock on that
 *      object.
 *
 * Test:
 * atest $ANDROID_BUILD_TOP/frameworks/base/services/tests/servicestests/src/com/android/server/job/JobStoreTest.java
 */
public final class JobStore {
    private static final String TAG = "JobStore";
    private static final boolean DEBUG = JobSchedulerService.DEBUG;

    /** Threshold to adjust how often we want to write to the db. */
    private static final long JOB_PERSIST_DELAY = 2000L;
    private static final long SCHEDULED_JOB_HIGH_WATER_MARK_PERIOD_MS = 30 * 60_000L;
    @VisibleForTesting
    static final String JOB_FILE_SPLIT_PREFIX = "jobs_";
    private static final Pattern SPLIT_FILE_PATTERN =
            Pattern.compile("^" + JOB_FILE_SPLIT_PREFIX + "\\d+.xml$");
    private static final int ALL_UIDS = -1;
    @VisibleForTesting
    static final int INVALID_UID = -2;

    final Object mLock;
    final Object mWriteScheduleLock;    // used solely for invariants around write scheduling
    final JobSet mJobSet; // per-caller-uid and per-source-uid tracking
    final Context mContext;

    // Bookkeeping around incorrect boot-time system clock
    private final long mXmlTimestamp;
    private boolean mRtcGood;

    @GuardedBy("mWriteScheduleLock")
    private boolean mWriteScheduled;

    @GuardedBy("mWriteScheduleLock")
    private boolean mWriteInProgress;

    @GuardedBy("mWriteScheduleLock")
    private boolean mSplitFileMigrationNeeded;

    private static final Object sSingletonLock = new Object();
    private final SystemConfigFileCommitEventLogger mEventLogger;
    private final AtomicFile mJobsFile;
    private final File mJobFileDirectory;
    private final SparseBooleanArray mPendingJobWriteUids = new SparseBooleanArray();
    /** Handler backed by IoThread for writing to disk. */
    private final Handler mIoHandler = IoThread.getHandler();
    private static JobStore sSingleton;

    private boolean mUseSplitFiles = JobSchedulerService.Constants.DEFAULT_PERSIST_IN_SPLIT_FILES;

    private JobStorePersistStats mPersistInfo = new JobStorePersistStats();

    /**
     * Separately updated value of the JobSet size to avoid recalculating it frequently for logging
     * purposes. Continue to use {@link JobSet#size()} for the up-to-date and accurate value.
     */
    private int mCurrentJobSetSize = 0;
    private int mScheduledJob30MinHighWaterMark = 0;
    private static final Histogram sScheduledJob30MinHighWaterMarkLogger = new Histogram(
            "job_scheduler.value_hist_scheduled_job_30_min_high_water_mark",
            new Histogram.ScaledRangeOptions(15, 1, 99, 1.5f));
    private final Runnable mScheduledJobHighWaterMarkLoggingRunnable = new Runnable() {
        @Override
        public void run() {
            AppSchedulingModuleThread.getHandler().removeCallbacks(this);
            synchronized (mLock) {
                sScheduledJob30MinHighWaterMarkLogger.logSample(mScheduledJob30MinHighWaterMark);
                mScheduledJob30MinHighWaterMark = mJobSet.size();
            }
            // The count doesn't need to be logged at exact times. Logging based on system uptime
            // should be fine.
            AppSchedulingModuleThread.getHandler()
                    .postDelayed(this, SCHEDULED_JOB_HIGH_WATER_MARK_PERIOD_MS);
        }
    };

    /** Used by the {@link JobSchedulerService} to instantiate the JobStore. */
    static JobStore get(JobSchedulerService jobManagerService) {
        synchronized (sSingletonLock) {
            if (sSingleton == null) {
                sSingleton = new JobStore(jobManagerService.getContext(),
                        jobManagerService.getLock(), Environment.getDataDirectory());
            }
            return sSingleton;
        }
    }

    /**
     * @return A freshly initialized job store object, with no loaded jobs.
     */
    @VisibleForTesting
    public static JobStore initAndGetForTesting(Context context, File dataDir) {
        JobStore jobStoreUnderTest = new JobStore(context, new Object(), dataDir);
        jobStoreUnderTest.init();
        jobStoreUnderTest.clearForTesting();
        return jobStoreUnderTest;
    }

    /**
     * Construct the instance of the job store. This results in a blocking read from disk.
     */
    private JobStore(Context context, Object lock, File dataDir) {
        mLock = lock;
        mWriteScheduleLock = new Object();
        mContext = context;

        File systemDir = new File(dataDir, "system");
        mJobFileDirectory = new File(systemDir, "job");
        mJobFileDirectory.mkdirs();
        mEventLogger = new SystemConfigFileCommitEventLogger("jobs");
        mJobsFile = createJobFile(new File(mJobFileDirectory, "jobs.xml"));

        mJobSet = new JobSet();

        // If the current RTC is earlier than the timestamp on our persisted jobs file,
        // we suspect that the RTC is uninitialized and so we cannot draw conclusions
        // about persisted job scheduling.
        //
        // Note that if the persisted jobs file does not exist, we proceed with the
        // assumption that the RTC is good.  This is less work and is safe: if the
        // clock updates to sanity then we'll be saving the persisted jobs file in that
        // correct state, which is normal; or we'll wind up writing the jobs file with
        // an incorrect historical timestamp.  That's fine; at worst we'll reboot with
        // a *correct* timestamp, see a bunch of overdue jobs, and run them; then
        // settle into normal operation.
        mXmlTimestamp = mJobsFile.exists()
                ? mJobsFile.getLastModifiedTime() : mJobFileDirectory.lastModified();
        mRtcGood = (sSystemClock.millis() > mXmlTimestamp);

        AppSchedulingModuleThread.getHandler().postDelayed(
                mScheduledJobHighWaterMarkLoggingRunnable, SCHEDULED_JOB_HIGH_WATER_MARK_PERIOD_MS);
    }

    private void init() {
        readJobMapFromDisk(mJobSet, mRtcGood);
    }

    void initAsync(CountDownLatch completionLatch) {
        mIoHandler.post(new ReadJobMapFromDiskRunnable(mJobSet, mRtcGood, completionLatch));
    }

    private AtomicFile createJobFile(String baseName) {
        return createJobFile(new File(mJobFileDirectory, baseName + ".xml"));
    }

    private AtomicFile createJobFile(File file) {
        return new AtomicFile(file, mEventLogger);
    }

    public boolean jobTimesInflatedValid() {
        return mRtcGood;
    }

    public boolean clockNowValidToInflate(long now) {
        return now >= mXmlTimestamp;
    }

    /**
     * Runs any necessary work asynchronously. If this is called after
     * {@link #initAsync(CountDownLatch)}, this ensures the given work runs after
     * the JobStore is initialized.
     */
    void runWorkAsync(@NonNull Runnable r) {
        mIoHandler.post(r);
    }

    /**
     * Find all the jobs that were affected by RTC clock uncertainty at boot time.  Returns
     * parallel lists of the existing JobStatus objects and of new, equivalent JobStatus instances
     * with now-corrected time bounds.
     */
    public void getRtcCorrectedJobsLocked(final ArrayList<JobStatus> toAdd,
            final ArrayList<JobStatus> toRemove) {
        final long elapsedNow = sElapsedRealtimeClock.millis();

        // Find the jobs that need to be fixed up, collecting them for post-iteration
        // replacement with their new versions
        forEachJob(job -> {
            final Pair<Long, Long> utcTimes = job.getPersistedUtcTimes();
            if (utcTimes != null) {
                Pair<Long, Long> elapsedRuntimes =
                        convertRtcBoundsToElapsed(utcTimes, elapsedNow);
                JobStatus newJob = new JobStatus(job,
                        elapsedRuntimes.first, elapsedRuntimes.second,
                        0 /* numFailures */, 0 /* numAbandonedFailures */,
                        0 /* numSystemStops */, job.getLastSuccessfulRunTime(),
                        job.getLastFailedRunTime(),
                        job.getCumulativeExecutionTimeMs());
                newJob.prepareLocked();
                toAdd.add(newJob);
                toRemove.add(job);
            }
        });
    }

    /**
     * Add a job to the master list, persisting it if necessary.
     * Similar jobs to the new job will not be removed.
     *
     * @param jobStatus Job to add.
     */
    public void add(JobStatus jobStatus) {
        if (mJobSet.add(jobStatus)) {
            mCurrentJobSetSize++;
            maybeUpdateHighWaterMark();
        }
        if (jobStatus.isPersisted()) {
            mPendingJobWriteUids.put(jobStatus.getUid(), true);
            maybeWriteStatusToDiskAsync();
        }
        if (DEBUG) {
            Slog.d(TAG, "Added job status to store: " + jobStatus);
        }
    }

    /**
     * The same as above but does not schedule writing. This makes perf benchmarks more stable.
     */
    @VisibleForTesting
    public void addForTesting(JobStatus jobStatus) {
        if (mJobSet.add(jobStatus)) {
            mCurrentJobSetSize++;
            maybeUpdateHighWaterMark();
        }
        if (jobStatus.isPersisted()) {
            mPendingJobWriteUids.put(jobStatus.getUid(), true);
        }
    }

    boolean containsJob(JobStatus jobStatus) {
        return mJobSet.contains(jobStatus);
    }

    public int size() {
        return mJobSet.size();
    }

    public JobStorePersistStats getPersistStats() {
        return mPersistInfo;
    }

    public int countJobsForUid(int uid) {
        return mJobSet.countJobsForUid(uid);
    }

