/*
* Copyright (c) 2010-2012 Grid Dynamics Consulting Services, Inc, All Rights Reserved
* http://www.griddynamics.com
*
* This library is free software; you can redistribute it and/or modify it under the terms of
* the Apache License; either
* version 2.0 of the License, or any later version.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.griddynamics.jagger.invoker;
import static com.google.common.base.Preconditions.checkState;
import com.griddynamics.jagger.util.Pair;
import com.google.common.collect.ImmutableList;
import java.util.ArrayList;
import java.util.Iterator;
public class RoundRobinPairSupplierFactory<Q, E> implements PairSupplierFactory<Q, E> {
@Override
public PairSupplier<Q, E> create(Iterable<Q> queries, Iterable<E> endpoints) {
ArrayList<Pair<Q, E>> tempList = new ArrayList<>();
Iterator<E> endpointIt = endpoints.iterator();
checkState(endpointIt.hasNext(), "Empty EndpointProvider");
if (queries == null) {
while (endpointIt.hasNext()) {
tempList.add(Pair.of(null, endpointIt.next()));
}
} else {
Iterator<Q> queryIt = queries.iterator();
E currentEndpoint;
Q currentQuery;
while (endpointIt.hasNext() || queryIt.hasNext()) {
if (!endpointIt.hasNext()) {
endpointIt = endpoints.iterator();
}
if (!queryIt.hasNext()) {
queryIt = queries.iterator();
}
currentEndpoint = endpointIt.next();
currentQuery = queryIt.next();
tempList.add(Pair.of(currentQuery, currentEndpoint));
}
}
return new PairSupplierImpl<>(ImmutableList.copyOf(tempList));
}
}