WriteDamsel.cpp

Go to the documentation of this file.

/* WriteDamsel.cpp
 * The Damsel library provides mesh-aware parallel I/O; see
 * http://cucis.ece.northwestern.edu/projects/DAMSEL/ for details, though for now that site is
 * restricted to project participants.  Damsel uses a data model that's very similar to that used in
 * MOAB and ITAPS.  It uses the same basic data model concepts of entities, sets, tags, and
 * interface. In theory, we should be able to completely save/restore to/from Damsel any data that
 * can be saved/restored to/from our native HDF5-based reader/writer.
 *
 * Mapping between MOAB-Damsel data models
 * =======================================
 * Basic data model entities, MOAB <--> Damsel:
 *        Entity <--> Entity
 *     EntitySet <--> Collection
 *           Tag <--> Tag
 * API/data strutures:
 *          Range (n1) <--> Sequence container
 *         std::vector <--> Vector container
 *          Range (n2) <--> Tree container
 *
 * n1: single contiguous subrange
 * n2: multiple subranges
 *
 * Conventions
 * ===========
 * There are parts of MOAB data structures that need to be stored to Damsel that aren't represented
 * in the Damsel data model, e.g. dense vs. sparse storage type, set tracking flags.
 * - We need to store these as tags in Damsel.
 * - Since Damsel tags need to have a MOAB counterpart, we have to create those as tag data in MOAB
 * too (duplicating the data in the data structures, bummer).
 * - Because we may want to use these tags for multiple Damsel writes/models, we create the
 * MOAB-side tags in the WriteDamsel constructor, not in the init_tags function that's called for
 * every write
 * - Conventional tags have names prefixed with mbdmsl_ to avoid name conflicts with other MOAB
 * tags. Here we list the conventional tags used by MOAB's Damsel reader/writer.
 *
 * Tag name                   Tag char's (storage type, data type, length, def val)       Values,
 * used for what
 * --------                   -----------------------------------------------------
 * -------------------- mbdmsl_XCOORDS             dense; double[1]; 0.0 MOAB vertex x coordinate
 * mbdmsl_YCOORDS             dense; double[1]; 0.0                                       MOAB
 * vertex y coordinate mbdmsl_ZCOORDS             dense; double[1]; 0.0 MOAB vertex z coordinate
 * mbdmsl_COLL_FLAGS          sparse; char; 1; 0x0                                        bit 0:
 * 0=set-type, 1=vector-type 1: 1=tracking, 0=not tracking mbdmsl_PARENTS      sparse; handle; var;
 * (list of parent sets) mbdmsl_CHILDS       sparse; handle; var; (list of child sets)
 *
 *
 *
 */

#include "WriteDamsel.hpp"

#include "DamselUtil.hpp"
#include "damsel.h"
#include "assert.h"
#include "moab/Interface.hpp"
#include "moab/Core.hpp"
#include "moab/Range.hpp"
#include "moab/Error.hpp"
#include "moab/WriteUtilIface.hpp"
#include "MBTagConventions.hpp"
#include "EntitySequence.hpp"
#include "Internals.hpp"
#include "DenseTag.hpp"
#include "SparseTag.hpp"

namespace moab
{

WriterIface* WriteDamsel::factory( Interface* iface )
{
    return new WriteDamsel( iface );
}

WriteDamsel::WriteDamsel( Interface* impl )
    : mbImpl( impl ), mWriteIface( NULL ), sequenceManager( NULL ), dU(), DAMSEL_FLAGS( DAMSEL_IS_TRACKING )
{
    assert( impl != NULL );

    impl->query_interface( mWriteIface );
    assert( mWriteIface );

    sequenceManager = dynamic_cast< Core* >( impl )->sequence_manager();
    assert( sequenceManager );