    /**
     * Remove the provided job. Will also delete the job if it was persisted.
     * @param removeFromPersisted If true, the job will be removed from the persisted job list
     *                            immediately (if it was persisted).
     * @return Whether or not the job existed to be removed.
     */
    public boolean remove(JobStatus jobStatus, boolean removeFromPersisted) {
        boolean removed = mJobSet.remove(jobStatus);
        if (!removed) {
            if (DEBUG) {
                Slog.d(TAG, "Couldn't remove job: didn't exist: " + jobStatus);
            }
            return false;
        }
        mCurrentJobSetSize--;
        if (removeFromPersisted && jobStatus.isPersisted()) {
            mPendingJobWriteUids.put(jobStatus.getUid(), true);
            maybeWriteStatusToDiskAsync();
        }
        return removed;
    }

    /**
     * Like {@link #remove(JobStatus, boolean)}, but doesn't schedule a disk write.
     */
    @VisibleForTesting
    public void removeForTesting(JobStatus jobStatus) {
        if (mJobSet.remove(jobStatus)) {
            mCurrentJobSetSize--;
        }
        if (jobStatus.isPersisted()) {
            mPendingJobWriteUids.put(jobStatus.getUid(), true);
        }
    }

    /**
     * Remove the jobs of users not specified in the keepUserIds.
     * @param keepUserIds Array of User IDs whose jobs should be kept and not removed.
     */
    public void removeJobsOfUnlistedUsers(int[] keepUserIds) {
        mJobSet.removeJobsOfUnlistedUsers(keepUserIds);
        mCurrentJobSetSize = mJobSet.size();
    }

    /** Note a change in the specified JobStatus that necessitates writing job state to disk. */
    void touchJob(@NonNull JobStatus jobStatus) {
        if (!jobStatus.isPersisted()) {
            return;
        }
        mPendingJobWriteUids.put(jobStatus.getUid(), true);
        maybeWriteStatusToDiskAsync();
    }

    @VisibleForTesting
    public void clear() {
        mJobSet.clear();
        mPendingJobWriteUids.put(ALL_UIDS, true);
        mCurrentJobSetSize = 0;
        maybeWriteStatusToDiskAsync();
    }

    /**
     * The same as above but does not schedule writing. This makes perf benchmarks more stable.
     */
    @VisibleForTesting
    public void clearForTesting() {
        mJobSet.clear();
        mPendingJobWriteUids.put(ALL_UIDS, true);
        mCurrentJobSetSize = 0;
    }

    void setUseSplitFiles(boolean useSplitFiles) {
        synchronized (mLock) {
            if (mUseSplitFiles != useSplitFiles) {
                mUseSplitFiles = useSplitFiles;
                migrateJobFilesAsync();
            }
        }
    }

    /**
     * The same as above but does not schedule writing. This makes perf benchmarks more stable.
     */
    @VisibleForTesting
    public void setUseSplitFilesForTesting(boolean useSplitFiles) {
        final boolean changed;
        synchronized (mLock) {
            changed = mUseSplitFiles != useSplitFiles;
            if (changed) {
                mUseSplitFiles = useSplitFiles;
                mPendingJobWriteUids.put(ALL_UIDS, true);
            }
        }
        if (changed) {
            synchronized (mWriteScheduleLock) {
                mSplitFileMigrationNeeded = true;
            }
        }
    }

    /**
     * @param sourceUid Uid of the source app.
     * @return A list of all the jobs scheduled for the source app. Never null.
     */
    @NonNull
    public ArraySet<JobStatus> getJobsBySourceUid(int sourceUid) {
        return mJobSet.getJobsBySourceUid(sourceUid);
    }

    public void getJobsBySourceUid(int sourceUid, @NonNull Set<JobStatus> insertInto) {
        mJobSet.getJobsBySourceUid(sourceUid, insertInto);
    }

    /**
     * @param uid Uid of the requesting app.
     * @return All JobStatus objects for a given uid from the master list. Never null.
     */
    @NonNull
    public ArraySet<JobStatus> getJobsByUid(int uid) {
        return mJobSet.getJobsByUid(uid);
    }

    public void getJobsByUid(int uid, @NonNull Set<JobStatus> insertInto) {
        mJobSet.getJobsByUid(uid, insertInto);
    }

    /**
     * @param uid Uid of the requesting app.
     * @param jobId Job id, specified at schedule-time.
     * @return the JobStatus that matches the provided uId and jobId, or null if none found.
     */
    @Nullable
    public JobStatus getJobByUidAndJobId(int uid, @Nullable String namespace, int jobId) {
        return mJobSet.get(uid, namespace, jobId);
    }

    /**
     * Iterate over the set of all jobs, invoking the supplied functor on each.  This is for
     * customers who need to examine each job; we'd much rather not have to generate
     * transient unified collections for them to iterate over and then discard, or creating
     * iterators every time a client needs to perform a sweep.
     */
    public void forEachJob(Consumer<JobStatus> functor) {
        mJobSet.forEachJob(null, functor);
    }

    public void forEachJob(@Nullable Predicate<JobStatus> filterPredicate,
            Consumer<JobStatus> functor) {
        mJobSet.forEachJob(filterPredicate, functor);
    }

    public void forEachJob(int uid, Consumer<JobStatus> functor) {
        mJobSet.forEachJob(uid, functor);
    }

    public void forEachJobForSourceUid(int sourceUid, Consumer<JobStatus> functor) {
        mJobSet.forEachJobForSourceUid(sourceUid, functor);
    }

    private void maybeUpdateHighWaterMark() {
        if (mScheduledJob30MinHighWaterMark < mCurrentJobSetSize) {
            mScheduledJob30MinHighWaterMark = mCurrentJobSetSize;
        }
    }

    /** Version of the db schema. */
    private static final int JOBS_FILE_VERSION = 1;
    /**
     * For legacy reasons, this tag is used to encapsulate the entire job list.
     */
    private static final String XML_TAG_JOB_INFO = "job-info";
    /**
     * For legacy reasons, this tag represents a single {@link JobStatus} object.
     */
    private static final String XML_TAG_JOB = "job";
    /** Tag corresponds to constraints this job needs. */
    private static final String XML_TAG_PARAMS_CONSTRAINTS = "constraints";
    /** Tag corresponds to execution parameters. */
    private static final String XML_TAG_PERIODIC = "periodic";
    private static final String XML_TAG_ONEOFF = "one-off";
    private static final String XML_TAG_EXTRAS = "extras";
    private static final String XML_TAG_JOB_WORK_ITEM = "job-work-item";
    private static final String XML_TAG_DEBUG_INFO = "debug-info";
    private static final String XML_TAG_DEBUG_TAG = "debug-tag";

    private void migrateJobFilesAsync() {
        synchronized (mLock) {
            mPendingJobWriteUids.put(ALL_UIDS, true);
        }
        synchronized (mWriteScheduleLock) {
            mSplitFileMigrationNeeded = true;
            maybeWriteStatusToDiskAsync();
        }
    }

    /**
     * Every time the state changes we write all the jobs in one swath, instead of trying to
     * track incremental changes.
     */
    private void maybeWriteStatusToDiskAsync() {
        synchronized (mWriteScheduleLock) {
            if (!mWriteScheduled) {
                if (DEBUG) {
                    Slog.v(TAG, "Scheduling persist of jobs to disk.");
                }
                mIoHandler.postDelayed(mWriteRunnable, JOB_PERSIST_DELAY);
                mWriteScheduled = true;
            }
        }
    }

    @VisibleForTesting
    public void readJobMapFromDisk(JobSet jobSet, boolean rtcGood) {
        new ReadJobMapFromDiskRunnable(jobSet, rtcGood).run();
    }

    /** Write persisted JobStore state to disk synchronously. Should only be used for testing. */
    @VisibleForTesting
    public void writeStatusToDiskForTesting() {
        synchronized (mWriteScheduleLock) {
            if (mWriteScheduled) {
                throw new IllegalStateException("An asynchronous write is already scheduled.");
            }

            mWriteScheduled = true;
            mWriteRunnable.run();
        }
    }

    /**
     * Wait for any pending write to the persistent store to clear
     * @param maxWaitMillis Maximum time from present to wait
     * @return {@code true} if I/O cleared as expected, {@code false} if the wait
     *     timed out before the pending write completed.
     */
    @VisibleForTesting
    public boolean waitForWriteToCompleteForTesting(long maxWaitMillis) {
        final long start = SystemClock.uptimeMillis();
        final long end = start + maxWaitMillis;
        synchronized (mWriteScheduleLock) {
            while (mWriteScheduled || mWriteInProgress) {
                final long now = SystemClock.uptimeMillis();
                if (now >= end) {
                    // still not done and we've hit the end; failure
                    return false;
                }
                try {
                    mWriteScheduleLock.wait(now - start + maxWaitMillis);
                } catch (InterruptedException e) {
                    // Spurious; keep waiting
                    break;
                }
            }
        }
        return true;
    }

    /**
     * Returns a single string representation of the contents of the specified intArray.
     * If the intArray is [1, 2, 4] as the input, the return result will be the string "1,2,4".
     */
    @VisibleForTesting
    static String intArrayToString(int[] values) {
        final StringJoiner sj = new StringJoiner(",");
        for (final int value : values) {
            sj.add(String.valueOf(value));
        }
        return sj.toString();
    }


   /**
    * Converts a string containing a comma-separated list of decimal representations
    * of ints into an array of int. If the string is not correctly formatted,
    * or if any value doesn't fit into an int, NumberFormatException is thrown.
    */
    @VisibleForTesting
    static int[] stringToIntArray(String str) {
        if (TextUtils.isEmpty(str)) return new int[0];
        final String[] arr = str.split(",");
        final int[] values = new int[arr.length];
        for (int i = 0; i < arr.length; i++) {
            values[i] = Integer.parseInt(arr[i]);
        }
        return values;
    }

