| /* |
| * 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.pig; |
| |
| import java.util.List; |
| |
| import org.apache.pig.classification.InterfaceAudience; |
| import org.apache.pig.classification.InterfaceStability; |
| |
| /** |
| * A class to communicate Filter expressions to LoadFuncs. |
| * @since Pig 0.7 |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public abstract class Expression { |
| |
| // Operator type |
| public static enum OpType { |
| |
| // binary arith ops |
| OP_PLUS (" + "), |
| OP_MINUS(" - "), |
| OP_TIMES(" * "), |
| OP_DIV(" / "), |
| OP_MOD(" % "), |
| |
| //binary ops |
| OP_EQ(" == "), |
| OP_NE(" != "), |
| OP_GT(" > "), |
| OP_GE(" >= "), |
| OP_LT(" < "), |
| OP_LE(" <= "), |
| OP_MATCH(" matches "), |
| |
| //Only used by PredicatePushdown, not used by PartitionPushdown |
| OP_IN (" in "), |
| OP_BETWEEN (" between "), |
| |
| //unary ops |
| OP_NULL(" is null"), |
| OP_NOT(" not"), |
| |
| //binary logical |
| OP_AND(" and "), |
| OP_OR(" or "), |
| TERM_COL(" Column "), |
| TERM_CONST(" Constant "); |
| |
| private String str = ""; |
| private OpType(String rep){ |
| this.str = rep; |
| } |
| private OpType(){ |
| } |
| |
| @Override |
| public String toString(){ |
| return this.str; |
| } |
| |
| } |
| |
| protected OpType opType; |
| |
| /** |
| * @return the opType |
| */ |
| public OpType getOpType() { |
| return opType; |
| } |
| |
| //TODO: Apply a optimizer to Expression from PredicatePushdownOptimizer and |
| // convert OR clauses to BETWEEN OR IN |
| public static class BetweenExpression extends Expression { |
| |
| private Object lower; |
| private Object upper; |
| |
| public BetweenExpression(Object lower, Object upper) { |
| this.opType = OpType.OP_BETWEEN; |
| this.lower = lower; |
| this.upper = upper; |
| } |
| |
| public Object getLower() { |
| return lower; |
| } |
| |
| public Object getUpper() { |
| return upper; |
| } |
| |
| @Override |
| public String toString() { |
| return " between " + lower + " and " + upper; |
| } |
| |
| } |
| |
| public static class InExpression extends Expression { |
| |
| private List<Object> values; |
| |
| public InExpression(List<Object> values) { |
| this.opType = OpType.OP_IN; |
| this.values = values; |
| } |
| |
| public List<Object> getValues() { |
| return values; |
| } |
| |
| @Override |
| public String toString() { |
| StringBuilder sb = new StringBuilder(); |
| sb.append(" in ("); |
| for (Object value : values) { |
| if (value instanceof String) { |
| sb.append("'").append(value).append("', "); |
| } else { |
| sb.append(value).append(", "); |
| } |
| } |
| sb.deleteCharAt(sb.length() - 1); |
| sb.append(")"); |
| return sb.toString(); |
| } |
| |
| } |
| |
| public static class UnaryExpression extends Expression { |
| |
| Expression expr; |
| |
| public UnaryExpression(Expression expr, OpType opType) { |
| this.opType = opType; |
| this.expr = expr; |
| } |
| |
| public Expression getExpression() { |
| return expr; |
| } |
| |
| @Override |
| public String toString() { |
| // TODO: Change toString() for OP_NOT to say (col is not null) |
| // instead of ((col is null) not). If any one relies on expr.toString() might be useful |
| return "(" + expr.toString() + opType.toString() + ")"; |
| } |
| |
| } |
| |
| public static class BinaryExpression extends Expression { |
| |
| /** |
| * left hand operand |
| */ |
| Expression lhs; |
| |
| /** |
| * right hand operand |
| */ |
| Expression rhs; |
| |
| |
| /** |
| * @param lhs |
| * @param rhs |
| */ |
| public BinaryExpression(Expression lhs, Expression rhs, OpType opType) { |
| this.opType = opType; |
| this.lhs = lhs; |
| this.rhs = rhs; |
| } |
| |
| /** |
| * @return the left hand operand |
| */ |
| public Expression getLhs() { |
| return lhs; |
| } |
| |
| /** |
| * @return the right hand operand |
| */ |
| public Expression getRhs() { |
| return rhs; |
| } |
| |
| @Override |
| public String toString() { |
| return "(" + lhs.toString() + opType.toString() + rhs.toString() |
| + ")"; |
| } |
| } |
| |
| public static class Column extends Expression { |
| |
| /** |
| * name of column |
| */ |
| private String name; |
| |
| /** |
| * @param name |
| */ |
| public Column(String name) { |
| this.opType = OpType.TERM_COL; |
| this.name = name; |
| } |
| |
| @Override |
| public String toString() { |
| return name; |
| } |
| |
| /** |
| * @return the name |
| */ |
| public String getName() { |
| return name; |
| } |
| |
| /** |
| * @param name the name to set |
| */ |
| public void setName(String name) { |
| this.name = name; |
| } |
| } |
| |
| public static class Const extends Expression { |
| |
| /** |
| * value of the constant |
| */ |
| Object value; |
| |
| /** |
| * @return the value |
| */ |
| public Object getValue() { |
| return value; |
| } |
| |
| /** |
| * @param value |
| */ |
| public Const(Object value) { |
| this.opType = OpType.TERM_CONST; |
| this.value = value; |
| } |
| |
| @Override |
| public String toString() { |
| return (value instanceof String) ? "\'" + value + "\'": |
| value.toString(); |
| } |
| } |
| |
| } |
| |
| |