Grid.cc

 
// -*- mode: c++; c-basic-offset:4 -*-
 
// This file is part of libdap, A C++ implementation of the OPeNDAP Data
// Access Protocol.
 
// Copyright (c) 2002,2003 OPeNDAP, Inc.
// Author: James Gallagher <jgallagher@opendap.org>
//
// 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.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
//
// You can contact OPeNDAP, Inc. at PO Box 112, Saunderstown, RI. 02874-0112.
 
// (c) COPYRIGHT URI/MIT 1994-1999
// Please read the full copyright statement in the file COPYRIGHT_URI.
//
// Authors:
//      jhrg,jimg       James Gallagher <jgallagher@gso.uri.edu>
 
// implementation for Grid.
//
// jhrg 9/15/94
 
#include "config.h"
 
#include <algorithm>
#include <functional>
#include <sstream>
 
#include "Array.h" // for downcasts
#include "DDS.h"
#include "Grid.h"
#include "InternalErr.h"
#include "XDRStreamMarshaller.h"
#include "debug.h"
#include "escaping.h"
#include "util.h"
 
#include "D4Attributes.h"
#include "D4Group.h"
#include "D4Maps.h"
#include "DMR.h"
#include "XMLWriter.h"
 
#include "DapIndent.h"
 
using namespace std;
 
namespace libdap {
 
void Grid::m_duplicate(const Grid &s) { d_is_array_set = s.d_is_array_set; }

Grid::Grid(const string &n) : Constructor(n, dods_grid_c), d_is_array_set(false) {}

Grid::Grid(const string &n, const string &d) : Constructor(n, d, dods_grid_c), d_is_array_set(false) {}

Grid::Grid(const Grid &rhs) : Constructor(rhs) { m_duplicate(rhs); }
 
Grid::~Grid() {
    // d_array_var = 0; // Weak pointer; object will be freed by Constructor
}
 
BaseType *Grid::ptr_duplicate() { return new Grid(*this); }
 
Grid &Grid::operator=(const Grid &rhs) {
    if (this == &rhs)
        return *this;
    Constructor::operator=(rhs);
    m_duplicate(rhs);
    return *this;
}

void Grid::transform_to_dap4(D4Group *root, Constructor *container) {
    DBG(cerr << __func__ << "() - BEGIN (name:" << name() << ")(type:" << type_name() << ")(root:'" << root->name()
             << "':" << (void *)root << ")(container:'" << container->name() << "':" << (void *)container << ")"
             << endl;);
 
    vector<Array *> d4_map_arrays;
 
    // We do the Map Arrays first because some people expect to see them
    // declared prior to the coverage array the utilizes them - even though that
    // is not a requirement of DAP4 I did it here to make people happier.
    // We add the maps arrays to the current container if needed and make a
    // vector of them so that we can add D4Map objects to our Precious down
    // below.
    for (Map_iter i = map_begin(), e = map_end(); i != e; ++i) {
        DBG(cerr << __func__ << "() - Processing Map Array:  '" << (*i)->name() << "' (" << (void *)(*i) << ")"
                 << endl;);
        // Only add the map/array if it's not already present in the target DAP2 container.
        // Given the scoping rules for DAP2 and the assumption the DDS is valid, testing for
        // the same name is good enough. The point here is to be sure to only use the
        // existing maps. This is an important issue when there are multiple Grids in the same
        // dataset that utilize the same Map arrays data.
        Array *the_map_array;
        Array *container_map_array = static_cast<Array *>(container->var((*i)->name()));
        if (!container_map_array) {
            DBG(cerr << __func__ << "() - No Map Array '" << (*i)->name() << "' present in the current DAP4 container ("
                     << container->name() << ":" << (void *)container << "). Let's fix that..." << endl;);
            // Not in the container, so we check root group
            Array *root_map_array = static_cast<Array *>(root->var((*i)->name()));
            if (!root_map_array) {
                // Not in the root group so we transform a new array and add it to container.
                DBG(cerr << __func__ << "() - No Map Array '" << (*i)->name() << "' present in the root Group ("
                         << root->name() << ":" << (void *)root << "). Let's fix that..." << endl;);
                // transform it and add it to the container
                (*i)->transform_to_dap4(root, container);
                // Recover the new dap4 version from the container.
                the_map_array = static_cast<Array *>(container->var((*i)->name()));
                DBG(cerr << __func__ << "() - Transformed array '" << the_map_array->name() << "' to DAP4 Array ("
                         << (void *)the_map_array << ") added to container: '" << container->name() << "'" << endl;);
            } else {
                the_map_array = root_map_array;
                DBG(cerr << __func__ << "() - Located Map Array '" << the_map_array->name() << "' ("
                         << (void *)the_map_array << ") present in the root group (" << root->name() << ":"
                         << (void *)root << ")" << endl;);
            }
        } else {
            the_map_array = container_map_array;
            DBG(cerr << __func__ << "() - Located Map Array '" << the_map_array->name() << "' ("
                     << (void *)the_map_array << ") present in the current DAP4 container (" << container->name() << ":"
                     << (void *)container << ")" << endl;);
        }
        // We'll use these (below) to make D4Map objects for the coverage
        d4_map_arrays.push_back(the_map_array);
    }
 