    @VisibleForTesting
    static int extractUidFromJobFileName(@NonNull File file) {
        final String fileName = file.getName();
        if (fileName.startsWith(JOB_FILE_SPLIT_PREFIX)) {
            try {
                final int subEnd = fileName.length() - 4; // -4 for ".xml"
                final int uid = Integer.parseInt(
                        fileName.substring(JOB_FILE_SPLIT_PREFIX.length(), subEnd));
                if (uid < 0) {
                    return INVALID_UID;
                }
                return uid;
            } catch (Exception e) {
                Slog.e(TAG, "Unexpected file name format", e);
            }
        }
        return INVALID_UID;
    }

    /**
     * Runnable that writes {@link #mJobSet} out to xml.
     * NOTE: This Runnable locks on mLock
     */
    private final Runnable mWriteRunnable = new Runnable() {
        private final SparseArray<AtomicFile> mJobFiles = new SparseArray<>();
        private final CopyConsumer mPersistedJobCopier = new CopyConsumer();

        class CopyConsumer implements Consumer<JobStatus> {
            private final SparseArray<List<JobStatus>> mJobStoreCopy = new SparseArray<>();
            private boolean mCopyAllJobs;

            private void prepare() {
                mCopyAllJobs = !mUseSplitFiles || mPendingJobWriteUids.get(ALL_UIDS);
                if (mUseSplitFiles) {
                    // Put the set of changed UIDs in the copy list so that we update each file,
                    // especially if we've dropped all jobs for that UID.
                    if (mPendingJobWriteUids.get(ALL_UIDS)) {
                        // ALL_UIDS is only used when we switch file splitting policy or for tests,
                        // so going through the file list here shouldn't be
                        // a large performance hit on user devices.

                        final File[] files;
                        try {
                            files = mJobFileDirectory.listFiles();
                        } catch (SecurityException e) {
                            Slog.wtf(TAG, "Not allowed to read job file directory", e);
                            return;
                        }
                        if (files == null) {
                            Slog.wtfStack(TAG, "Couldn't get job file list");
                        } else {
                            for (File file : files) {
                                final int uid = extractUidFromJobFileName(file);
                                if (uid != INVALID_UID) {
                                    mJobStoreCopy.put(uid, new ArrayList<>());
                                }
                            }
                        }
                    } else {
                        for (int i = 0; i < mPendingJobWriteUids.size(); ++i) {
                            mJobStoreCopy.put(mPendingJobWriteUids.keyAt(i), new ArrayList<>());
                        }
                    }
                } else {
                    // Single file mode.
                    // Put the catchall UID in the copy list so that we update the single file,
                    // especially if we've dropped all persisted jobs.
                    mJobStoreCopy.put(ALL_UIDS, new ArrayList<>());
                }
            }

            @Override
            public void accept(JobStatus jobStatus) {
                final int uid = mUseSplitFiles ? jobStatus.getUid() : ALL_UIDS;
                if (jobStatus.isPersisted() && (mCopyAllJobs || mPendingJobWriteUids.get(uid))) {
                    List<JobStatus> uidJobList = mJobStoreCopy.get(uid);
                    if (uidJobList == null) {
                        uidJobList = new ArrayList<>();
                        mJobStoreCopy.put(uid, uidJobList);
                    }
                    uidJobList.add(new JobStatus(jobStatus));
                }
            }

            private void reset() {
                mJobStoreCopy.clear();
            }
        }

        @Override
        public void run() {
            final long startElapsed = sElapsedRealtimeClock.millis();
            // Intentionally allow new scheduling of a write operation *before* we clone
            // the job set.  If we reset it to false after cloning, there's a window in
            // which no new write will be scheduled but mLock is not held, i.e. a new
            // job might appear and fail to be recognized as needing a persist.  The
            // potential cost is one redundant write of an identical set of jobs in the
            // rare case of that specific race, but by doing it this way we avoid quite
            // a bit of lock contention.
            synchronized (mWriteScheduleLock) {
                mWriteScheduled = false;
                if (mWriteInProgress) {
                    // Another runnable is currently writing. Postpone this new write task.
                    maybeWriteStatusToDiskAsync();
                    return;
                }
                mWriteInProgress = true;
            }
            final boolean useSplitFiles;
            synchronized (mLock) {
                // Clone the jobs so we can release the lock before writing.
                useSplitFiles = mUseSplitFiles;
                mPersistedJobCopier.prepare();
                mJobSet.forEachJob(null, mPersistedJobCopier);
                mPendingJobWriteUids.clear();
            }
            mPersistInfo.countAllJobsSaved = 0;
            mPersistInfo.countSystemServerJobsSaved = 0;
            mPersistInfo.countSystemSyncManagerJobsSaved = 0;
            for (int i = mPersistedJobCopier.mJobStoreCopy.size() - 1; i >= 0; --i) {
                AtomicFile file;
                if (useSplitFiles) {
                    final int uid = mPersistedJobCopier.mJobStoreCopy.keyAt(i);
                    file = mJobFiles.get(uid);
                    if (file == null) {
                        file = createJobFile(JOB_FILE_SPLIT_PREFIX + uid);
                        mJobFiles.put(uid, file);
                    }
                } else {
                    file = mJobsFile;
                }
                if (DEBUG) {
                    Slog.d(TAG, "Writing for " + mPersistedJobCopier.mJobStoreCopy.keyAt(i)
                            + " to " + file.getBaseFile().getName() + ": "
                            + mPersistedJobCopier.mJobStoreCopy.valueAt(i).size() + " jobs");
                }
                writeJobsMapImpl(file, mPersistedJobCopier.mJobStoreCopy.valueAt(i));
            }
            if (DEBUG) {
                Slog.v(TAG, "Finished writing, took " + (sElapsedRealtimeClock.millis()
                        - startElapsed) + "ms");
            }
            mPersistedJobCopier.reset();
            if (!useSplitFiles) {
                mJobFiles.clear();
            }
            // Update the last modified time of the directory to aid in RTC time verification
            // (see the JobStore constructor).
            mJobFileDirectory.setLastModified(sSystemClock.millis());
            synchronized (mWriteScheduleLock) {
                if (mSplitFileMigrationNeeded) {
                    final File[] files = mJobFileDirectory.listFiles();
                    for (File file : files) {
                        if (useSplitFiles) {
                            if (!file.getName().startsWith(JOB_FILE_SPLIT_PREFIX)) {
                                // Delete the now unused file so there's no confusion in the future.
                                file.delete();
                            }
                        } else if (file.getName().startsWith(JOB_FILE_SPLIT_PREFIX)) {
                            // Delete the now unused file so there's no confusion in the future.
                            file.delete();
                        }
                    }
                }
                mWriteInProgress = false;
                mWriteScheduleLock.notifyAll();
            }
        }

        private void writeJobsMapImpl(@NonNull AtomicFile file, @NonNull List<JobStatus> jobList) {
            int numJobs = 0;
            int numSystemJobs = 0;
            int numSyncJobs = 0;
            mEventLogger.setStartTime(SystemClock.uptimeMillis());
            try (FileOutputStream fos = file.startWrite()) {
                TypedXmlSerializer out = Xml.resolveSerializer(fos);
                out.startDocument(null, true);
                out.setFeature("http://xmlpull.org/v1/doc/features.html#indent-output", true);

                out.startTag(null, XML_TAG_JOB_INFO);
                out.attribute(null, "version", Integer.toString(JOBS_FILE_VERSION));
                for (int i=0; i<jobList.size(); i++) {
                    JobStatus jobStatus = jobList.get(i);
                    if (DEBUG) {
                        Slog.d(TAG, "Saving job " + jobStatus.getJobId());
                    }
                    out.startTag(null, XML_TAG_JOB);
                    addAttributesToJobTag(out, jobStatus);
                    writeConstraintsToXml(out, jobStatus);
                    writeExecutionCriteriaToXml(out, jobStatus);
                    writeBundleToXml(jobStatus.getJob().getExtras(), out);
                    writeJobWorkItemsToXml(out, jobStatus);
                    writeDebugInfoToXml(out, jobStatus);
                    out.endTag(null, XML_TAG_JOB);

                    numJobs++;
                    if (jobStatus.getUid() == Process.SYSTEM_UID) {
                        numSystemJobs++;
                        if (isSyncJob(jobStatus)) {
                            numSyncJobs++;
                        }
                    }
                }
                out.endTag(null, XML_TAG_JOB_INFO);
                out.endDocument();

                file.finishWrite(fos);
            } catch (IOException e) {
                if (DEBUG) {
                    Slog.v(TAG, "Error writing out job data.", e);
                }
            } catch (XmlPullParserException e) {
                if (DEBUG) {
                    Slog.d(TAG, "Error persisting bundle.", e);
                }
            } finally {
                mPersistInfo.countAllJobsSaved += numJobs;
                mPersistInfo.countSystemServerJobsSaved += numSystemJobs;
                mPersistInfo.countSystemSyncManagerJobsSaved += numSyncJobs;
            }
        }

