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[Android] Use StringSet in SharedPreferences #1

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[Android] Use StringSet in SharedPreferences #1

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c81ce8b
Use setAlarmClock
JeroenvdV Dec 17, 2021
c9c07a4
Google Java Format
Dec 17, 2021
2b16361
[WIP] Use StringSet to avoid very big json strings, test performance
JeroenvdV Jan 10, 2022
4302ce1
[WIP] Don't parse all jsons on add, improve performance 85%
JeroenvdV Jan 10, 2022
e358b3b
Add data migration from big String to StringSet
JeroenvdV Jan 11, 2022
c5c5e76
Remove log of example json
JeroenvdV Jan 11, 2022
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109 changes: 79 additions & 30 deletions ...rc/main/java/com/dexterous/flutterlocalnotifications/FlutterLocalNotificationsPlugin.java
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Original file line number Diff line number Diff line change
Expand Up @@ -84,9 +84,11 @@
import java.util.Arrays;
import java.util.Calendar;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

/** FlutterLocalNotificationsPlugin */
@Keep
Expand All @@ -99,7 +101,9 @@ public class FlutterLocalNotificationsPlugin
private static final String DRAWABLE = "drawable";
private static final String DEFAULT_ICON = "defaultIcon";
private static final String SELECT_NOTIFICATION = "SELECT_NOTIFICATION";
private static final String SCHEDULED_NOTIFICATIONS = "scheduled_notifications";
private static final String SCHEDULED_NOTIFICATIONS_FILE = "scheduled_notifications";
private static final String SCHEDULED_NOTIFICATIONS_STRING = "scheduled_notifications";
private static final String SCHEDULED_NOTIFICATIONS_SET = "scheduled_notifications_set";
private static final String INITIALIZE_METHOD = "initialize";
private static final String GET_CALLBACK_HANDLE_METHOD = "getCallbackHandle";
private static final String ARE_NOTIFICATIONS_ENABLED_METHOD = "areNotificationsEnabled";
Expand Down Expand Up @@ -392,24 +396,63 @@ static Gson buildGson() {
private static ArrayList<NotificationDetails> loadScheduledNotifications(Context context) {
ArrayList<NotificationDetails> scheduledNotifications = new ArrayList<>();
SharedPreferences sharedPreferences =
context.getSharedPreferences(SCHEDULED_NOTIFICATIONS, Context.MODE_PRIVATE);
String json = sharedPreferences.getString(SCHEDULED_NOTIFICATIONS, null);
if (json != null) {
context.getSharedPreferences(SCHEDULED_NOTIFICATIONS_FILE, Context.MODE_PRIVATE);
Set<String> jsonNotifications = getScheduledNotificationsJsonSet(sharedPreferences);
if (jsonNotifications != null) {
Gson gson = buildGson();
Type type = new TypeToken<ArrayList<NotificationDetails>>() {}.getType();
scheduledNotifications = gson.fromJson(json, type);
Type type = new TypeToken<NotificationDetails>() {}.getType();
for (String json : jsonNotifications) {
scheduledNotifications.add(gson.fromJson(json, type));
}
}
return scheduledNotifications;
}

/**
* Get scheduled notifications from shared preferences, converting from old format if present.
*
* Returns null if neither are present
* The returned Set may not be mutated!
*/
private static Set<String> getScheduledNotificationsJsonSet(SharedPreferences sharedPreferences) {
Set<String> jsonNotifications = sharedPreferences.getStringSet(SCHEDULED_NOTIFICATIONS_SET, null);
if (jsonNotifications != null) {
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@Kavantix Kavantix Jan 11, 2022

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This check implies that we cannot switch back to the old implementation and again to this one, the migration will always happen only once

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@JeroenvdV JeroenvdV Jan 11, 2022

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This is true, in an attempt to reduce the number of extra queries to Shared Preferences made during normal use.

When switching back to the old implementation, the notifications will be lost. When re-switching to the new implementation, the lost notifications will be restored and any new ones will be lost.

Preventing the initial loss is only possible by additionally saving the alarms the old way, which would defeat the purpose of the change.
Doing a second migration is only possible by always checking for presence of an old data object, which would incur a performance penalty each time.

My suggestion to solve the second migration problem is to make it the responsibility of the app and not the plugin. App developers can ensure notifications are explicitly re-scheduled by the app if such a rare situation occurs.

return jsonNotifications;
}
String notificationsJson = sharedPreferences.getString(SCHEDULED_NOTIFICATIONS_STRING, null);
if (notificationsJson == null) {
return null;
}

// Convert (once) from the old format to the new format and delete the old
Gson gson = buildGson();
Type type = new TypeToken<ArrayList<NotificationDetails>>() {}.getType();
ArrayList<NotificationDetails> notificationsList = gson.fromJson(notificationsJson, type);
int amount = notificationsList.size();
String[] jsonNotificationsToSave = new String[amount];
for (int i = 0; i < amount; i++) {
jsonNotificationsToSave[i] = gson.toJson(notificationsList.get(i));
}
Set<String> scheduledNotifications = Set.of(jsonNotificationsToSave);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.remove(SCHEDULED_NOTIFICATIONS_STRING);
editor.putStringSet(SCHEDULED_NOTIFICATIONS_SET, scheduledNotifications);
editor.apply();
return scheduledNotifications;
}

private static void saveScheduledNotifications(
Context context, ArrayList<NotificationDetails> scheduledNotifications) {
Gson gson = buildGson();
String json = gson.toJson(scheduledNotifications);
int amount = scheduledNotifications.size();
String[] jsonNotificationsToSave = new String[amount];
for (int i = 0; i < amount; i++) {
jsonNotificationsToSave[i] = gson.toJson(scheduledNotifications.get(i));
}
SharedPreferences sharedPreferences =
context.getSharedPreferences(SCHEDULED_NOTIFICATIONS, Context.MODE_PRIVATE);
context.getSharedPreferences(SCHEDULED_NOTIFICATIONS_FILE, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString(SCHEDULED_NOTIFICATIONS, json);
editor.putStringSet(SCHEDULED_NOTIFICATIONS_SET, Set.of(jsonNotificationsToSave));
editor.apply();
}

