1 /* 2 * Copyright 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package androidx.room.guava; 17 18 import static com.google.common.util.concurrent.MoreExecutors.directExecutor; 19 20 import androidx.annotation.RestrictTo; 21 import androidx.arch.core.executor.ArchTaskExecutor; 22 import androidx.room.RoomSQLiteQuery; 23 24 import com.google.common.util.concurrent.FutureCallback; 25 import com.google.common.util.concurrent.Futures; 26 import com.google.common.util.concurrent.ListenableFuture; 27 import com.google.common.util.concurrent.ListenableFutureTask; 28 29 import java.util.concurrent.Callable; 30 31 /** 32 * A class to hold static methods used by code generation in Room's Guava compatibility library. 33 * 34 * @hide 35 */ 36 @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP) 37 @SuppressWarnings("unused") // Used in GuavaListenableFutureQueryResultBinder code generation. 38 public class GuavaRoom { 39 40 private GuavaRoom() {} 41 42 /** 43 * Returns a {@link ListenableFuture<T>} created by submitting the input {@code callable} to 44 * {@link ArchTaskExecutor}'s background-threaded Executor. 45 */ 46 public static <T> ListenableFuture<T> createListenableFuture( 47 final Callable<T> callable, 48 final RoomSQLiteQuery query, 49 final boolean releaseQuery) { 50 ListenableFutureTask<T> listenableFutureTask = ListenableFutureTask.create(callable); 51 ArchTaskExecutor.getInstance().executeOnDiskIO(listenableFutureTask); 52 53 if (releaseQuery) { 54 Futures.addCallback( 55 listenableFutureTask, 56 new FutureCallback<T>() { 57 @Override 58 public void onSuccess(T t) { 59 query.release(); 60 } 61 62 @Override 63 public void onFailure(Throwable throwable) { 64 query.release(); 65 } 66 }, 67 directExecutor()); 68 } 69 70 return listenableFutureTask; 71 } 72 } 73