        /**
         * Write out a tag with data comprising the required fields and bias of this job and
         * its client.
         */
        private void addAttributesToJobTag(TypedXmlSerializer out, JobStatus jobStatus)
                throws IOException {
            out.attribute(null, "jobid", Integer.toString(jobStatus.getJobId()));
            out.attribute(null, "package", jobStatus.getServiceComponent().getPackageName());
            out.attribute(null, "class", jobStatus.getServiceComponent().getClassName());
            if (jobStatus.getSourcePackageName() != null) {
                out.attribute(null, "sourcePackageName", jobStatus.getSourcePackageName());
            }
            if (jobStatus.getNamespace() != null) {
                out.attribute(null, "namespace", jobStatus.getNamespace());
            }
            if (jobStatus.getSourceTag() != null) {
                out.attribute(null, "sourceTag", jobStatus.getSourceTag());
            }
            out.attribute(null, "sourceUserId", String.valueOf(jobStatus.getSourceUserId()));
            out.attribute(null, "uid", Integer.toString(jobStatus.getUid()));
            out.attribute(null, "bias", String.valueOf(jobStatus.getBias()));
            out.attribute(null, "priority", String.valueOf(jobStatus.getJob().getPriority()));
            out.attribute(null, "flags", String.valueOf(jobStatus.getFlags()));
            if (jobStatus.getInternalFlags() != 0) {
                out.attribute(null, "internalFlags", String.valueOf(jobStatus.getInternalFlags()));
            }

            out.attribute(null, "lastSuccessfulRunTime",
                    String.valueOf(jobStatus.getLastSuccessfulRunTime()));
            out.attribute(null, "lastFailedRunTime",
                    String.valueOf(jobStatus.getLastFailedRunTime()));

            out.attributeLong(null, "cumulativeExecutionTime",
                    jobStatus.getCumulativeExecutionTimeMs());
        }

        private void writeBundleToXml(PersistableBundle extras, XmlSerializer out)
                throws IOException, XmlPullParserException {
            out.startTag(null, XML_TAG_EXTRAS);
            PersistableBundle extrasCopy = deepCopyBundle(extras, 10);
            extrasCopy.saveToXml(out);
            out.endTag(null, XML_TAG_EXTRAS);
        }

        private PersistableBundle deepCopyBundle(PersistableBundle bundle, int maxDepth) {
            if (maxDepth <= 0) {
                return null;
            }
            PersistableBundle copy = (PersistableBundle) bundle.clone();
            Set<String> keySet = bundle.keySet();
            for (String key: keySet) {
                Object o = copy.get(key);
                if (o instanceof PersistableBundle) {
                    PersistableBundle bCopy = deepCopyBundle((PersistableBundle) o, maxDepth-1);
                    copy.putPersistableBundle(key, bCopy);
                }
            }
            return copy;
        }

        /**
         * Write out a tag with data identifying this job's constraints. If the constraint isn't here
         * it doesn't apply.
         * TODO: b/183455312 Update this code to use proper serialization for NetworkRequest,
         *       because currently store is not including everything (like, UIDs, bandwidth,
         *       signal strength etc. are lost).
         */
        private void writeConstraintsToXml(TypedXmlSerializer out, JobStatus jobStatus)
                throws IOException {
            out.startTag(null, XML_TAG_PARAMS_CONSTRAINTS);
            final JobInfo job = jobStatus.getJob();
            if (jobStatus.hasConnectivityConstraint()) {
                final NetworkRequest network = jobStatus.getJob().getRequiredNetwork();
                out.attribute(null, "net-capabilities-csv", intArrayToString(
                        network.getCapabilities()));
                out.attribute(null, "net-forbidden-capabilities-csv", intArrayToString(
                        network.getForbiddenCapabilities()));
                out.attribute(null, "net-transport-types-csv", intArrayToString(
                        network.getTransportTypes()));
                if (job.getEstimatedNetworkDownloadBytes() != JobInfo.NETWORK_BYTES_UNKNOWN) {
                    out.attributeLong(null, "estimated-download-bytes",
                            job.getEstimatedNetworkDownloadBytes());
                }
                if (job.getEstimatedNetworkUploadBytes() != JobInfo.NETWORK_BYTES_UNKNOWN) {
                    out.attributeLong(null, "estimated-upload-bytes",
                            job.getEstimatedNetworkUploadBytes());
                }
                if (job.getMinimumNetworkChunkBytes() != JobInfo.NETWORK_BYTES_UNKNOWN) {
                    out.attributeLong(null, "minimum-network-chunk-bytes",
                            job.getMinimumNetworkChunkBytes());
                }
            }
            if (job.isRequireDeviceIdle()) {
                out.attribute(null, "idle", Boolean.toString(true));
            }
            if (job.isRequireCharging()) {
                out.attribute(null, "charging", Boolean.toString(true));
            }
            if (job.isRequireBatteryNotLow()) {
                out.attribute(null, "battery-not-low", Boolean.toString(true));
            }
            if (job.isRequireStorageNotLow()) {
                out.attribute(null, "storage-not-low", Boolean.toString(true));
            }
            out.endTag(null, XML_TAG_PARAMS_CONSTRAINTS);
        }

        private void writeExecutionCriteriaToXml(XmlSerializer out, JobStatus jobStatus)
                throws IOException {
            final JobInfo job = jobStatus.getJob();
            if (jobStatus.getJob().isPeriodic()) {
                out.startTag(null, XML_TAG_PERIODIC);
                out.attribute(null, "period", Long.toString(job.getIntervalMillis()));
                out.attribute(null, "flex", Long.toString(job.getFlexMillis()));
            } else {
                out.startTag(null, XML_TAG_ONEOFF);
            }

            // If we still have the persisted times, we need to record those directly because
            // we haven't yet been able to calculate the usual elapsed-timebase bounds
            // correctly due to wall-clock uncertainty.
            Pair <Long, Long> utcJobTimes = jobStatus.getPersistedUtcTimes();
            if (DEBUG && utcJobTimes != null) {
                Slog.i(TAG, "storing original UTC timestamps for " + jobStatus);
            }

            final long nowRTC = sSystemClock.millis();
            final long nowElapsed = sElapsedRealtimeClock.millis();
            if (jobStatus.hasDeadlineConstraint()) {
                // Wall clock deadline.
                final long deadlineWallclock = (utcJobTimes == null)
                        ? nowRTC + (jobStatus.getLatestRunTimeElapsed() - nowElapsed)
                        : utcJobTimes.second;
                out.attribute(null, "deadline", Long.toString(deadlineWallclock));
            }
            if (jobStatus.hasTimingDelayConstraint()) {
                final long delayWallclock = (utcJobTimes == null)
                        ? nowRTC + (jobStatus.getEarliestRunTime() - nowElapsed)
                        : utcJobTimes.first;
                out.attribute(null, "delay", Long.toString(delayWallclock));
            }

            // Only write out back-off policy if it differs from the default.
            // This also helps the case where the job is idle -> these aren't allowed to specify
            // back-off.
            if (jobStatus.getJob().getInitialBackoffMillis() != JobInfo.DEFAULT_INITIAL_BACKOFF_MILLIS
                    || jobStatus.getJob().getBackoffPolicy() != JobInfo.DEFAULT_BACKOFF_POLICY) {
                out.attribute(null, "backoff-policy", Integer.toString(job.getBackoffPolicy()));
                out.attribute(null, "initial-backoff", Long.toString(job.getInitialBackoffMillis()));
            }
            if (job.isPeriodic()) {
                out.endTag(null, XML_TAG_PERIODIC);
            } else {
                out.endTag(null, XML_TAG_ONEOFF);
            }
        }

        private void writeDebugInfoToXml(@NonNull TypedXmlSerializer out,
                @NonNull JobStatus jobStatus) throws IOException, XmlPullParserException {
            final ArraySet<String> debugTags = jobStatus.getJob().getDebugTagsArraySet();
            final int numTags = debugTags.size();
            final String traceTag = jobStatus.getJob().getTraceTag();
            if (traceTag == null && numTags == 0) {
                return;
            }
            out.startTag(null, XML_TAG_DEBUG_INFO);
            if (traceTag != null) {
                out.attribute(null, "trace-tag", traceTag);
            }
            for (int i = 0; i < numTags; ++i) {
                out.startTag(null, XML_TAG_DEBUG_TAG);
                out.attribute(null, "tag", debugTags.valueAt(i));
                out.endTag(null, XML_TAG_DEBUG_TAG);
            }
            out.endTag(null, XML_TAG_DEBUG_INFO);
        }

        private void writeJobWorkItemsToXml(@NonNull TypedXmlSerializer out,
                @NonNull JobStatus jobStatus) throws IOException, XmlPullParserException {
            // Write executing first since they're technically at the front of the queue.
            writeJobWorkItemListToXml(out, jobStatus.executingWork);
            writeJobWorkItemListToXml(out, jobStatus.pendingWork);
        }

        private void writeJobWorkItemListToXml(@NonNull TypedXmlSerializer out,
                @Nullable List<JobWorkItem> jobWorkItems)
                throws IOException, XmlPullParserException {
            if (jobWorkItems == null) {
                return;
            }
            // Write the items in list order to maintain the enqueue order.
            final int size = jobWorkItems.size();
            for (int i = 0; i < size; ++i) {
                final JobWorkItem item = jobWorkItems.get(i);
                if (item.getGrants() != null) {
                    // We currently don't allow persisting jobs when grants are involved.
                    // TODO(256618122): allow persisting JobWorkItems with grant flags
                    continue;
                }
                if (item.getIntent() != null) {
                    // Intent.saveToXml() doesn't persist everything, so we shouldn't attempt to
                    // persist these JobWorkItems at all.
                    Slog.wtf(TAG, "Encountered JobWorkItem with Intent in persisting list");
                    continue;
                }
                out.startTag(null, XML_TAG_JOB_WORK_ITEM);
                out.attributeInt(null, "delivery-count", item.getDeliveryCount());
                if (item.getEstimatedNetworkDownloadBytes() != JobInfo.NETWORK_BYTES_UNKNOWN) {
                    out.attributeLong(null, "estimated-download-bytes",
                            item.getEstimatedNetworkDownloadBytes());
                }
                if (item.getEstimatedNetworkUploadBytes() != JobInfo.NETWORK_BYTES_UNKNOWN) {
                    out.attributeLong(null, "estimated-upload-bytes",
                            item.getEstimatedNetworkUploadBytes());
                }
                if (item.getMinimumNetworkChunkBytes() != JobInfo.NETWORK_BYTES_UNKNOWN) {
                    out.attributeLong(null, "minimum-network-chunk-bytes",
                            item.getMinimumNetworkChunkBytes());
                }
                writeBundleToXml(item.getExtras(), out);
                out.endTag(null, XML_TAG_JOB_WORK_ITEM);
            }
        }
    };

