DTAFileReaderSpi.java

/*
   Copyright (C) 2005-2014, by the President and Fellows of Harvard College.

   Licensed 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.

   Dataverse Network - A web application to share, preserve and analyze research data.
   Developed at the Institute for Quantitative Social Science, Harvard University.
   Version 3.0.
*/

package edu.harvard.iq.dataverse.ingest.tabulardata.impl.plugins.dta;


import edu.harvard.iq.dataverse.ingest.tabulardata.TabularDataFileReader;
import edu.harvard.iq.dataverse.ingest.tabulardata.spi.TabularDataFileReaderSpi;

import java.io.*;
import java.nio.*;
import java.nio.channels.*;
import java.util.logging.*;

import javax.imageio.IIOException;
import java.util.*;

import org.apache.commons.codec.binary.Hex;


/**
 * Service Provider registration class for the Stata/DTA ingest plugin.
 * Based on the code originally developed by Akio Sone, HMDC/ODUM 
 * for v.2 of the DVN.
 * 
 * @author Leonid Andreev
 * @author asone
 */
public class DTAFileReaderSpi extends TabularDataFileReaderSpi{

    private static Map<Byte, String> stataReleaseNumber = new HashMap<Byte, String>();

    static {
        stataReleaseNumber.put((byte) 104, "rel_3");
        stataReleaseNumber.put((byte) 105, "rel_4or5");
        stataReleaseNumber.put((byte) 108, "rel_6");
        stataReleaseNumber.put((byte) 110, "rel_7first");
        stataReleaseNumber.put((byte) 111, "rel_7scnd");
        stataReleaseNumber.put((byte) 113, "rel_8_or_9");
        stataReleaseNumber.put((byte) 114, "rel_10");
    }

    private static String[] formatNames = {"dta", "DTA"};
    private static String[] extensions = {"dta"};
    private static String[] mimeType = {"application/x-stata"};
    
    
    private static Logger dbgLog = Logger.getLogger(
            DTAFileReaderSpi.class.getPackage().getName());

    private static int DTA_HEADER_SIZE = 4;
    
    public DTAFileReaderSpi() {
        super("HU-IQSS-DataVerse-project",
            "4.0",
            formatNames,
            extensions,
            mimeType,
            "edu.harvard.iq.dataverse.ingest.tabulardata.impl.plugins.dta.DTAFileReaderSpi");
         dbgLog.fine("DTAFileReaderSpi is called");
    }

    public String getDescription(Locale locale) {
        return "HU-IQSS-DataVerse-project Stata File Ingest plugin";
    }

    @Override
    public boolean canDecodeInput(Object source) throws IOException {
        if (!(source instanceof BufferedInputStream)) {
            return false;
        }
        if (source ==null){
            throw new IllegalArgumentException("stream == null!");
        }
        BufferedInputStream stream = (BufferedInputStream)source;
        dbgLog.fine("applying the dta test\n");

        byte[] b = new byte[DTA_HEADER_SIZE];

        if (stream.markSupported()){
            stream.mark(0);
        }
        int nbytes = stream.read(b, 0, DTA_HEADER_SIZE);

        if (nbytes == 0){
            throw new IOException();
        }

        if (stream.markSupported()){
            stream.reset();
        }

       dbgLog.info("hex dump: 1st 4bytes =>" +
                new String(Hex.encodeHex(b)) + "<-");

        if (b[2] != 1) {
            dbgLog.fine("3rd byte is not 1: given file is not stata-dta type");
            return false;
        } else if ((b[1] != 1) && (b[1] != 2)) {
            dbgLog.fine("2nd byte is neither 0 nor 1: this file is not stata-dta type");
            return false;
        } else if (!DTAFileReaderSpi.stataReleaseNumber.containsKey(b[0])) {
            dbgLog.fine("1st byte (" + b[0]+
                    ") is not within the ingestable range [rel. 3-10]:"+
                    "this file is NOT stata-dta type");
            return false;
        } else {
            dbgLog.fine("this file is stata-dta type: " +
                    DTAFileReaderSpi.stataReleaseNumber.get(b[0]) +
                    "(No in byte=" + b[0] + ")");
            return true;
        }
    }

    @Override
    public boolean canDecodeInput(BufferedInputStream stream) throws IOException {
        if (stream ==null){
            throw new IllegalArgumentException("stream == null!");
        }

        dbgLog.fine("applying the dta test\n");

        byte[] b = new byte[DTA_HEADER_SIZE];
        
        if (stream.markSupported()){
            stream.mark(0);
        }
        int nbytes = stream.read(b, 0, DTA_HEADER_SIZE);

        if (nbytes == 0){
            throw new IOException();
        }

        if (stream.markSupported()){
            stream.reset();
        }
        
       dbgLog.info("hex dump: 1st 4bytes =>" +
                new String(Hex.encodeHex(b)) + "<-");

        if (b[2] != 1) {
            dbgLog.fine("3rd byte is not 1: given file is not stata-dta type");
            return false;
        } else if ((b[1] != 1) && (b[1] != 2)) {
            dbgLog.fine("2nd byte is neither 0 nor 1: this file is not stata-dta type");
            return false;
        } else if (!DTAFileReaderSpi.stataReleaseNumber.containsKey(b[0])) {
            dbgLog.fine("1st byte (" + b[0]+
                    ") is not within the ingestable range [rel. 3-10]:"+
                    "this file is NOT stata-dta type");
            return false;
        } else {
            dbgLog.fine("this file is stata-dta type: " +
                    DTAFileReaderSpi.stataReleaseNumber.get(b[0]) +
                    "(No in HEX=" + b[0] + ")");
            return true;
        }

    }


    @Override
    public boolean canDecodeInput(File file) throws IOException {
        if (file ==null){
            throw new IllegalArgumentException("file == null!");
        }
        if (!file.canRead()){
            throw new IIOException("cannot read the input file");
        }

        // set-up a FileChannel instance for a given file object
        FileChannel srcChannel = new FileInputStream(file).getChannel();

        // create a read-only MappedByteBuffer
        MappedByteBuffer buff = srcChannel.map(FileChannel.MapMode.READ_ONLY, 0, DTA_HEADER_SIZE);

        //printHexDump(buff, "hex dump of the byte-buffer");

        buff.rewind();

        dbgLog.fine("applying the dta test\n");

        byte[] hdr4 = new byte[4];
        buff.get(hdr4, 0, 4);

       dbgLog.fine("hex dump: 1st 4bytes =>" +
                new String(Hex.encodeHex(hdr4)) + "<-");

        if (hdr4[2] != 1) {
            dbgLog.fine("3rd byte is not 1: given file is not stata-dta type");
            return false;
        } else if ((hdr4[1] != 1) && (hdr4[1] != 2)) {
            dbgLog.fine("2nd byte is neither 0 nor 1: this file is not stata-dta type");
            return false;
        } else if (!stataReleaseNumber.containsKey(hdr4[0])) {
            dbgLog.fine("1st byte (" + hdr4[0] +
            ") is not within the ingestable range [rel. 3-10]: this file is NOT stata-dta type");
            return false;
        } else {
            dbgLog.fine("this file is stata-dta type: " +
                    stataReleaseNumber.get(hdr4[0]) +
                    "(No in HEX=" + hdr4[0] + ")");
            return true;
        }
    }
    
    @Override
    public TabularDataFileReader createReaderInstance(Object ext) throws IIOException {
        return new DTAFileReader(this);
    }
}