/*
* 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.dual;
import com.facebook.presto.metadata.MetadataManager;
import com.facebook.presto.spi.ColumnHandle;
import com.facebook.presto.spi.ColumnMetadata;
import com.facebook.presto.spi.ConnectorMetadata;
import com.facebook.presto.spi.SchemaTableName;
import com.facebook.presto.spi.SchemaTablePrefix;
import com.facebook.presto.spi.TableHandle;
import com.facebook.presto.spi.TableMetadata;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import java.util.List;
import java.util.Map;
import static com.facebook.presto.spi.ColumnType.STRING;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
public class DualMetadata
implements ConnectorMetadata
{
@VisibleForTesting
public static final MetadataManager DUAL_METADATA_MANAGER;
static {
DUAL_METADATA_MANAGER = new MetadataManager();
DUAL_METADATA_MANAGER.addInternalSchemaMetadata(new DualMetadata());
}
public static final String NAME = "dual";
public static final String COLUMN_NAME = "dummy";
public static final ColumnMetadata COLUMN_METADATA = new ColumnMetadata(COLUMN_NAME, STRING, 0, false);
@Override
public boolean canHandle(TableHandle tableHandle)
{
return tableHandle instanceof DualTableHandle;
}
@Override
public List<String> listSchemaNames()
{
return ImmutableList.of();
}
@Override
public TableHandle getTableHandle(SchemaTableName table)
{
checkNotNull(table, "table is null");
if (!table.getTableName().equals(NAME)) {
return null;
}
return new DualTableHandle(table.getSchemaName());
}
@Override
public TableMetadata getTableMetadata(TableHandle tableHandle)
{
checkNotNull(tableHandle, "tableHandle is null");
checkArgument(tableHandle instanceof DualTableHandle, "tableHandle is not a dual table handle");
SchemaTableName tableName = new SchemaTableName(((DualTableHandle) tableHandle).getSchemaName(), NAME);
return new TableMetadata(tableName, ImmutableList.of(COLUMN_METADATA));
}
@Override
public List<SchemaTableName> listTables(String schemaNameOrNull)
{
// don't list dual
return ImmutableList.of();
}
@Override
public ColumnHandle getColumnHandle(TableHandle tableHandle, String columnName)
{
checkNotNull(tableHandle, "tableHandle is null");
checkArgument(tableHandle instanceof DualTableHandle, "tableHandle is not a dual table handle");
checkNotNull(columnName, "columnName is null");
if (!columnName.equals(COLUMN_NAME)) {
return null;
}
return new DualColumnHandle(COLUMN_NAME);
}
public Map<String, ColumnHandle> getColumnHandles(TableHandle tableHandle)
{
checkNotNull(tableHandle, "tableHandle is null");
checkArgument(tableHandle instanceof DualTableHandle, "tableHandle is not a dual table handle");
return ImmutableMap.<String, ColumnHandle>of(COLUMN_NAME, new DualColumnHandle(COLUMN_NAME));
}
@Override
public ColumnMetadata getColumnMetadata(TableHandle tableHandle, ColumnHandle columnHandle)
{
checkNotNull(tableHandle, "tableHandle is null");
checkArgument(tableHandle instanceof DualTableHandle, "tableHandle is not a dual table handle");
checkArgument(columnHandle instanceof DualColumnHandle, "columnHandle is not an instance of DualColumnHandle");
DualColumnHandle dualColumnHandle = (DualColumnHandle) columnHandle;
checkArgument(dualColumnHandle.getColumnName().equals(COLUMN_NAME), "column handle is not for DUAL");
return COLUMN_METADATA;
}
@Override
public Map<SchemaTableName, List<ColumnMetadata>> listTableColumns(SchemaTablePrefix prefix)
{
// dual can not be a listed at catalog level because dual is in all possible schemas
if (prefix.getSchemaName() == null) {
return ImmutableMap.of();
}
if (prefix.getTableName() != null && !prefix.getTableName().equals(NAME)) {
return ImmutableMap.of();
}
SchemaTableName tableName = new SchemaTableName(prefix.getSchemaName(), NAME);
return ImmutableMap.<SchemaTableName, List<ColumnMetadata>>of(tableName, ImmutableList.of(COLUMN_METADATA));
}
@Override
public TableHandle createTable(TableMetadata tableMetadata)
{
throw new UnsupportedOperationException();
}
@Override
public void dropTable(TableHandle tableHandle)
{
throw new UnsupportedOperationException();
}
public List<ColumnMetadata> listTableColumns(TableHandle tableHandle)
{
checkNotNull(tableHandle, "tableHandle is null");
checkArgument(tableHandle instanceof DualTableHandle, "tableHandle is not a dual table handle");
return ImmutableList.of(COLUMN_METADATA);
}
}