    ErrorCode rval =
        mbImpl->tag_get_handle( "mbdmsl_XCOORDS", 1, MB_TYPE_DOUBLE, dU.xcoordsTag.mTagh, MB_TAG_DENSE | MB_TAG_CREAT );MB_CHK_SET_ERR_CONT( rval, "Failed to create_tag mbdmsl_XCOORDS" );
    dU.xcoordsTag.tagType = MB_TAG_ANY;
    dU.tagMap.push_back( dU.xcoordsTag );
    rval =
        mbImpl->tag_get_handle( "mbdmsl_YCOORDS", 1, MB_TYPE_DOUBLE, dU.ycoordsTag.mTagh, MB_TAG_DENSE | MB_TAG_CREAT );MB_CHK_SET_ERR_CONT( rval, "Failed to create_tag mbdmsl_YCOORDS" );
    dU.ycoordsTag.tagType = MB_TAG_ANY;
    dU.tagMap.push_back( dU.ycoordsTag );

    rval =
        mbImpl->tag_get_handle( "mbdmsl_ZCOORDS", 1, MB_TYPE_DOUBLE, dU.zcoordsTag.mTagh, MB_TAG_DENSE | MB_TAG_CREAT );MB_CHK_SET_ERR_CONT( rval, "Failed to create_tag mbdmsl_ZCOORDS" );
    dU.zcoordsTag.tagType = MB_TAG_ANY;
    dU.tagMap.push_back( dU.zcoordsTag );

    rval = mbImpl->tag_get_handle( "mbdmsl_COLL_FLAGS", 1, MB_TYPE_INTEGER, dU.collFlagsTag.mTagh,
                                   MB_TAG_DENSE | MB_TAG_CREAT );MB_CHK_SET_ERR_CONT( rval, "Failed to create_tag mbdmsl_COLL_FLAGS" );
    dU.collFlagsTag.tagType = MB_TAG_ANY;
    dU.tagMap.push_back( dU.collFlagsTag );

    /*
      rval = mbImpl->tag_get_handle("mbdmsl_PARENTS", 1, MB_TYPE_HANDLE,
                                   dU.parentsTag.mTagh, MB_TAG_DENSE | MB_TAG_CREAT |
      MB_TAG_VARLEN);MB_CHK_SET_ERR_CONT(rval, "Failed to create_tag mbdmsl_PARENTS");
      dU.parentsTag.tagType = MB_TAG_DENSE;
      dU.tagMap.push_back(dU.parentsTag);

      rval = mbImpl->tag_get_handle("mbdmsl_CHILDREN", 1, MB_TYPE_HANDLE,
                                   dU.childrenTag.mTagh, MB_TAG_DENSE | MB_TAG_CREAT |
      MB_TAG_VARLEN);MB_CHK_SET_ERR_CONT(rval, "Failed to create_tag mbdmsl_CHILDREN");
      dU.childrenTag.tagType = MB_TAG_DENSE;
      dU.tagMap.push_back(dU.childrenTag);
    */

    dU.moabHandleType = ( sizeof( EntityHandle ) == 64 ? DAMSEL_HANDLE_TYPE_HANDLE64 : DAMSEL_HANDLE_TYPE_HANDLE32 );
}

WriteDamsel::~WriteDamsel()
{
    if( mWriteIface ) mbImpl->release_interface( mWriteIface );
}

ErrorCode WriteDamsel::write_file( const char* file_name, const bool /* overwrite */, const FileOptions& opts,
                                   const EntityHandle* meshset_list, const int num_sets,
                                   const std::vector< std::string >& /* qa_records */, const Tag* /* tag_list */,
                                   int /* num_tags */, int /* requested_output_dimension */ )
{
    // Gather all entities into one big range
    Range all_ents;
    ErrorCode rval;
    damsel_err_t err;

    dU.dmslLib = DMSLlib_init();

    // Create a damsel model
    dU.dmslModel =
        DMSLmodel_create( sizeof( EntityHandle ) == 8 ? DAMSEL_HANDLE_TYPE_HANDLE64 : DAMSEL_HANDLE_TYPE_HANDLE32 );

    // Attach to a file, since we need it for creating containers
    MPI_Comm comm = MPI_COMM_WORLD;
    unlink( file_name );
    err = DMSLmodel_attach( dU.dmslModel, file_name, comm, NULL );
    CHK_DMSL_ERR( err, "DMSLmodel_attach failed" );

    rval = mWriteIface->gather_entities( all_ents, meshset_list, num_sets );MB_CHK_SET_ERR( rval, "Gather entities failed in WriteDamsel" );

    if( all_ents.empty() ) return MB_SUCCESS;

