src/com/android/car/settings/datausage/DataUsageSummaryPreferenceController.java - platform/packages/apps/Car/Settings - Git at Google

 /*
  * Copyright (C) 2019 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.car.settings.datausage;

 import android.car.drivingstate.CarUxRestrictions;
 import android.content.Context;
 import android.content.Intent;
 import android.net.NetworkTemplate;
 import android.telephony.SubscriptionInfo;
 import android.telephony.SubscriptionManager;
 import android.telephony.SubscriptionPlan;
 import android.telephony.TelephonyManager;
 import android.text.Spannable;
 import android.text.SpannableString;
 import android.text.TextUtils;
 import android.text.format.Formatter;
 import android.text.style.AbsoluteSizeSpan;
 import android.util.RecurrenceRule;

 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;

 import com.android.car.settings.R;
 import com.android.car.settings.common.FragmentController;
 import com.android.car.settings.common.PreferenceController;
 import com.android.car.settings.network.NetworkUtils;
 import com.android.settingslib.net.DataUsageController;
 import com.android.settingslib.utils.StringUtil;

 import java.util.List;
 import java.util.concurrent.TimeUnit;

 /**
  * Business logic for setting the {@link DataUsageSummaryPreference} with the current data usage and
  * the appropriate summary text.
  */
 public class DataUsageSummaryPreferenceController extends
         PreferenceController<DataUsageSummaryPreference> {

     private static final long MILLIS_IN_A_DAY = TimeUnit.DAYS.toMillis(1);
     private static final long MILLIS_IN_AN_HOUR = TimeUnit.HOURS.toMillis(1);
     private static final long MILLIS_IN_A_MINUTE = TimeUnit.MINUTES.toMillis(1);
     private static final long MILLIS_IN_A_SECOND = TimeUnit.SECONDS.toMillis(1);
     private static final int MAX_PROGRESS_BAR_VALUE = 1000;

     @VisibleForTesting
     static final long WARNING_AGE = TimeUnit.HOURS.toMillis(6L);

     private final SubscriptionManager mSubscriptionManager;
     private final TelephonyManager mTelephonyManager;
     private final DataUsageController mDataUsageController;
     private final NetworkTemplate mDefaultTemplate;

     /** Name of the carrier, or null if not available */
     @Nullable
     private CharSequence mCarrierName;
     /** The number of registered plans, [0,N] */
     private int mDataplanCount;
     /** The time of the last update in milliseconds since the epoch, or -1 if unknown */
     private long mSnapshotTime;
     /** The size of the first registered plan if one exists. -1 if no information is available. */
     private long mDataplanSize = -1;
     /**
      * Limit to track. Size of the first registered plan if one exists. Otherwise size of data limit
      * or warning.
      */
     private long mDataplanTrackingThreshold;
     /** The number of bytes used since the start of the cycle. */
     private long mDataplanUse;
     /** The ending time of the billing cycle in ms since the epoch */
     private long mCycleEnd;
     private Intent mManageSubscriptionIntent;

     public DataUsageSummaryPreferenceController(Context context, String preferenceKey,
             FragmentController fragmentController, CarUxRestrictions uxRestrictions) {
         super(context, preferenceKey, fragmentController, uxRestrictions);
         mSubscriptionManager = context.getSystemService(SubscriptionManager.class);
         mTelephonyManager = context.getSystemService(TelephonyManager.class);
         mDataUsageController = new DataUsageController(context);

         int defaultSubId = DataUsageUtils.getDefaultSubscriptionId(mSubscriptionManager);
         mDefaultTemplate = DataUsageUtils.getMobileNetworkTemplate(mTelephonyManager, defaultSubId);
     }

     @Override
     protected Class<DataUsageSummaryPreference> getPreferenceType() {
         return DataUsageSummaryPreference.class;
     }

     @Override
     protected int getAvailabilityStatus() {
         return NetworkUtils.hasSim(mTelephonyManager) ? AVAILABLE : CONDITIONALLY_UNAVAILABLE;
     }

     @Override
     protected void onCreateInternal() {
         getPreference().setMin(0);
         getPreference().setMax(MAX_PROGRESS_BAR_VALUE);
     }