    // Adds the coverage array to the container.
    array_var()->transform_to_dap4(root, container);
    // Get the new coverage array
    BaseType *btp = container->var(array_var()->name());
    Array *coverage = static_cast<Array *>(btp);
    DBG(cerr << __func__ << "() - Transformed and added DAP4 coverage Array '" << coverage->name()
             << "' to parent container: '" << container->name() << "'" << endl;);
 
    coverage->attributes()->transform_to_dap4(get_attr_table());
 
    DBG(cerr << __func__ << "() - " << "Coverage Array '" << coverage->name() << "' attributes: " << endl;
        XMLWriter xmlw; coverage->get_attr_table().print_dap4(xmlw); cerr << xmlw.get_doc() << endl;);
 
    // Add the D4Maps
    vector<Array *>::iterator d4aItr = d4_map_arrays.begin();
    vector<Array *>::iterator end = d4_map_arrays.end();
    for (; d4aItr != end; d4aItr++) {
        Array *the_map_array = *d4aItr;
        // Here we use the Map Array that we saved the Map
        // name and Map Array reference for our map.
        // Removed this line in favor of the following one while re-working the D4Maps design.
        // jhrg 9/16/22
        // D4Map *d4_map = new D4Map(the_map_array->FQN(), the_map_array, coverage); // bind the 'map' to the coverage
        D4Map *d4_map = new D4Map(the_map_array->FQN(), the_map_array);
        coverage->maps()->add_map(d4_map); // bind the coverage to the map
        // Clear the vector entry to ensure that ~Array doesn't
        // get called when the (stack declared) vector goes out of scope.
        *d4aItr = 0;
        DBG(cerr << __func__ << "() - Added DAP4 Map Array:  '" << d4_map->name() << "' (" << (void *)d4_map->array()
                 << ") to coverage: '" << coverage->name() << "'" << endl;);
    }
    DBG(cerr << __func__ << "() - END (grid:" << name() << ")" << endl;);
}

bool Grid::is_dap2_only_type() { return true; }

void Grid::add_var(BaseType *bt, Part part) {
    if (!bt)
        throw InternalErr(__FILE__, __LINE__, "Passing NULL pointer as variable to be added.");
 
    if (bt->is_dap4())
        throw Error(string("A method usable only with DAP2 variables was called on a DAP4 variable (")
                        .append(name())
                        .append(")."),
                    __FILE__, __LINE__);
 
    if (part == array && d_is_array_set /*get_array()*/) {
        // Avoid leaking memory...  Function is add, not set, so it is an error to call again for the array part.
        throw InternalErr(__FILE__, __LINE__,
                          "Error: Grid::add_var called with part==Array, but the array was already set!");
    }
 
