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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.cql;
import com.datastax.oss.driver.api.core.CqlSession;
import com.datastax.oss.driver.api.core.cql.AsyncResultSet;
import com.datastax.oss.driver.api.core.cql.ColumnDefinitions;
import com.datastax.oss.driver.api.core.cql.ExecutionInfo;
import com.datastax.oss.driver.api.core.cql.Row;
import com.datastax.oss.driver.api.core.cql.Statement;
import com.datastax.oss.driver.api.core.type.DataTypes;
import com.datastax.oss.driver.internal.core.context.InternalDriverContext;
import com.datastax.oss.driver.internal.core.util.CountingIterator;
import edu.umd.cs.findbugs.annotations.NonNull;
import java.nio.ByteBuffer;
import java.util.Collections;
import java.util.List;
import java.util.Queue;
import java.util.concurrent.CompletionStage;
import net.jcip.annotations.NotThreadSafe;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@NotThreadSafe // wraps a mutable queue
public class DefaultAsyncResultSet implements AsyncResultSet {
private static final Logger LOG = LoggerFactory.getLogger(DefaultAsyncResultSet.class);
private final ColumnDefinitions definitions;
private final ExecutionInfo executionInfo;
private final CqlSession session;
private final CountingIterator iterator;
private final Iterable currentPage;
public DefaultAsyncResultSet(
ColumnDefinitions definitions,
ExecutionInfo executionInfo,
Queue> data,
CqlSession session,
InternalDriverContext context) {
this.definitions = definitions;
this.executionInfo = executionInfo;
this.session = session;
this.iterator =
new CountingIterator(data.size()) {
@Override
protected Row computeNext() {
List rowData = data.poll();
return (rowData == null) ? endOfData() : new DefaultRow(definitions, rowData, context);
}
};
this.currentPage = () -> iterator;
}
@NonNull
@Override
public ColumnDefinitions getColumnDefinitions() {
return definitions;
}
@NonNull
@Override
public ExecutionInfo getExecutionInfo() {
return executionInfo;
}
@NonNull
@Override
public Iterable currentPage() {
return currentPage;
}
@Override
public int remaining() {
return iterator.remaining();
}
@Override
public boolean hasMorePages() {
return executionInfo.getPagingState() != null;
}
@NonNull
@Override
public CompletionStage fetchNextPage() throws IllegalStateException {
ByteBuffer nextState = executionInfo.getPagingState();
if (nextState == null) {
throw new IllegalStateException(
"No next page. Use #hasMorePages before calling this method to avoid this error.");
}
Statement statement = (Statement) executionInfo.getRequest();
LOG.trace("Fetching next page for {}", statement);
Statement nextStatement = statement.copy(nextState);
return session.executeAsync(nextStatement);
}
@Override
public boolean wasApplied() {
if (!definitions.contains("[applied]")
|| !definitions.get("[applied]").getType().equals(DataTypes.BOOLEAN)) {
return true;
} else if (iterator.hasNext()) {
// Note that [applied] has the same value for all rows, so as long as we have a row we don't
// care which one it is.
return iterator.peek().getBoolean("[applied]");
} else {
// If the server provided [applied], it means there was at least one row. So if we get here it
// means the client consumed all the rows before, we can't handle that case because we have
// nowhere left to read the boolean from.
throw new IllegalStateException("This method must be called before consuming all the rows");
}
}
static AsyncResultSet empty(final ExecutionInfo executionInfo) {
return new AsyncResultSet() {
@NonNull
@Override
public ColumnDefinitions getColumnDefinitions() {
return EmptyColumnDefinitions.INSTANCE;
}
@NonNull
@Override
public ExecutionInfo getExecutionInfo() {
return executionInfo;
}
@NonNull
@Override
public Iterable currentPage() {
return Collections.emptyList();
}
@Override
public int remaining() {
return 0;
}
@Override
public boolean hasMorePages() {
return false;
}
@NonNull
@Override
public CompletionStage fetchNextPage() throws IllegalStateException {
throw new IllegalStateException(
"No next page. Use #hasMorePages before calling this method to avoid this error.");
}
@Override
public boolean wasApplied() {
return true;
}
};
}
}