Merge "Avoid downloading the metadata in quick succession."

This commit is contained in:
Jean Chalard 2014-10-02 04:31:07 +00:00 committed by Android (Google) Code Review
commit c91166de54
4 changed files with 79 additions and 26 deletions

View file

@ -76,19 +76,29 @@ public final class DictionaryService extends Service {
* How often, in milliseconds, we want to update the metadata. This is a
* floor value; actually, it may happen several hours later, or even more.
*/
private static final long UPDATE_FREQUENCY = TimeUnit.DAYS.toMillis(4);
private static final long UPDATE_FREQUENCY_MILLIS = TimeUnit.DAYS.toMillis(4);
/**
* We are waked around midnight, local time. We want to wake between midnight and 6 am,
* roughly. So use a random time between 0 and this delay.
*/
private static final int MAX_ALARM_DELAY = (int)TimeUnit.HOURS.toMillis(6);
private static final int MAX_ALARM_DELAY_MILLIS = (int)TimeUnit.HOURS.toMillis(6);
/**
* How long we consider a "very long time". If no update took place in this time,
* the content provider will trigger an update in the background.
*/
private static final long VERY_LONG_TIME = TimeUnit.DAYS.toMillis(14);
private static final long VERY_LONG_TIME_MILLIS = TimeUnit.DAYS.toMillis(14);
/**
* After starting a download, how long we wait before considering it may be stuck. After this
* period is elapsed, if the keyboard tries to download again, then we cancel and re-register
* the request; if it's within this time, we just leave it be.
* It's important to note that we do not re-submit the request merely because the time is up.
* This is only to decide whether to cancel the old one and re-requesting when the keyboard
* fires a new request for the same data.
*/
public static final long NO_CANCEL_DOWNLOAD_PERIOD_MILLIS = TimeUnit.SECONDS.toMillis(30);
/**
* An executor that serializes tasks given to it.
@ -188,16 +198,16 @@ public final class DictionaryService extends Service {
*/
private static void checkTimeAndMaybeSetupUpdateAlarm(final Context context) {
// Of all clients, if the one that hasn't been updated for the longest
// is still more recent than UPDATE_FREQUENCY, do nothing.
if (!isLastUpdateAtLeastThisOld(context, UPDATE_FREQUENCY)) return;
// is still more recent than UPDATE_FREQUENCY_MILLIS, do nothing.
if (!isLastUpdateAtLeastThisOld(context, UPDATE_FREQUENCY_MILLIS)) return;
PrivateLog.log("Date changed - registering alarm");
AlarmManager alarmManager = (AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
// Best effort to wake between midnight and MAX_ALARM_DELAY in the morning.
// Best effort to wake between midnight and MAX_ALARM_DELAY_MILLIS in the morning.
// It doesn't matter too much if this is very inexact.
final long now = System.currentTimeMillis();
final long alarmTime = now + new Random().nextInt(MAX_ALARM_DELAY);
final long alarmTime = now + new Random().nextInt(MAX_ALARM_DELAY_MILLIS);
final Intent updateIntent = new Intent(DictionaryPackConstants.UPDATE_NOW_INTENT_ACTION);
final PendingIntent pendingIntent = PendingIntent.getBroadcast(context, 0,
updateIntent, PendingIntent.FLAG_CANCEL_CURRENT);
@ -223,11 +233,11 @@ public final class DictionaryService extends Service {
/**
* Refreshes data if it hasn't been refreshed in a very long time.
*
* This will check the last update time, and if it's been more than VERY_LONG_TIME,
* This will check the last update time, and if it's been more than VERY_LONG_TIME_MILLIS,
* update metadata now - and possibly take subsequent update actions.
*/
public static void updateNowIfNotUpdatedInAVeryLongTime(final Context context) {
if (!isLastUpdateAtLeastThisOld(context, VERY_LONG_TIME)) return;
if (!isLastUpdateAtLeastThisOld(context, VERY_LONG_TIME_MILLIS)) return;
UpdateHandler.tryUpdate(context, false);
}

View file

@ -0,0 +1,29 @@
/*
* 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.inputmethod.dictionarypack;
/**
* A simple container of download ID and download start date.
*/
public class DownloadIdAndStartDate {
public final long mId;
public final long mStartDate;
public DownloadIdAndStartDate(final long id, final long startDate) {
mId = id;
mStartDate = startDate;
}
}

