| /* |
| * 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.flink.table.expressions |
| |
| import org.apache.calcite.rex.RexNode |
| import org.apache.calcite.tools.RelBuilder |
| import org.apache.flink.table.api.UnresolvedException |
| import org.apache.flink.table.api.types.{DataTypes, InternalType, RowType} |
| import org.apache.flink.table.plan.logical.LogicalExprVisitor |
| import org.apache.flink.table.validate.{ValidationFailure, ValidationResult, ValidationSuccess} |
| |
| /** |
| * Flattening of composite types. All flattenings are resolved into |
| * `GetCompositeField` expressions. |
| */ |
| case class Flattening(child: Expression) extends UnaryExpression { |
| |
| override def toString = s"$child.flatten()" |
| |
| override private[flink] def resultType: InternalType = |
| throw UnresolvedException(s"Invalid call to on ${this.getClass}.") |
| |
| override private[flink] def validateInput(): ValidationResult = |
| ValidationFailure(s"Unresolved flattening of $child") |
| |
| override def accept[T](logicalExprVisitor: LogicalExprVisitor[T]): T = |
| logicalExprVisitor.visit(this) |
| } |
| |
| case class GetCompositeField(child: Expression, key: Any) extends UnaryExpression { |
| |
| private var fieldIndex: Option[Int] = None |
| |
| override def toString = s"$child.get($key)" |
| |
| override private[flink] def validateInput(): ValidationResult = { |
| // check for composite type |
| if (!child.resultType.isInstanceOf[RowType]) { |
| return ValidationFailure(s"Cannot access field of non-composite type '${child.resultType}'.") |
| } |
| val compositeType = child.resultType.asInstanceOf[RowType] |
| |
| // check key |
| key match { |
| case name: String => |
| val index = compositeType.getFieldIndex(name) |
| if (index < 0) { |
| ValidationFailure(s"Field name '$name' could not be found.") |
| } else { |
| fieldIndex = Some(index) |
| ValidationSuccess |
| } |
| case index: Int => |
| if (index >= compositeType.getArity) { |
| ValidationFailure(s"Field index '$index' exceeds arity.") |
| } else { |
| fieldIndex = Some(index) |
| ValidationSuccess |
| } |
| case _ => |
| ValidationFailure(s"Invalid key '$key'.") |
| } |
| } |
| |
| override private[flink] def resultType: InternalType = |
| child.resultType.asInstanceOf[RowType].getInternalTypeAt(fieldIndex.get) |
| |
| override private[flink] def toRexNode(implicit relBuilder: RelBuilder): RexNode = { |
| relBuilder |
| .getRexBuilder |
| .makeFieldAccess(child.toRexNode, fieldIndex.get) |
| } |
| |
| override private[flink] def makeCopy(anyRefs: Array[AnyRef]): this.type = { |
| val child: Expression = anyRefs.head.asInstanceOf[Expression] |
| copy(child, key).asInstanceOf[this.type] |
| } |
| |
| /** |
| * Gives a meaningful alias if possible (e.g. a$mypojo$field). |
| */ |
| private[flink] def aliasName(): Option[String] = child match { |
| case gcf: GetCompositeField => |
| val alias = gcf.aliasName() |
| if (alias.isDefined) { |
| Some(s"${alias.get}$$$key") |
| } else { |
| None |
| } |
| case c: ResolvedFieldReference => Some(s"${c.name}$$$key") |
| case _ => None |
| } |
| |
| override def accept[T](logicalExprVisitor: LogicalExprVisitor[T]): T = |
| logicalExprVisitor.visit(this) |
| } |