Cppcheck report - MOAB: src/io/ReadVtk.cpp

/**
 * MOAB, a Mesh-Oriented datABase, is a software component for creating,
 * storing and accessing finite element mesh data.
 *
 * Copyright 2004 Sandia Corporation.  Under the terms of Contract
 * DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government
 * retains certain rights in this software.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 */

/**
 * \class ReadVtk
 * \brief VTK reader from Mesquite
 * \author Jason Kraftcheck
 */

#include <cassert>
#include <cstdlib>
#include <cstring>

#include "ReadVtk.hpp"
#include "moab/Range.hpp"
#include "Internals.hpp"
#include "moab/Interface.hpp"
#include "moab/ReadUtilIface.hpp"
#include "moab/FileOptions.hpp"
#include "FileTokenizer.hpp"
#include "moab/VtkUtil.hpp"
#include "MBTagConventions.hpp"

// #define MB_VTK_MATERIAL_SETS
#ifdef MB_VTK_MATERIAL_SETS
#include <map>
#endif

namespace moab
{

#ifdef MB_VTK_MATERIAL_SETS

class Hash
{
  public:
    unsigned long value;

    Hash()
    {
        this->value = 5381L;
    }

    Hash( const unsigned char* bytes, size_t len )
    {  // djb2, a hash by dan bernstein presented on comp.lang.c for hashing strings.
        this->value = 5381L;
        for( ; len; --len, ++bytes )
            this->value = this->value * 33 + ( *bytes );
    }

    Hash( bool duh )
<--- Class 'Hash' has a constructor with 1 argument that is not explicit. [+]
Class 'Hash' has a constructor with 1 argument that is not explicit. Such constructors should in general be explicit for type safety reasons. Using the explicit keyword in the constructor means some mistakes when using the class can be avoided.
    {
        this->value = duh;  // Hashing a single bit with a long is stupid but easy.
    }

    Hash( const Hash& src )
    {
        this->value = src.value;
    }

    Hash& operator=( const Hash& src )
    {
        this->value = src.value;
        return *this;
    }

    bool operator<( const Hash& other ) const
    {
        return this->value < other.value;
    }
};

// Pass this class opaque data + a handle and it adds the handle to a set
// whose opaque data has the same hash. If no set exists for the hash,
// it creates one. Each set is tagged with the opaque data.
// When entities with different opaque data have the same hash, they
// will be placed into the same set.
// There will be no collisions when the opaque data is shorter than an
// unsigned long, and this is really the only case we need to support.
// The rest is bonus. Hash does quite well with strings, even those
// with identical prefixes.
class Modulator : public std::map< Hash, EntityHandle >
{
  public:
    Modulator( Interface* iface ) : mesh( iface ) {}
<--- Class 'Modulator' has a constructor with 1 argument that is not explicit. [+]
Class 'Modulator' has a constructor with 1 argument that is not explicit. Such constructors should in general be explicit for type safety reasons. Using the explicit keyword in the constructor means some mistakes when using the class can be avoided.

    ErrorCode initialize( std::string tag_name, DataType mb_type, size_t sz, size_t per_elem )
    {
        std::vector< unsigned char > default_val;
        default_val.resize( sz * per_elem );
        ErrorCode rval = this->mesh->tag_get_handle( tag_name.c_str(), per_elem, mb_type, this->tag,
                                                     MB_TAG_SPARSE | MB_TAG_BYTES | MB_TAG_CREAT, &default_val[0] );
        return rval;
    }

    void add_entity( EntityHandle ent, const unsigned char* bytes, size_t len )
    {
        Hash h( bytes, len );
        EntityHandle mset = this->congruence_class( h, bytes );
        ErrorCode rval;
        rval = this->mesh->add_entities( mset, &ent, 1 );MB_CHK_SET_ERR_RET( rval, "Failed to add entities to mesh" );
    }

    void add_entities( Range& range, const unsigned char* bytes, size_t bytes_per_ent )
    {
        for( Range::iterator it = range.begin(); it != range.end(); ++it, bytes += bytes_per_ent )
        {
            Hash h( bytes, bytes_per_ent );
            EntityHandle mset = this->congruence_class( h, bytes );
            ErrorCode rval;
            rval = this->mesh->add_entities( mset, &*it, 1 );MB_CHK_SET_ERR_RET( rval, "Failed to add entities to mesh" );
        }
    }

    EntityHandle congruence_class( const Hash& h, const void* tag_data )
    {
        std::map< Hash, EntityHandle >::iterator it = this->find( h );
        if( it == this->end() )
        {
            EntityHandle mset;
            Range preexist;
            ErrorCode rval;
            rval = this->mesh->get_entities_by_type_and_tag( 0, MBENTITYSET, &this->tag, &tag_data, 1, preexist );MB_CHK_SET_ERR_RET_VAL( rval, "Failed to get entities by type and tag", (EntityHandle)0 );
            if( preexist.size() )
            {
                mset = *preexist.begin();
            }
            else
            {
                rval = this->mesh->create_meshset( MESHSET_SET, mset );MB_CHK_SET_ERR_RET_VAL( rval, "Failed to create mesh set", (EntityHandle)0 );
                rval = this->mesh->tag_set_data( this->tag, &mset, 1, tag_data );MB_CHK_SET_ERR_RET_VAL( rval, "Failed to set tag data", (EntityHandle)0 );
            }
            ( *this )[h] = mset;
            return mset;
        }
        return it->second;
    }

    Interface* mesh;
    Tag tag;
};
#endif  // MB_VTK_MATERIAL_SETS

ReaderIface* ReadVtk::factory( Interface* iface )
{
    return new ReadVtk( iface );
}

ReadVtk::ReadVtk( Interface* impl ) : mdbImpl( impl ), mPartitionTagName( MATERIAL_SET_TAG_NAME )
{
    mdbImpl->query_interface( readMeshIface );
}

