/**
* 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.drill.exec.record;
import java.util.List;
import java.util.Set;
import org.apache.drill.exec.exception.SchemaChangeException;
import org.apache.drill.exec.record.BatchSchema.SelectionVectorMode;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
/**
* A reusable builder that supports the creation of BatchSchemas. Can have a supporting expected object. If the expected Schema object is defined, the
* builder will always check that this schema is a equal or more materialized version of the current schema.
*/
public class SchemaBuilder {
private Set<MaterializedField> fields = Sets.newHashSet();
private BatchSchema.SelectionVectorMode selectionVectorMode = SelectionVectorMode.NONE;
SchemaBuilder() {
}
// /**
// * Add a field where we don't have type information. In this case, DataType will be set to LATEBIND and valueClass
// * will be set to null.
// *
// * @param fieldId
// * The desired fieldId. Should be unique for this BatchSchema.
// * @param nullable
// * Whether this field supports nullability.
// * @param mode
// * @throws SchemaChangeException
// */
// public void addLateBindField(short fieldId, boolean nullable, ValueMode mode) throws SchemaChangeException {
// addTypedField(fieldId, DataType.LATEBIND, nullable, mode, Void.class);
// }
public SchemaBuilder setSelectionVectorMode(BatchSchema.SelectionVectorMode selectionVectorMode) {
this.selectionVectorMode = selectionVectorMode;
return this;
}
public SchemaBuilder addFields(Iterable<MaterializedField> fields){
for(MaterializedField f : fields){
addField(f);
}
return this;
}
// private void setTypedField(short fieldId, DataType type, boolean nullable, ValueMode mode, Class<?> valueClass)
// throws SchemaChangeException {
// MaterializedField f = new MaterializedField(fieldId, type, nullable, mode, valueClass);
// if (expectedFields != null) {
// if (!expectedFields.containsKey(f.getFieldId()))
// throw new SchemaChangeException(
// String
// .format(
// "You attempted to add a field for Id An attempt was made to add a duplicate fieldId to the schema. The offending fieldId was %d",
// fieldId));
// f.checkMaterialization(expectedFields.lget());
// }
// fields.put(f.getFieldId(), f);
// }
public SchemaBuilder addField(MaterializedField f){
fields.add(f);
return this;
}
// public void addTypedField(short fieldId, DataType type, boolean nullable, ValueMode mode, Class<?> valueClass)
// throws SchemaChangeException {
// if (fields.containsKey(fieldId))
// throw new SchemaChangeException(String.format(
// "An attempt was made to add a duplicate fieldId to the schema. The offending fieldId was %d", fieldId));
// setTypedField(fieldId, type, nullable, mode, valueClass);
// }
//
// public void replaceTypedField(short fieldId, DataType type, boolean nullable, ValueMode mode, Class<?> valueClass)
// throws SchemaChangeException {
// if (!fields.containsKey(fieldId))
// throw new SchemaChangeException(
// String.format("An attempt was made to replace a field in the schema, however the schema does " +
// "not currently contain that field id. The offending fieldId was %d", fieldId));
// setTypedField(fieldId, type, nullable, mode, valueClass);
// }
public SchemaBuilder removeField(MaterializedField f) throws SchemaChangeException{
if(!fields.remove(f)) throw new SchemaChangeException("You attempted to remove an nonexistent field.");
return this;
}
/**
* Generate a new BatchSchema object based on the current state of the builder.
* @return
* @throws SchemaChangeException
*/
public BatchSchema build(){
List<MaterializedField> fieldList = Lists.newArrayList(fields);
return new BatchSchema(this.selectionVectorMode, fieldList);
}
}