    /**
     * Translate the supplied RTC times to the elapsed timebase, with clamping appropriate
     * to interpreting them as a job's delay + deadline times for alarm-setting purposes.
     * @param rtcTimes a Pair<Long, Long> in which {@code first} is the "delay" earliest
     *     allowable runtime for the job, and {@code second} is the "deadline" time at which
     *     the job becomes overdue.
     */
    private static Pair<Long, Long> convertRtcBoundsToElapsed(Pair<Long, Long> rtcTimes,
            long nowElapsed) {
        final long nowWallclock = sSystemClock.millis();
        final long earliest = (rtcTimes.first > JobStatus.NO_EARLIEST_RUNTIME)
                ? nowElapsed + Math.max(rtcTimes.first - nowWallclock, 0)
                : JobStatus.NO_EARLIEST_RUNTIME;
        final long latest = (rtcTimes.second < JobStatus.NO_LATEST_RUNTIME)
                ? nowElapsed + Math.max(rtcTimes.second - nowWallclock, 0)
                : JobStatus.NO_LATEST_RUNTIME;
        return Pair.create(earliest, latest);
    }

    private static boolean isSyncJob(JobStatus status) {
        return com.android.server.content.SyncJobService.class.getName()
                .equals(status.getServiceComponent().getClassName());
    }

    /**
     * Runnable that reads list of persisted job from xml. This is run once at start up, so doesn't
     * need to go through {@link JobStore#add(com.android.server.job.controllers.JobStatus)}.
     */
    private final class ReadJobMapFromDiskRunnable implements Runnable {
        private final JobSet jobSet;
        private final boolean rtcGood;
        private final CountDownLatch mCompletionLatch;

        /**
         * @param jobSet Reference to the (empty) set of JobStatus objects that back the JobStore,
         *               so that after disk read we can populate it directly.
         */
        ReadJobMapFromDiskRunnable(JobSet jobSet, boolean rtcIsGood) {
            this(jobSet, rtcIsGood, null);
        }

        ReadJobMapFromDiskRunnable(JobSet jobSet, boolean rtcIsGood,
                @Nullable CountDownLatch completionLatch) {
            this.jobSet = jobSet;
            this.rtcGood = rtcIsGood;
            this.mCompletionLatch = completionLatch;
        }

        @Override
        public void run() {
            if (!mJobFileDirectory.isDirectory()) {
                Slog.wtf(TAG, "jobs directory isn't a directory O.O");
                mJobFileDirectory.mkdirs();
                return;
            }

            int numJobs = 0;
            int numSystemJobs = 0;
            int numSyncJobs = 0;
            List<JobStatus> jobs;
            final File[] files;
            try {
                files = mJobFileDirectory.listFiles();
            } catch (SecurityException e) {
                Slog.wtf(TAG, "Not allowed to read job file directory", e);
                return;
            }
            if (files == null) {
                Slog.wtfStack(TAG, "Couldn't get job file list");
                return;
            }
            boolean needFileMigration = false;
            long nowElapsed = sElapsedRealtimeClock.millis();
            int numDuplicates = 0;
            synchronized (mLock) {
                for (File file : files) {
                    if (!file.getName().equals("jobs.xml")
                            && !SPLIT_FILE_PATTERN.matcher(file.getName()).matches()) {
                        // Skip temporary or other files.
                        continue;
                    }
                    final AtomicFile aFile = createJobFile(file);
                    try (FileInputStream fis = aFile.openRead()) {
                        jobs = readJobMapImpl(fis, rtcGood, nowElapsed);
                        if (jobs != null) {
                            for (int i = 0; i < jobs.size(); i++) {
                                JobStatus js = jobs.get(i);
                                final JobStatus existingJob = this.jobSet.get(
                                        js.getUid(), js.getNamespace(), js.getJobId());
                                if (existingJob != null) {
                                    numDuplicates++;
                                    // Jobs are meant to have unique uid-namespace-jobId
                                    // combinations, but we've somehow read multiple jobs with the
                                    // combination. Drop the latter one since keeping both will
                                    // result in other issues.
                                    continue;
                                }
                                js.prepareLocked();
                                js.enqueueTime = nowElapsed;
                                this.jobSet.add(js);

                                numJobs++;
                                if (js.getUid() == Process.SYSTEM_UID) {
                                    numSystemJobs++;
                                    if (isSyncJob(js)) {
                                        numSyncJobs++;
                                    }
                                }
                            }
                        }
                    } catch (FileNotFoundException e) {
                        // mJobFileDirectory.listFiles() gave us this file...why can't we find it???
                        Slog.e(TAG, "Could not find jobs file: " + file.getName());
                    } catch (XmlPullParserException | IOException e) {
                        Slog.wtf(TAG, "Error in " + file.getName(), e);
                    } catch (Exception e) {
                        // Crashing at this point would result in a boot loop, so live with a
                        // generic Exception for system stability's sake.
                        Slog.wtf(TAG, "Unexpected exception", e);
                    }
                    if (mUseSplitFiles) {
                        if (!file.getName().startsWith(JOB_FILE_SPLIT_PREFIX)) {
                            // We're supposed to be using the split file architecture,
                            // but we still have
                            // the old job file around. Fully migrate and remove the old file.
                            needFileMigration = true;
                        }
                    } else if (file.getName().startsWith(JOB_FILE_SPLIT_PREFIX)) {
                        // We're supposed to be using the legacy single file architecture,
                        // but we still have some job split files around. Fully migrate
                        // and remove the split files.
                        needFileMigration = true;
                    }
                }
                if (mPersistInfo.countAllJobsLoaded < 0) { // Only set them once.
                    mPersistInfo.countAllJobsLoaded = numJobs;
                    mPersistInfo.countSystemServerJobsLoaded = numSystemJobs;
                    mPersistInfo.countSystemSyncManagerJobsLoaded = numSyncJobs;
                }
            }
            Slog.i(TAG, "Read " + numJobs + " jobs");
            if (needFileMigration) {
                migrateJobFilesAsync();
            }

            if (numDuplicates > 0) {
                Slog.wtf(TAG, "Encountered " + numDuplicates + " duplicate persisted jobs");
            }

            // Log the count immediately after loading from boot.
            mCurrentJobSetSize = numJobs;
            mScheduledJob30MinHighWaterMark = mCurrentJobSetSize;
            mScheduledJobHighWaterMarkLoggingRunnable.run();

            if (mCompletionLatch != null) {
                mCompletionLatch.countDown();
            }
        }

        /** Returns the {@link String#intern() interned} String if it's not null. */
        @Nullable
        private static String intern(@Nullable String val) {
            return val == null ? null : val.intern();
        }

        private List<JobStatus> readJobMapImpl(InputStream fis, boolean rtcIsGood, long nowElapsed)
                throws XmlPullParserException, IOException {
            TypedXmlPullParser parser = Xml.resolvePullParser(fis);

            int eventType = parser.getEventType();
            while (eventType != XmlPullParser.START_TAG &&
                    eventType != XmlPullParser.END_DOCUMENT) {
                eventType = parser.next();
                Slog.d(TAG, "Start tag: " + parser.getName());
            }
            if (eventType == XmlPullParser.END_DOCUMENT) {
                if (DEBUG) {
                    Slog.d(TAG, "No persisted jobs.");
                }
                return null;
            }

            String tagName = parser.getName();
            if (XML_TAG_JOB_INFO.equals(tagName)) {
                final List<JobStatus> jobs = new ArrayList<JobStatus>();
                final int version = parser.getAttributeInt(null, "version");
                // Read in version info.
                if (version > JOBS_FILE_VERSION || version < 0) {
                    Slog.d(TAG, "Invalid version number, aborting jobs file read.");
                    return null;
                }

                eventType = parser.next();
                do {
                    // Read each <job/>
                    if (eventType == XmlPullParser.START_TAG) {
                        tagName = parser.getName();
                        // Start reading job.
                        if (XML_TAG_JOB.equals(tagName)) {
                            JobStatus persistedJob =
                                    restoreJobFromXml(rtcIsGood, parser, version, nowElapsed);
                            if (persistedJob != null) {
                                if (DEBUG) {
                                    Slog.d(TAG, "Read out " + persistedJob);
                                }
                                jobs.add(persistedJob);
                            } else {
                                Slog.d(TAG, "Error reading job from file.");
                            }
                        }
                    }
                    eventType = parser.next();
                } while (eventType != XmlPullParser.END_DOCUMENT);
                return jobs;
            }
            return null;
        }

        /**
         * @param parser Xml parser at the beginning of a "<job/>" tag. The next "parser.next()" call
         *               will take the parser into the body of the job tag.
         * @return Newly instantiated job holding all the information we just read out of the xml tag.
         */
        private JobStatus restoreJobFromXml(boolean rtcIsGood, TypedXmlPullParser parser,
                int schemaVersion, long nowElapsed) throws XmlPullParserException, IOException {
            JobInfo.Builder jobBuilder;
            int uid, sourceUserId;
            long lastSuccessfulRunTime;
            long lastFailedRunTime;
            long cumulativeExecutionTime;
            int internalFlags = 0;

