| /* |
| * 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.backend.hadoop.executionengine.physicalLayer.relationalOperators; |
| |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.apache.pig.backend.executionengine.ExecException; |
| import org.apache.pig.backend.hadoop.executionengine.physicalLayer.POStatus; |
| import org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator; |
| import org.apache.pig.backend.hadoop.executionengine.physicalLayer.Result; |
| import org.apache.pig.backend.hadoop.executionengine.physicalLayer.plans.PhyPlanVisitor; |
| import org.apache.pig.data.DataBag; |
| import org.apache.pig.data.DataType; |
| import org.apache.pig.data.Tuple; |
| import org.apache.pig.data.TupleFactory; |
| import org.apache.pig.impl.plan.OperatorKey; |
| import org.apache.pig.impl.plan.VisitorException; |
| import org.apache.pig.pen.util.ExampleTuple; |
| import org.apache.pig.pen.util.LineageTracer; |
| |
| /** |
| * Recover this class for nested cross operation. |
| * |
| * |
| */ |
| public class POCross extends PhysicalOperator { |
| |
| private static final long serialVersionUID = 1L; |
| |
| protected transient DataBag[] inputBags; |
| |
| protected transient Tuple[] data; |
| |
| protected transient Iterator<Tuple>[] its; |
| |
| protected transient Tuple tupleOfLastBag; |
| |
| public POCross(OperatorKey k) { |
| super(k); |
| } |
| |
| public POCross(OperatorKey k, int rp, List<PhysicalOperator> inp) { |
| super(k, rp, inp); |
| } |
| |
| public POCross(OperatorKey k, int rp) { |
| super(k, rp); |
| } |
| |
| public POCross(OperatorKey k, List<PhysicalOperator> inp) { |
| super(k, inp); |
| } |
| |
| @Override |
| public void visit(PhyPlanVisitor v) throws VisitorException { |
| v.visitCross(this); |
| } |
| |
| @Override |
| public String name() { |
| return getAliasString() + "POCross" + "[" |
| + DataType.findTypeName(resultType) + "]" + " - " |
| + mKey.toString(); |
| } |
| |
| @Override |
| public boolean supportsMultipleInputs() { |
| return true; |
| } |
| |
| @Override |
| public boolean supportsMultipleOutputs() { |
| return false; |
| } |
| |
| @Override |
| public Tuple illustratorMarkup(Object in, Object out, int eqClassIndex) { |
| if (illustrator != null) { |
| ExampleTuple tOut = new ExampleTuple((Tuple) out); |
| illustrator.addData(tOut); |
| illustrator.getEquivalenceClasses().get(eqClassIndex).add( |
| (Tuple) out); |
| LineageTracer lineageTracer = illustrator.getLineage(); |
| lineageTracer.insert(tOut); |
| for (int i = 0; i < data.length; i++) { |
| lineageTracer.union(tOut, data[i]); |
| } |
| return tOut; |
| } else { |
| return (Tuple) out; |
| } |
| } |
| |
| @Override |
| public Result getNextTuple() throws ExecException { |
| Result res = new Result(); |
| int noItems = inputs.size(); |
| if (inputBags == null) { |
| accumulateData(); |
| if (!loadLastBag()) { |
| res.returnStatus = POStatus.STATUS_EOP; |
| clearMemory(); |
| return res; |
| } |
| } |
| |
| if (its != null) { |
| // we check if we are done with processing |
| // we do that by checking if all the iterators are used up |
| boolean finished = true; |
| boolean empty = false; |
| for (int i = 0; i < its.length; i++) { |
| if (inputBags[i].size() == 0) { |
| empty = true; |
| break; |
| } |
| finished &= !its[i].hasNext(); |
| } |
| if (empty) { |
| // if one bag is empty, there doesn't exist non-null cross product. |
| // simply clear all the input tuples of the first bag and finish. |
| int index = inputs.size() - 1; |
| for (Result resOfLastBag = inputs.get(index).getNextTuple(); resOfLastBag.returnStatus != |
| POStatus.STATUS_EOP; resOfLastBag = inputs.get(index).getNextTuple()); |
| res.returnStatus = POStatus.STATUS_EOP; |
| clearMemory(); |