ReadVtk::~ReadVtk()
{
    if( readMeshIface )
    {
        mdbImpl->release_interface( readMeshIface );
        readMeshIface = 0;
    }
}

const char* const vtk_type_names[] = {
    "bit",  "char",          "unsigned_char", "short",  "unsigned_short", "int", "unsigned_int",
    "long", "unsigned_long", "float",         "double", "vtkIdType",      0 };

ErrorCode ReadVtk::read_tag_values( const char* /* file_name */,
                                    const char* /* tag_name */,
                                    const FileOptions& /* opts */,
                                    std::vector< int >& /* tag_values_out */,
                                    const SubsetList* /* subset_list */ )
{
    return MB_NOT_IMPLEMENTED;
}

ErrorCode ReadVtk::load_file( const char* filename,
                              const EntityHandle* /* file_set */,
                              const FileOptions& opts,
                              const ReaderIface::SubsetList* subset_list,
                              const Tag* file_id_tag )
{
    ErrorCode result;

    int major, minor;
    char vendor_string[257];
    std::vector< Range > element_list;
    Range vertices;

    if( subset_list )
    {
        MB_SET_ERR( MB_UNSUPPORTED_OPERATION, "Reading subset of files not supported for VTK" );
    }

    // Does the caller want a field to be used for partitioning the entities?
    // If not, we'll assume any scalar integer field named MATERIAL_SET specifies partitions.
    std::string partition_tag_name;
    result = opts.get_option( "PARTITION", partition_tag_name );
    if( result == MB_SUCCESS ) mPartitionTagName = partition_tag_name;

    FILE* file = fopen( filename, "r" );
    if( !file ) return MB_FILE_DOES_NOT_EXIST;

    // Read file header

    if( !fgets( vendor_string, sizeof( vendor_string ), file ) )
    {
        fclose( file );
        return MB_FAILURE;
    }

    if( !strchr( vendor_string, '\n' ) || 2 != sscanf( vendor_string, "# vtk DataFile Version %d.%d", &major, &minor ) )
    {
        fclose( file );
        return MB_FAILURE;
    }

    if( !fgets( vendor_string, sizeof( vendor_string ), file ) )
    {
        fclose( file );
        return MB_FAILURE;
    }

    // VTK spec says this should not exceed 256 chars.
    if( !strchr( vendor_string, '\n' ) )
    {
        fclose( file );
        MB_SET_ERR( MB_FAILURE, "Vendor string (line 2) exceeds 256 characters" );
    }

    // Check file type

    FileTokenizer tokens( file, readMeshIface );
    const char* const file_type_names[] = { "ASCII", "BINARY", 0 };
    int filetype                        = tokens.match_token( file_type_names );
    switch( filetype )
    {
        case 2:  // BINARY
            MB_SET_ERR( MB_FAILURE, "Cannot read BINARY VTK files" );
        default:  // ERROR
            return MB_FAILURE;
        case 1:  // ASCII
            break;
    }

    // Read the mesh
    if( !tokens.match_token( "DATASET" ) ) return MB_FAILURE;
    result = vtk_read_dataset( tokens, vertices, element_list );
    if( MB_SUCCESS != result ) return result;

    if( file_id_tag )
    {
        result = store_file_ids( *file_id_tag, vertices, element_list );
        if( MB_SUCCESS != result ) return result;
    }

    // Count the number of elements read
    long elem_count = 0;
    for( std::vector< Range >::iterator it = element_list.begin(); it != element_list.end(); ++it )
        elem_count += it->size();

    // Read attribute data until end of file.
    const char* const block_type_names[] = { "POINT_DATA", "CELL_DATA", 0 };
    std::vector< Range > vertex_list( 1 );
    vertex_list[0] = vertices;
    int blocktype  = 0;
    while( !tokens.eof() )
    {
        // Get POINT_DATA or CELL_DATA
        int new_block_type = tokens.match_token( block_type_names, false );
        if( tokens.eof() ) break;

        if( !new_block_type )
        {
            // If next token was neither POINT_DATA nor CELL_DATA,
            // then there's another attribute under the current one.
            if( blocktype )
                tokens.unget_token();
            else
                break;
        }
        else
        {
            blocktype = new_block_type;
            long count;
            if( !tokens.get_long_ints( 1, &count ) ) return MB_FAILURE;

            if( blocktype == 1 && (unsigned long)count != vertices.size() )
            {
                MB_SET_ERR( MB_FAILURE, "Count inconsistent with number of vertices at line " << tokens.line_number() );
            }
            else if( blocktype == 2 && count != elem_count )
            {
                MB_SET_ERR( MB_FAILURE, "Count inconsistent with number of elements at line " << tokens.line_number() );
            }
        }

        if( blocktype == 1 )
            result = vtk_read_attrib_data( tokens, vertex_list );
        else
            result = vtk_read_attrib_data( tokens, element_list );

        if( MB_SUCCESS != result ) return result;
    }

    return MB_SUCCESS;
}

ErrorCode ReadVtk::allocate_vertices( long num_verts,
                                      EntityHandle& start_handle_out,
                                      double*& x_coord_array_out,
                                      double*& y_coord_array_out,
                                      double*& z_coord_array_out )
{
    ErrorCode result;

    // Create vertices
    std::vector< double* > arrays;
    start_handle_out = 0;
    result           = readMeshIface->get_node_coords( 3, num_verts, MB_START_ID, start_handle_out, arrays );
    if( MB_SUCCESS != result ) return result;

    x_coord_array_out = arrays[0];
    y_coord_array_out = arrays[1];
    z_coord_array_out = arrays[2];

    return MB_SUCCESS;
}

ErrorCode ReadVtk::read_vertices( FileTokenizer& tokens, long num_verts, EntityHandle& start_handle_out )
{
    ErrorCode result;
    double *x, *y, *z;

    result = allocate_vertices( num_verts, start_handle_out, x, y, z );
    if( MB_SUCCESS != result ) return result;