    // Create damsel tags for MOAB dense, sparse, and conventional tags
    rval = init_tag_info();MB_CHK_ERR( rval );

    // Iterate through the groups of contiguous sequences of handles
    RangeSeqIntersectIter rsi( sequenceManager );
    rval = rsi.init( all_ents.begin(), all_ents.end() );

    while( MB_SUCCESS == rval )
    {
        // Write subrange of things to damsel: map handles, map entity definition data
        // (connectivity/coords/set contents), map dense tags
        rval = write_subrange( rsi );MB_CHK_SET_ERR( rval, "Failed to write subrange" );

        rval = rsi.step();
        while( MB_ENTITY_NOT_FOUND == rval )
            rval = rsi.step();
    }

    // Write sparse tags
    rval = map_sparse_tags();MB_CHK_SET_ERR( rval, "Failed to write sparse tags" );

    // damsel_request_t request;
    // err = DMSLmodel_transfer_async(dU.dmslModel, DAMSEL_TRANSFER_TYPE_WRITE, &request);
    err = DMSLmodel_transfer_sync( dU.dmslModel, DAMSEL_TRANSFER_TYPE_WRITE );
    CHK_DMSL_ERR( err, "DMSLmodel_transfer_asynch failed" );

    // damsel_status_t status;
    // err = DMSLmodel_wait(request, &status);CHK_DMSL_ERR(err, "DMSLmodel_wait failed");

    DMSLmodel_close( dU.dmslModel );

    DMSLlib_finalize( dU.dmslLib );

    // We should be done
    return MB_SUCCESS;
}

ErrorCode WriteDamsel::init_tag_info()
{
    // Initialize allTags and tagIndices
    std::vector< Tag > tmp_mtags;
    ErrorCode rval = mbImpl->tag_get_tags( tmp_mtags );MB_CHK_SET_ERR( rval, "Failed to get all tag handles." );
    int dum_size;
    damsel_err_t err;

    // Define damsel tag handles for all dense/sparse tags
    for( std::vector< Tag >::iterator vit = tmp_mtags.begin(); vit != tmp_mtags.end(); ++vit )
    {
        if( ( ( *vit )->get_storage_type() != MB_TAG_DENSE && ( *vit )->get_storage_type() != MB_TAG_SPARSE ) ||
            mbImpl->tag_get_length( *vit, dum_size ) == MB_VARIABLE_DATA_LENGTH || dum_size != 1 )
        {
            std::cerr << "Warning: tag " << ( *vit )->get_name()
                      << "is not of type dense or sparse, and is not currently supported by the "
                         "damsel writer."
                      << std::endl;
            continue;
        }

        std::vector< DamselUtil::tinfo >::iterator vit2 =
            std::find_if( dU.tagMap.begin(), dU.tagMap.end(), DamselUtil::MtagP< DamselUtil::tinfo >( *vit ) );

        if( vit2 != dU.tagMap.end() && ( *vit2 ).tagType == MB_TAG_ANY )
            // Conventional tag - skip
            continue;

        else if( vit2 == dU.tagMap.end() )
        {
            // Create a damsel counterpart for this tag
            Tag thandle = *vit;
            err         = DMSLtag_define( dU.dmslModel, (damsel_handle_ptr)&thandle,
                                  DamselUtil::mtod_data_type[( *vit )->get_data_type()], ( *vit )->get_name().c_str() );
            CHK_DMSL_ERR( err, "Failure to get Damsel tag for MOAB tag" );
            dU.tagMap.push_back( DamselUtil::tinfo( thandle, 0, ( *vit )->get_storage_type() ) );
        }
        else
        {
            // Assert there's a corresponding moab tag handle
            assert( ( *vit2 ).mTagh );
        }
    }

    // Do the same for conventional tags:
    // XCOORDS
    err = DMSLtag_define( dU.dmslModel, ( damsel_handle_ptr ) & ( dU.xcoordsTag.mTagh ),
                          DamselUtil::mtod_data_type[MB_TYPE_DOUBLE], dU.xcoordsTag.mTagh->get_name().c_str() );
    dU.tagMap.push_back( dU.xcoordsTag );
    CHK_DMSL_ERR( err, "Failure to get Damsel tag for MOAB tag" );

