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* 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.pen;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.pig.ExecType;
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.PhysicalPlan;
import org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POLoad;
import org.apache.pig.backend.local.executionengine.physicalLayer.LocalLogToPhyTranslationVisitor;
import org.apache.pig.data.BagFactory;
import org.apache.pig.data.DataBag;
import org.apache.pig.data.Tuple;
import org.apache.pig.impl.PigContext;
import org.apache.pig.impl.logicalLayer.FrontendException;
import org.apache.pig.impl.logicalLayer.LOLoad;
import org.apache.pig.impl.logicalLayer.LogicalOperator;
import org.apache.pig.impl.logicalLayer.LogicalPlan;
import org.apache.pig.impl.logicalLayer.PlanSetter;
import org.apache.pig.impl.logicalLayer.optimizer.LogicalOptimizer;
import org.apache.pig.impl.logicalLayer.schema.Schema;
import org.apache.pig.impl.logicalLayer.validators.LogicalPlanValidationExecutor;
import org.apache.pig.impl.plan.CompilationMessageCollector;
import org.apache.pig.impl.plan.VisitorException;
import org.apache.pig.pen.util.DisplayExamples;
import org.apache.pig.pen.util.FunctionalLogicalOptimizer;
import org.apache.pig.pen.util.LineageTracer;
public class ExampleGenerator {
LogicalPlan plan;
Map<LOLoad, DataBag> baseData;
PigContext pigContext;
Map<LogicalOperator, PhysicalOperator> LogToPhyMap;
PhysicalPlan physPlan;
Log log = LogFactory.getLog(getClass());
private int MAX_RECORDS = 10000;
public ExampleGenerator(LogicalPlan plan, PigContext hadoopPigContext) {
this.plan = plan;
// pigContext = new PigContext(ExecType.LOCAL, hadoopPigContext
// .getProperties());
pigContext = hadoopPigContext;
try {
pigContext.connect();
} catch (ExecException e) {
log.error("Error connecting to the cluster "
+ e.getLocalizedMessage());
}
}
public void setMaxRecords(int max) {
MAX_RECORDS = max;
}
public Map<LogicalOperator, DataBag> getExamples() {
compilePlan(plan);
List<LogicalOperator> loads = plan.getRoots();
try {
readBaseData(loads);
} catch (ExecException e) {
// TODO Auto-generated catch block
log.error("Error reading data. " + e.getMessage());
throw new RuntimeException(e.getMessage());
} catch (FrontendException e) {
// TODO Auto-generated catch block
log.error("Error reading data. " + e.getMessage());
}
DerivedDataVisitor derivedData = null;
try {
// create derived data and trim base data
LineageTrimmingVisitor trimmer = new LineageTrimmingVisitor(plan,
baseData, LogToPhyMap, physPlan, pigContext);
trimmer.visit();
// System.out.println(
// "Obtained the first level derived and trimmed data");
// create new derived data from trimmed basedata
derivedData = new DerivedDataVisitor(plan, null, baseData,
trimmer.LogToPhyMap, physPlan);
derivedData.visit();
// System.out.println(
// "Got new derived data from the trimmed base data");
// augment base data
AugmentBaseDataVisitor augment = new AugmentBaseDataVisitor(plan,
baseData, derivedData.derivedData);
augment.visit();
this.baseData = augment.getNewBaseData();
// System.out.println("Obtained augmented base data");
// create new derived data and trim the base data after augmenting
// base data with synthetic tuples
trimmer = new LineageTrimmingVisitor(plan, baseData,
derivedData.LogToPhyMap, physPlan, pigContext);
trimmer.visit();
// System.out.println("Final trimming");
// create the final version of derivedData to give to the output
derivedData = new DerivedDataVisitor(plan, null, baseData,
trimmer.LogToPhyMap, physPlan);
derivedData.visit();
// System.out.println("Obtaining final derived data for output");
} catch (VisitorException e) {
// TODO Auto-generated catch block
log.error("Visitor exception while creating example data "
+ e.getMessage());
}
// DisplayExamples.PrintSimple(plan.getLeaves().get(0),
// derivedData.derivedData);
System.out.println(DisplayExamples.PrintTabular(plan,
derivedData.derivedData));
return derivedData.derivedData;
}
private void readBaseData(List<LogicalOperator> loads) throws ExecException, FrontendException {
baseData = new HashMap<LOLoad, DataBag>();
for (LogicalOperator op : loads) {
Schema schema = op.getSchema();
if(schema == null) {
throw new ExecException("Example Generator requires a schema. Please provide a schema while loading data.");
}
DataBag opBaseData = BagFactory.getInstance().newDefaultBag();
POLoad poLoad = (POLoad) LogToPhyMap.get(op);
// PigContext oldPC = poLoad.getPc();
// poLoad.setPc(pigContext);
poLoad.setLineageTracer(new LineageTracer());
Tuple t = null;
int count = 0;
for (Result res = poLoad.getNext(t); res.returnStatus != POStatus.STATUS_EOP
&& count < MAX_RECORDS; res = poLoad.getNext(t)) {
if (res.returnStatus == POStatus.STATUS_NULL)
continue;
if (res.returnStatus == POStatus.STATUS_ERR) {
log.error("Error reading Tuple");
} else {
opBaseData.add((Tuple) res.result);
count++;
}
}
baseData.put((LOLoad) op, opBaseData);
// poLoad.setPc(oldPC);
poLoad.setLineageTracer(null);
}
}
private void compilePlan(LogicalPlan plan) {
plan = refineLogicalPlan(plan);
LocalLogToPhyTranslationVisitor visitor = new LocalLogToPhyTranslationVisitor(
plan);
visitor.setPigContext(pigContext);
try {
visitor.visit();
} catch (VisitorException e) {
// TODO Auto-generated catch block
e.printStackTrace();
log.error("Error visiting the logical plan in ExampleGenerator");
}
physPlan = visitor.getPhysicalPlan();
LogToPhyMap = visitor.getLogToPhyMap();
}
private LogicalPlan refineLogicalPlan(LogicalPlan plan) {
PlanSetter ps = new PlanSetter(plan);
try {
ps.visit();
} catch (VisitorException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// run through validator
CompilationMessageCollector collector = new CompilationMessageCollector();
FrontendException caught = null;
try {
LogicalPlanValidationExecutor validator = new LogicalPlanValidationExecutor(
plan, pigContext);
validator.validate(plan, collector);
FunctionalLogicalOptimizer optimizer = new FunctionalLogicalOptimizer(
plan);
optimizer.optimize();
} catch (FrontendException fe) {
// Need to go through and see what the collector has in it. But
// remember what we've caught so we can wrap it into what we
// throw.
caught = fe;
}
return plan;
}
}