| /* |
| * Copyright (C) 2018 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.server.backup.remote; |
| |
| import android.annotation.IntDef; |
| |
| import com.android.internal.util.Preconditions; |
| |
| import java.lang.annotation.Retention; |
| import java.lang.annotation.RetentionPolicy; |
| import java.util.Objects; |
| |
| /** |
| * Represents the result of a {@link RemoteCall}. It can be either {@link #FAILED_TIMED_OUT}, {@link |
| * #FAILED_CANCELLED}, {@link #FAILED_THREAD_INTERRUPTED} or a successful result, in which case |
| * {@link #get()} returns its value. |
| * |
| * <p>Use {@link #isPresent()} to check for successful result, or direct identity comparison to |
| * check for specific failures, like {@code result == RemoteResult.FAILED_CANCELLED}. |
| */ |
| public class RemoteResult { |
| public static final RemoteResult FAILED_TIMED_OUT = new RemoteResult(Type.FAILED_TIMED_OUT, 0); |
| public static final RemoteResult FAILED_CANCELLED = new RemoteResult(Type.FAILED_CANCELLED, 0); |
| public static final RemoteResult FAILED_THREAD_INTERRUPTED = |
| new RemoteResult(Type.FAILED_THREAD_INTERRUPTED, 0); |
| |
| public static RemoteResult of(long value) { |
| return new RemoteResult(Type.SUCCESS, value); |
| } |
| |
| @Type private final int mType; |
| private final long mValue; |
| |
| private RemoteResult(@Type int type, long value) { |
| mType = type; |
| mValue = value; |
| } |
| |
| public boolean isPresent() { |
| return mType == Type.SUCCESS; |
| } |
| |
| /** |
| * Returns the value of this result. |
| * |
| * @throws IllegalStateException in case this is not a successful result. |
| */ |
| public long get() { |
| Preconditions.checkState(isPresent(), "Can't obtain value of failed result"); |
| return mValue; |
| } |
| |
| @Override |
| public String toString() { |
| return "RemoteResult{" + toStringDescription() + "}"; |
| } |
| |
| private String toStringDescription() { |
| switch (mType) { |
| case Type.SUCCESS: |
| return Long.toString(mValue); |
| case Type.FAILED_TIMED_OUT: |
| return "FAILED_TIMED_OUT"; |
| case Type.FAILED_CANCELLED: |
| return "FAILED_CANCELLED"; |
| case Type.FAILED_THREAD_INTERRUPTED: |
| return "FAILED_THREAD_INTERRUPTED"; |
| default: |
| throw new AssertionError("Unknown type"); |
| } |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) { |
| return true; |
| } |
| if (!(o instanceof RemoteResult)) { |
| return false; |
| } |
| RemoteResult that = (RemoteResult) o; |
| return mType == that.mType && mValue == that.mValue; |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(mType, mValue); |
| } |
| |
| @IntDef({ |
| Type.SUCCESS, |
| Type.FAILED_TIMED_OUT, |
| Type.FAILED_CANCELLED, |
| Type.FAILED_THREAD_INTERRUPTED |
| }) |
| @Retention(RetentionPolicy.SOURCE) |
| private @interface Type { |
| int SUCCESS = 0; |
| int FAILED_TIMED_OUT = 1; |
| int FAILED_CANCELLED = 2; |
| int FAILED_THREAD_INTERRUPTED = 3; |
| } |
| } |