    // YCOORDS
    err = DMSLtag_define( dU.dmslModel, ( damsel_handle_ptr ) & ( dU.ycoordsTag.mTagh ),
                          DamselUtil::mtod_data_type[MB_TYPE_DOUBLE], dU.ycoordsTag.mTagh->get_name().c_str() );
    dU.tagMap.push_back( dU.ycoordsTag );
    CHK_DMSL_ERR( err, "Failure to get Damsel tag for MOAB tag" );

    // ZCOORDS
    err = DMSLtag_define( dU.dmslModel, ( damsel_handle_ptr ) & ( dU.zcoordsTag.mTagh ),
                          DamselUtil::mtod_data_type[MB_TYPE_DOUBLE], dU.zcoordsTag.mTagh->get_name().c_str() );
    dU.tagMap.push_back( dU.zcoordsTag );
    CHK_DMSL_ERR( err, "Failure to get Damsel tag for MOAB tag" );

    // COLL_FLAGS
    err = DMSLtag_define( dU.dmslModel, ( damsel_handle_ptr ) & ( dU.collFlagsTag.mTagh ),
                          DamselUtil::mtod_data_type[MB_TYPE_INTEGER], dU.collFlagsTag.mTagh->get_name().c_str() );
    dU.tagMap.push_back( dU.collFlagsTag );
    CHK_DMSL_ERR( err, "Failure to get Damsel tag for MOAB tag" );

    /*
      SKIP PARENTS/CHILDREN FOR NOW, UNTIL WE HAVE VAR LENGTH TAGS IN DAMSEL

      // PARENTS
      dU.parentsTagPair.second = DMSLtag_define(dU.dmslModel,
      (damsel_handle_ptr)&(dU.collFlagsTagPair.first),
                                               DamselUtil::mtod_data_type[(dU.collFlagsTagPair.first)->get_data_type()],
                                               (dU.parentsTagPair.first)->get_name().c_str());
      if (DAMSEL_TAG_INVALID == dtag)
        MB_SET_ERR(MB_FAILURE, "Failure to get Damsel tag for MOAB tag " <<
      (dU.parentsTagPair.first)->get_name());

      // CHILDREN
      dU.childrenTagPair.second = DMSLtag_define(dU.dmslModel,
      (damsel_handle_ptr)&(dU.collFlagsTagPair.first),
                                               DamselUtil::mtod_data_type[(dU.collFlagsTagPair.first)->get_data_type()],
                                               (dU.childrenTagPair.first)->get_name().c_str());
      if (DAMSEL_TAG_INVALID == dtag)
        MB_SET_ERR(MB_FAILURE, "Failure to get Damsel tag for MOAB tag " <<
      (dU.childrenTagPair.first)->get_name());
    */

    // Map the tag handles in one big call
    int num_tags = dU.tagMap.size();
    std::vector< Tag > moab_taghs;
    moab_taghs.reserve( num_tags );
    for( std::vector< DamselUtil::tinfo >::iterator vit = dU.tagMap.begin(); vit != dU.tagMap.end(); ++vit )
    {
        moab_taghs.push_back( ( *vit ).mTagh );
    }

    damsel_container mtags =
        DMSLcontainer_create_vector( dU.dmslModel, (damsel_handle_ptr)&moab_taghs[0], moab_taghs.size() );
    std::cerr << "MOAB: created model container: mtags = " << mtags << std::endl;

    err = DMSLmodel_map_handles_inventing_file_handles( mtags );
    CHK_DMSL_ERR( err, "Failed to map tag handles" );

    err = DMSLcontainer_release( mtags );
    CHK_DMSL_ERR( err, "Problem releasing tag handle container" );

    return MB_SUCCESS;
}

ErrorCode WriteDamsel::write_vertices( RangeSeqIntersectIter& rsi )
{
    // Write the vertices; these vertices will be in the same sequence and will be contiguous,
    // guaranteed
    EntityHandle start_vert = rsi.get_start_handle(), end_vert = rsi.get_end_handle();

