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// Copyright 2014 The Bazel Authors. All rights reserved.
//
// 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.google.devtools.build.skyframe;
import com.google.common.annotations.VisibleForTesting;
import javax.annotation.Nullable;
/** Wrapper for a value or the typed exception thrown when trying to compute it. */
public abstract class ValueOrException2<E1 extends Exception, E2 extends Exception>
extends ValueOrUntypedException {
/** Gets the stored value. Throws an exception if one was thrown when computing this value. */
@Nullable
public abstract SkyValue get() throws E1, E2;
@VisibleForTesting
public static <E1 extends Exception, E2 extends Exception>
ValueOrException2<E1, E2> fromUntypedException(
ValueOrUntypedException voe, Class<E1> exceptionClass1, Class<E2> exceptionClass2) {
SkyValue value = voe.getValue();
if (value != null) {
return ofValue(value);
}
Exception e = voe.getException();
if (e != null) {
if (exceptionClass1.isInstance(e)) {
return ofExn1(exceptionClass1.cast(e));
}
if (exceptionClass2.isInstance(e)) {
return ofExn2(exceptionClass2.cast(e));
}
}
return ofNullValue();
}
private static <E1 extends Exception, E2 extends Exception>
ValueOrException2<E1, E2> ofNullValue() {
return ValueOrException2ValueImpl.ofNullValue();
}
private static <E1 extends Exception, E2 extends Exception> ValueOrException2<E1, E2> ofValue(
SkyValue value) {
return new ValueOrException2ValueImpl<>(value);
}
private static <E1 extends Exception, E2 extends Exception> ValueOrException2<E1, E2> ofExn1(
E1 e) {
return new ValueOrException2Exn1Impl<>(e);
}
private static <E1 extends Exception, E2 extends Exception> ValueOrException2<E1, E2> ofExn2(
E2 e) {
return new ValueOrException2Exn2Impl<>(e);
}
private static class ValueOrException2ValueImpl<E1 extends Exception, E2 extends Exception>
extends ValueOrException2<E1, E2> {
private static final ValueOrException2ValueImpl<Exception, Exception> NULL =
new ValueOrException2ValueImpl<>(null);
@Nullable private final SkyValue value;
ValueOrException2ValueImpl(@Nullable SkyValue value) {
this.value = value;
}
@Override
@Nullable
public SkyValue get() {
return value;
}
@Override
@Nullable
public Exception getException() {
return null;
}
@Override
@Nullable
public SkyValue getValue() {
return value;
}
@SuppressWarnings("unchecked")
static <E1 extends Exception, E2 extends Exception>
ValueOrException2ValueImpl<E1, E2> ofNullValue() {
return (ValueOrException2ValueImpl<E1, E2>) NULL;
}
}
private static class ValueOrException2Exn1Impl<E1 extends Exception, E2 extends Exception>
extends ValueOrException2<E1, E2> {
private final E1 e;
private ValueOrException2Exn1Impl(E1 e) {
this.e = e;
}
@Override
public SkyValue get() throws E1 {
throw e;
}
@Override
public Exception getException() {
return e;
}
@Override
@Nullable
public SkyValue getValue() {
return null;
}
}
private static class ValueOrException2Exn2Impl<E1 extends Exception, E2 extends Exception>
extends ValueOrException2<E1, E2> {
private final E2 e;
private ValueOrException2Exn2Impl(E2 e) {
this.e = e;
}
@Override
public SkyValue get() throws E2 {
throw e;
}
@Override
public Exception getException() {
return e;
}
@Override
@Nullable
public SkyValue getValue() {
return null;
}
}
}