| /* |
| * 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; |
| |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.apache.pig.classification.InterfaceAudience; |
| import org.apache.pig.classification.InterfaceStability; |
| import org.apache.pig.impl.logicalLayer.FrontendException; |
| import org.apache.pig.impl.util.Pair; |
| import org.apache.pig.newplan.logical.relational.LOLoad; |
| import org.apache.pig.newplan.logical.relational.LOStore; |
| |
| /** |
| * An interface that defines graph operations on plans. Plans are modeled as |
| * graphs with restrictions on the types of connections and operations allowed. |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Unstable |
| public interface OperatorPlan { |
| |
| /** |
| * Get number of nodes in the plan. |
| * @return number of nodes in the plan |
| */ |
| public int size(); |
| |
| /** |
| * Get all operators in the plan that have no predecessors. |
| * @return all operators in the plan that have no predecessors, or |
| * an empty list if the plan is empty. |
| */ |
| public List<Operator> getSources(); |
| |
| /** |
| * Get all operators in the plan that have no successors. |
| * @return all operators in the plan that have no successors, or |
| * an empty list if the plan is empty. |
| */ |
| public List<Operator> getSinks(); |
| |
| /** |
| * For a given operator, get all operators immediately before it in the |
| * plan. |
| * @param op operator to fetch predecessors of |
| * @return list of all operators immediately before op, or an empty list |
| * if op is a root. |
| */ |
| public List<Operator> getPredecessors(Operator op); |
| |
| /** |
| * For a given operator, get all operators immediately after it. |
| * @param op operator to fetch successors of |
| * @return list of all operators immediately after op, or an empty list |
| * if op is a leaf. |
| */ |
| public List<Operator> getSuccessors(Operator op); |
| |
| /** |
| * For a given operator, get all operators softly immediately before it in the |
| * plan. |
| * @param op operator to fetch predecessors of |
| * @return list of all operators immediately before op, or an empty list |
| * if op is a root. |
| */ |
| public List<Operator> getSoftLinkPredecessors(Operator op); |
| |
| /** |
| * For a given operator, get all operators softly immediately after it. |
| * @param op operator to fetch successors of |
| * @return list of all operators immediately after op, or an empty list |
| * if op is a leaf. |
| */ |
| public List<Operator> getSoftLinkSuccessors(Operator op); |
| |
| /** |
| * Add a new operator to the plan. It will not be connected to any |
| * existing operators. |
| * @param op operator to add |
| */ |
| public void add(Operator op); |
| |
| /** |
| * Remove an operator from the plan. |
| * @param op Operator to be removed |
| * @throws FrontendException if the remove operation attempts to |
| * remove an operator that is still connected to other operators. |
| */ |
| public void remove(Operator op) throws FrontendException; |
| |
| /** |
| * Connect two operators in the plan, controlling which position in the |
| * edge lists that the from and to edges are placed. |
| * @param from Operator edge will come from |
| * @param fromPos Position in the array for the from edge |
| * @param to Operator edge will go to |
| * @param toPos Position in the array for the to edge |
| */ |
| public void connect(Operator from, int fromPos, Operator to, int toPos); |
| |
| /** |
| * Connect two operators in the plan. |
| * @param from Operator edge will come from |
| * @param to Operator edge will go to |
| */ |
| public void connect(Operator from, Operator to); |
| |
| /** |
| * Create an soft edge between two nodes. |
| * @param from Operator dependent upon |
| * @param to Operator having the dependency |
| */ |
| public void createSoftLink(Operator from, Operator to); |
| |
| /** |
| * Remove an soft edge |
| * @param from Operator dependent upon |
| * @param to Operator having the dependency |
| */ |
| public void removeSoftLink(Operator from, Operator to); |
| |
| /** |
| * Disconnect two operators in the plan. |
| * @param from Operator edge is coming from |
| * @param to Operator edge is going to |
| * @return pair of positions, indicating the position in the from and |
| * to arrays. |
| * @throws FrontendException if the two operators aren't connected. |
| */ |
| public Pair<Integer, Integer> disconnect(Operator from, Operator to) throws FrontendException; |
| |
| |
| /** |
| * Get an iterator of all operators in this plan |
| * @return an iterator of all operators in this plan |
| */ |
| public Iterator<Operator> getOperators(); |
| |
| /** |
| * This is like a shallow comparison. |
| * Two plans are equal if they have equivalent operators and equivalent |
| * structure. |
| * @param other object to compare |
| * @return boolean if both the plans are equivalent |
| * @throws FrontendException |
| */ |
| public boolean isEqual( OperatorPlan other ) throws FrontendException; |
| |
| /** |
| * This method replace the oldOperator with the newOperator, make all connection |
| * to the new operator in the place of old operator |
| * @param oldOperator operator to be replaced |
| * @param newOperator operator to replace |
| * @throws FrontendException |
| */ |
| public void replace(Operator oldOperator, Operator newOperator) throws FrontendException; |
| |
| /** |
| * This method remove a node operatorToRemove. It also Connect all its successors to |
| * predecessor/connect all it's predecessors to successor |
| * @param operatorToRemove operator to remove |
| * @throws FrontendException |
| */ |
| public void removeAndReconnect(Operator operatorToRemove) throws FrontendException; |
| |
| /** |
| * This method insert node operatorToInsert between pred and succ. Both pred and succ cannot be null |
| * @param pred predecessor of inserted node after this method |
| * @param operatorToInsert operato to insert |
| * @param succ successor of inserted node after this method |
| * @throws FrontendException |
| */ |
| public void insertBetween(Operator pred, Operator operatorToInsert, Operator succ) throws FrontendException; |
| |
| /** |
| * check if there is a path in the plan graph between the load operator to the store operator. |
| * @param load load operator |
| * @param store store operator |
| * @return true if yes, no otherwise. |
| */ |
| public boolean pathExists(Operator load, Operator store); |
| } |