    // Read vertex coordinates
    for( long vtx = 0; vtx < num_verts; ++vtx )
    {
        if( !tokens.get_doubles( 1, x++ ) || !tokens.get_doubles( 1, y++ ) || !tokens.get_doubles( 1, z++ ) )
            return MB_FAILURE;
    }

    return MB_SUCCESS;
}

ErrorCode ReadVtk::allocate_elements( long num_elements,
                                      int vert_per_element,
                                      EntityType type,
                                      EntityHandle& start_handle_out,
                                      EntityHandle*& conn_array_out,
                                      std::vector< Range >& append_to_this )
{
    ErrorCode result;

    start_handle_out = 0;
    result = readMeshIface->get_element_connect( num_elements, vert_per_element, type, MB_START_ID, start_handle_out,
                                                 conn_array_out );
    if( MB_SUCCESS != result ) return result;

    Range range( start_handle_out, start_handle_out + num_elements - 1 );
    append_to_this.push_back( range );
    return MB_SUCCESS;
}

ErrorCode ReadVtk::vtk_read_dataset( FileTokenizer& tokens, Range& vertex_list, std::vector< Range >& element_list )
{
    const char* const data_type_names[] = {
        "STRUCTURED_POINTS", "STRUCTURED_GRID", "UNSTRUCTURED_GRID", "POLYDATA", "RECTILINEAR_GRID", "FIELD", 0 };
    int datatype = tokens.match_token( data_type_names );
    switch( datatype )
    {
        case 1:
            return vtk_read_structured_points( tokens, vertex_list, element_list );
        case 2:
            return vtk_read_structured_grid( tokens, vertex_list, element_list );
        case 3:
            return vtk_read_unstructured_grid( tokens, vertex_list, element_list );
        case 4:
            return vtk_read_polydata( tokens, vertex_list, element_list );
        case 5:
            return vtk_read_rectilinear_grid( tokens, vertex_list, element_list );
        case 6:
            return vtk_read_field( tokens );
        default:
            return MB_FAILURE;
    }
}

ErrorCode ReadVtk::vtk_read_structured_points( FileTokenizer& tokens,
                                               Range& vertex_list,
                                               std::vector< Range >& elem_list )
{
    long i, j, k;
    long dims[3];
    double origin[3], space[3];
    ErrorCode result;

    if( !tokens.match_token( "DIMENSIONS" ) || !tokens.get_long_ints( 3, dims ) || !tokens.get_newline() )
        return MB_FAILURE;

    if( dims[0] < 1 || dims[1] < 1 || dims[2] < 1 )
    {
        MB_SET_ERR( MB_FAILURE, "Invalid dimension at line " << tokens.line_number() );
    }

    if( !tokens.match_token( "ORIGIN" ) || !tokens.get_doubles( 3, origin ) || !tokens.get_newline() )
        return MB_FAILURE;

    const char* const spacing_names[] = { "SPACING", "ASPECT_RATIO", 0 };
    if( !tokens.match_token( spacing_names ) || !tokens.get_doubles( 3, space ) || !tokens.get_newline() )
        return MB_FAILURE;

    // Create vertices
    double *x, *y, *z;
    EntityHandle start_handle = 0;
    long num_verts            = dims[0] * dims[1] * dims[2];
    result                    = allocate_vertices( num_verts, start_handle, x, y, z );
    if( MB_SUCCESS != result ) return result;
    vertex_list.insert( start_handle, start_handle + num_verts - 1 );

    for( k = 0; k < dims[2]; ++k )
        for( j = 0; j < dims[1]; ++j )
            for( i = 0; i < dims[0]; ++i )
            {
                *x = origin[0] + i * space[0];
                ++x;
                *y = origin[1] + j * space[1];
                ++y;
                *z = origin[2] + k * space[2];
                ++z;
            }

    return vtk_create_structured_elems( dims, start_handle, elem_list );
}

ErrorCode ReadVtk::vtk_read_structured_grid( FileTokenizer& tokens,
                                             Range& vertex_list,
                                             std::vector< Range >& elem_list )
{
    long num_verts, dims[3];
    ErrorCode result;

    if( !tokens.match_token( "DIMENSIONS" ) || !tokens.get_long_ints( 3, dims ) || !tokens.get_newline() )
        return MB_FAILURE;

    if( dims[0] < 1 || dims[1] < 1 || dims[2] < 1 )
    {
        MB_SET_ERR( MB_FAILURE, "Invalid dimension at line " << tokens.line_number() );
    }

    if( !tokens.match_token( "POINTS" ) || !tokens.get_long_ints( 1, &num_verts ) ||
        !tokens.match_token( vtk_type_names ) || !tokens.get_newline() )
        return MB_FAILURE;

    if( num_verts != ( dims[0] * dims[1] * dims[2] ) )
    {
        MB_SET_ERR( MB_FAILURE, "Point count not consistent with dimensions at line " << tokens.line_number() );
    }