     @Override
     protected void updateState(DataUsageSummaryPreference preference) {
         DataUsageController.DataUsageInfo info = mDataUsageController.getDataUsageInfo(
                 mDefaultTemplate);

         if (mSubscriptionManager != null) {
             refreshDataplanInfo(info);
         }

         preference.setTitle(getUsageText());
         preference.setManageSubscriptionIntent(mManageSubscriptionIntent);

         preference.setDataLimitText(getLimitText(info));
         preference.setRemainingBillingCycleText(getRemainingBillingCycleTimeText());

         // Carrier Info has special styling based on when it was last updated.
         preference.setCarrierInfoText(getCarrierInfoText());
         long updateAgeMillis = calculateTruncatedUpdateAge(mSnapshotTime);
         if (updateAgeMillis <= WARNING_AGE) {
             preference.setCarrierInfoTextStyle(R.style.DataUsageSummaryCarrierInfoTextAppearance);
         } else {
             preference.setCarrierInfoTextStyle(
                     R.style.DataUsageSummaryCarrierInfoWarningTextAppearance);
         }

         // Set the progress bar values.
         preference.setMinLabel(DataUsageUtils.bytesToIecUnits(getContext(), /* byteValue= */ 0));
         preference.setMaxLabel(
                 DataUsageUtils.bytesToIecUnits(getContext(), mDataplanTrackingThreshold));
         preference.setProgress(scaleUsage(mDataplanUse, mDataplanTrackingThreshold));
     }

     private CharSequence getUsageText() {
         Formatter.BytesResult usedResult = Formatter.formatBytes(getContext().getResources(),
                 mDataplanUse, Formatter.FLAG_CALCULATE_ROUNDED | Formatter.FLAG_IEC_UNITS);
         SpannableString usageNumberText = new SpannableString(usedResult.value);
         int textSize = getContext().getResources().getDimensionPixelSize(
                 R.dimen.usage_number_text_size);

         // Set the usage text (only the number) to the size defined by usage_number_text_size.
         usageNumberText.setSpan(new AbsoluteSizeSpan(textSize), /* start= */ 0,
                 usageNumberText.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

         CharSequence template = getContext().getText(R.string.data_used_formatted);
         CharSequence usageText = TextUtils.expandTemplate(template, usageNumberText,
                 usedResult.units);
         return usageText;
     }


     private CharSequence getLimitText(DataUsageController.DataUsageInfo info) {
         if (info.warningLevel > 0 && info.limitLevel > 0) {
             return TextUtils.expandTemplate(
                     getContext().getText(R.string.cell_data_warning_and_limit),
                     DataUsageUtils.bytesToIecUnits(getContext(), info.warningLevel),
                     DataUsageUtils.bytesToIecUnits(getContext(), info.limitLevel));
         } else if (info.warningLevel > 0) {
             return TextUtils.expandTemplate(getContext().getText(R.string.cell_data_warning),
                     DataUsageUtils.bytesToIecUnits(getContext(), info.warningLevel));
         } else if (info.limitLevel > 0) {
             return TextUtils.expandTemplate(getContext().getText(R.string.cell_data_limit),
                     DataUsageUtils.bytesToIecUnits(getContext(), info.limitLevel));
         }

         return null;
     }

     private CharSequence getRemainingBillingCycleTimeText() {
         long millisLeft = mCycleEnd - System.currentTimeMillis();
         if (millisLeft <= 0) {
             return getContext().getString(R.string.billing_cycle_none_left);
         } else {
             int daysLeft = (int) (millisLeft / MILLIS_IN_A_DAY);
             return daysLeft < 1
                     ? getContext().getString(R.string.billing_cycle_less_than_one_day_left)
                     : getContext().getResources().getQuantityString(
                             R.plurals.billing_cycle_days_left, daysLeft, daysLeft);
         }
     }

     private CharSequence getCarrierInfoText() {
         if (mDataplanCount > 0 && mSnapshotTime >= 0L) {
             long updateAgeMillis = calculateTruncatedUpdateAge(mSnapshotTime);