            // Read out job identifier attributes and bias.
            try {
                jobBuilder = buildBuilderFromXml(parser);
                jobBuilder.setPersisted(true);
                uid = Integer.parseInt(parser.getAttributeValue(null, "uid"));

                String val;
                if (schemaVersion == 0) {
                    val = parser.getAttributeValue(null, "priority");
                    if (val != null) {
                        jobBuilder.setBias(Integer.parseInt(val));
                    }
                } else if (schemaVersion >= 1) {
                    val = parser.getAttributeValue(null, "bias");
                    if (val != null) {
                        jobBuilder.setBias(Integer.parseInt(val));
                    }
                    val = parser.getAttributeValue(null, "priority");
                    if (val != null) {
                        jobBuilder.setPriority(Integer.parseInt(val));
                    }
                }
                val = parser.getAttributeValue(null, "flags");
                if (val != null) {
                    jobBuilder.setFlags(Integer.parseInt(val));
                }
                val = parser.getAttributeValue(null, "internalFlags");
                if (val != null) {
                    internalFlags = Integer.parseInt(val);
                }
                val = parser.getAttributeValue(null, "sourceUserId");
                sourceUserId = val == null ? -1 : Integer.parseInt(val);

                val = parser.getAttributeValue(null, "lastSuccessfulRunTime");
                lastSuccessfulRunTime = val == null ? 0 : Long.parseLong(val);

                val = parser.getAttributeValue(null, "lastFailedRunTime");
                lastFailedRunTime = val == null ? 0 : Long.parseLong(val);

                cumulativeExecutionTime =
                        parser.getAttributeLong(null, "cumulativeExecutionTime", 0);
            } catch (NumberFormatException e) {
                Slog.e(TAG, "Error parsing job's required fields, skipping");
                return null;
            }

            String sourcePackageName = parser.getAttributeValue(null, "sourcePackageName");
            final String namespace = intern(parser.getAttributeValue(null, "namespace"));
            final String sourceTag = intern(parser.getAttributeValue(null, "sourceTag"));

            int eventType;
            // Read out constraints tag.
            do {
                eventType = parser.next();
            } while (eventType == XmlPullParser.TEXT);  // Push through to next START_TAG.

            if (!(eventType == XmlPullParser.START_TAG &&
                    XML_TAG_PARAMS_CONSTRAINTS.equals(parser.getName()))) {
                // Expecting a <constraints> start tag.
                return null;
            }
            try {
                buildConstraintsFromXml(jobBuilder, parser);
            } catch (NumberFormatException e) {
                Slog.d(TAG, "Error reading constraints, skipping.");
                return null;
            } catch (XmlPullParserException e) {
                Slog.d(TAG, "Error Parser Exception.", e);
                return null;
            } catch (IOException e) {
                Slog.d(TAG, "Error I/O Exception.", e);
                return null;
            } catch (IllegalArgumentException e) {
                Slog.e(TAG, "Constraints contained invalid data", e);
                return null;
            }

            parser.next(); // Consume </constraints>

            // Read out execution parameters tag.
            do {
                eventType = parser.next();
            } while (eventType == XmlPullParser.TEXT);
            if (eventType != XmlPullParser.START_TAG) {
                return null;
            }

            // Tuple of (earliest runtime, latest runtime) in UTC.
            final Pair<Long, Long> rtcRuntimes = buildRtcExecutionTimesFromXml(parser);

            Pair<Long, Long> elapsedRuntimes = convertRtcBoundsToElapsed(rtcRuntimes, nowElapsed);

            if (XML_TAG_PERIODIC.equals(parser.getName())) {
                try {
                    String val = parser.getAttributeValue(null, "period");
                    final long periodMillis = Long.parseLong(val);
                    val = parser.getAttributeValue(null, "flex");
                    final long flexMillis = (val != null) ? Long.valueOf(val) : periodMillis;
                    jobBuilder.setPeriodic(periodMillis, flexMillis);
                    // As a sanity check, cap the recreated run time to be no later than flex+period
                    // from now. This is the latest the periodic could be pushed out. This could
                    // happen if the periodic ran early (at flex time before period), and then the
                    // device rebooted.
                    if (elapsedRuntimes.second > nowElapsed + periodMillis + flexMillis) {
                        final long clampedLateRuntimeElapsed = nowElapsed + flexMillis
                                + periodMillis;
                        final long clampedEarlyRuntimeElapsed = clampedLateRuntimeElapsed
                                - flexMillis;
                        Slog.w(TAG,
                                String.format("Periodic job for uid='%d' persisted run-time is" +
                                                " too big [%s, %s]. Clamping to [%s,%s]",
                                        uid,
                                        DateUtils.formatElapsedTime(elapsedRuntimes.first / 1000),
                                        DateUtils.formatElapsedTime(elapsedRuntimes.second / 1000),
                                        DateUtils.formatElapsedTime(
                                                clampedEarlyRuntimeElapsed / 1000),
                                        DateUtils.formatElapsedTime(
                                                clampedLateRuntimeElapsed / 1000))
                        );
                        elapsedRuntimes =
                                Pair.create(clampedEarlyRuntimeElapsed, clampedLateRuntimeElapsed);
                    }
                } catch (NumberFormatException e) {
                    Slog.d(TAG, "Error reading periodic execution criteria, skipping.");
                    return null;
                }
            } else if (XML_TAG_ONEOFF.equals(parser.getName())) {
                try {
                    if (elapsedRuntimes.first != JobStatus.NO_EARLIEST_RUNTIME) {
                        jobBuilder.setMinimumLatency(elapsedRuntimes.first - nowElapsed);
                    }
                    if (elapsedRuntimes.second != JobStatus.NO_LATEST_RUNTIME) {
                        jobBuilder.setOverrideDeadline(
                                elapsedRuntimes.second - nowElapsed);
                    }
                } catch (NumberFormatException e) {
                    Slog.d(TAG, "Error reading job execution criteria, skipping.");
                    return null;
                }
            } else {
                if (DEBUG) {
                    Slog.d(TAG, "Invalid parameter tag, skipping - " + parser.getName());
                }
                // Expecting a parameters start tag.
                return null;
            }
            maybeBuildBackoffPolicyFromXml(jobBuilder, parser);

            parser.nextTag(); // Consume parameters end tag.

            // Read out extras Bundle.
            do {
                eventType = parser.next();
            } while (eventType == XmlPullParser.TEXT);
            if (!(eventType == XmlPullParser.START_TAG
                    && XML_TAG_EXTRAS.equals(parser.getName()))) {
                if (DEBUG) {
                    Slog.d(TAG, "Error reading extras, skipping.");
                }
                return null;
            }

            final PersistableBundle extras;
            try {
                extras = PersistableBundle.restoreFromXml(parser);
                jobBuilder.setExtras(extras);
            } catch (IllegalArgumentException e) {
                Slog.e(TAG, "Persisted extras contained invalid data", e);
                return null;
            }
            eventType = parser.nextTag(); // Consume </extras>

            List<JobWorkItem> jobWorkItems = null;
            if (eventType == XmlPullParser.START_TAG
                    && XML_TAG_JOB_WORK_ITEM.equals(parser.getName())) {
                jobWorkItems = readJobWorkItemsFromXml(parser);
            }

            if (eventType == XmlPullParser.START_TAG
                    && XML_TAG_DEBUG_INFO.equals(parser.getName())) {
                try {
                    jobBuilder.setTraceTag(parser.getAttributeValue(null, "trace-tag"));
                } catch (Exception e) {
                    Slog.wtf(TAG, "Invalid trace tag persisted to disk", e);
                }
                parser.next();
                jobBuilder.addDebugTags(readDebugTagsFromXml(parser));
                eventType = parser.nextTag(); // Consume </debug-info>
            }

            final JobInfo builtJob;
            try {
                // Don't perform prefetch-deadline check here. Apps targeting S- shouldn't have
                // any prefetch-with-deadline jobs accidentally dropped. It's not worth doing
                // target SDK version checks here for apps targeting T+. There's no way for an
                // app to keep a perpetually scheduled prefetch job with a deadline. Prefetch jobs
                // with a deadline would run and then any newly scheduled prefetch jobs wouldn't
                // have a deadline. If a job is rescheduled (via jobFinished(true) or onStopJob()'s
                // return value), the deadline is dropped. Periodic jobs require all constraints
                // to be met, so there's no issue with their deadlines.
                // The same logic applies for other target SDK-based validation checks.
                builtJob = jobBuilder.build(false, false, false, false);
            } catch (Exception e) {
                Slog.w(TAG, "Unable to build job from XML, ignoring: " + jobBuilder.summarize(), e);
                return null;
            }

            // Migrate sync jobs forward from earlier, incomplete representation
            if ("android".equals(sourcePackageName)
                    && extras != null
                    && extras.getBoolean("SyncManagerJob", false)) {
                sourcePackageName = extras.getString("owningPackage", sourcePackageName);
                if (DEBUG) {
                    Slog.i(TAG, "Fixing up sync job source package name from 'android' to '"
                            + sourcePackageName + "'");
                }
            }

