| /* |
| * 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.newplan.logical.relational; |
| |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| import org.apache.pig.data.DataType; |
| import org.apache.pig.impl.logicalLayer.FrontendException; |
| import org.apache.pig.newplan.Operator; |
| import org.apache.pig.newplan.OperatorPlan; |
| import org.apache.pig.newplan.PlanVisitor; |
| import org.apache.pig.newplan.logical.expression.LogicalExpression; |
| import org.apache.pig.newplan.logical.expression.LogicalExpressionPlan; |
| |
| /** |
| * RANK operator implementation. |
| * Operator Syntax: |
| * <pre> |
| * {@code alias = RANK rel ( BY (col_ref) (ASC|DESC)? ( DENSE )? )?;} |
| * alias - output alias |
| * RANK - operator |
| * rel - input relation |
| * BY - operator |
| * col_ref - STAR or Column References or a range in the schema of rel |
| * DENSE - dense rank means a sequential value without gasp among different tuple values. |
| * </pre> |
| */ |
| |
| public class LORank extends LogicalRelationalOperator{ |
| |
| private final static String RANK_COL_NAME = "rank"; |
| private final static String SEPARATOR = "_"; |
| |
| /** |
| * A List within logical expression plans in case of RANK BY |
| */ |
| private List<LogicalExpressionPlan> rankColPlans; |
| |
| /** |
| * A List within ascending columns on a RANK BY |
| */ |
| private List<Boolean> ascCols; |
| |
| /** |
| * In case of RANK BY, it could by dense or not. |
| * Being a dense rank means to assign consecutive ranking |
| * to different tuples. |
| */ |
| private boolean isDenseRank = false; |
| |
| /** |
| * In case of simple RANK, namely row number mode |
| * which is a consecutive number assigned to each tuple. |
| */ |
| private boolean isRowNumber = false; |
| |
| public LORank( OperatorPlan plan) { |
| super("LORank", plan); |
| } |
| |
| public LORank( OperatorPlan plan, List<LogicalExpressionPlan> rankColPlans, List<Boolean> ascCols) { |
| this( plan ); |
| this.rankColPlans = rankColPlans; |
| this.ascCols = ascCols; |
| } |
| |
| public List<LogicalExpressionPlan> getRankColPlans() { |
| return rankColPlans; |
| } |
| |
| public void setRankColPlan(List<LogicalExpressionPlan> rankColPlans) { |
| this.rankColPlans = rankColPlans; |
| } |
| |
| public List<Boolean> getAscendingCol() { |
| return ascCols; |
| } |
| |
| public void setAscendingCol(List<Boolean> ascCols) { |
| this.ascCols = ascCols; |
| } |
| |
| /** |
| * Get the schema for the output of LORank. |
| * Composed by long value prepended to the |
| * rest of the input schema |
| * @return the schema |
| * @throws FrontendException |
| */ |
| @Override |
| public LogicalSchema getSchema() throws FrontendException { |
| |
| // if schema is calculated before, just return |
| if (schema != null) { |
| return schema; |
| } |
| |
| LogicalRelationalOperator input = null; |
| |
| //Same schema of previous predecessor |
| input = (LogicalRelationalOperator)plan.getPredecessors(this).get(0); |
| if (input == null) { |
| return null; |
| } |
| |
| LogicalSchema inputSchema = input.getSchema(); |
| |
| // the schema of one input is unknown, so the rank schema is unknown, just return |
| if (inputSchema == null) { |
| schema = null; |
| return schema; |
| } |
| |
| //Complete copy from previous schema for each LogicalFieldSchema |
| List<LogicalSchema.LogicalFieldSchema> fss = new ArrayList<LogicalSchema.LogicalFieldSchema>(); |
| |
| for (int i=0; i<inputSchema.size(); i++) { |
| LogicalSchema.LogicalFieldSchema fs = inputSchema.getField(i); |
| LogicalSchema.LogicalFieldSchema newFS = null; |
| newFS = new LogicalSchema.LogicalFieldSchema(fs.alias, fs.schema, fs.type, fs.uid); |
| fss.add(newFS); |
| } |
| |
| schema = new LogicalSchema(); |
| |
| schema.addField(new LogicalSchema.LogicalFieldSchema(RANK_COL_NAME+SEPARATOR+input.getAlias(), null, DataType.LONG)); |
| schema.getField(0).uid = LogicalExpression.getNextUid(); |
| |
| for(LogicalSchema.LogicalFieldSchema fieldSchema: fss) { |
| schema.addField(fieldSchema); |
| } |
| |
| return schema; |
| |
| } |
| |
| @Override |
| public void accept(PlanVisitor v) throws FrontendException { |
| if (!(v instanceof LogicalRelationalNodesVisitor)) { |
| throw new FrontendException("Expected LogicalPlanVisitor", 2223); |
| } |
| ((LogicalRelationalNodesVisitor)v).visit(this); |
| } |
| |
| @Override |
| public boolean isEqual(Operator other) throws FrontendException { |
| if (other != null && other instanceof LORank) { |
| LORank oR = (LORank)other; |
| if (!rankColPlans.equals(oR.rankColPlans)) |
| return false; |
| } else { |
| return false; |
| } |
| |
| return checkEquality((LogicalRelationalOperator)other); |
| } |
| |
| /** |
| * Get if it is a dense RANK BY |
| * @return boolean |
| */ |
| public boolean isDenseRank() { |
| return isDenseRank; |
| } |
| |
| /** |
| * Set if it is a dense RANK BY |
| * @param isDenseRank if is dense rank or not |
| */ |
| public void setIsDenseRank(boolean isDenseRank) { |
| this.isDenseRank = isDenseRank; |
| } |
| |
| /** |
| * Get if it is a simple RANK operation. |
| * Which means a row number attached to each tuple. |
| * @return boolean |
| */ |
| public boolean isRowNumber() { |
| return isRowNumber; |
| } |
| |
| /** |
| * Set if it is a simple RANK operation. |
| * @param rowNumber if is a row number operation |
| */ |
| public void setIsRowNumber(boolean rowNumber) { |
| this.isRowNumber = rowNumber; |
| } |
| } |