             int textResourceId;
             CharSequence updateTime = null;
             if (updateAgeMillis == 0) {
                 if (mCarrierName != null) {
                     textResourceId = R.string.carrier_and_update_now_text;
                 } else {
                     textResourceId = R.string.no_carrier_update_now_text;
                 }
             } else {
                 if (mCarrierName != null) {
                     textResourceId = R.string.carrier_and_update_text;
                 } else {
                     textResourceId = R.string.no_carrier_update_text;
                 }
                 updateTime = StringUtil.formatElapsedTime(getContext(),
                         updateAgeMillis, /* withSeconds= */ false);
             }
             return TextUtils.expandTemplate(getContext().getText(textResourceId), mCarrierName,
                     updateTime);
         }

         return null;
     }

     private void refreshDataplanInfo(DataUsageController.DataUsageInfo info) {
         // Reset data before overwriting.
         mCarrierName = null;
         mDataplanCount = 0;
         mSnapshotTime = -1L;
         mDataplanSize = -1L;
         mDataplanTrackingThreshold = getSummaryLimit(info);
         mDataplanUse = info.usageLevel;
         mCycleEnd = info.cycleEnd;

         int defaultSubId = SubscriptionManager.getDefaultSubscriptionId();
         SubscriptionInfo subInfo = mSubscriptionManager.getDefaultDataSubscriptionInfo();
         if (subInfo != null) {
             mCarrierName = subInfo.getCarrierName();
             List<SubscriptionPlan> plans = mSubscriptionManager.getSubscriptionPlans(defaultSubId);
             SubscriptionPlan primaryPlan = DataUsageUtils.getPrimaryPlan(mSubscriptionManager,
                     defaultSubId);
             if (primaryPlan != null) {
                 mDataplanCount = plans.size();
                 mDataplanSize = primaryPlan.getDataLimitBytes();
                 if (mDataplanSize == SubscriptionPlan.BYTES_UNLIMITED) {
                     mDataplanSize = -1L;
                 }
                 mDataplanTrackingThreshold = mDataplanSize;
                 mDataplanUse = primaryPlan.getDataUsageBytes();

                 RecurrenceRule rule = primaryPlan.getCycleRule();
                 if (rule != null && rule.start != null && rule.end != null) {
                     mCycleEnd = rule.end.toEpochSecond() * MILLIS_IN_A_SECOND;
                 }
                 mSnapshotTime = primaryPlan.getDataUsageTime();
             }
         }
         mManageSubscriptionIntent = mSubscriptionManager.createManageSubscriptionIntent(
                 defaultSubId);
     }

     /** Scales the current usage to be an integer between 0 and {@link #MAX_PROGRESS_BAR_VALUE}. */
     private int scaleUsage(long usage, long maxUsage) {
         if (maxUsage == 0) {
             return 0;
         }
         return (int) ((usage / (float) maxUsage) * MAX_PROGRESS_BAR_VALUE);
     }

     /**
      * Gets the max displayed limit based on {@link DataUsageController.DataUsageInfo}.
      *
      * @return the most appropriate limit for the data usage summary. Use the total usage when it
      * is higher than the limit and warning level. Use the limit when it is set and less than usage.
      * Otherwise use warning level.
      */
     private static long getSummaryLimit(DataUsageController.DataUsageInfo info) {
         long limit = info.limitLevel;
         if (limit <= 0) {
             limit = info.warningLevel;
         }
         if (info.usageLevel > limit) {
             limit = info.usageLevel;
         }
         return limit;
     }

     /**
      * Returns the time since the last carrier update, as defined by {@link #mSnapshotTime},
      * truncated to the nearest day / hour / minute in milliseconds, or 0 if less than 1 min.
      */
     private long calculateTruncatedUpdateAge(long snapshotTime) {
         long updateAgeMillis = System.currentTimeMillis() - snapshotTime;

