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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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 com.datastax.oss.driver.internal.core;
import com.datastax.oss.driver.api.core.PagingIterable;
import com.datastax.oss.driver.api.core.cql.ColumnDefinitions;
import com.datastax.oss.driver.api.core.cql.ExecutionInfo;
import com.datastax.oss.driver.internal.core.cql.PagingIterableSpliterator;
import com.datastax.oss.driver.shaded.guava.common.collect.AbstractIterator;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.util.Iterator;
import java.util.List;
import java.util.Spliterator;
import java.util.function.Function;
public class PagingIterableWrapper implements PagingIterable {
private final PagingIterable source;
private final boolean sized;
private final Iterator iterator;
/**
* Creates a {@link PagingIterableWrapper} for the given source, with unknown size. Spliterators
* for this iterable will never report {@link Spliterator#SIZED}.
*
* @param source The source to wrap.
* @param elementMapper The element mapper.
*/
public PagingIterableWrapper(
@NonNull PagingIterable source,
@NonNull Function elementMapper) {
this(source, elementMapper, false);
}
/**
* Creates a {@link PagingIterableWrapper} for the given source. If {@code sized} is {@code true},
* spliterators for this iterable will report {@link Spliterator#SIZED} and {@link
* Spliterator#SUBSIZED} and their estimated size will be {@link #getAvailableWithoutFetching()}.
*
* @param source The source to wrap.
* @param elementMapper The element mapper.
* @param sized Whether this iterable has a known size or not.
*/
public PagingIterableWrapper(
@NonNull PagingIterable source,
@NonNull Function elementMapper,
boolean sized) {
this.source = source;
this.sized = sized;
Iterator sourceIterator = source.iterator();
this.iterator =
new AbstractIterator() {
@Override
protected TargetT computeNext() {
return sourceIterator.hasNext()
? elementMapper.apply(sourceIterator.next())
: endOfData();
}
};
}
@NonNull
@Override
public ColumnDefinitions getColumnDefinitions() {
return source.getColumnDefinitions();
}
@NonNull
@Override
public List getExecutionInfos() {
return source.getExecutionInfos();
}
@Override
public boolean isFullyFetched() {
return source.isFullyFetched();
}
@Override
public int getAvailableWithoutFetching() {
return source.getAvailableWithoutFetching();
}
@Override
public boolean wasApplied() {
return source.wasApplied();
}
@NonNull
@Override
public Iterator iterator() {
return iterator;
}
@NonNull
@Override
public Spliterator spliterator() {
PagingIterableSpliterator.Builder builder = PagingIterableSpliterator.builder(this);
if (sized) {
builder.withEstimatedSize(getAvailableWithoutFetching());
}
return builder.build();
}
@NonNull
@Override
public PagingIterable map(
Function elementMapper) {
return new PagingIterableWrapper<>(this, elementMapper, sized);
}
}