| return res; |
| } else if (finished && !loadLastBag()) { |
| res.returnStatus = POStatus.STATUS_EOP; |
| clearMemory(); |
| return res; |
| } |
| |
| } |
| |
| if (data == null) { |
| // getNext being called for the first time or starting on new input |
| // data we instantiate the template array and start populating it |
| // with data |
| data = new Tuple[noItems]; |
| data[noItems - 1] = tupleOfLastBag; |
| for (int i = 0; i < noItems - 1; ++i) { |
| data[i] = its[i].next(); |
| |
| } |
| res.result = createTuple(data); |
| res.returnStatus = POStatus.STATUS_OK; |
| return res; |
| } else { |
| data[noItems - 1] = tupleOfLastBag; |
| int length = noItems - 1; |
| for (int index = 0; index < length; ++index) { |
| if (its[index].hasNext()) { |
| data[index] = its[index].next(); |
| res.result = createTuple(data); |
| res.returnStatus = POStatus.STATUS_OK; |
| return res; |
| } else { |
| // reset this index's iterator so cross product can be |
| // achieved we would be resetting this way only for the |
| // indexes from the end when the first index which needs to |
| // be flattened has reached the last element in its |
| // iterator, we won't come here - instead, we reset all |
| // iterators at the beginning of this method. |
| its[index] = (inputBags[index]).iterator(); |
| data[index] = its[index].next(); |
| } |
| } |
| res.result = createTuple(data); |
| res.returnStatus = POStatus.STATUS_OK; |
| return res; |
| } |
| } |
| |
| @SuppressWarnings("unchecked") |
| private void accumulateData() throws ExecException { |
| int count = 0; |
| int length = inputs.size() - 1; |
| inputBags = new DataBag[length]; |
| its = new Iterator[length]; |
| for (int i = 0; i < length; ++i) { |
| PhysicalOperator op = inputs.get(i); |
| DataBag bag = mBagFactory.newDefaultBag(); |
| inputBags[count] = bag; |
| for (Result res = op.getNextTuple(); res.returnStatus != POStatus.STATUS_EOP; res = op |
| .getNextTuple()) { |
| if (res.returnStatus == POStatus.STATUS_NULL) |
| continue; |
| if (res.returnStatus == POStatus.STATUS_ERR) |
| throw new ExecException( |
| "Error accumulating data in the local Cross operator"); |
| if (res.returnStatus == POStatus.STATUS_OK) |
| bag.add((Tuple) res.result); |
| } |
| its[count++] = bag.iterator(); |
| } |
| } |
| |
| private Tuple createTuple(Tuple[] data) throws ExecException { |
| Tuple out = TupleFactory.getInstance().newTuple(); |
| |
| for (int i = 0; i < data.length; ++i) { |
| Tuple t = data[i]; |
| int size = t.size(); |
| for (int j = 0; j < size; ++j) { |
| out.append(t.get(j)); |
| } |
| } |
| |
| return illustratorMarkup(out, out, 0); |
| } |
| |
| private boolean loadLastBag() throws ExecException { |
| Result resOfLastBag = null; |
| int index = inputs.size() - 1; |
| for (resOfLastBag = inputs.get(index).getNextTuple(); resOfLastBag.returnStatus == |
| POStatus.STATUS_NULL; inputs.get(index).getNextTuple()); |
| switch (resOfLastBag.returnStatus) { |
| case POStatus.STATUS_EOP: |
| return false; |
| case POStatus.STATUS_OK: |
| // each time when an tuple of last bag is ejected, traverse all the |
| // combinations of the tuples from the other n - 1 bags to save the |
| // memory for one bag. |
| tupleOfLastBag = (Tuple) resOfLastBag.result; |
| return true; |
| case POStatus.STATUS_ERR: |
| default: |
| throw new ExecException( |
| "Error accumulating data in the local Cross operator"); |
| } |
| } |
| |
| private void clearMemory() { |
| // reset inputBags, its, data and tupleOfLastBag to null so that in the |
| // next round of getNext, the new input data will be loaded. |
| tupleOfLastBag = null; |
| inputBags = null; |
| its = null; |
| data = null; |
| } |
| |
| @Override |
| public void reset() { |
| clearMemory(); |
| } |
| |
| } |