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ucar.nc2.iosp.hdf5.H5header Maven / Gradle / Ivy

/*
 * Copyright 1998-2009 University Corporation for Atmospheric Research/Unidata
 *
 * Portions of this software were developed by the Unidata Program at the
 * University Corporation for Atmospheric Research.
 *
 * Access and use of this software shall impose the following obligations
 * and understandings on the user. The user is granted the right, without
 * any fee or cost, to use, copy, modify, alter, enhance and distribute
 * this software, and any derivative works thereof, and its supporting
 * documentation for any purpose whatsoever, provided that this entire
 * notice appears in all copies of the software, derivative works and
 * supporting documentation.  Further, UCAR requests that the user credit
 * UCAR/Unidata in any publications that result from the use of this
 * software or in any product that includes this software. The names UCAR
 * and/or Unidata, however, may not be used in any advertising or publicity
 * to endorse or promote any products or commercial entity unless specific
 * written permission is obtained from UCAR/Unidata. The user also
 * understands that UCAR/Unidata is not obligated to provide the user with
 * any support, consulting, training or assistance of any kind with regard
 * to the use, operation and performance of this software nor to provide
 * the user with any updates, revisions, new versions or "bug fixes."
 *
 * THIS SOFTWARE IS PROVIDED BY UCAR/UNIDATA "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL UCAR/UNIDATA BE LIABLE FOR ANY SPECIAL,
 * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE ACCESS, USE OR PERFORMANCE OF THIS SOFTWARE.
 */
package ucar.nc2.iosp.hdf5;

import ucar.unidata.io.RandomAccessFile;
import ucar.nc2.units.DateFormatter;
import ucar.nc2.*;
import ucar.nc2.EnumTypedef;
import ucar.nc2.iosp.netcdf3.N3iosp;
import ucar.nc2.iosp.LayoutTiled;
import ucar.nc2.iosp.Layout;
import ucar.nc2.iosp.LayoutRegular;
import ucar.ma2.*;
import ucar.unidata.util.SpecialMathFunction;

import java.util.*;
import java.text.*;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.*;
import java.nio.charset.Charset;

/**
 * Read all of the metadata of an HD5 file.
 *
 * @author caron
 */

/* Implementation notes
 * any field called address is actually reletive to the base address.
 * any field called filePos or dataPos is a byte offset within the file.
 */
public class H5header {
  static private org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(H5header.class);
  static private String utf8CharsetName = "UTF-8";
  static private Charset utf8Charset = Charset.forName(utf8CharsetName); // cant use until 1.6

  // debugging
  static private boolean debugEnum = false, debugVlen = false;
  static private boolean debug1 = false, debugDetail = false, debugPos = false, debugHeap = false, debugV = false;
  static private boolean debugGroupBtree = false, debugDataBtree = false, debugDataChunk = false, debugBtree2 = false;
  static private boolean debugContinueMessage = false, debugTracker = false, debugSoftLink = false, debugSymbolTable = false;
  static private boolean warnings = false, debugReference = false, debugRegionReference = false, debugCreationOrder = false, debugFractalHeap = false;
  static private boolean debugDimensionScales = false;

  static public void setDebugFlags(ucar.nc2.util.DebugFlags debugFlag) {
    debug1 = debugFlag.isSet("H5header/header");
    debugBtree2 = debugFlag.isSet("H5header/btree2");
    debugContinueMessage = debugFlag.isSet("H5header/continueMessage");
    debugDetail = debugFlag.isSet("H5header/headerDetails");
    debugDataBtree = debugFlag.isSet("H5header/dataBtree");
    debugDataChunk = debugFlag.isSet("H5header/dataChunk");
    debugGroupBtree = debugFlag.isSet("H5header/groupBtree");
    debugFractalHeap = debugFlag.isSet("H5header/fractalHeap");
    debugHeap = debugFlag.isSet("H5header/Heap");
    debugPos = debugFlag.isSet("H5header/filePos");
    debugReference = debugFlag.isSet("H5header/reference");
    debugSoftLink = debugFlag.isSet("H5header/softLink");
    debugSymbolTable = debugFlag.isSet("H5header/symbolTable");
    debugTracker = debugFlag.isSet("H5header/memTracker");
    debugV = debugFlag.isSet("H5header/Variable");
  }

  static private final byte[] head = {(byte) 0x89, 'H', 'D', 'F', '\r', '\n', 0x1a, '\n'};
  static private final String hdf5magic = new String(head);
  static private final long maxHeaderPos = 500000; // header's gotta be within this
  static private boolean transformReference = true;

  static boolean isValidFile(ucar.unidata.io.RandomAccessFile raf) throws IOException {
    long filePos = 0;
    long size = raf.length();
    byte[] b = new byte[8];