Expand Down Expand Up @@ -450,11 +493,8 @@ private static void scheduleNotification(

AlarmManager alarmManager = getAlarmManager(context);
if (BooleanUtils.getValue(notificationDetails.allowWhileIdle)) {
AlarmManagerCompat.setExactAndAllowWhileIdle(
alarmManager,
AlarmManager.RTC_WAKEUP,
notificationDetails.millisecondsSinceEpoch,
pendingIntent);
AlarmManagerCompat.setAlarmClock(
alarmManager, notificationDetails.millisecondsSinceEpoch, pendingIntent, pendingIntent);
} else {
AlarmManagerCompat.setExact(
alarmManager,
Expand Down Expand Up @@ -492,8 +532,7 @@ private static void zonedScheduleNotification(
.toInstant()
.toEpochMilli();
if (BooleanUtils.getValue(notificationDetails.allowWhileIdle)) {
AlarmManagerCompat.setExactAndAllowWhileIdle(
alarmManager, AlarmManager.RTC_WAKEUP, epochMilli, pendingIntent);
AlarmManagerCompat.setAlarmClock(alarmManager, epochMilli, pendingIntent, pendingIntent);
} else {
AlarmManagerCompat.setExact(alarmManager, AlarmManager.RTC_WAKEUP, epochMilli, pendingIntent);
}
Expand All @@ -515,8 +554,8 @@ static void scheduleNextRepeatingNotification(
PendingIntent pendingIntent =
getBroadcastPendingIntent(context, notificationDetails.id, notificationIntent);
AlarmManager alarmManager = getAlarmManager(context);
AlarmManagerCompat.setExactAndAllowWhileIdle(
alarmManager, AlarmManager.RTC_WAKEUP, notificationTriggerTime, pendingIntent);
AlarmManagerCompat.setAlarmClock(
alarmManager, notificationTriggerTime, pendingIntent, pendingIntent);
saveScheduledNotification(context, notificationDetails);
}

Expand Down Expand Up @@ -568,8 +607,8 @@ private static void repeatNotification(
AlarmManager alarmManager = getAlarmManager(context);

if (BooleanUtils.getValue(notificationDetails.allowWhileIdle)) {
AlarmManagerCompat.setExactAndAllowWhileIdle(
alarmManager, AlarmManager.RTC_WAKEUP, notificationTriggerTime, pendingIntent);
AlarmManagerCompat.setAlarmClock(
alarmManager, notificationTriggerTime, pendingIntent, pendingIntent);
} else {
alarmManager.setInexactRepeating(
AlarmManager.RTC_WAKEUP, notificationTriggerTime, repeatInterval, pendingIntent);
Expand Down Expand Up @@ -610,18 +649,24 @@ private static long calculateRepeatIntervalMilliseconds(NotificationDetails noti
return repeatInterval;
}

// Note: This will now allow duplicate notifications on ID which would be overwritten before.
private static void saveScheduledNotification(
Context context, NotificationDetails notificationDetails) {
ArrayList<NotificationDetails> scheduledNotifications = loadScheduledNotifications(context);
ArrayList<NotificationDetails> scheduledNotificationsToSave = new ArrayList<>();
for (NotificationDetails scheduledNotification : scheduledNotifications) {
if (scheduledNotification.id.equals(notificationDetails.id)) {
continue;
}
scheduledNotificationsToSave.add(scheduledNotification);
SharedPreferences sharedPreferences =
context.getSharedPreferences(SCHEDULED_NOTIFICATIONS_FILE, Context.MODE_PRIVATE);
Set<String> jsonNotifications = getScheduledNotificationsJsonSet(sharedPreferences);
if (jsonNotifications == null) {
jsonNotifications = new HashSet<String>();
}
scheduledNotificationsToSave.add(notificationDetails);
saveScheduledNotifications(context, scheduledNotificationsToSave);

// Mutations on the Set from getStringSet() are not allowed!
Set<String> jsonNotificationsToSave = new HashSet<String>(jsonNotifications);

Gson gson = buildGson();
jsonNotificationsToSave.add(gson.toJson(notificationDetails));
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@Kavantix Kavantix Jan 11, 2022

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notifications should have unique ids not unique json strings

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@JeroenvdV JeroenvdV Jan 11, 2022

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I ignored this explicitly, although we can solve this by using a HashMap instead of ArrayList in loadScheduledNotifications.

SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putStringSet(SCHEDULED_NOTIFICATIONS_SET, jsonNotificationsToSave);
editor.apply();
}

private static int getDrawableResourceId(Context context, String name) {
Expand Down Expand Up @@ -1619,7 +1664,11 @@ private void cancelAllNotifications(Result result) {
alarmManager.cancel(pendingIntent);
}

saveScheduledNotifications(applicationContext, new ArrayList<>());
SharedPreferences sharedPreferences =
applicationContext.getSharedPreferences(SCHEDULED_NOTIFICATIONS_FILE, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.remove(SCHEDULED_NOTIFICATIONS_SET);
editor.apply();
result.success(null);
}

Expand Down