    // Create and read vertices
    EntityHandle start_handle = 0;
    result                    = read_vertices( tokens, num_verts, start_handle );
    if( MB_SUCCESS != result ) return result;
    vertex_list.insert( start_handle, start_handle + num_verts - 1 );

    return vtk_create_structured_elems( dims, start_handle, elem_list );
}

ErrorCode ReadVtk::vtk_read_rectilinear_grid( FileTokenizer& tokens,
                                              Range& vertex_list,
                                              std::vector< Range >& elem_list )
{
    int i, j, k;
    long dims[3];
    const char* labels[] = { "X_COORDINATES", "Y_COORDINATES", "Z_COORDINATES" };
    std::vector< double > coords[3];
    ErrorCode result;

    if( !tokens.match_token( "DIMENSIONS" ) || !tokens.get_long_ints( 3, dims ) || !tokens.get_newline() )
        return MB_FAILURE;

    if( dims[0] < 1 || dims[1] < 1 || dims[2] < 1 )
    {
        MB_SET_ERR( MB_FAILURE, "Invalid dimension at line " << tokens.line_number() );
    }

    for( i = 0; i < 3; i++ )
    {
        long count;
        if( !tokens.match_token( labels[i] ) || !tokens.get_long_ints( 1, &count ) ||
            !tokens.match_token( vtk_type_names ) )
            return MB_FAILURE;

        if( count != dims[i] )
        {
            MB_SET_ERR( MB_FAILURE, "Coordinate count inconsistent with dimensions at line " << tokens.line_number() );
        }

        coords[i].resize( count );
        if( !tokens.get_doubles( count, &coords[i][0] ) ) return MB_FAILURE;
    }

    // Create vertices
    double *x, *y, *z;
    EntityHandle start_handle = 0;
    long num_verts            = dims[0] * dims[1] * dims[2];
    result                    = allocate_vertices( num_verts, start_handle, x, y, z );
    if( MB_SUCCESS != result ) return result;
    vertex_list.insert( start_handle, start_handle + num_verts - 1 );

    // Calculate vertex coordinates
    for( k = 0; k < dims[2]; ++k )
        for( j = 0; j < dims[1]; ++j )
            for( i = 0; i < dims[0]; ++i )
            {
                *x = coords[0][i];
                ++x;
                *y = coords[1][j];
                ++y;
                *z = coords[2][k];
                ++z;
            }

    return vtk_create_structured_elems( dims, start_handle, elem_list );
}

ErrorCode ReadVtk::vtk_read_polydata( FileTokenizer& tokens, Range& vertex_list, std::vector< Range >& elem_list )
{
    ErrorCode result;
    long num_verts;
    const char* const poly_data_names[] = { "VERTICES", "LINES", "POLYGONS", "TRIANGLE_STRIPS", 0 };

    if( !tokens.match_token( "POINTS" ) || !tokens.get_long_ints( 1, &num_verts ) ||
        !tokens.match_token( vtk_type_names ) || !tokens.get_newline() )
        return MB_FAILURE;

    if( num_verts < 1 )
    {
        MB_SET_ERR( MB_FAILURE, "Invalid point count at line " << tokens.line_number() );
    }

    // Create vertices and read coordinates
    EntityHandle start_handle = 0;
    result                    = read_vertices( tokens, num_verts, start_handle );
    if( MB_SUCCESS != result ) return result;
    vertex_list.insert( start_handle, start_handle + num_verts - 1 );

    int poly_type = tokens.match_token( poly_data_names );
    switch( poly_type )
    {
        case 0:
            result = MB_FAILURE;
            break;
        case 1:
            MB_SET_ERR( MB_FAILURE, "Vertex element type at line " << tokens.line_number() );
            break;
        case 2:
            MB_SET_ERR( MB_FAILURE, "Unsupported type: polylines at line " << tokens.line_number() );
            result = MB_FAILURE;
            break;
        case 3:
            result = vtk_read_polygons( tokens, start_handle, elem_list );
            break;
        case 4:
            MB_SET_ERR( MB_FAILURE, "Unsupported type: triangle strips at line " << tokens.line_number() );
            result = MB_FAILURE;
            break;
    }

    return result;
}

ErrorCode ReadVtk::vtk_read_polygons( FileTokenizer& tokens, EntityHandle first_vtx, std::vector< Range >& elem_list )
{
    ErrorCode result;
    long size[2];

    if( !tokens.get_long_ints( 2, size ) || !tokens.get_newline() ) return MB_FAILURE;

    const Range empty;
    std::vector< EntityHandle > conn_hdl;
    std::vector< long > conn_idx;
    EntityHandle first = 0, prev = 0, handle;
    for( int i = 0; i < size[0]; ++i )
    {
        long count;
        if( !tokens.get_long_ints( 1, &count ) ) return MB_FAILURE;
        conn_idx.resize( count );
        conn_hdl.resize( count );
        if( !tokens.get_long_ints( count, &conn_idx[0] ) ) return MB_FAILURE;

        for( long j = 0; j < count; ++j )
            conn_hdl[j] = first_vtx + conn_idx[j];

        result = mdbImpl->create_element( MBPOLYGON, &conn_hdl[0], count, handle );
        if( MB_SUCCESS != result ) return result;

        if( prev + 1 != handle )
        {
            if( first )
            {  // True except for first iteration (first == 0)
                if( elem_list.empty() || first < elem_list.back().front() )  // Only need new range if order would get
                                                                             // mixed up, or we just began inserting
                    elem_list.push_back( empty );
                elem_list.back().insert( first, prev );
            }
            first = handle;
        }
        prev = handle;
    }
    if( first )
    {                                                                // True unless no elements (size[0] == 0)
        if( elem_list.empty() || first < elem_list.back().front() )  // Only need new range if order would get mixed
                                                                     // up, or we just began inserting
            elem_list.push_back( empty );
        elem_list.back().insert( first, prev );
    }

    return MB_SUCCESS;
}

ErrorCode ReadVtk::vtk_read_unstructured_grid( FileTokenizer& tokens,
                                               Range& vertex_list,
                                               std::vector< Range >& elem_list )
{
    ErrorCode result;
    long i, num_verts, num_elems[2];
    EntityHandle tmp_conn_list[27];