    // search forward for the header
    while ((filePos < size) && (filePos < maxHeaderPos)) {
      raf.seek(filePos);
      raf.read(b);
      String magic = new String(b);
      if (magic.equals(hdf5magic))
        return true;
      filePos = (filePos == 0) ? 512 : 2 * filePos;
    }

    return false;
  }

  ////////////////////////////////////////////////////////////////////////////////

  private RandomAccessFile raf;
  private ucar.nc2.NetcdfFile ncfile;
  private H5iosp h5iosp;

  private long baseAddress;
  private byte sizeOffsets, sizeLengths;
  private boolean isOffsetLong, isLengthLong;

  private H5Group rootGroup;
  private Map symlinkMap = new HashMap(200);
  private Map addressMap = new HashMap(200);

  private Map heapMap = new HashMap();
  //private Map hashGroups = new HashMap(100);

  DateFormatter formatter = new DateFormatter();
  private java.text.SimpleDateFormat hdfDateParser;

  private java.io.PrintStream debugOut = System.out;
  //private Formatter debugOut = new Formatter(System.out);
  private MemTracker memTracker;

  H5header(RandomAccessFile myRaf, ucar.nc2.NetcdfFile ncfile, H5iosp h5iosp) {
    this.ncfile = ncfile;
    this.raf = myRaf;
    this.h5iosp = h5iosp;
  }

  public void read(java.io.PrintStream debugPS) throws IOException {
    if (debugPS != null)
      debugOut = debugPS;

    long actualSize = raf.length();
    memTracker = new MemTracker(actualSize);

    if (!isValidFile(raf))
      throw new IOException("Not a netCDF4/HDF5 file ");
    // if (debug1) debugOut.format("H5header 0pened file to read:'%s' size= %d %n", ncfile.getLocation(), + actualSize);
    if (debug1) debugOut.println("H5header 0pened file to read:'" + raf.getLocation() +"' size= " + actualSize);
    // now we are positioned right after the header

    // header information is in le byte order
    raf.order(RandomAccessFile.LITTLE_ENDIAN);

    long superblockStart = raf.getFilePointer() - 8;
    memTracker.add("header", 0, superblockStart);

    // superblock version
    byte versionSB = raf.readByte();

    if (versionSB < 2) {
      readSuperBlock1(superblockStart, versionSB);
    } else if (versionSB == 2) {
      readSuperBlock2(superblockStart);
    } else {
      throw new IOException("Unknown superblock version= " + versionSB);
    }

    // now look for symbolic links
    replaceSymbolicLinks(rootGroup);

    // recursively run through all the dataObjects and add them to the ncfile
    makeNetcdfGroup(ncfile.getRootGroup(), rootGroup);

    /*if (debugReference) {
     System.out.println("DataObjects");
     for (DataObject ob : addressMap.values())
       System.out.println("  " + ob.name + " address= " + ob.address + " filePos= " + getFileOffset(ob.address));
   } */
    if (debugTracker) memTracker.report();
  }

  private void readSuperBlock1(long superblockStart, byte versionSB) throws IOException {
    byte versionFSS, versionGroup, versionSHMF;
    short btreeLeafNodeSize, btreeInternalNodeSize;
    int fileFlags;

    long heapAddress;
    long eofAddress;
    long driverBlockAddress;

    versionFSS = raf.readByte();
    versionGroup = raf.readByte();
    raf.readByte(); // skip 1 byte
    versionSHMF = raf.readByte();
    if (debugDetail)
      debugOut.println(" versionSB= " + versionSB + " versionFSS= " + versionFSS + " versionGroup= " + versionGroup +
          " versionSHMF= " + versionSHMF);

