/*
* 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.facebook.presto.connector.system;
import com.facebook.presto.operator.Operator;
import com.facebook.presto.operator.OperatorContext;
import com.facebook.presto.operator.RecordProjectOperator;
import com.facebook.presto.spi.ColumnHandle;
import com.facebook.presto.spi.ColumnMetadata;
import com.facebook.presto.spi.RecordSet;
import com.facebook.presto.spi.SchemaTableName;
import com.facebook.presto.spi.Split;
import com.facebook.presto.spi.SystemTable;
import com.facebook.presto.split.ConnectorDataStreamProvider;
import com.facebook.presto.split.MappedRecordSet;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Maps;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import static com.facebook.presto.metadata.MetadataUtil.columnNameGetter;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
public class SystemDataStreamProvider
implements ConnectorDataStreamProvider
{
private final ConcurrentMap<SchemaTableName, SystemTable> tables = new ConcurrentHashMap<>();
public void addTable(SystemTable systemTable)
{
checkNotNull(systemTable, "systemTable is null");
SchemaTableName tableName = systemTable.getTableMetadata().getTable();
checkArgument(tables.putIfAbsent(tableName, systemTable) == null, "Table %s is already registered", tableName);
}
@Override
public boolean canHandle(Split split)
{
return split instanceof SystemSplit && tables.containsKey(((SystemSplit) split).getTableHandle().getSchemaTableName());
}
@Override
public Operator createNewDataStream(OperatorContext operatorContext, Split split, List<ColumnHandle> columns)
{
return new RecordProjectOperator(operatorContext, createRecordSet(split, columns));
}
private RecordSet createRecordSet(Split split, List<ColumnHandle> columns)
{
checkNotNull(split, "split is null");
checkArgument(split instanceof SystemSplit, "Split must be of type %s, not %s", SystemSplit.class.getName(), split.getClass().getName());
SchemaTableName tableName = ((SystemSplit) split).getTableHandle().getSchemaTableName();
checkNotNull(columns, "columns is null");
checkArgument(!columns.isEmpty(), "must provide at least one column");
SystemTable systemTable = tables.get(tableName);
checkArgument(systemTable != null, "Table %s does not exist", tableName);
Map<String, ColumnMetadata> columnsByName = Maps.uniqueIndex(systemTable.getTableMetadata().getColumns(), columnNameGetter());
ImmutableList.Builder<Integer> userToSystemFieldIndex = ImmutableList.builder();
for (ColumnHandle column : columns) {
checkArgument(column instanceof SystemColumnHandle, "column must be of type %s, not %s", SystemColumnHandle.class.getName(), column.getClass().getName());
String columnName = ((SystemColumnHandle) column).getColumnName();
ColumnMetadata columnMetadata = columnsByName.get(columnName);
checkArgument(columnMetadata != null, "Column %s.%s does not exist", tableName, columnName);
userToSystemFieldIndex.add(columnMetadata.getOrdinalPosition());
}
return new MappedRecordSet(systemTable, userToSystemFieldIndex.build());
}
}