    // avoid obvious broken semantics
    if (!dynamic_cast<Array *>(bt)) {
        throw InternalErr(__FILE__, __LINE__, "Grid::add_var(): object is not an Array!");
    }
 
    // Set to the clone of bt if we get that far.
    BaseType *bt_clone = 0;
 
    switch (part) {
 
    case array: {
        // Add it as a copy to preserve old semantics.  This sets parent too.
        bt_clone = bt->ptr_duplicate();
        set_array(static_cast<Array *>(bt_clone));
    } break;
 
    case maps: {
        bt_clone = bt->ptr_duplicate();
        bt_clone->set_parent(this);
        d_vars.push_back(bt_clone);
    } break;
 
    default: {
        if (!d_is_array_set ) {
            // Add it as a copy to preserve old semantics.  This sets parent too.
            bt_clone = bt->ptr_duplicate();
            set_array(static_cast<Array *>(bt_clone));
        } else {
            bt_clone = bt->ptr_duplicate();
            bt_clone->set_parent(this);
            d_vars.push_back(bt_clone);
        }
    } break;
    }
}

void Grid::add_var_nocopy(BaseType *bt, Part part) {
    if (!bt)
        throw InternalErr(__FILE__, __LINE__, "Passing NULL pointer as variable to be added.");
 
    if (bt->is_dap4())
        throw Error(string("A method usable only with DAP2 variables was called on a DAP4 variable (")
                        .append(name())
                        .append(")."),
                    __FILE__, __LINE__);
 
    if (part == array && d_is_array_set /*get_array()*/) {
        // Avoid leaking memory...  Function is add, not set, so it is an error to call again for the array part.
        throw InternalErr(__FILE__, __LINE__,
                          "Error: Grid::add_var called with part==Array, but the array was already set!");
    }
 
    // avoid obvious broken semantics
    if (!dynamic_cast<Array *>(bt)) {
        throw InternalErr(__FILE__, __LINE__, "Grid::add_var(): object is not an Array!");
    }
 
    bt->set_parent(this);
 
    switch (part) {
 
    case array: {
        // Refactored to use new set_array ([mjohnson 11 nov 2009])
        set_array(static_cast<Array *>(bt));
    } break;
 
    case maps: {
        // FIXME Why is this commented out?
        // bt->set_parent(this);
        d_vars.push_back(bt);
    } break;
 
    default: {
        if (!d_is_array_set ) {
            // Refactored to use new set_array ([mjohnson 11 nov 2009])
            // avoid obvious broken semantics
            set_array(static_cast<Array *>(bt));
        } else {
            d_vars.push_back(bt);
        }
    } break;
    }
}

void Grid::set_array(Array *p_new_arr) {
    if (!p_new_arr) {
        throw InternalErr(__FILE__, __LINE__, "Grid::set_array(): Cannot set to null!");
    }
 
    // Make sure not same memory, this would be evil.
    if (p_new_arr == get_array()) {
        return;
    }
 
    p_new_arr->set_parent(this);
 
    // Three cases: 1. There are no variables set for this grid at all
    // 2. There are maps but no array
    // 3. There is already an array set (and maybe maps).
    // NB: d_array_var is a weak pointer to the Grid's Array
    if (d_vars.size() == 0) {
        d_vars.push_back(p_new_arr);
    } else if (!d_is_array_set ) {
        d_vars.insert(d_vars.begin(), p_new_arr);
    } else {
        // clean out old array
        delete get_array();
        d_vars[0] = p_new_arr;
    }
 
    d_is_array_set = true;
#if 0
    // store the array pointer locally
    d_array_var = p_new_arr;
 
    // Set the  parent
    d_array_var->set_parent(this);
#endif
}

Array *Grid::add_map(Array *p_new_map, bool add_as_copy) {
    if (!p_new_map)
        throw InternalErr(__FILE__, __LINE__, "Grid::add_map(): cannot have p_new_map null!");
 
    if (add_as_copy)
        p_new_map = static_cast<Array *>(p_new_map->ptr_duplicate());
 
    p_new_map->set_parent(this);
 
    d_vars.push_back(p_new_map);
 