View file

@ -433,18 +433,18 @@ public class MetadataDbHelper extends SQLiteOpenHelper {
*
* @param context a context instance to open the database on
* @param uri the URI to retrieve the metadata download ID of
* @return the metadata download ID, or NOT_AN_ID if no download is in progress
* @return the download id and start date, or null if the URL is not known
*/
public static long getMetadataDownloadIdForURI(final Context context,
final String uri) {
public static DownloadIdAndStartDate getMetadataDownloadIdAndStartDateForURI(
final Context context, final String uri) {
SQLiteDatabase defaultDb = getDb(context, null);
final Cursor cursor = defaultDb.query(CLIENT_TABLE_NAME,
new String[] { CLIENT_PENDINGID_COLUMN },
new String[] { CLIENT_PENDINGID_COLUMN, CLIENT_LAST_UPDATE_DATE_COLUMN },
CLIENT_METADATA_URI_COLUMN + " = ?", new String[] { uri },
null, null, null, null);
try {
if (!cursor.moveToFirst()) return UpdateHandler.NOT_AN_ID;
return cursor.getInt(0); // Only one column, return it
if (!cursor.moveToFirst()) return null;
return new DownloadIdAndStartDate(cursor.getInt(0), cursor.getLong(1));
} finally {
cursor.close();
}
@ -922,6 +922,7 @@ public class MetadataDbHelper extends SQLiteOpenHelper {
final long downloadId) {
final ContentValues values = new ContentValues();
values.put(CLIENT_PENDINGID_COLUMN, downloadId);
values.put(CLIENT_LAST_UPDATE_DATE_COLUMN, System.currentTimeMillis());
final SQLiteDatabase defaultDb = getDb(context, "");
final Cursor cursor = MetadataDbHelper.queryClientIds(context);
if (null == cursor) return;

View file

@ -251,12 +251,16 @@ public final class UpdateHandler {
res.getBoolean(R.bool.metadata_downloads_visible_in_download_UI));
final DownloadManagerWrapper manager = new DownloadManagerWrapper(context);
cancelUpdateWithDownloadManager(context, metadataUri, manager);
if (maybeCancelUpdateAndReturnIfStillRunning(context, metadataUri, manager,
DictionaryService.NO_CANCEL_DOWNLOAD_PERIOD_MILLIS)) {
// We already have a recent download in progress. Don't register a new download.
return;
}
final long downloadId;
synchronized (sSharedIdProtector) {
downloadId = manager.enqueue(metadataRequest);
DebugLogUtils.l("Metadata download requested with id", downloadId);
// If there is already a download in progress, it's been there for a while and
// If there is still a download in progress, it's been there for a while and
// there is probably something wrong with download manager. It's best to just
// overwrite the id and request it again. If the old one happens to finish
// anyway, we don't know about its ID any more, so the downloadFinished
@ -267,21 +271,29 @@ public final class UpdateHandler {
}
/**
* Cancels downloading a file, if there is one for this URI.
* Cancels downloading a file if there is one for this URI and it's too long.
*
* If we are not currently downloading the file at this URI, this is a no-op.
*
* @param context the context to open the database on
* @param metadataUri the URI to cancel
* @param manager an wrapped instance of DownloadManager
* @param graceTime if there was a download started less than this many milliseconds, don't
* cancel and return true
* @return whether the download is still active
*/
private static void cancelUpdateWithDownloadManager(final Context context,
final String metadataUri, final DownloadManagerWrapper manager) {
private static boolean maybeCancelUpdateAndReturnIfStillRunning(final Context context,
final String metadataUri, final DownloadManagerWrapper manager, final long graceTime) {
synchronized (sSharedIdProtector) {
final long metadataDownloadId =
MetadataDbHelper.getMetadataDownloadIdForURI(context, metadataUri);
if (NOT_AN_ID == metadataDownloadId) return;
manager.remove(metadataDownloadId);
final DownloadIdAndStartDate metadataDownloadIdAndStartDate =
MetadataDbHelper.getMetadataDownloadIdAndStartDateForURI(context, metadataUri);
if (null == metadataDownloadIdAndStartDate) return false;
if (NOT_AN_ID == metadataDownloadIdAndStartDate.mId) return false;
if (metadataDownloadIdAndStartDate.mStartDate + graceTime
> System.currentTimeMillis()) {
return true;
}
manager.remove(metadataDownloadIdAndStartDate.mId);
writeMetadataDownloadId(context, metadataUri, NOT_AN_ID);
}
// Consider a cancellation as a failure. As such, inform listeners that the download
@ -289,6 +301,7 @@ public final class UpdateHandler {
for (UpdateEventListener listener : linkedCopyOfList(sUpdateEventListeners)) {
listener.downloadedMetadata(false);
}
return false;
}
/**
@ -303,7 +316,7 @@ public final class UpdateHandler {
public static void cancelUpdate(final Context context, final String clientId) {
final DownloadManagerWrapper manager = new DownloadManagerWrapper(context);
final String metadataUri = MetadataDbHelper.getMetadataUriAsString(context, clientId);
cancelUpdateWithDownloadManager(context, metadataUri, manager);
maybeCancelUpdateAndReturnIfStillRunning(context, metadataUri, manager, 0 /* graceTime */);
}
/**
@ -387,7 +400,7 @@ public final class UpdateHandler {
// If any of these is metadata, we should update the DB
boolean hasMetadata = false;
for (DownloadRecord record : downloadRecords) {
if (null == record.mAttributes) {
if (record.isMetadata()) {
hasMetadata = true;
break;
}