| // Copyright 2016 The Vanadium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package io.v.todos.persistence.syncbase; |
| |
| import android.app.Activity; |
| import android.os.Bundle; |
| import android.support.annotation.NonNull; |
| import android.util.Log; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.common.util.concurrent.AsyncFunction; |
| import com.google.common.util.concurrent.Futures; |
| import com.google.common.util.concurrent.ListenableFuture; |
| |
| import java.util.HashMap; |
| import java.util.Map; |
| import java.util.concurrent.Callable; |
| import java.util.concurrent.ExecutionException; |
| import java.util.concurrent.TimeUnit; |
| |
| import javax.annotation.Nullable; |
| |
| import io.v.impl.google.services.syncbase.SyncbaseServer; |
| import io.v.todos.model.ListMetadata; |
| import io.v.todos.model.ListSpec; |
| import io.v.todos.persistence.ListEventListener; |
| import io.v.todos.persistence.MainPersistence; |
| import io.v.v23.InputChannelCallback; |
| import io.v.v23.security.access.Permissions; |
| import io.v.v23.services.syncbase.CollectionRow; |
| import io.v.v23.services.syncbase.Id; |
| import io.v.v23.services.syncbase.SyncgroupJoinFailedException; |
| import io.v.v23.services.syncbase.SyncgroupMemberInfo; |
| import io.v.v23.services.syncbase.SyncgroupSpec; |
| import io.v.v23.syncbase.ChangeType; |
| import io.v.v23.syncbase.Collection; |
| import io.v.v23.syncbase.WatchChange; |
| import io.v.v23.verror.NoExistException; |
| import io.v.v23.verror.VException; |
| |
| public class SyncbaseMain extends SyncbasePersistence implements MainPersistence { |
| private static final String |
| TAG = SyncbaseMain.class.getSimpleName(); |
| |
| private static int DEFAULT_MAX_JOIN_ATTEMPTS = 5; |
| |
| private final IdGenerator mIdGenerator = new IdGenerator(IdAlphabets.COLLECTION_ID, true); |
| private final Map<String, MainListTracker> mTaskTrackers = new HashMap<>(); |
| |
| /** |
| * This constructor blocks until the instance is ready for use. |
| */ |
| public SyncbaseMain(Activity activity, Bundle savedInstanceState, |
| final ListEventListener<ListMetadata> listener) |
| throws VException, SyncbaseServer.StartException { |
| super(activity, savedInstanceState); |
| |
| // Prepare a watch on top of the userdata collection to determine which todo lists need to |
| // be tracked by this application. |
| trap(watchUserCollection(new InputChannelCallback<WatchChange>() { |
| @Override |
| public ListenableFuture<Void> onNext(WatchChange change) { |
| final String listId = change.getRowName(); |
| final String ownerBlessing = SyncbasePersistence.castFromSyncbase(change.getValue(), |
| String.class); |
| |
| if (change.getChangeType() == ChangeType.DELETE_CHANGE) { |
| // (this is idempotent) |
| Log.d(TAG, listId + " removed from index"); |
| deleteTodoList(listId); |
| } else { |
| // If we are tracking this list already, don't bother doing anything. |
| // This might happen if a same-user device did a simultaneous put into the |
| // userdata collection. |
| if (mTaskTrackers.get(listId) != null) { |
| return null; |
| } |
| |
| mIdGenerator.registerId(change.getRowName().substring(LISTS_PREFIX.length())); |
| |
| Log.d(TAG, "Found a list id from userdata watch: " + listId + " with owner: " |
| + ownerBlessing); |
| trap(joinWithBackoff(listId, ownerBlessing)); |
| |
| MainListTracker listTracker = new MainListTracker(getVContext(), getDatabase(), |
| listId, listener); |
| mTaskTrackers.put(listId, listTracker); |
| |
| // If the watch fails with NoExistException, the collection has been deleted. |
| Futures.addCallback(listTracker.watchFuture, new SyncTrappingCallback<Void>() { |
| @Override |
| public void onFailure(@NonNull Throwable t) { |
| if (t instanceof NoExistException) { |
| // (this is idempotent) |
| trap(getUserCollection().delete(getVContext(), listId)); |
| } else { |
| super.onFailure(t); |
| } |
| } |
| }); |
| } |
| return null; |
| } |
| })); |
| } |
| |
| @Override |
