/**
* 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 org.apache.tajo.engine.function.string;
import com.google.gson.annotations.Expose;
import org.apache.commons.lang.StringUtils;
import org.apache.tajo.catalog.Column;
import org.apache.tajo.common.TajoDataTypes;
import org.apache.tajo.datum.Datum;
import org.apache.tajo.datum.DatumFactory;
import org.apache.tajo.datum.NullDatum;
import org.apache.tajo.engine.eval.FunctionEval;
import org.apache.tajo.engine.function.GeneralFunction;
import org.apache.tajo.storage.Tuple;
/**
* Function definition
*
* text ltrim(string text [, characters text])
*/
public class LTrim extends GeneralFunction {
@Expose private boolean hasTrimCharacters;
public LTrim() {
super(new Column[] {
new Column("string", TajoDataTypes.Type.TEXT),
new Column("characters", TajoDataTypes.Type.TEXT),
});
}
public void init(FunctionEval.ParamType[] paramTypes) {
if (paramTypes.length == 2) {
hasTrimCharacters = true;
}
}
@Override
public Datum eval(Tuple params) {
Datum datum = params.get(0);
if(datum instanceof NullDatum) return NullDatum.get();
if (!hasTrimCharacters) {
return DatumFactory.createText(StringUtils.stripStart(datum.asChars(), null));
} else {
return DatumFactory.createText(StringUtils.stripStart(datum.asChars(), params.get(1).asChars()));
}
}
}