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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.AsyncPagingIterable;
import com.datastax.oss.driver.api.core.MappedAsyncPagingIterable;
import com.datastax.oss.driver.api.core.cql.ColumnDefinitions;
import com.datastax.oss.driver.api.core.cql.ExecutionInfo;
import com.datastax.oss.driver.shaded.guava.common.collect.AbstractIterator;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.util.Iterator;
import java.util.concurrent.CompletionStage;
import java.util.function.Function;
public class AsyncPagingIterableWrapper
implements MappedAsyncPagingIterable {
private final AsyncPagingIterable source;
private final Function elementMapper;
private final Iterable currentPage;
public AsyncPagingIterableWrapper(
AsyncPagingIterable source,
Function elementMapper) {
this.source = source;
this.elementMapper = elementMapper;
Iterator sourceIterator = source.currentPage().iterator();
Iterator iterator =
new AbstractIterator() {
@Override
protected TargetT computeNext() {
return sourceIterator.hasNext()
? elementMapper.apply(sourceIterator.next())
: endOfData();
}
};
this.currentPage = () -> iterator;
}
@NonNull
@Override
public ColumnDefinitions getColumnDefinitions() {
return source.getColumnDefinitions();
}
@NonNull
@Override
public ExecutionInfo getExecutionInfo() {
return source.getExecutionInfo();
}
@Override
public int remaining() {
return source.remaining();
}
@NonNull
@Override
public Iterable currentPage() {
return currentPage;
}
@Override
public boolean hasMorePages() {
return source.hasMorePages();
}
@NonNull
@Override
public CompletionStage> fetchNextPage()
throws IllegalStateException {
return source
.fetchNextPage()
.thenApply(
nextSource ->
new AsyncPagingIterableWrapper(nextSource, elementMapper));
}
@Override
public boolean wasApplied() {
return source.wasApplied();
}
}