         // Round to nearest whole unit
         if (updateAgeMillis >= MILLIS_IN_A_DAY) {
             return (updateAgeMillis / MILLIS_IN_A_DAY) * MILLIS_IN_A_DAY;
         } else if (updateAgeMillis >= MILLIS_IN_AN_HOUR) {
             return (updateAgeMillis / MILLIS_IN_AN_HOUR) * MILLIS_IN_AN_HOUR;
         } else if (updateAgeMillis >= MILLIS_IN_A_MINUTE) {
             return (updateAgeMillis / MILLIS_IN_A_MINUTE) * MILLIS_IN_A_MINUTE;
         } else {
             return 0;
         }
     }
 }
	/*
	* Copyright (C) 2019 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.car.settings.datausage;

	import android.car.drivingstate.CarUxRestrictions;
	import android.content.Context;
	import android.content.Intent;
	import android.net.NetworkTemplate;
	import android.telephony.SubscriptionInfo;
	import android.telephony.SubscriptionManager;
	import android.telephony.SubscriptionPlan;
	import android.telephony.TelephonyManager;
	import android.text.Spannable;
	import android.text.SpannableString;
	import android.text.TextUtils;
	import android.text.format.Formatter;
	import android.text.style.AbsoluteSizeSpan;
	import android.util.RecurrenceRule;

	import androidx.annotation.Nullable;
	import androidx.annotation.VisibleForTesting;

	import com.android.car.settings.R;
	import com.android.car.settings.common.FragmentController;
	import com.android.car.settings.common.PreferenceController;
	import com.android.car.settings.network.NetworkUtils;
	import com.android.settingslib.net.DataUsageController;
	import com.android.settingslib.utils.StringUtil;

	import java.util.List;
	import java.util.concurrent.TimeUnit;

	/**
	* Business logic for setting the {@link DataUsageSummaryPreference} with the current data usage and
	* the appropriate summary text.
	*/
	public class DataUsageSummaryPreferenceController extends
	PreferenceController<DataUsageSummaryPreference> {

	private static final long MILLIS_IN_A_DAY = TimeUnit.DAYS.toMillis(1);
	private static final long MILLIS_IN_AN_HOUR = TimeUnit.HOURS.toMillis(1);
	private static final long MILLIS_IN_A_MINUTE = TimeUnit.MINUTES.toMillis(1);
	private static final long MILLIS_IN_A_SECOND = TimeUnit.SECONDS.toMillis(1);
	private static final int MAX_PROGRESS_BAR_VALUE = 1000;

	@VisibleForTesting
	static final long WARNING_AGE = TimeUnit.HOURS.toMillis(6L);

	private final SubscriptionManager mSubscriptionManager;
	private final TelephonyManager mTelephonyManager;
	private final DataUsageController mDataUsageController;
	private final NetworkTemplate mDefaultTemplate;

	/** Name of the carrier, or null if not available */
	@Nullable
	private CharSequence mCarrierName;
	/** The number of registered plans, [0,N] */
	private int mDataplanCount;
	/** The time of the last update in milliseconds since the epoch, or -1 if unknown */
	private long mSnapshotTime;
	/** The size of the first registered plan if one exists. -1 if no information is available. */
	private long mDataplanSize = -1;
	/**
	* Limit to track. Size of the first registered plan if one exists. Otherwise size of data limit
	* or warning.
	*/
	private long mDataplanTrackingThreshold;
	/** The number of bytes used since the start of the cycle. */
	private long mDataplanUse;
	/** The ending time of the billing cycle in ms since the epoch */
	private long mCycleEnd;
	private Intent mManageSubscriptionIntent;

	public DataUsageSummaryPreferenceController(Context context, String preferenceKey,
	FragmentController fragmentController, CarUxRestrictions uxRestrictions) {
	super(context, preferenceKey, fragmentController, uxRestrictions);
	mSubscriptionManager = context.getSystemService(SubscriptionManager.class);
	mTelephonyManager = context.getSystemService(TelephonyManager.class);
	mDataUsageController = new DataUsageController(context);

	int defaultSubId = DataUsageUtils.getDefaultSubscriptionId(mSubscriptionManager);
	mDefaultTemplate = DataUsageUtils.getMobileNetworkTemplate(mTelephonyManager, defaultSubId);
	}

	@Override
	protected Class<DataUsageSummaryPreference> getPreferenceType() {
	return DataUsageSummaryPreference.class;
	}

	@Override
	protected int getAvailabilityStatus() {
	return NetworkUtils.hasSim(mTelephonyManager) ? AVAILABLE : CONDITIONALLY_UNAVAILABLE;
	}

	@Override
	protected void onCreateInternal() {
	getPreference().setMin(0);
	getPreference().setMax(MAX_PROGRESS_BAR_VALUE);
	}