    // return the one that got put into the Grid.
    return p_new_map;
}

Array *Grid::prepend_map(Array *p_new_map, bool add_copy) {
    if (add_copy) {
        p_new_map = static_cast<Array *>(p_new_map->ptr_duplicate());
    }
 
    p_new_map->set_parent(this);
    d_vars.insert(map_begin(), p_new_map);
 
    return p_new_map;
}

BaseType *Grid::array_var() { return d_is_array_set ? *d_vars.begin() : nullptr; }

Array *Grid::get_array() { return dynamic_cast<Array *>(array_var()); }

Grid::Map_iter Grid::map_begin() {
    // The maps are stored in the second and subsequent elements of the
    // d_var vector<BaseType*> of Constructor _unless_ the Array part
    // has yet to be set. In the latter case, there are only maps in
    // d_vars
    return d_is_array_set ? d_vars.begin() + 1 : d_vars.begin();
}

Grid::Map_iter Grid::map_end() { return d_vars.end(); }

Grid::Map_riter Grid::map_rbegin() {
    // see above
    return d_vars.rbegin();
}

Grid::Map_riter Grid::map_rend() { return d_is_array_set ? d_vars.rend() - 1 : d_vars.rend(); }

Grid::Map_iter Grid::get_map_iter(int i) { return d_is_array_set ? d_vars.begin() + 1 + i : d_vars.begin() + i; }

int Grid::components(bool constrained) {
    int comp;
 
    if (constrained) {
        comp = get_array()->send_p() ? 1 : 0;
 
        for (Map_iter i = map_begin(); i != map_end(); i++) {
            if ((*i)->send_p()) {
                comp++;
            }
        }
    } else {
        comp = d_vars.size();
    }
 
    return comp;
}

void Grid::transfer_attributes(AttrTable *at_container) {
    DBG(cerr << __func__ << "() - BEGIN " << type_name() << " " << name()
             << " (at_container:" << at_container->get_name() << ":" << (void *)at_container << ")" << endl;);
 
    // The variable 'at' should be the attribute table for the Grid
    AttrTable *at = at_container->get_attr_table(name());
    if (at) {
        DBG(cerr << __func__ << "() - Found AttrTable (" << at->get_name() << ":" << (void *)at << ")" << endl;);
        at->set_is_global_attribute(false);
 
#if 0
        // Removing this is left over from a previous version, unknown date.
        // If the line is added back, some of the DMR round trip tests fail
        // and the dapreader behavior is changed - tests that build responses
        // from .dods and .das files fail when they include Grids. jhrg 5/23/18
        //
        // See also HYARX-766
        array_var()->transfer_attributes(at);
#endif
 
        // If the AttrTable with the name of this Grid (which is also the
        // name of the Grid's Array) contains a child AttrTable with that
        // name, mark the attributes as 'not global' and ignore them. This
        // code has been here for some time; I just added this comment. jhrg 5/23/18
        AttrTable *dvat = at->get_attr_table(array_var()->name());
        if (dvat) {
            dvat->set_is_global_attribute(false);
        }
 
        Map_iter map = map_begin();
        while (map != map_end()) {
            (*map)->transfer_attributes(at);
            map++;
        }
 
