/*
* Copyright (C) 2012-2015 DataStax Inc.
*
* 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.datastax.driver.core;
import com.datastax.driver.core.utils.CassandraVersion;
import com.google.common.util.concurrent.AsyncFunction;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;
import java.util.Set;
import java.util.concurrent.ConcurrentSkipListSet;
import static org.assertj.core.api.Assertions.assertThat;
@CassandraVersion(value = "2.0.0", description = "uses paging")
public class AsyncResultSetTest extends CCMTestsSupport {
@Override
public void onTestContextInitialized() {
execute(
"create table ints (i int primary key)");
}
@BeforeMethod(groups = "short")
public void cleanup() {
session().execute("truncate ints");
}
@Test(groups = "short")
public void should_iterate_single_page_result_set_asynchronously() {
should_iterate_result_set_asynchronously(100, 500);
}
@Test(groups = "short")
public void should_iterate_multi_page_result_set_asynchronously() {
should_iterate_result_set_asynchronously(1000, 20);
}
private void should_iterate_result_set_asynchronously(int totalCount, int fetchSize) {
for (int i = 0; i < totalCount; i++)
session().execute(String.format("insert into ints (i) values (%d)", i));
Statement statement = new SimpleStatement("select * from ints").setFetchSize(fetchSize);
ResultsAccumulator results = new ResultsAccumulator();
ListenableFuture<ResultSet> future = GuavaCompatibility.INSTANCE.transformAsync(
session().executeAsync(statement),
results);
Futures.getUnchecked(future);
assertThat(results.all.size()).isEqualTo(totalCount);
}
/**
* Dummy transformation that accumulates all traversed results
*/
static class ResultsAccumulator implements AsyncFunction<ResultSet, ResultSet> {
final Set<Integer> all = new ConcurrentSkipListSet<Integer>();
@Override
public ListenableFuture<ResultSet> apply(ResultSet rs) throws Exception {
int remainingInPage = rs.getAvailableWithoutFetching();
for (Row row : rs) {
all.add(row.getInt(0));
if (--remainingInPage == 0)
break;
}
boolean wasLastPage = rs.getExecutionInfo().getPagingState() == null;
if (wasLastPage)
return Futures.immediateFuture(rs);
else
return GuavaCompatibility.INSTANCE.transformAsync(rs.fetchMoreResults(), this);
}
}
}