	@Override
	protected void updateState(DataUsageSummaryPreference preference) {
	DataUsageController.DataUsageInfo info = mDataUsageController.getDataUsageInfo(
	mDefaultTemplate);

	if (mSubscriptionManager != null) {
	refreshDataplanInfo(info);
	}

	preference.setTitle(getUsageText());
	preference.setManageSubscriptionIntent(mManageSubscriptionIntent);

	preference.setDataLimitText(getLimitText(info));
	preference.setRemainingBillingCycleText(getRemainingBillingCycleTimeText());

	// Carrier Info has special styling based on when it was last updated.
	preference.setCarrierInfoText(getCarrierInfoText());
	long updateAgeMillis = calculateTruncatedUpdateAge(mSnapshotTime);
	if (updateAgeMillis <= WARNING_AGE) {
	preference.setCarrierInfoTextStyle(R.style.DataUsageSummaryCarrierInfoTextAppearance);
	} else {
	preference.setCarrierInfoTextStyle(
	R.style.DataUsageSummaryCarrierInfoWarningTextAppearance);
	}

	// Set the progress bar values.
	preference.setMinLabel(DataUsageUtils.bytesToIecUnits(getContext(), /* byteValue= */ 0));
	preference.setMaxLabel(
	DataUsageUtils.bytesToIecUnits(getContext(), mDataplanTrackingThreshold));
	preference.setProgress(scaleUsage(mDataplanUse, mDataplanTrackingThreshold));
	}

	private CharSequence getUsageText() {
	Formatter.BytesResult usedResult = Formatter.formatBytes(getContext().getResources(),
	mDataplanUse, Formatter.FLAG_CALCULATE_ROUNDED \| Formatter.FLAG_IEC_UNITS);
	SpannableString usageNumberText = new SpannableString(usedResult.value);
	int textSize = getContext().getResources().getDimensionPixelSize(
	R.dimen.usage_number_text_size);

	// Set the usage text (only the number) to the size defined by usage_number_text_size.
	usageNumberText.setSpan(new AbsoluteSizeSpan(textSize), /* start= */ 0,
	usageNumberText.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

	CharSequence template = getContext().getText(R.string.data_used_formatted);
	CharSequence usageText = TextUtils.expandTemplate(template, usageNumberText,
	usedResult.units);
	return usageText;
	}


	private CharSequence getLimitText(DataUsageController.DataUsageInfo info) {
	if (info.warningLevel > 0 && info.limitLevel > 0) {
	return TextUtils.expandTemplate(
	getContext().getText(R.string.cell_data_warning_and_limit),
	DataUsageUtils.bytesToIecUnits(getContext(), info.warningLevel),
	DataUsageUtils.bytesToIecUnits(getContext(), info.limitLevel));
	} else if (info.warningLevel > 0) {
	return TextUtils.expandTemplate(getContext().getText(R.string.cell_data_warning),
	DataUsageUtils.bytesToIecUnits(getContext(), info.warningLevel));
	} else if (info.limitLevel > 0) {
	return TextUtils.expandTemplate(getContext().getText(R.string.cell_data_limit),
	DataUsageUtils.bytesToIecUnits(getContext(), info.limitLevel));
	}

	return null;
	}

	private CharSequence getRemainingBillingCycleTimeText() {
	long millisLeft = mCycleEnd - System.currentTimeMillis();
	if (millisLeft <= 0) {
	return getContext().getString(R.string.billing_cycle_none_left);
	} else {
	int daysLeft = (int) (millisLeft / MILLIS_IN_A_DAY);
	return daysLeft < 1
	? getContext().getString(R.string.billing_cycle_less_than_one_day_left)
	: getContext().getResources().getQuantityString(
	R.plurals.billing_cycle_days_left, daysLeft, daysLeft);
	}
	}

	private CharSequence getCarrierInfoText() {
	if (mDataplanCount > 0 && mSnapshotTime >= 0L) {
	long updateAgeMillis = calculateTruncatedUpdateAge(mSnapshotTime);