    // Create a damsel container for these vertex handles
    damsel_container vertex_cont =
        DMSLcontainer_create_sequence( dU.dmslModel, start_vert, (int)( end_vert - start_vert + 1 ), 1 );
    std::cerr << "MOAB: created model container: vertex_cont = " << vertex_cont << std::endl;
    if( DAMSEL_CONTAINER_INVALID == vertex_cont )
        MB_SET_ERR( MB_FAILURE,
                    "Failed to create vertex sequence for vertices starting with handle " << rsi.get_start_handle() );

    damsel_err_t err = DMSLmodel_map_handles_inventing_file_handles( vertex_cont );
    CHK_DMSL_ERR( err, "Failed to map handles" );

    // Define the entities to damsel
    err = DMSLentity_define( vertex_cont, DAMSEL_ENTITY_TYPE_VERTEX, 1, vertex_cont );
    CHK_DMSL_ERR( err, "Failure in DMSLentity_define for vertices starting with handle " << rsi.get_start_handle() );

    // Get the vertex coordinates storage locations and pass to damsel
    Range vert_range( start_vert, end_vert );
    double *xcoords = NULL, *ycoords = NULL, *zcoords = NULL;
    int count;
    ErrorCode rval = mbImpl->coords_iterate( vert_range.begin(), vert_range.end(), xcoords, ycoords, zcoords, count );MB_CHK_SET_ERR( rval,
                    "Failed to get coordinate iterator for vertices starting with handle " << rsi.get_start_handle() );
    if( count != (int)vert_range.size() )
    {
        MB_SET_ERR( MB_FAILURE, "Vertex subrange not in the same sequence for vertices starting with handle "
                                    << rsi.get_start_handle() );
    }

    if( xcoords && !ycoords && !zcoords )
    {
        // Interleaved

        // Map the data to damsel
        err = DMSLmodel_map_tag( xcoords, vertex_cont, (damsel_handle_ptr)&dU.xcoordsTag.mTagh );
        CHK_DMSL_ERR( err, "Failed to assign vertex coordinates tag for vertices starting with handle "
                               << rsi.get_start_handle() );
    }
    else
    {
        // Map the data to damsel
        err = DMSLmodel_map_tag( xcoords, vertex_cont, (damsel_handle_ptr)&dU.xcoordsTag.mTagh );
        CHK_DMSL_ERR( err, "Failed to assign vertex x coordinates tag for vertices starting with handle "
                               << rsi.get_start_handle() );
        err = DMSLmodel_map_tag( ycoords, vertex_cont, (damsel_handle_ptr)&dU.ycoordsTag.mTagh );
        CHK_DMSL_ERR( err, "Failed to assign vertex y coordinates tag for vertices starting with handle "
                               << rsi.get_start_handle() );
        err = DMSLmodel_map_tag( zcoords, vertex_cont, (damsel_handle_ptr)&dU.zcoordsTag.mTagh );
        CHK_DMSL_ERR( err, "Failed to assign vertex z coordinates tag for vertices starting with handle "
                               << rsi.get_start_handle() );
    }

    // Write/map dense tags
    rval = map_dense_tags( rsi, vertex_cont );MB_CHK_ERR( rval );

    err = DMSLcontainer_release( vertex_cont );
    CHK_DMSL_ERR( err, "Problem releasing vertex handle container" );

    return MB_SUCCESS;
}

ErrorCode WriteDamsel::write_entities( RangeSeqIntersectIter& rsi )
{
    // Write the entities; these entities will be in the same sequence and will be contiguous,
    // guaranteed
    EntityHandle start_ent = rsi.get_start_handle(), end_ent = rsi.get_end_handle();

    // Create a damsel container for these entity handles
    damsel_container ent_cont;
    ent_cont = DMSLcontainer_create_sequence( dU.dmslModel, start_ent, (int)( end_ent - start_ent + 1 ), 1 );
    std::cerr << "MOAB: created model container: ent_cont = " << ent_cont << std::endl;
    if( DAMSEL_CONTAINER_INVALID == ent_cont ) MB_SET_ERR( MB_FAILURE, "Bad sequence returned by Damsel" );

    damsel_err_t err = DMSLmodel_map_handles_inventing_file_handles( ent_cont );
    CHK_DMSL_ERR( err, "Failed to map handles" );

