spork-master/src/org/apache/pig/newplan/logical/visitor/InputOutputFileValidatorVisitor.java
/*
 * 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.visitor;

import java.io.IOException;

import org.apache.hadoop.mapred.FileAlreadyExistsException;
import org.apache.hadoop.mapreduce.Job;
import org.apache.pig.OverwritableStoreFunc;
import org.apache.pig.PigException;
import org.apache.pig.ResourceSchema;
import org.apache.pig.StoreFuncInterface;
import org.apache.pig.backend.hadoop.datastorage.ConfigurationUtil;
import org.apache.pig.impl.PigContext;
import org.apache.pig.impl.logicalLayer.FrontendException;
import org.apache.pig.impl.plan.VisitorException;
import org.apache.pig.newplan.DepthFirstWalker;
import org.apache.pig.newplan.OperatorPlan;
import org.apache.pig.newplan.logical.relational.LOStore;
import org.apache.pig.newplan.logical.relational.LogicalRelationalNodesVisitor;

public class InputOutputFileValidatorVisitor extends LogicalRelationalNodesVisitor {
    private PigContext pigCtx;
    public InputOutputFileValidatorVisitor(OperatorPlan plan, PigContext pigContext) throws FrontendException {
        super(plan, new DepthFirstWalker(plan));
        pigCtx = pigContext;
    }

    @Override
    public void visit(LOStore store) throws FrontendException {
        StoreFuncInterface sf = store.getStoreFunc();
        String outLoc = store.getOutputSpec().getFileName();
        int errCode = 2116;
        String validationErrStr ="Output Location Validation Failed for: '" + outLoc ;
        Job dummyJob;
        
        try {
            if(store.getSchema() != null){
                sf.checkSchema(new ResourceSchema(store.getSchema(), store.getSortInfo()));                
            }
            dummyJob = new Job(ConfigurationUtil.toConfiguration(pigCtx.getProperties()));
            sf.setStoreLocation(outLoc, dummyJob);
        } catch (Exception ioe) {
            if(ioe instanceof PigException){
                errCode = ((PigException)ioe).getErrorCode();
            } 
            String exceptionMsg = ioe.getMessage();
            validationErrStr += (exceptionMsg == null) ? "" : " More info to follow:\n" +exceptionMsg;
            throw new VisitorException(store, validationErrStr, errCode, pigCtx.getErrorSource(), ioe);
        }
        
        validationErrStr += " More info to follow:\n";
        try {
            sf.getOutputFormat().checkOutputSpecs(dummyJob);
        } catch (IOException ioe) {
            byte errSrc = pigCtx.getErrorSource();
            switch(errSrc) {
            case PigException.BUG:
                errCode = 2002;
                break;
            case PigException.REMOTE_ENVIRONMENT:
                errCode = 6000;
                break;
            case PigException.USER_ENVIRONMENT:
                errCode = 4000;
                break;
            }

            boolean shouldThrowException = true;
            if (sf instanceof OverwritableStoreFunc) {
                if (((OverwritableStoreFunc) sf).shouldOverwrite()) {
                    if (ioe instanceof FileAlreadyExistsException
                            || ioe instanceof org.apache.hadoop.fs.FileAlreadyExistsException) {
                        shouldThrowException = false;
                    }
                }
            }
            if (shouldThrowException) {
                validationErrStr += ioe.getMessage();
                throw new VisitorException(store, validationErrStr,
                        errCode, errSrc, ioe);
            }
        } catch (InterruptedException ie) {
            validationErrStr += ie.getMessage();
            throw new VisitorException(store, validationErrStr, errCode, pigCtx.getErrorSource(), ie);
        }
    }
}