	int textResourceId;
	CharSequence updateTime = null;
	if (updateAgeMillis == 0) {
	if (mCarrierName != null) {
	textResourceId = R.string.carrier_and_update_now_text;
	} else {
	textResourceId = R.string.no_carrier_update_now_text;
	}
	} else {
	if (mCarrierName != null) {
	textResourceId = R.string.carrier_and_update_text;
	} else {
	textResourceId = R.string.no_carrier_update_text;
	}
	updateTime = StringUtil.formatElapsedTime(getContext(),
	updateAgeMillis, /* withSeconds= */ false);
	}
	return TextUtils.expandTemplate(getContext().getText(textResourceId), mCarrierName,
	updateTime);
	}

	return null;
	}

	private void refreshDataplanInfo(DataUsageController.DataUsageInfo info) {
	// Reset data before overwriting.
	mCarrierName = null;
	mDataplanCount = 0;
	mSnapshotTime = -1L;
	mDataplanSize = -1L;
	mDataplanTrackingThreshold = getSummaryLimit(info);
	mDataplanUse = info.usageLevel;
	mCycleEnd = info.cycleEnd;

	int defaultSubId = SubscriptionManager.getDefaultSubscriptionId();
	SubscriptionInfo subInfo = mSubscriptionManager.getDefaultDataSubscriptionInfo();
	if (subInfo != null) {
	mCarrierName = subInfo.getCarrierName();
	List<SubscriptionPlan> plans = mSubscriptionManager.getSubscriptionPlans(defaultSubId);
	SubscriptionPlan primaryPlan = DataUsageUtils.getPrimaryPlan(mSubscriptionManager,
	defaultSubId);
	if (primaryPlan != null) {
	mDataplanCount = plans.size();
	mDataplanSize = primaryPlan.getDataLimitBytes();
	if (mDataplanSize == SubscriptionPlan.BYTES_UNLIMITED) {
	mDataplanSize = -1L;
	}
	mDataplanTrackingThreshold = mDataplanSize;
	mDataplanUse = primaryPlan.getDataUsageBytes();

	RecurrenceRule rule = primaryPlan.getCycleRule();
	if (rule != null && rule.start != null && rule.end != null) {
	mCycleEnd = rule.end.toEpochSecond() * MILLIS_IN_A_SECOND;
	}
	mSnapshotTime = primaryPlan.getDataUsageTime();
	}
	}
	mManageSubscriptionIntent = mSubscriptionManager.createManageSubscriptionIntent(
	defaultSubId);
	}

	/** Scales the current usage to be an integer between 0 and {@link #MAX_PROGRESS_BAR_VALUE}. */
	private int scaleUsage(long usage, long maxUsage) {
	if (maxUsage == 0) {
	return 0;
	}
	return (int) ((usage / (float) maxUsage) * MAX_PROGRESS_BAR_VALUE);
	}

	/**
	* Gets the max displayed limit based on {@link DataUsageController.DataUsageInfo}.
	*
	* @return the most appropriate limit for the data usage summary. Use the total usage when it
	* is higher than the limit and warning level. Use the limit when it is set and less than usage.
	* Otherwise use warning level.
	*/
	private static long getSummaryLimit(DataUsageController.DataUsageInfo info) {
	long limit = info.limitLevel;
	if (limit <= 0) {
	limit = info.warningLevel;
	}
	if (info.usageLevel > limit) {
	limit = info.usageLevel;
	}
	return limit;
	}

	/**
	* Returns the time since the last carrier update, as defined by {@link #mSnapshotTime},
	* truncated to the nearest day / hour / minute in milliseconds, or 0 if less than 1 min.
	*/
	private long calculateTruncatedUpdateAge(long snapshotTime) {
	long updateAgeMillis = System.currentTimeMillis() - snapshotTime;

	// Round to nearest whole unit
	if (updateAgeMillis >= MILLIS_IN_A_DAY) {
	return (updateAgeMillis / MILLIS_IN_A_DAY) * MILLIS_IN_A_DAY;
	} else if (updateAgeMillis >= MILLIS_IN_AN_HOUR) {
	return (updateAgeMillis / MILLIS_IN_AN_HOUR) * MILLIS_IN_AN_HOUR;
	} else if (updateAgeMillis >= MILLIS_IN_A_MINUTE) {
	return (updateAgeMillis / MILLIS_IN_A_MINUTE) * MILLIS_IN_A_MINUTE;
	} else {
	return 0;
	}
	}
	}