    // Get # verts per entity and entity type
    EntityType etype = mbImpl->type_from_handle( start_ent );
    assert( MBMAXTYPE != etype );
    int num_connect = rsi.get_sequence()->values_per_entity();
    assert( 0 < num_connect );

    // Get the connectivity storage location and pass to damsel
    Range ent_range( start_ent, end_ent );
    int count;
    EntityHandle* connect;
    int verts_per_ent;
    ErrorCode rval = mbImpl->connect_iterate( ent_range.begin(), ent_range.end(), connect, verts_per_ent, count );MB_CHK_SET_ERR( rval,
                    "Failed to get connect iterator for entities starting with handle " << rsi.get_start_handle() );
    if( count != (int)ent_range.size() )
        MB_SET_ERR( MB_FAILURE, "Entity subrange not in the same sequence for entities starting with handle "
                                    << rsi.get_start_handle() );

    // Define the entities to damsel
    err = DMSLentity_define_fast( ent_cont, DamselUtil::mtod_entity_type[etype], num_connect, (damsel_handle*)connect );
    CHK_DMSL_ERR( err, "DMSLentity_define failed for entities starting with handle " << rsi.get_start_handle() );

    // Write dense tags
    rval = map_dense_tags( rsi, ent_cont );MB_CHK_ERR( rval );

    err = DMSLcontainer_release( ent_cont );
    CHK_DMSL_ERR( err, "Problem releasing entity handle container" );

    return MB_SUCCESS;
}

ErrorCode WriteDamsel::map_dense_tags( RangeSeqIntersectIter& rsi, damsel_container& ent_cont )
{
    // All dense_tags have been initialized before this, so here we just go through
    // them and map data if there is any
    const unsigned char* val_ptr;
    ErrorCode rval = MB_SUCCESS;
    std::vector< DamselUtil::tinfo >::iterator tagit;
    damsel_err_t err;
    for( tagit = dU.tagMap.begin(); tagit != dU.tagMap.end(); ++tagit )
    {
        if( ( *tagit ).tagType != MB_TAG_DENSE ) continue;

        // Get a ptr to memory for this tag/sequence
        DenseTag* dtag = dynamic_cast< DenseTag* >( ( *tagit ).mTagh );
        assert( dtag );
        rval = dtag->get_array( rsi.get_sequence(), val_ptr );MB_CHK_SET_ERR( rval, "Failed to get tag coordinates pointer for vertices starting with handle "
                                  << rsi.get_start_handle() );

        // If ptr is NULL, no data for this tag in this sequence
        if( !val_ptr ) continue;

        // Else, register with damsel
        err = DMSLmodel_map_tag( (void*)val_ptr, ent_cont, (damsel_handle_ptr)&dtag );
        CHK_DMSL_ERR( err,
                      "Failed to write coordinates tag for vertices starting with handle " << rsi.get_start_handle() );
    }

    return rval;
}

ErrorCode WriteDamsel::map_sparse_tags()
{
    // All sparse_tags have been initialized before this, so here we just go through
    // them and map data if there is any
    ErrorCode rval = MB_SUCCESS;
    damsel_err_t err;
    std::vector< DamselUtil::tinfo >::iterator tagit;
    std::vector< unsigned char > tag_values;
    std::vector< EntityHandle > tagged_ents;
    damsel_container ent_cont;
    for( tagit = dU.tagMap.begin(); tagit != dU.tagMap.end(); ++tagit )
    {
        if( ( *tagit ).tagType != MB_TAG_SPARSE ) continue;
        // Get a ptr to memory for this tag/sequence
        SparseTag* stag = dynamic_cast< SparseTag* >( ( *tagit ).mTagh );
        assert( stag );
        Range output_ents;
        rval = stag->get_tagged_entities( sequenceManager, output_ents );MB_CHK_SET_ERR( rval, "Trouble getting tagged entities for tag " << stag->get_name() );

        // If no entities have this tag set, don't map it
        if( output_ents.empty() ) continue;

        // Else, register with damsel
        // Allocate space for and get values
        tag_values.resize( stag->get_size() * output_ents.size() );
        rval = mbImpl->tag_get_data( stag, output_ents, &tag_values[0] );MB_CHK_SET_ERR( rval, "Trouble getting tag values for tag " << stag->get_name() );