| public void addTodoList(final ListSpec listSpec) { |
| final String listName = LISTS_PREFIX + mIdGenerator.generateTailId(); |
| final Collection listCollection = getDatabase().getCollection(getVContext(), listName); |
| |
| // TODO(alexfandrianto): Syncgroup creation is slow if you specify a cloud and are offline. |
| // We'll try to connect to the cloud and then time out our RPC. The error is swallowed, so |
| // we'll just think there's a blank space of time. Maybe we should just write to these |
| // collections anyway. If https://github.com/vanadium/issues/issues/1326 is done, however, |
| // we won't need to change this code. |
| Futures.addCallback(listCollection.create(getVContext(), null), |
| new SyncTrappingCallback<Void>() { |
| @Override |
| public void onSuccess(@Nullable Void result) { |
| Futures.addCallback(createListSyncgroup(listCollection.id()), |
| new SyncTrappingCallback<Void>() { |
| @Override |
| public void onSuccess(@Nullable Void result) { |
| // These can happen in either order. |
| trap(rememberTodoList(listName)); |
| trap(listCollection.put(getVContext(), |
| SyncbaseTodoList.LIST_METADATA_ROW_NAME, listSpec, |
| ListSpec.class)); |
| } |
| }); |
| } |
| }); |
| } |
| |
| private ListenableFuture<SyncgroupSpec> joinListSyncgroup(String listId, String ownerBlessing) { |
| SyncgroupMemberInfo memberInfo = getDefaultMemberInfo(); |
| String sgName = computeListSyncgroupName(listId); |
| return getDatabase().getSyncgroup(new Id(ownerBlessing, sgName)).join(getVContext(), |
| CLOUD_NAME, CLOUD_BLESSING, memberInfo); |
| } |
| |
| private ListenableFuture<SyncgroupSpec> joinWithBackoff(String listId, String ownerBlessing) { |
| return joinWithBackoff(listId, ownerBlessing, 0, DEFAULT_MAX_JOIN_ATTEMPTS); |
| } |
| |
| private ListenableFuture<SyncgroupSpec> joinWithBackoff(final String listId, final String |
| ownerBlessing, final int numTimes, final int limit) { |
| final String debugString = (numTimes + 1) + "/" + limit + " for: " + listId; |
| Log.d(TAG, "Join attempt " + debugString); |
| if (numTimes + 1 == limit) { // final attempt! |
| return joinListSyncgroup(listId, ownerBlessing); |
| } |
| final long delay = RETRY_DELAY * (1 << numTimes); |
| return Futures.catchingAsync( |
| joinListSyncgroup(listId, ownerBlessing), |
| SyncgroupJoinFailedException.class, |
| new AsyncFunction<SyncgroupJoinFailedException, SyncgroupSpec>() { |
| public ListenableFuture<SyncgroupSpec> apply(@Nullable |
| SyncgroupJoinFailedException |
| input) { |
| Log.d(TAG, "Join failed. Sleeping " + debugString + " with delay " + delay); |
| return sExecutor.schedule(new Callable<SyncgroupSpec>() { |
| |
| |
| @Override |
| public SyncgroupSpec call() { |
| Log.d(TAG, "Sleep done. Retry " + debugString); |
| |
| // If this errors, then we will not get another chance to |
| // see this syncgroup until the app is restarted. |
| try { |
| return joinWithBackoff(listId, ownerBlessing, |
| numTimes + 1, limit).get(); |
| } catch (InterruptedException | ExecutionException e) { |
| return null; |
| } |
| } |
| }, delay, TimeUnit.MILLISECONDS); |
| } |
| }); |
| } |
| |
| private ListenableFuture<Void> createListSyncgroup(Id id) { |
| String listId = id.getName(); |
| final String sgName = computeListSyncgroupName(listId); |
| Permissions permissions = |
| computePermissionsFromBlessings(getPersonalBlessings()); |
| |
| SyncgroupMemberInfo memberInfo = getDefaultMemberInfo(); |
| |
| SyncgroupSpec spec = new SyncgroupSpec( |
| "TODOs User Data Collection", CLOUD_NAME, permissions, |
| ImmutableList.of(new CollectionRow(id, "")), |
| ImmutableList.of(MOUNTPOINT), false); |
| String blessingStr = getPersonalBlessingsString(); |
| return getDatabase().getSyncgroup(new Id(blessingStr, sgName)).create(getVContext(), |
| spec, memberInfo); |
| } |
| |
| @Override |
| public void deleteTodoList(String key) { |
| MainListTracker tracker = mTaskTrackers.remove(key); |
| if (tracker != null) { |
| trap(tracker.collection.destroy(getVContext())); |
| } |
| } |
| } |