    sizeOffsets = raf.readByte();
    isOffsetLong = (sizeOffsets == 8);

    sizeLengths = raf.readByte();
    isLengthLong = (sizeLengths == 8);
    if (debugDetail) debugOut.println(" sizeOffsets= " + sizeOffsets + " sizeLengths= " + sizeLengths);
    if (debugDetail) debugOut.println(" isLengthLong= " + isLengthLong + " isOffsetLong= " + isOffsetLong);

    raf.read(); // skip 1 byte
    //debugOut.println(" position="+mapBuffer.position());

    btreeLeafNodeSize = raf.readShort();
    btreeInternalNodeSize = raf.readShort();
    if (debugDetail)
      debugOut.println(" btreeLeafNodeSize= " + btreeLeafNodeSize + " btreeInternalNodeSize= " + btreeInternalNodeSize);

    //debugOut.println(" position="+mapBuffer.position());

    fileFlags = raf.readInt();
    if (debugDetail) debugOut.println(" fileFlags= 0x" + Integer.toHexString(fileFlags));

    if (versionSB == 1) {
      short storageInternalNodeSize = raf.readShort();
      raf.skipBytes(2);
    }

    baseAddress = readOffset();
    heapAddress = readOffset();
    eofAddress = readOffset();
    driverBlockAddress = readOffset();

    if (baseAddress != superblockStart) {
      baseAddress = superblockStart;
      eofAddress += superblockStart;
      if (debugDetail) debugOut.println(" baseAddress set to superblockStart");
    }

    if (debugDetail) {
      debugOut.println(" baseAddress= 0x" + Long.toHexString(baseAddress));
      debugOut.println(" global free space heap Address= 0x" + Long.toHexString(heapAddress));
      debugOut.println(" eof Address=" + eofAddress);
      debugOut.println(" driver BlockAddress= 0x" + Long.toHexString(driverBlockAddress));
      debugOut.println();
    }
    memTracker.add("superblock", superblockStart, raf.getFilePointer());

    // look for file truncation
    long fileSize = raf.length();
    if (fileSize < eofAddress)
      throw new IOException("File is truncated should be= " + eofAddress + " actual = " + fileSize+"%nlocation= "+raf.getLocation());

    // next comes the root objext's SymbolTableEntry
    SymbolTableEntry rootEntry = new SymbolTableEntry(raf.getFilePointer());

    // extract the root group object, recursively read all objects
    long rootObjectAddress = rootEntry.getObjectAddress();
    DataObjectFacade f = new DataObjectFacade(null, "", rootObjectAddress);
    rootGroup = new H5Group(f);

    /* LOOK what is this crap ??
    if (rootGroup.group == null) {
      // if the root object doesnt have a group message, check if the rootEntry is cache type 2
      if (rootEntry.btreeAddress != 0) {
        rootGroup.group = new GroupOld(null, "", rootEntry.btreeAddress, rootEntry.nameHeapAddress);
      } else {
        throw new IllegalStateException("root object not a group");
      }
    } */
  }

  private void readSuperBlock2(long superblockStart) throws IOException {
    sizeOffsets = raf.readByte();
    isOffsetLong = (sizeOffsets == 8);

    sizeLengths = raf.readByte();
    isLengthLong = (sizeLengths == 8);
    if (debugDetail) debugOut.println(" sizeOffsets= " + sizeOffsets + " sizeLengths= " + sizeLengths);
    if (debugDetail) debugOut.println(" isLengthLong= " + isLengthLong + " isOffsetLong= " + isOffsetLong);

    byte fileFlags = raf.readByte();
    if (debugDetail) debugOut.println(" fileFlags= 0x" + Integer.toHexString(fileFlags));

    baseAddress = readOffset();
    long extensionAddress = readOffset();
    long eofAddress = readOffset();
    long rootObjectAddress = readOffset();
    int checksum = raf.readInt();

    if (debugDetail) {
      debugOut.println(" baseAddress= 0x" + Long.toHexString(baseAddress));
      debugOut.println(" extensionAddress= 0x" + Long.toHexString(extensionAddress));
      debugOut.println(" eof Address=" + eofAddress);
      debugOut.println(" rootObjectAddress= 0x" + Long.toHexString(rootObjectAddress));
      debugOut.println();
    }

    memTracker.add("superblock", superblockStart, raf.getFilePointer());

    if (baseAddress != superblockStart) {
      baseAddress = superblockStart;
      eofAddress += superblockStart;
      if (debugDetail) debugOut.println(" baseAddress set to superblockStart");
    }