    // Poorly formatted VTK legacy format document seems to
    // lead many to think that a FIELD block can occur within
    // an UNSTRUCTURED_GRID dataset rather than as its own data
    // set. So allow for field data between other blocks of
    // data.

    const char* pts_str[] = { "FIELD", "POINTS", 0 };
    while( 1 == ( i = tokens.match_token( pts_str ) ) )
    {
        result = vtk_read_field( tokens );
        if( MB_SUCCESS != result ) return result;
    }
    if( i != 2 ) return MB_FAILURE;

    if( !tokens.get_long_ints( 1, &num_verts ) || !tokens.match_token( vtk_type_names ) || !tokens.get_newline() )
        return MB_FAILURE;

    if( num_verts < 1 )
    {
        MB_SET_ERR( MB_FAILURE, "Invalid point count at line " << tokens.line_number() );
    }

    // Create vertices and read coordinates
    EntityHandle first_vertex = 0;
    result                    = read_vertices( tokens, num_verts, first_vertex );
    if( MB_SUCCESS != result ) return result;
    vertex_list.insert( first_vertex, first_vertex + num_verts - 1 );

    const char* cell_str[] = { "FIELD", "CELLS", 0 };
    while( 1 == ( i = tokens.match_token( cell_str ) ) )
    {
        result = vtk_read_field( tokens );
        if( MB_SUCCESS != result ) return result;
    }
    if( i != 2 ) return MB_FAILURE;

    if( !tokens.get_long_ints( 2, num_elems ) || !tokens.get_newline() ) return MB_FAILURE;

    // Read element connectivity for all elements
    std::vector< long > connectivity( num_elems[1] );
    if( !tokens.get_long_ints( num_elems[1], &connectivity[0] ) ) return MB_FAILURE;

    if( !tokens.match_token( "CELL_TYPES" ) || !tokens.get_long_ints( 1, &num_elems[1] ) || !tokens.get_newline() )
        return MB_FAILURE;

    // Read element types
    std::vector< long > types( num_elems[0] );
    if( !tokens.get_long_ints( num_elems[0], &types[0] ) ) return MB_FAILURE;

    // Create elements in blocks of the same type
    // It is important to preserve the order in
    // which the elements were read for later reading
    // attribute data.
    long id                                 = 0;
    std::vector< long >::iterator conn_iter = connectivity.begin();
    while( id < num_elems[0] )
    {
        unsigned vtk_type = types[id];
        if( vtk_type >= VtkUtil::numVtkElemType ) return MB_FAILURE;

        EntityType type = VtkUtil::vtkElemTypes[vtk_type].mb_type;
        if( type == MBMAXTYPE )
        {
            MB_SET_ERR( MB_FAILURE, "Unsupported VTK element type: " << VtkUtil::vtkElemTypes[vtk_type].name << " ("
                                                                     << vtk_type << ")" );
        }

        int num_vtx = *conn_iter;
        if( type != MBPOLYGON && type != MBPOLYHEDRON && num_vtx != (int)VtkUtil::vtkElemTypes[vtk_type].num_nodes )
        {
            MB_SET_ERR( MB_FAILURE, "Cell " << id << " is of type '" << VtkUtil::vtkElemTypes[vtk_type].name
                                            << "' but has " << num_vtx << " vertices" );
        }

        // Find any subsequent elements of the same type
        // if polyhedra, need to look at the number of faces to put in the same range
        std::vector< long >::iterator conn_iter2 = conn_iter + num_vtx + 1;
        long end_id                              = id + 1;
        if( MBPOLYHEDRON != type )
        {
            while( end_id < num_elems[0] && (unsigned)types[end_id] == vtk_type && *conn_iter2 == num_vtx )
            {
                ++end_id;
                conn_iter2 += num_vtx + 1;
            }
        }
        else
        {
            // advance only if next is polyhedron too, and if number of faces is the same
            int num_faces = conn_iter[1];
            while( end_id < num_elems[0] && (unsigned)types[end_id] == vtk_type && conn_iter2[1] == num_faces )
            {
                ++end_id;
                conn_iter2 += num_vtx + 1;
            }
            // num_vtx becomes in this case num_faces
            num_vtx = num_faces;  // for polyhedra, this is what we want
            // trigger vertex adjacency call
            Range firstFaces;
            mdbImpl->get_adjacencies( &first_vertex, 1, 2, false, firstFaces );
        }

        // Allocate element block
        long num_elem             = end_id - id;
        EntityHandle start_handle = 0;
        EntityHandle* conn_array;

        // if type is MBVERTEX, skip, we will not create elements with one vertex
        if( MBVERTEX == type )
        {
            id += num_elem;
            conn_iter += 2 * num_elem;  // skip 2 * number of 1-vertex elements
            continue;
        }

        result = allocate_elements( num_elem, num_vtx, type, start_handle, conn_array, elem_list );
        if( MB_SUCCESS != result ) return result;

        EntityHandle* conn_sav = conn_array;

        // Store element connectivity
        if( type != MBPOLYHEDRON )
        {
            for( ; id < end_id; ++id )
            {
                if( conn_iter == connectivity.end() )
                {
                    MB_SET_ERR( MB_FAILURE, "Connectivity data truncated at cell " << id );
                }
                // Make sure connectivity length is correct.
                if( *conn_iter != num_vtx )
                {
                    MB_SET_ERR( MB_FAILURE, "Cell " << id << " is of type '" << VtkUtil::vtkElemTypes[vtk_type].name
                                                    << "' but has " << num_vtx << " vertices" );
                }
                ++conn_iter;

                for( i = 0; i < num_vtx; ++i, ++conn_iter )
                {
                    if( conn_iter == connectivity.end() )
                    {
                        MB_SET_ERR( MB_FAILURE, "Connectivity data truncated at cell " << id );
                    }

