/*
* 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.scalar;
import io.crate.metadata.*;
import io.crate.data.Input;
import io.crate.types.DataType;
import io.crate.types.DataTypes;
import java.util.Collection;
import java.util.List;
public class CollectionCountFunction extends Scalar<Long, Collection<DataType>> {
public static final String NAME = "collection_count";
private final FunctionInfo info;
private static final FunctionResolver collectionCountResolver = new CollectionCountResolver();
public static void register(ScalarFunctionModule mod) {
mod.register(NAME, collectionCountResolver);
}
CollectionCountFunction(FunctionInfo info) {
this.info = info;
}
@Override
public Long evaluate(Input<Collection<DataType>>... args) {
// TODO: eliminate Integer.MAX_VALUE limitation of Set.size()
Collection<DataType> arg0Value = args[0].value();
if (arg0Value == null) {
return null;
}
return ((Integer) (arg0Value.size())).longValue();
}
@Override
public FunctionInfo info() {
return info;
}
static class CollectionCountResolver extends BaseFunctionResolver {
CollectionCountResolver() {
super(Signature.of(Signature.ArgMatcher.ANY_SET));
}
@Override
public FunctionImplementation getForTypes(List<DataType> dataTypes) throws IllegalArgumentException {
return new CollectionCountFunction(new FunctionInfo(
new FunctionIdent(NAME, dataTypes),
DataTypes.LONG
));
}
}
}