    // look for file truncation
    long fileSize = raf.length();
    if (fileSize < eofAddress)
      throw new IOException("File is truncated should be= " + eofAddress + " actual = " + fileSize);

    DataObjectFacade f = new DataObjectFacade(null, "", rootObjectAddress);
    rootGroup = new H5Group(f);
  }

  private void replaceSymbolicLinks(H5Group group) {
    if (group == null) return;

    List objList = group.nestedObjects;
    int count = 0;
    while (count < objList.size()) {
      DataObjectFacade dof = objList.get(count);

      if (dof.group != null) {           // group - recurse
        replaceSymbolicLinks(dof.group);

      } else if (dof.linkName != null) { // symbolic links
        DataObjectFacade link = symlinkMap.get(dof.linkName);
        if (link == null) {
          log.error(" WARNING Didnt find symbolic link=" + dof.linkName + " from " + dof.name);
          objList.remove(count);
          continue;
        }

        // dont allow loops
        if (link.group != null) {
          if (group.isChildOf(link.group)) {
            log.error(" ERROR Symbolic Link loop found =" + dof.linkName);
            objList.remove(count);
            continue;
          }
        }

        objList.set(count, link);
        if (debugSoftLink) debugOut.println("  Found symbolic link=" + dof.linkName);
      }

      count++;
    }
  }

  ///////////////////////////////////////////////////////////////
  // construct netcdf objects

  private void makeNetcdfGroup(ucar.nc2.Group ncGroup, H5Group h5group) throws IOException {
    if (h5group == null) return;

    // look for dimension scales
    for (DataObjectFacade facade : h5group.nestedObjects) {
      if (facade.isVariable)
        findDimensionScales(ncGroup, h5group, facade);
    }
    for (DataObjectFacade facade : h5group.nestedObjects) {
      if (facade.isVariable)
        findDimensionLists(ncGroup, h5group, facade);
    }
    createDimensions(ncGroup, h5group);

    // nested objects - groups and variables
    for (DataObjectFacade facadeNested : h5group.nestedObjects) {

      if (facadeNested.isGroup) {
        ucar.nc2.Group nestedGroup = new ucar.nc2.Group(ncfile, ncGroup, facadeNested.name);
        ncGroup.addGroup(nestedGroup);
        if (debug1) debugOut.println("--made Group " + nestedGroup.getName() + " add to " + ncGroup.getName());
        H5Group h5groupNested = new H5Group(facadeNested);
        makeNetcdfGroup(nestedGroup, h5groupNested);

      } else if (facadeNested.isVariable) {
        if (debugReference && facadeNested.dobj.mdt.type == 7) debugOut.println(facadeNested);

        Variable v = makeVariable(ncGroup, facadeNested);
        if ((v != null) && (v.getDataType() != null)) {
          v.setParentGroup(ncGroup);
          ncGroup.addVariable(v);

          if (v.getDataType().isEnum()) {
            EnumTypedef enumTypedef = ncGroup.findEnumeration(facadeNested.name);
            if (enumTypedef == null) {
              enumTypedef = new EnumTypedef(facadeNested.name, facadeNested.dobj.mdt.map);
              ncGroup.addEnumeration(enumTypedef);
            }
            v.setEnumTypedef(enumTypedef);
          }

          Vinfo vinfo = (Vinfo) v.getSPobject();
          if (debugV) debugOut.println("  made Variable " + v.getName() + "  vinfo= " + vinfo + "\n" + v);
        }

      } else if (facadeNested.isTypedef) {
        if (debugReference && facadeNested.dobj.mdt.type == 7) debugOut.println(facadeNested);

        if (facadeNested.dobj.mdt.map != null) {
          EnumTypedef enumTypedef = ncGroup.findEnumeration(facadeNested.name);
          if (enumTypedef == null) {
            enumTypedef = new EnumTypedef(facadeNested.name, facadeNested.dobj.mdt.map);
            ncGroup.addEnumeration(enumTypedef);
          }
        }
        if (debugV) debugOut.println("  made enumeration " + facadeNested.name);

