/*
* Licensed to CRATE Technology GmbH ("Crate") under one or more contributor
* license agreements. See the NOTICE file distributed with this work for
* additional information regarding copyright ownership. Crate 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.
*
* However, if you have executed another commercial license agreement
* with Crate these terms will supersede the license and you may use the
* software solely pursuant to the terms of the relevant commercial agreement.
*/
package io.crate.operation.reference.file;
import com.google.common.collect.ImmutableMap;
import io.crate.metadata.ColumnIdent;
import io.crate.metadata.Reference;
import io.crate.operation.collect.files.LineCollectorExpression;
import java.util.Map;
import java.util.function.Supplier;
public final class FileLineReferenceResolver {
// need to create a new instance here so that each collector will have its own instance.
// otherwise multiple collectors would share the same state.
private static final Map<String, Supplier<LineCollectorExpression<?>>> EXPRESSION_BUILDER =
ImmutableMap.of(
SourceLineExpression.COLUMN_NAME, SourceLineExpression::new,
SourceAsMapLineExpression.COLUMN_NAME, SourceAsMapLineExpression::new);
private FileLineReferenceResolver() {
}
public static LineCollectorExpression<?> getImplementation(Reference refInfo) {
ColumnIdent columnIdent = refInfo.ident().columnIdent();
Supplier<LineCollectorExpression<?>> supplier = EXPRESSION_BUILDER.get(columnIdent.name());
if (supplier == null) {
return new ColumnExtractingLineExpression(columnIdent);
}
return supplier.get();
}
}