            // And now we're done
            final int appBucket = JobSchedulerService.standbyBucketForPackage(sourcePackageName,
                    sourceUserId, nowElapsed);
            JobStatus js = new JobStatus(
                    builtJob, uid, intern(sourcePackageName), sourceUserId,
                    appBucket, namespace, sourceTag,
                    elapsedRuntimes.first, elapsedRuntimes.second,
                    lastSuccessfulRunTime, lastFailedRunTime, cumulativeExecutionTime,
                    (rtcIsGood) ? null : rtcRuntimes, internalFlags, /* dynamicConstraints */ 0);
            if (jobWorkItems != null) {
                for (int i = 0; i < jobWorkItems.size(); ++i) {
                    js.enqueueWorkLocked(jobWorkItems.get(i));
                }
            }
            return js;
        }

        private JobInfo.Builder buildBuilderFromXml(TypedXmlPullParser parser)
                throws XmlPullParserException {
            // Pull out required fields from <job> attributes.
            int jobId = parser.getAttributeInt(null, "jobid");
            String packageName = intern(parser.getAttributeValue(null, "package"));
            String className = intern(parser.getAttributeValue(null, "class"));
            ComponentName cname = new ComponentName(packageName, className);

            return new JobInfo.Builder(jobId, cname);
        }

        /**
         * In S, there has been a change in format to make the code more robust and more
         * maintainable.
         * If the capabities are bits 4, 14, 15, the format in R, it is a long string as
         * netCapabilitiesLong = '49168' from the old XML file attribute "net-capabilities".
         * The format in S is the int array string as netCapabilitiesIntArray = '4,14,15'
         * from the new XML file attribute "net-capabilities-array".
         * For backward compatibility, when reading old XML the old format is still supported in
         * reading, but in order to avoid issues with OEM-defined flags, the accepted capabilities
         * are limited to that(maxNetCapabilityInR & maxTransportInR) defined in R.
         */
        private void buildConstraintsFromXml(JobInfo.Builder jobBuilder, TypedXmlPullParser parser)
                throws XmlPullParserException, IOException {
            String val;
            String netCapabilitiesLong = null;
            String netForbiddenCapabilitiesLong = null;
            String netTransportTypesLong = null;

            final String netCapabilitiesIntArray = parser.getAttributeValue(
                    null, "net-capabilities-csv");
            final String netForbiddenCapabilitiesIntArray = parser.getAttributeValue(
                    null, "net-forbidden-capabilities-csv");
            final String netTransportTypesIntArray = parser.getAttributeValue(
                    null, "net-transport-types-csv");
            if (netCapabilitiesIntArray == null || netTransportTypesIntArray == null) {
                netCapabilitiesLong = parser.getAttributeValue(null, "net-capabilities");
                netForbiddenCapabilitiesLong = parser.getAttributeValue(
                        null, "net-unwanted-capabilities");
                netTransportTypesLong = parser.getAttributeValue(null, "net-transport-types");
            }

            if ((netCapabilitiesIntArray != null) && (netTransportTypesIntArray != null)) {
                // S+ format. No capability or transport validation since the values should be in
                // line with what's defined in the Connectivity mainline module.
                final NetworkRequest.Builder builder = new NetworkRequest.Builder()
                        .clearCapabilities();

                for (int capability : stringToIntArray(netCapabilitiesIntArray)) {
                    builder.addCapability(capability);
                }

                for (int forbiddenCapability : stringToIntArray(netForbiddenCapabilitiesIntArray)) {
                    builder.addForbiddenCapability(forbiddenCapability);
                }

                for (int transport : stringToIntArray(netTransportTypesIntArray)) {
                    builder.addTransportType(transport);
                }
                jobBuilder
                        .setRequiredNetwork(builder.build())
                        .setEstimatedNetworkBytes(
                                parser.getAttributeLong(null,
                                        "estimated-download-bytes", JobInfo.NETWORK_BYTES_UNKNOWN),
                                parser.getAttributeLong(null,
                                        "estimated-upload-bytes", JobInfo.NETWORK_BYTES_UNKNOWN))
                        .setMinimumNetworkChunkBytes(
                                parser.getAttributeLong(null,
                                        "minimum-network-chunk-bytes",
                                        JobInfo.NETWORK_BYTES_UNKNOWN));
            } else if (netCapabilitiesLong != null && netTransportTypesLong != null) {
                // Format used on R- builds. Drop any unexpected capabilities and transports.
                final NetworkRequest.Builder builder = new NetworkRequest.Builder()
                        .clearCapabilities();
                final int maxNetCapabilityInR = NET_CAPABILITY_TEMPORARILY_NOT_METERED;
                // We're okay throwing NFE here; caught by caller
                for (int capability : BitUtils.unpackBits(Long.parseLong(
                        netCapabilitiesLong))) {
                    if (capability <= maxNetCapabilityInR) {
                        builder.addCapability(capability);
                    }
                }
                for (int forbiddenCapability : BitUtils.unpackBits(Long.parseLong(
                        netForbiddenCapabilitiesLong))) {
                    if (forbiddenCapability <= maxNetCapabilityInR) {
                        builder.addForbiddenCapability(forbiddenCapability);
                    }
                }

                final int maxTransportInR = TRANSPORT_TEST;
                for (int transport : BitUtils.unpackBits(Long.parseLong(
                        netTransportTypesLong))) {
                    if (transport <= maxTransportInR) {
                        builder.addTransportType(transport);
                    }
                }
                jobBuilder.setRequiredNetwork(builder.build());
                // Estimated bytes weren't persisted on R- builds, so no point querying for the
                // attributes here.
            } else {
                // Read legacy values
                val = parser.getAttributeValue(null, "connectivity");
                if (val != null) {
                    jobBuilder.setRequiredNetworkType(JobInfo.NETWORK_TYPE_ANY);
                }
                val = parser.getAttributeValue(null, "metered");
                if (val != null) {
                    jobBuilder.setRequiredNetworkType(JobInfo.NETWORK_TYPE_METERED);
                }
                val = parser.getAttributeValue(null, "unmetered");
                if (val != null) {
                    jobBuilder.setRequiredNetworkType(JobInfo.NETWORK_TYPE_UNMETERED);
                }
                val = parser.getAttributeValue(null, "not-roaming");
                if (val != null) {
                    jobBuilder.setRequiredNetworkType(JobInfo.NETWORK_TYPE_NOT_ROAMING);
                }
            }

            val = parser.getAttributeValue(null, "idle");
            if (val != null) {
                jobBuilder.setRequiresDeviceIdle(true);
            }
            val = parser.getAttributeValue(null, "charging");
            if (val != null) {
                jobBuilder.setRequiresCharging(true);
            }
            val = parser.getAttributeValue(null, "battery-not-low");
            if (val != null) {
                jobBuilder.setRequiresBatteryNotLow(true);
            }
            val = parser.getAttributeValue(null, "storage-not-low");
            if (val != null) {
                jobBuilder.setRequiresStorageNotLow(true);
            }
        }

        /**
         * Builds the back-off policy out of the params tag. These attributes may not exist, depending
         * on whether the back-off was set when the job was first scheduled.
         */
        private void maybeBuildBackoffPolicyFromXml(JobInfo.Builder jobBuilder, XmlPullParser parser) {
            String val = parser.getAttributeValue(null, "initial-backoff");
            if (val != null) {
                long initialBackoff = Long.parseLong(val);
                val = parser.getAttributeValue(null, "backoff-policy");
                int backoffPolicy = Integer.parseInt(val);  // Will throw NFE which we catch higher up.
                jobBuilder.setBackoffCriteria(initialBackoff, backoffPolicy);
            }
        }

        /**
         * Extract a job's earliest/latest run time data from XML.  These are returned in
         * unadjusted UTC wall clock time, because we do not yet know whether the system
         * clock is reliable for purposes of calculating deltas from 'now'.
         *
         * @param parser
         * @return A Pair of timestamps in UTC wall-clock time.  The first is the earliest
         *     time at which the job is to become runnable, and the second is the deadline at
         *     which it becomes overdue to execute.
         */
        private Pair<Long, Long> buildRtcExecutionTimesFromXml(TypedXmlPullParser parser) {
            // Pull out execution time data.
            final long earliestRunTimeRtc =
                    parser.getAttributeLong(null, "delay", JobStatus.NO_EARLIEST_RUNTIME);
            final long latestRunTimeRtc =
                    parser.getAttributeLong(null, "deadline", JobStatus.NO_LATEST_RUNTIME);
            return Pair.create(earliestRunTimeRtc, latestRunTimeRtc);
        }

        @NonNull
        private List<JobWorkItem> readJobWorkItemsFromXml(TypedXmlPullParser parser)
                throws IOException, XmlPullParserException {
            List<JobWorkItem> jobWorkItems = new ArrayList<>();

            for (int eventType = parser.getEventType(); eventType != XmlPullParser.END_DOCUMENT;
                    eventType = parser.next()) {
                final String tagName = parser.getName();
                if (!XML_TAG_JOB_WORK_ITEM.equals(tagName)) {
                    // We're no longer operating with work items.
                    break;
                }
                try {
                    JobWorkItem jwi = readJobWorkItemFromXml(parser);
                    if (jwi != null) {
                        jobWorkItems.add(jwi);
                    }
                } catch (Exception e) {
                    // If there's an issue with one JobWorkItem, drop only the one item and not the
                    // whole job.
                    Slog.e(TAG, "Problem with persisted JobWorkItem", e);
                }
            }

            return jobWorkItems;
        }

        @Nullable
        private JobWorkItem readJobWorkItemFromXml(TypedXmlPullParser parser)
                throws IOException, XmlPullParserException {
            JobWorkItem.Builder jwiBuilder = new JobWorkItem.Builder();

            jwiBuilder
                    .setDeliveryCount(parser.getAttributeInt(null, "delivery-count"))
                    .setEstimatedNetworkBytes(
                            parser.getAttributeLong(null,
                                    "estimated-download-bytes", JobInfo.NETWORK_BYTES_UNKNOWN),
                            parser.getAttributeLong(null,
                                    "estimated-upload-bytes", JobInfo.NETWORK_BYTES_UNKNOWN))
                    .setMinimumNetworkChunkBytes(parser.getAttributeLong(null,
                            "minimum-network-chunk-bytes", JobInfo.NETWORK_BYTES_UNKNOWN));
            parser.next();
            try {
                final PersistableBundle extras = PersistableBundle.restoreFromXml(parser);
                jwiBuilder.setExtras(extras);
            } catch (IllegalArgumentException e) {
                Slog.e(TAG, "Persisted extras contained invalid data", e);
                return null;
            }

            try {
                return jwiBuilder.build();
            } catch (Exception e) {
                Slog.e(TAG, "Invalid JobWorkItem", e);
                return null;
            }
        }