                    conn_array[i] = *conn_iter + first_vertex;
                }

                const unsigned* order = VtkUtil::vtkElemTypes[vtk_type].node_order;
                if( order )
                {
                    assert( num_vtx * sizeof( EntityHandle ) <= sizeof( tmp_conn_list ) );
                    memcpy( tmp_conn_list, conn_array, num_vtx * sizeof( EntityHandle ) );
                    for( int j = 0; j < num_vtx; ++j )
                        conn_array[order[j]] = tmp_conn_list[j];
                }

                conn_array += num_vtx;
            }
        }
        else  // type == MBPOLYHEDRON
        {
            // in some cases, we may need to create new elements; will it screw the tags?
            // not if the file was not from moab
            ErrorCode rv = MB_SUCCESS;
            for( ; id < end_id; ++id )
            {
                if( conn_iter == connectivity.end() )
                {
                    MB_SET_ERR( MB_FAILURE, "Connectivity data truncated at polyhedra cell " << id );
                }
                ++conn_iter;
                // iterator is now at number of faces
                // we should check it is indeed num_vtx
                int num_faces = *conn_iter;
                if( num_faces != num_vtx ) MB_SET_ERR( MB_FAILURE, "Connectivity data wrong at polyhedra cell " << id );

                EntityHandle connec[20];  // we bet we will have only 20 vertices at most, in a
                                          // face in a polyhedra
                for( int j = 0; j < num_faces; j++ )
                {
                    conn_iter++;
<--- Prefer prefix ++/-- operators for non-primitive types. [+]
Prefix ++/-- operators should be preferred for non-primitive types. Pre-increment/decrement can be more efficient than post-increment/decrement. Post-increment/decrement usually involves keeping a copy of the previous value around and adds a little extra code.
                    int numverticesInFace = (int)*conn_iter;
                    if( numverticesInFace > 20 )
                        MB_SET_ERR( MB_FAILURE,
                                    "too many vertices in face index " << j << " for polyhedra cell " << id );
                    // need to find the face, but first fill with vertices
                    for( int k = 0; k < numverticesInFace; k++ )
                    {
                        connec[k] = first_vertex + *( ++conn_iter );  //
                    }
                    Range adjFaces;
                    // find a face with these vertices; if not, we need to create one, on the fly :(
                    rv = mdbImpl->get_adjacencies( connec, numverticesInFace, 2, false, adjFaces );MB_CHK_ERR( rv );
                    if( adjFaces.size() >= 1 )
                    {
                        conn_array[j] = adjFaces[0];  // get the first face found
                    }
                    else
                    {
                        // create the face; tri, quad or polygon
                        EntityType etype = MBTRI;
                        if( 4 == numverticesInFace ) etype = MBQUAD;
                        if( 4 < numverticesInFace ) etype = MBPOLYGON;

                        rv = mdbImpl->create_element( etype, connec, numverticesInFace, conn_array[j] );MB_CHK_ERR( rv );
                    }
                }

                conn_array += num_vtx;  // advance for next polyhedra
                conn_iter++;            // advance to the next field
<--- Prefer prefix ++/-- operators for non-primitive types. [+]
Prefix ++/-- operators should be preferred for non-primitive types. Pre-increment/decrement can be more efficient than post-increment/decrement. Post-increment/decrement usually involves keeping a copy of the previous value around and adds a little extra code.
            }
        }

        // Notify MOAB of the new elements
        result = readMeshIface->update_adjacencies( start_handle, num_elem, num_vtx, conn_sav );
        if( MB_SUCCESS != result ) return result;
    }

    return MB_SUCCESS;
}

ErrorCode ReadVtk::vtk_create_structured_elems( const long* dims,
                                                EntityHandle first_vtx,
                                                std::vector< Range >& elem_list )
{
    ErrorCode result;
    // int non_zero[3] = {0, 0, 0}; // True if dim > 0 for x, y, z respectively
    long elem_dim  = 0;           // Element dimension (2->quad, 3->hex)
    long num_elems = 1;           // Total number of elements
    long vert_per_elem;           // Element connectivity length
    long edims[3] = { 1, 1, 1 };  // Number of elements in each grid direction

    // Populate above data
    for( int d = 0; d < 3; d++ )
    {
        if( dims[d] > 1 )
        {
            // non_zero[elem_dim] = d;
            ++elem_dim;
            edims[d] = dims[d] - 1;
            num_elems *= edims[d];
        }
    }
    vert_per_elem = 1 << elem_dim;

    // Get element type from element dimension
    EntityType type;
    switch( elem_dim )
    {
        case 1:
            type = MBEDGE;
            break;
        case 2:
            type = MBQUAD;
            break;
        case 3:
            type = MBHEX;
            break;
        default:
            MB_SET_ERR( MB_FAILURE, "Invalid dimension for structured elements: " << elem_dim );
    }

    // Allocate storage for elements
    EntityHandle start_handle = 0;
    EntityHandle* conn_array;
    result = allocate_elements( num_elems, vert_per_elem, type, start_handle, conn_array, elem_list );
    if( MB_SUCCESS != result ) return MB_FAILURE;

    EntityHandle* conn_sav = conn_array;

    // Offsets of element vertices in grid relative to corner closest to origin
    long k                = dims[0] * dims[1];
    const long corners[8] = { 0, 1, 1 + dims[0], dims[0], k, k + 1, k + 1 + dims[0], k + dims[0] };

    // Populate element list
    for( long z = 0; z < edims[2]; ++z )
        for( long y = 0; y < edims[1]; ++y )
            for( long x = 0; x < edims[0]; ++x )
            {
                const long index = x + y * dims[0] + z * ( dims[0] * dims[1] );
                for( long j = 0; j < vert_per_elem; ++j, ++conn_array )
                    *conn_array = index + corners[j] + first_vtx;
            }

    // Notify MOAB of the new elements
    result = readMeshIface->update_adjacencies( start_handle, num_elems, vert_per_elem, conn_sav );
    if( MB_SUCCESS != result ) return result;

    return MB_SUCCESS;
}

ErrorCode ReadVtk::vtk_read_field( FileTokenizer& tokens )
{
    // This is not supported yet.
    // Parse the data but throw it away because
    // Mesquite has no internal representation for it.

