| /** |
| * 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.algebra; |
| |
| import com.google.gson.*; |
| import com.google.gson.annotations.Expose; |
| import com.google.gson.annotations.SerializedName; |
| import org.apache.tajo.algebra.LiteralValue.LiteralType; |
| import org.apache.tajo.json.CommonGsonHelper; |
| |
| import java.lang.reflect.Type; |
| |
| public abstract class Expr implements JsonSerializable, Cloneable { |
| @Expose @SerializedName("type") |
| private static final String SERIALIZED_NAME_OF_OP_TYPE = "OpType"; |
| @Expose @SerializedName(SERIALIZED_NAME_OF_OP_TYPE) |
| protected OpType opType; |
| |
| public Expr(OpType opType) { |
| this.opType = opType; |
| } |
| |
| public OpType getType() { |
| return this.opType; |
| } |
| |
| @Override |
| public abstract int hashCode(); |
| |
| /** |
| * This method only compares this Expr contents with those of another Expr. It does not compare |
| * those expressions' child nodes. |
| * |
| * @param expr The Expr instance to be compared. |
| * @return true Return TRUE if this Expr and another Expr's contents except for child node(s) are equivalent to |
| * each other. Otherwise, it will return FALSE. |
| */ |
| abstract boolean equalsTo(Expr expr); |
| |
| @Override |
| public boolean equals(Object obj) { |
| if (obj instanceof Expr) { |
| Expr casted = (Expr) obj; |
| |
| if (this.opType == casted.opType && equalsTo(casted)) { |
| if (this instanceof UnaryOperator) { |
| UnaryOperator one = (UnaryOperator) this; |
| UnaryOperator another = (UnaryOperator) casted; |
| return one.getChild().equals(another.getChild()); |
| } else if (this instanceof BinaryOperator) { |
| |
| BinaryOperator bin = (BinaryOperator) this; |
| BinaryOperator anotherBin = (BinaryOperator) casted; |
| |
| if (!bin.getLeft().equals(anotherBin.getLeft())) { |
| return false; |
| } |
| if (!bin.getRight().equals(anotherBin.getRight())) { |
| return false; |
| } |
| |
| return true; |
| } else { |
| return this.equalsTo(casted); |
| } |
| } |
| } |
| |
| return false; |
| } |
| |
| @Override |
| public Object clone() throws CloneNotSupportedException { |
| Expr newExpr = (Expr) super.clone(); |
| newExpr.opType = opType; |
| return newExpr; |
| } |
| |
| @Override |
| public String toString() { |
| return toJson(); |
| } |
| |
| public String toJson() { |
| return JsonHelper.toJson(this); |
| } |
| |
| /** |
| * This method provides a visiting way in the post order. |
| */ |
| public void accept(ExprVisitor visitor) { |
| if (this instanceof UnaryOperator) { |
| UnaryOperator unary = (UnaryOperator) this; |
| unary.getChild().accept(visitor); |
| } else if (this instanceof BinaryOperator) { |
| BinaryOperator bin = (BinaryOperator) this; |
| bin.getLeft().accept(visitor); |
| bin.getRight().accept(visitor); |
| } |
| |
| visitor.visit(this); |
| } |
| |
| static class JsonSerDer |
| implements JsonSerializer<Expr>, JsonDeserializer<Expr> { |
| |
| @Override |
| public Expr deserialize(JsonElement json, Type typeOfT, |
| JsonDeserializationContext context) |
| throws JsonParseException { |
| JsonObject jsonObject = json.getAsJsonObject(); |
| String opType = CommonGsonHelper.getOrDie(jsonObject, SERIALIZED_NAME_OF_OP_TYPE).getAsString(); |
| if (OpType.valueOf(opType).equals(OpType.Literal)) { |
| String value = CommonGsonHelper.getOrDie(jsonObject, "Value").getAsString(); |
| JsonElement valueTypeElem = jsonObject.get("ValueType"); |
| if (valueTypeElem != null) { |
| return new LiteralValue(value, LiteralType.valueOf(valueTypeElem.getAsString())); |
| } else { |
| return new LiteralValue(value, LiteralValue.getLiteralType(value)); |
| } |
| } else { |
| return context.deserialize(json, OpType.valueOf(opType).getBaseClass()); |
| } |
| } |
| |
| |
| @Override |
| public JsonElement serialize(Expr src, Type typeOfSrc, |
| JsonSerializationContext context) { |
| return context.serialize(src, src.opType.getBaseClass()); |
| } |
| } |
| } |