        @NonNull
        private Set<String> readDebugTagsFromXml(TypedXmlPullParser parser)
                throws IOException, XmlPullParserException {
            Set<String> debugTags = new ArraySet<>();

            for (int eventType = parser.getEventType(); eventType != XmlPullParser.END_DOCUMENT;
                    eventType = parser.next()) {
                final String tagName = parser.getName();
                if (!XML_TAG_DEBUG_TAG.equals(tagName)) {
                    // We're no longer operating with debug tags.
                    break;
                }
                if (debugTags.size() < JobInfo.MAX_NUM_DEBUG_TAGS) {
                    final String debugTag;
                    try {
                        debugTag = JobInfo.validateDebugTag(parser.getAttributeValue(null, "tag"));
                    } catch (Exception e) {
                        Slog.wtf(TAG, "Invalid debug tag persisted to disk", e);
                        continue;
                    }
                    debugTags.add(debugTag);
                }
            }

            return debugTags;
        }
    }

    /** Set of all tracked jobs. */
    @VisibleForTesting
    public static final class JobSet {
        @VisibleForTesting // Key is the getUid() originator of the jobs in each sheaf
        final SparseArray<ArraySet<JobStatus>> mJobs;

        @VisibleForTesting // Same data but with the key as getSourceUid() of the jobs in each sheaf
        final SparseArray<ArraySet<JobStatus>> mJobsPerSourceUid;

        public JobSet() {
            mJobs = new SparseArray<ArraySet<JobStatus>>();
            mJobsPerSourceUid = new SparseArray<>();
        }

        public ArraySet<JobStatus> getJobsByUid(int uid) {
            ArraySet<JobStatus> matchingJobs = new ArraySet<>();
            getJobsByUid(uid, matchingJobs);
            return matchingJobs;
        }

        public void getJobsByUid(int uid, Set<JobStatus> insertInto) {
            ArraySet<JobStatus> jobs = mJobs.get(uid);
            if (jobs != null) {
                insertInto.addAll(jobs);
            }
        }

        @NonNull
        public ArraySet<JobStatus> getJobsBySourceUid(int sourceUid) {
            final ArraySet<JobStatus> result = new ArraySet<>();
            getJobsBySourceUid(sourceUid, result);
            return result;
        }

        public void getJobsBySourceUid(int sourceUid, Set<JobStatus> insertInto) {
            final ArraySet<JobStatus> jobs = mJobsPerSourceUid.get(sourceUid);
            if (jobs != null) {
                insertInto.addAll(jobs);
            }
        }

        public boolean add(JobStatus job) {
            final int uid = job.getUid();
            final int sourceUid = job.getSourceUid();
            ArraySet<JobStatus> jobs = mJobs.get(uid);
            if (jobs == null) {
                jobs = new ArraySet<JobStatus>();
                mJobs.put(uid, jobs);
            }
            ArraySet<JobStatus> jobsForSourceUid = mJobsPerSourceUid.get(sourceUid);
            if (jobsForSourceUid == null) {
                jobsForSourceUid = new ArraySet<>();
                mJobsPerSourceUid.put(sourceUid, jobsForSourceUid);
            }
            final boolean added = jobs.add(job);
            final boolean addedInSource = jobsForSourceUid.add(job);
            if (added != addedInSource) {
                Slog.wtf(TAG, "mJobs and mJobsPerSourceUid mismatch; caller= " + added
                        + " source= " + addedInSource);
            }
            return added || addedInSource;
        }

        public boolean remove(JobStatus job) {
            final int uid = job.getUid();
            final ArraySet<JobStatus> jobs = mJobs.get(uid);
            final int sourceUid = job.getSourceUid();
            final ArraySet<JobStatus> jobsForSourceUid = mJobsPerSourceUid.get(sourceUid);
            final boolean didRemove = jobs != null && jobs.remove(job);
            final boolean sourceRemove = jobsForSourceUid != null && jobsForSourceUid.remove(job);
            if (didRemove != sourceRemove) {
                Slog.wtf(TAG, "Job presence mismatch; caller=" + didRemove
                        + " source=" + sourceRemove);
            }
            if (didRemove || sourceRemove) {
                // no more jobs for this uid?  let the now-empty set objects be GC'd.
                if (jobs != null && jobs.size() == 0) {
                    mJobs.remove(uid);
                }
                if (jobsForSourceUid != null && jobsForSourceUid.size() == 0) {
                    mJobsPerSourceUid.remove(sourceUid);
                }
                return true;
            }
            return false;
        }

        /**
         * Removes the jobs of all users not specified by the keepUserIds of user ids.
         * This will remove jobs scheduled *by* and *for* any unlisted users.
         */
        public void removeJobsOfUnlistedUsers(final int[] keepUserIds) {
            final Predicate<JobStatus> noSourceUser =
                    job -> !ArrayUtils.contains(keepUserIds, job.getSourceUserId());
            final Predicate<JobStatus> noCallingUser =
                    job -> !ArrayUtils.contains(keepUserIds, job.getUserId());
            removeAll(noSourceUser.or(noCallingUser));
        }

        private void removeAll(Predicate<JobStatus> predicate) {
            for (int jobSetIndex = mJobs.size() - 1; jobSetIndex >= 0; jobSetIndex--) {
                final ArraySet<JobStatus> jobs = mJobs.valueAt(jobSetIndex);
                jobs.removeIf(predicate);
                if (jobs.size() == 0) {
                    mJobs.removeAt(jobSetIndex);
                }
            }
            for (int jobSetIndex = mJobsPerSourceUid.size() - 1; jobSetIndex >= 0; jobSetIndex--) {
                final ArraySet<JobStatus> jobs = mJobsPerSourceUid.valueAt(jobSetIndex);
                jobs.removeIf(predicate);
                if (jobs.size() == 0) {
                    mJobsPerSourceUid.removeAt(jobSetIndex);
                }
            }
        }

        public boolean contains(JobStatus job) {
            final int uid = job.getUid();
            ArraySet<JobStatus> jobs = mJobs.get(uid);
            return jobs != null && jobs.contains(job);
        }

        public JobStatus get(int uid, @Nullable String namespace, int jobId) {
            ArraySet<JobStatus> jobs = mJobs.get(uid);
            if (jobs != null) {
                for (int i = jobs.size() - 1; i >= 0; i--) {
                    JobStatus job = jobs.valueAt(i);
                    if (job.getJobId() == jobId && Objects.equals(namespace, job.getNamespace())) {
                        return job;
                    }
                }
            }
            return null;
        }

        // Inefficient; use only for testing
        public List<JobStatus> getAllJobs() {
            ArrayList<JobStatus> allJobs = new ArrayList<JobStatus>(size());
            for (int i = mJobs.size() - 1; i >= 0; i--) {
                ArraySet<JobStatus> jobs = mJobs.valueAt(i);
                if (jobs != null) {
                    // Use a for loop over the ArraySet, so we don't need to make its
                    // optional collection class iterator implementation or have to go
                    // through a temporary array from toArray().
                    for (int j = jobs.size() - 1; j >= 0; j--) {
                        allJobs.add(jobs.valueAt(j));
                    }
                }
            }
            return allJobs;
        }

        public void clear() {
            mJobs.clear();
            mJobsPerSourceUid.clear();
        }

        public int size() {
            int total = 0;
            for (int i = mJobs.size() - 1; i >= 0; i--) {
                total += mJobs.valueAt(i).size();
            }
            return total;
        }

        // We only want to count the jobs that this uid has scheduled on its own
        // behalf, not those that the app has scheduled on someone else's behalf.
        public int countJobsForUid(int uid) {
            int total = 0;
            ArraySet<JobStatus> jobs = mJobs.get(uid);
            if (jobs != null) {
                for (int i = jobs.size() - 1; i >= 0; i--) {
                    JobStatus job = jobs.valueAt(i);
                    if (job.getUid() == job.getSourceUid()) {
                        total++;
                    }
                }
            }
            return total;
        }

        public void forEachJob(@Nullable Predicate<JobStatus> filterPredicate,
                @NonNull Consumer<JobStatus> functor) {
            for (int uidIndex = mJobs.size() - 1; uidIndex >= 0; uidIndex--) {
                ArraySet<JobStatus> jobs = mJobs.valueAt(uidIndex);
                if (jobs != null) {
                    for (int i = jobs.size() - 1; i >= 0; i--) {
                        final JobStatus jobStatus = jobs.valueAt(i);
                        if ((filterPredicate == null) || filterPredicate.test(jobStatus)) {
                            functor.accept(jobStatus);
                        }
                    }
                }
            }
        }

        public void forEachJob(int callingUid, Consumer<JobStatus> functor) {
            ArraySet<JobStatus> jobs = mJobs.get(callingUid);
            if (jobs != null) {
                for (int i = jobs.size() - 1; i >= 0; i--) {
                    functor.accept(jobs.valueAt(i));
                }
            }
        }

        public void forEachJobForSourceUid(int sourceUid, Consumer<JobStatus> functor) {
            final ArraySet<JobStatus> jobs = mJobsPerSourceUid.get(sourceUid);
            if (jobs != null) {
                for (int i = jobs.size() - 1; i >= 0; i--) {
                    functor.accept(jobs.valueAt(i));
                }
            }
        }
    }
}