    // Could save this in tags, but the only useful thing that
    // could be done with the data is to write it back out
    // with the modified mesh. As there's no way to save the
    // type of a tag in Mesquite, it cannot be written back
    // out correctly either.
    // FIXME: Don't know what to do with this data.
    // For now, read it and throw it out.

    long num_arrays;
    if( !tokens.get_string() ||  // Name
        !tokens.get_long_ints( 1, &num_arrays ) )
        return MB_FAILURE;

    for( long i = 0; i < num_arrays; ++i )
    {
        /*const char* name =*/tokens.get_string();

        long dims[2];
        if( !tokens.get_long_ints( 2, dims ) || !tokens.match_token( vtk_type_names ) ) return MB_FAILURE;

        long num_vals = dims[0] * dims[1];

        for( long j = 0; j < num_vals; j++ )
        {
            double junk;
            if( !tokens.get_doubles( 1, &junk ) ) return MB_FAILURE;
        }
    }

    return MB_SUCCESS;
}

ErrorCode ReadVtk::vtk_read_attrib_data( FileTokenizer& tokens, std::vector< Range >& entities )
{
    const char* const type_names[] = { "SCALARS", "COLOR_SCALARS", "VECTORS", "NORMALS", "TEXTURE_COORDINATES",
                                       "TENSORS", "FIELD",         0 };

    int type             = tokens.match_token( type_names );
    const char* tmp_name = tokens.get_string();
    if( !type || !tmp_name ) return MB_FAILURE;

    std::string name_alloc( tmp_name );
    const char* name = name_alloc.c_str();
    switch( type )
    {
        case 1:
            return vtk_read_scalar_attrib( tokens, entities, name );
        case 2:
            return vtk_read_color_attrib( tokens, entities, name );
        case 3:
            return vtk_read_vector_attrib( tokens, entities, name );
        case 4:
            return vtk_read_vector_attrib( tokens, entities, name );
        case 5:
            return vtk_read_texture_attrib( tokens, entities, name );
        case 6:
            return vtk_read_tensor_attrib( tokens, entities, name );
        case 7:
            return vtk_read_field_attrib( tokens, entities, name );
    }

    return MB_FAILURE;
}

ErrorCode ReadVtk::vtk_read_tag_data( FileTokenizer& tokens,
                                      int type,
                                      size_t per_elem,
                                      std::vector< Range >& entities,
                                      const char* name )
{
    ErrorCode result;
    DataType mb_type;
    if( type == 1 )
    {
        mb_type = MB_TYPE_BIT;
    }
    else if( type >= 2 && type <= 9 )
    {
        mb_type = MB_TYPE_INTEGER;
    }
    else if( type == 10 || type == 11 )
    {
        mb_type = MB_TYPE_DOUBLE;
    }
    else if( type == 12 )
    {
        mb_type = MB_TYPE_INTEGER;
    }
    else
        return MB_FAILURE;

#ifdef MB_VTK_MATERIAL_SETS
    size_t size;
    if( type == 1 )
    {
        size = sizeof( bool );
    }
    else if( type >= 2 && type <= 9 )
    {
        size = sizeof( int );
    }
    else if( type == 10 || type == 11 )
    {
        size = sizeof( double );
    }
    else /* (type == 12) */
    {
        size = 4;  // Could be 4 or 8, but we don't know. Hope it's 4 because MOAB doesn't support
                   // 64-bit ints.
    }
    Modulator materialMap( this->mdbImpl );
    result = materialMap.initialize( this->mPartitionTagName, mb_type, size, per_elem );MB_CHK_SET_ERR( result, "MaterialMap tag (" << this->mPartitionTagName << ") creation failed." );
    bool isMaterial = size * per_elem <= 4 &&              // Must have int-sized values (ParallelComm requires it)
                      !this->mPartitionTagName.empty() &&  // Must have a non-empty field name...
                      !strcmp( name, this->mPartitionTagName.c_str() );  // ... that matches our spec.
#endif                                                                   // MB_VTK_MATERIAL_SETS

    // Get/create tag
    Tag handle;
    result = mdbImpl->tag_get_handle( name, per_elem, mb_type, handle, MB_TAG_DENSE | MB_TAG_CREAT );MB_CHK_SET_ERR( result, "Tag name conflict for attribute \"" << name << "\" at line " << tokens.line_number() );

    std::vector< Range >::iterator iter;

    if( type == 1 )
    {
        for( iter = entities.begin(); iter != entities.end(); ++iter )
        {
            bool* data = new bool[iter->size() * per_elem];
            if( !tokens.get_booleans( per_elem * iter->size(), data ) )
            {
                delete[] data;
                return MB_FAILURE;
            }