      } else if (!facadeNested.isDimensionNotVariable && warnings) {
        debugOut.println("WARN:  DataObject ndo " + facadeNested + " not a Group or a Variable");
      }

    } // loop over nested objects

    // create group attributes last. need enums to be found first
    filterAttributes(h5group.facade.dobj.attributes);
    for (MessageAttribute matt : h5group.facade.dobj.attributes) {
      try {
        makeAttributes(null, matt, ncGroup.getAttributes());
      } catch (InvalidRangeException e) {
        throw new IOException(e.getMessage());
      }
    }

    // add system attributes
    processSystemAttributes(h5group.facade.dobj.messages, ncGroup.getAttributes());


  }

  private void findDimensionScales(ucar.nc2.Group g, H5Group h5group, DataObjectFacade facade) throws IOException {
    // first must look for coordinate variables (dimension scales)
    Iterator iter = facade.dobj.attributes.iterator();
    while (iter.hasNext()) {
      MessageAttribute matt = iter.next();
      if (matt.name.equals("CLASS")) {
        Attribute att = makeAttribute(matt);
        String val = att.getStringValue();
        if (val.equals("DIMENSION_SCALE")) { // create a dimension
          facade.dimList = addDimension(g, h5group, facade.name, facade.dobj.mds.dimLength[0], facade.dobj.mds.maxLength[0] == -1);
          iter.remove();
          if (debugDimensionScales) System.out.printf("Found dimScale %s for group '%s' matt=%s %n",
                  facade.dimList, g.getName(), matt);
        }
      }
    }
  }

  private void findDimensionLists(ucar.nc2.Group g, H5Group h5group, DataObjectFacade facade) throws IOException {
    // now look for dimension lists and clean up the attributes
    Iterator iter = facade.dobj.attributes.iterator();
    while (iter.hasNext()) {
      MessageAttribute matt = iter.next();
      // find the dimensions - set length to maximum
      if (matt.name.equals("DIMENSION_LIST")) { // references : may extend the dimension length
        Attribute att = makeAttribute(matt);
        StringBuilder sbuff = new StringBuilder();
        for (int i = 0; i < att.getLength(); i++) {
          String name = att.getStringValue(i);
          String dimName = extendDimension(g, h5group, name, facade.dobj.mds.dimLength[i]);
          sbuff.append(dimName).append(" ");
        }
        facade.dimList = sbuff.toString();
        if (debugDimensionScales) System.out.printf("Found dimList '%s' for group '%s' matt=%s %n",
                facade.dimList, g.getName(), matt);
        iter.remove();

      } else if (matt.name.equals("NAME")) {
        Attribute att = makeAttribute(matt);
        String val = att.getStringValue();
        if (val.startsWith("This is a netCDF dimension but not a netCDF variable")) {
          facade.isVariable = false;
          facade.isDimensionNotVariable = true;
        }
        iter.remove();
        if (debugDimensionScales) System.out.printf("Found %s %n", val);

      } else if (matt.name.equals("REFERENCE_LIST"))
        iter.remove();
    }

  }

   /* private String addDimension(ucar.nc2.Group g, H5Group h5group, String name, int length, boolean isUnlimited) {
    int pos = name.lastIndexOf("/");
    String dimName = (pos > 0) ? name.substring(pos + 1) : name;
    Dimension d = h5group.dimMap.get(dimName); // first look in current group
    if (d == null) {
      d = new Dimension(dimName, length, true, isUnlimited, false);
      d.setGroup(g);
      h5group.dimMap.put(dimName, d);
      h5group.dimList.add(d);
      if (debugDimensionScales) debugOut.println("addDimension name=" + name + " dim= " + d + " to group " + g);
    }

    return d.getName();
  }  */

  private String addDimension(ucar.nc2.Group g, H5Group h5group, String name, int length, boolean isUnlimited) {
    int pos = name.lastIndexOf("/");
    String dimName = (pos > 0) ? name.substring(pos + 1) : name;