        // Build a vector of entity handles from the range, and a container from that
        tagged_ents.resize( output_ents.size() );
        std::copy( output_ents.begin(), output_ents.end(), tagged_ents.begin() );
        ent_cont = DMSLcontainer_create_vector( dU.dmslModel, (damsel_handle_ptr)&tagged_ents[0], tagged_ents.size() );
        std::cerr << "MOAB: created model container: sparse_tag_ent_cont = " << ent_cont << std::endl;
        if( DAMSEL_CONTAINER_INVALID == ent_cont )
            MB_SET_ERR( MB_FAILURE, "Trouble creating entity handle container for tag " << stag->get_name() );

        // Now map it
        err = DMSLmodel_map_tag( (void*)&tag_values[0], ent_cont, (damsel_handle_ptr)&stag );
        CHK_DMSL_ERR( err, "Failed to write tag " << stag->get_name() );

        err = DMSLcontainer_release( ent_cont );
        CHK_DMSL_ERR( err, "Problem releasing entity handle container" );
    }

    return rval;
}

ErrorCode WriteDamsel::write_sets( RangeSeqIntersectIter& rsi )
{
    // Write the sets
    ErrorCode rval = MB_SUCCESS;
    std::vector< EntityHandle > ents;
    damsel_container mcont;
    damsel_err_t err;
    unsigned int i, num_sets = rsi.get_end_handle() - rsi.get_start_handle() + 1;
    std::vector< unsigned int > set_flags( num_sets, 0 );
    EntityHandle seth;
    for( seth = rsi.get_start_handle(), i = 0; seth <= rsi.get_end_handle(); seth++, i++ )
    {
        // Get all the entities in the set
        ents.clear();
        rval = mbImpl->get_entities_by_handle( seth, ents );MB_CHK_SET_ERR( rval, "get_entities_by_handle failed for set " << seth );
        if( !ents.empty() )
        { mcont = DMSLcontainer_create_vector( dU.dmslModel, (damsel_handle*)&ents[0], ents.size() ); }
        else
        {
            mcont = DMSLcontainer_create_vector( dU.dmslModel, (damsel_handle*)NULL, 0 );
        }
        std::cerr << "MOAB: created model container: sets_cont = " << mcont << std::endl;

        // Get the set type (range or set)
        unsigned int opts;
        rval = mbImpl->get_meshset_options( seth, opts );MB_CHK_SET_ERR( rval, "Failed to get options for meshset " << seth );
        damsel_collection_type coll_type =
            ( opts & MESHSET_SET ? DAMSEL_HANDLE_COLLECTION_TYPE_SET : DAMSEL_HANDLE_COLLECTION_TYPE_VECTOR );

        // Parents/children...

        // Set flags
        if( opts & MESHSET_TRACK_OWNER )
            set_flags[i] |= MESHSET_TRACK_OWNER;
        else
            set_flags[i] &= !MESHSET_TRACK_OWNER;

        // Create the collection
        DMSLcoll_create( dU.dmslModel, (damsel_handle_ptr)&seth, mcont, coll_type );

        // Release the container
        err = DMSLcontainer_release( mcont );
        CHK_DMSL_ERR( err, "Problem releasing set entity handle container" );
    }

    // Set the COLL_FLAGS tag, using assign (direct)
    // Make a container of set handles...
    mcont = DMSLcontainer_create_sequence( dU.dmslModel, rsi.get_start_handle(), num_sets, 1 );
    std::cerr << "MOAB: created model container: sets_cont = " << mcont << std::endl;

    // Assign the tags on them
    err = DMSLmodel_map_tag( &set_flags[0], mcont, ( damsel_handle_ptr ) & ( dU.collFlagsTag.mTagh ) );
    CHK_DMSL_ERR( err, "Failed to assign COLL_FLAGS tag for sets" );

    // Map set handles
    err = DMSLmodel_map_handles_inventing_file_handles( mcont );
    CHK_DMSL_ERR( err, "Failed to map set handles" );

    // Map other dense tags
    rval = map_dense_tags( rsi, mcont );MB_CHK_SET_ERR( rval, "Failed to map dense tags for sets" );

    return rval;
}

}  // namespace moab