            bool* data_iter          = data;
            Range::iterator ent_iter = iter->begin();
            for( ; ent_iter != iter->end(); ++ent_iter )
            {
                unsigned char bits = 0;
                for( unsigned j = 0; j < per_elem; ++j, ++data_iter )
                    bits |= (unsigned char)( *data_iter << j );
#ifdef MB_VTK_MATERIAL_SETS
                if( isMaterial ) materialMap.add_entity( *ent_iter, &bits, 1 );
#endif  // MB_VTK_MATERIAL_SETS
                result = mdbImpl->tag_set_data( handle, &*ent_iter, 1, &bits );
                if( MB_SUCCESS != result )
                {
                    delete[] data;
                    return result;
                }
            }
            delete[] data;
        }
    }
    else if( ( type >= 2 && type <= 9 ) || type == 12 )
    {
        std::vector< int > data;
        for( iter = entities.begin(); iter != entities.end(); ++iter )
        {
            data.resize( iter->size() * per_elem );
            if( !tokens.get_integers( iter->size() * per_elem, &data[0] ) ) return MB_FAILURE;
#ifdef MB_VTK_MATERIAL_SETS
            if( isMaterial ) materialMap.add_entities( *iter, (unsigned char*)&data[0], per_elem * size );
#endif  // MB_VTK_MATERIAL_SETS
            result = mdbImpl->tag_set_data( handle, *iter, &data[0] );
            if( MB_SUCCESS != result ) return result;
        }
    }
    else if( type == 10 || type == 11 )
    {
        std::vector< double > data;
        for( iter = entities.begin(); iter != entities.end(); ++iter )
        {
            data.resize( iter->size() * per_elem );
            if( !tokens.get_doubles( iter->size() * per_elem, &data[0] ) ) return MB_FAILURE;
#ifdef MB_VTK_MATERIAL_SETS
            if( isMaterial ) materialMap.add_entities( *iter, (unsigned char*)&data[0], per_elem * size );
#endif  // MB_VTK_MATERIAL_SETS
            result = mdbImpl->tag_set_data( handle, *iter, &data[0] );
            if( MB_SUCCESS != result ) return result;
        }
    }

    return MB_SUCCESS;
}

ErrorCode ReadVtk::vtk_read_scalar_attrib( FileTokenizer& tokens, std::vector< Range >& entities, const char* name )
{
    int type = tokens.match_token( vtk_type_names );
    if( !type ) return MB_FAILURE;

    long size;
    const char* tok = tokens.get_string();
    if( !tok ) return MB_FAILURE;

    const char* end = 0;
    size            = strtol( tok, (char**)&end, 0 );
    if( *end )
    {
        size = 1;
        tokens.unget_token();
    }

    // VTK spec says cannot be greater than 4--do we care?
    if( size < 1 )
    {  //|| size > 4)
        MB_SET_ERR( MB_FAILURE, "Scalar count out of range [1,4] at line " << tokens.line_number() );
    }

    if( !tokens.match_token( "LOOKUP_TABLE" ) || !tokens.match_token( "default" ) ) return MB_FAILURE;

    return vtk_read_tag_data( tokens, type, size, entities, name );
}

ErrorCode ReadVtk::vtk_read_color_attrib( FileTokenizer& tokens, std::vector< Range >& entities, const char* name )
{
    long size;
    if( !tokens.get_long_ints( 1, &size ) || size < 1 ) return MB_FAILURE;

    return vtk_read_tag_data( tokens, 10, size, entities, name );
}

ErrorCode ReadVtk::vtk_read_vector_attrib( FileTokenizer& tokens, std::vector< Range >& entities, const char* name )
{
    int type = tokens.match_token( vtk_type_names );
    if( !type ) return MB_FAILURE;

    return vtk_read_tag_data( tokens, type, 3, entities, name );
}

ErrorCode ReadVtk::vtk_read_texture_attrib( FileTokenizer& tokens, std::vector< Range >& entities, const char* name )
{
    int type, dim;
    if( !tokens.get_integers( 1, &dim ) || !( type = tokens.match_token( vtk_type_names ) ) ) return MB_FAILURE;

    if( dim < 1 || dim > 3 )
    {
        MB_SET_ERR( MB_FAILURE, "Invalid dimension (" << dim << ") at line " << tokens.line_number() );
    }

    return vtk_read_tag_data( tokens, type, dim, entities, name );
}

ErrorCode ReadVtk::vtk_read_tensor_attrib( FileTokenizer& tokens, std::vector< Range >& entities, const char* name )
{
    int type = tokens.match_token( vtk_type_names );
    if( !type ) return MB_FAILURE;

    return vtk_read_tag_data( tokens, type, 9, entities, name );
}

ErrorCode ReadVtk::vtk_read_field_attrib( FileTokenizer& tokens, std::vector< Range >& entities, const char* )
{
    long num_fields;
    if( !tokens.get_long_ints( 1, &num_fields ) ) return MB_FAILURE;

    long i;
    for( i = 0; i < num_fields; ++i )
    {
        const char* tok = tokens.get_string();
        if( !tok ) return MB_FAILURE;

        std::string name_alloc( tok );

        long num_comp;
        if( !tokens.get_long_ints( 1, &num_comp ) ) return MB_FAILURE;

        long num_tuples;
        if( !tokens.get_long_ints( 1, &num_tuples ) ) return MB_FAILURE;

        int type = tokens.match_token( vtk_type_names );
        if( !type ) return MB_FAILURE;

        ErrorCode result = vtk_read_tag_data( tokens, type, num_comp, entities, name_alloc.c_str() );MB_CHK_SET_ERR( result, "Error reading data for field \"" << name_alloc << "\" (" << num_comp << " components, "
                                                                  << num_tuples << " tuples, type " << type
                                                                  << ") at line " << tokens.line_number() );
    }

    return MB_SUCCESS;
}

ErrorCode ReadVtk::store_file_ids( Tag tag, const Range& verts, const std::vector< Range >& elems )
{
    ErrorCode rval;

    rval = readMeshIface->assign_ids( tag, verts );
    if( MB_SUCCESS != rval ) return rval;

    int id = 0;
    for( size_t i = 0; i < elems.size(); ++i )
    {
        rval = readMeshIface->assign_ids( tag, elems[i], id );<--- Variable 'rval' is assigned a value that is never used.
        id += elems[i].size();
    }

    return MB_SUCCESS;
}

}  // namespace moab