    Dimension d = h5group.dimMap.get(dimName); // first look in current group
    //if (d == null)
    //  d = g.findDimension(dimName); // then look in parent groups

    if (d == null) { // create if not found
      d = new Dimension(dimName, length, true, isUnlimited, false);
      d.setGroup(g);
      h5group.dimMap.put(dimName, d);
      h5group.dimList.add(d);
      if (debugDimensionScales) debugOut.println("addDimension name=" + name + " dim= " + d + " to group " + g);

    }

    return d.getName();
  }

  private String extendDimension(ucar.nc2.Group g, H5Group h5group, String name, int length) {
    int pos = name.lastIndexOf("/");
    String dimName = (pos > 0) ? name.substring(pos + 1) : name;

    Dimension d = h5group.dimMap.get(dimName); // first look in current group
    if (d == null)
      d = g.findDimension(dimName); // then look in parent groups

    if (d != null) {
      if (length > d.getLength())
        d.setLength(length);
      return d.getName();
    }

    return null;
  }

  private void createDimensions(ucar.nc2.Group g, H5Group h5group) throws IOException {
    for (Dimension d : h5group.dimList) {
      g.addDimension(d);
    }
  }

  private void filterAttributes(List attList) {
    Iterator iter = attList.iterator();
    while (iter.hasNext()) {
      MessageAttribute matt = iter.next();
      if (matt.name.equals("_nc3_strict")) iter.remove();
    }
  }

  /**
   * Create Attribute objects from the MessageAttribute and add to list
   *
   * @param s       if attribute for a Structure, then deconstruct and add to member variables
   * @param matt    attribute message
   * @param attList add Attribute to this list
   * @throws IOException on io error
   * @throws ucar.ma2.InvalidRangeException on shape error
   */
  private void makeAttributes(Structure s, MessageAttribute matt, List attList) throws IOException, InvalidRangeException {
    MessageDatatype mdt = matt.mdt;

    if (mdt.type == 6) { // structure
      Vinfo vinfo = new Vinfo(matt.mdt, matt.mds, matt.dataPos);
      ArrayStructure attData = (ArrayStructure) readAttributeData(matt, vinfo, DataType.STRUCTURE);

      if (null == s) {
        // flatten and add to list
        for (StructureMembers.Member sm : attData.getStructureMembers().getMembers()) {
          Array memberData = attData.extractMemberArray(sm);
          attList.add(new Attribute(matt.name+"."+sm.getName(), memberData));
        }

      } else {  // assign seperate attribute for each member
        StructureMembers smember = attData.getStructureMembers();
        for (Variable v : s.getVariables()) {
          StructureMembers.Member sm = smember.findMember(v.getShortName());
          if (null != sm) {
            Array memberData = attData.extractMemberArray(sm);
            v.addAttribute(new Attribute(matt.name, memberData));
          }
        }

        // look for unassigned membres, add to the list
        for (StructureMembers.Member sm : attData.getStructureMembers().getMembers()) {
          if (s.findVariable(sm.getName()) == null) {
            Array memberData = attData.extractMemberArray(sm);
            attList.add(new Attribute(matt.name+"."+sm.getName(), memberData));
          }
        }
      }

    } else {
      // make a single attribute
      attList.add( makeAttribute(matt));
    }

    // reading attribute values might change byte order during a read
    // put back to little endian for further header processing
    raf.order(RandomAccessFile.LITTLE_ENDIAN);
  }

  private Attribute makeAttribute(MessageAttribute matt) throws IOException {
    Vinfo vinfo = new Vinfo(matt.mdt, matt.mds, matt.dataPos);
    DataType dtype = vinfo.getNCDataType();

    // check for empty attribute case
    if (matt.mds.type == 2) {
      return new Attribute(matt.name, dtype);
    }

    Array attData = null;
    try {
      attData = readAttributeData(matt, vinfo, dtype);
      attData.setUnsigned(matt.mdt.unsigned);
      
    } catch (InvalidRangeException e) {
      log.error("failed to read Attribute "+matt.name, e);
      return null;
    }

    Attribute result;
    if (attData.getElementType() == Array.class) { // vlen LOOK
      List