/*
* Copyright 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.oss.driver.internal.core.adminrequest;
import com.datastax.oss.driver.api.core.ProtocolVersion;
import com.datastax.oss.driver.internal.core.util.concurrent.CompletableFutures;
import com.datastax.oss.driver.shaded.guava.common.collect.AbstractIterator;
import com.datastax.oss.driver.shaded.guava.common.collect.ImmutableMap;
import com.datastax.oss.protocol.internal.response.result.ColumnSpec;
import com.datastax.oss.protocol.internal.response.result.Rows;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.nio.ByteBuffer;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Queue;
import java.util.concurrent.CompletionStage;
import net.jcip.annotations.NotThreadSafe;
@NotThreadSafe // wraps a mutable queue
public class AdminResult implements Iterable<AdminRow> {
private final Queue<List<ByteBuffer>> data;
private final Map<String, ColumnSpec> columnSpecs;
private final AdminRequestHandler nextHandler;
private final ProtocolVersion protocolVersion;
public AdminResult(Rows rows, AdminRequestHandler nextHandler, ProtocolVersion protocolVersion) {
this.data = rows.getData();
ImmutableMap.Builder<String, ColumnSpec> columnSpecsBuilder = ImmutableMap.builder();
for (ColumnSpec spec : rows.getMetadata().columnSpecs) {
columnSpecsBuilder.put(spec.name, spec);
}
// Admin queries are simple selects only, so there are no duplicate names (if that ever
// changes, build() will fail and we'll have to do things differently)
this.columnSpecs = columnSpecsBuilder.build();
this.nextHandler = nextHandler;
this.protocolVersion = protocolVersion;
}
This consumes the result's data and can be called only once. /** This consumes the result's data and can be called only once. */
@NonNull
@Override
public Iterator<AdminRow> iterator() {
return new AbstractIterator<AdminRow>() {
@Override
protected AdminRow computeNext() {
List<ByteBuffer> rowData = data.poll();
return (rowData == null)
? endOfData()
: new AdminRow(columnSpecs, rowData, protocolVersion);
}
};
}
public boolean hasNextPage() {
return nextHandler != null;
}
public CompletionStage<AdminResult> nextPage() {
return (nextHandler == null)
? CompletableFutures.failedFuture(
new AssertionError("No next page, use hasNextPage() before you call this method"))
: nextHandler.start();
}
}