io.druid.java.util.common.guava.WrappingSequence Maven / Gradle / Ivy
/*
* Licensed to Metamarkets Group Inc. (Metamarkets) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. Metamarkets licenses this file
* to you 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 io.druid.java.util.common.guava;
import com.google.common.base.Preconditions;
import com.google.common.base.Supplier;
import com.google.common.base.Throwables;
/**
*/
final class WrappingSequence implements Sequence
{
private final Sequence baseSequence;
private final SequenceWrapper wrapper;
WrappingSequence(Sequence baseSequence, SequenceWrapper wrapper)
{
this.baseSequence = Preconditions.checkNotNull(baseSequence, "baseSequence");
this.wrapper = Preconditions.checkNotNull(wrapper, "wrapper");
}
@Override
public OutType accumulate(final OutType outType, final Accumulator accumulator)
{
OutType result;
try {
wrapper.before();
result = wrapper.wrap(new Supplier()
{
@Override
public OutType get()
{
return baseSequence.accumulate(outType, accumulator);
}
});
}
catch (Throwable t) {
// Close on failure
try {
wrapper.after(false, t);
}
catch (Exception e) {
t.addSuppressed(e);
}
throw Throwables.propagate(t);
}
// "Normal" close
try {
wrapper.after(true, null);
}
catch (Exception e) {
throw Throwables.propagate(e);
}
return result;
}
@Override
public Yielder toYielder(
final OutType initValue,
final YieldingAccumulator accumulator
)
{
try {
wrapper.before();
return wrapper.wrap(new Supplier>()
{
@Override
public Yielder get()
{
return new WrappingYielder<>(baseSequence.toYielder(initValue, accumulator), wrapper);
}
});
}
catch (Throwable t) {
// Close on failure
try {
wrapper.after(false, t);
}
catch (Exception e) {
t.addSuppressed(e);
}
throw Throwables.propagate(t);
}
}
}