        // Trick: If an attribute that's within the container 'at' still has its
        // is_global_attribute property set, then it's not really a global attr
        // but instead an attribute that belongs to this Grid.
        AttrTable::Attr_iter at_p = at->attr_begin();
        while (at_p != at->attr_end()) {
            if (at->is_global_attribute(at_p)) {
                DBG(cerr << __func__ << "() - " << "Adding unclaimed Attribute (" << at->get_type(at_p) << ":"
                         << at->get_name(at_p) << ":" << (void *)(*map) << ") from AttrTable (" << at->get_name() << ":"
                         << (void *)at << ")" << " to the variable " << type_name() << " " << name() << endl;);
 
                if (at->get_attr_type(at_p) == Attr_container)
                    get_attr_table().append_container(new AttrTable(*at->get_attr_table(at_p)), at->get_name(at_p));
                else
                    get_attr_table().append_attr(at->get_name(at_p), at->get_type(at_p), at->get_attr_vector(at_p),
                                                 (*at_p)->is_utf8_str);
            }
 
            at_p++;
        }
    } else {
        DBG(cerr << __func__ << "() - No AttrTable named '" << name() << "' was found in at_container ("
                 << at_container->get_name() << ":" << (void *)at << ")" << endl;);
    }
    DBG(cerr << __func__ << "() - END " << type_name() << " " << name() << " (at_container:" << at_container->get_name()
             << ":" << (void *)at_container << ")" << endl;);
}
 
// When projected (using whatever the current constraint provides in the way
// of a projection), is the object still a Grid?

bool Grid::projection_yields_grid() {
    // For each dimension in the Array part, check the corresponding Map
    // vector to make sure it is present in the projected Grid. If for each
    // projected dimension in the Array component, there is a matching Map
    // vector, then the Grid is valid.
    bool valid = true;
    Array *a = get_array();
 
    // Don't bother checking if the Array component is not included.
    if (!a->send_p())
        return false;
 
    // If only one part is being sent, it's clearly not a grid (it must be
    // the array part of the Grid that's being sent (given that the above
    // test passed and the array is being sent).
    if (components(true) == 1)
        return false;
 
    Array::Dim_iter d = a->dim_begin();
    Map_iter m = map_begin();
 
    while (valid && d != a->dim_end() && m != map_end()) {
        Array &map = dynamic_cast<Array &>(**m);
        if (a->dimension_size(d, true) && map.send_p()) {
            // Check the matching Map vector; the Map projection must equal
            // the Array dimension projection
            Array::Dim_iter fd = map.dim_begin(); // Maps have only one dim!
            valid = map.dimension_start(fd, true) == a->dimension_start(d, true) &&
                    map.dimension_stop(fd, true) == a->dimension_stop(d, true) &&
                    map.dimension_stride(fd, true) == a->dimension_stride(d, true);
        } else {
            valid = false;
        }
 
        d++, m++;
    }
 
    return valid;
}

void Grid::clear_constraint() {
    get_array()->clear_constraint();
    for (Map_iter m = map_begin(); m != map_end(); ++m)
        dynamic_cast<Array &>(*(*m)).clear_constraint();
}
 
void Grid::print_decl(FILE *out, string space, bool print_semi, bool constraint_info, bool constrained) {
    ostringstream oss;
    print_decl(oss, space, print_semi, constraint_info, constrained);
    fwrite(oss.str().data(), sizeof(char), oss.str().length(), out);
}
 
void Grid::print_decl(ostream &out, string space, bool print_semi, bool constraint_info, bool constrained) {
    if (constrained && !send_p())
        return;
 
    // See comment for the FILE* version of this method.
    if (constrained && !projection_yields_grid()) {
        out << space << "Structure {\n";
 
        get_array()->print_decl(out, space + "    ", true, constraint_info, constrained);
 
        for (Map_citer i = map_begin(); i != map_end(); i++) {
            (*i)->print_decl(out, space + "    ", true, constraint_info, constrained);
        }
 
        out << space << "} " << id2www(name());
    } else {
        // The number of elements in the (projected) Grid must be such that
        // we have a valid Grid object; send it as such.
        out << space << type_name() << " {\n";
 
        out << space << "  Array:\n";
        get_array()->print_decl(out, space + "    ", true, constraint_info, constrained);
 
        out << space << "  Maps:\n";
        for (Map_citer i = map_begin(); i != map_end(); i++) {
            (*i)->print_decl(out, space + "    ", true, constraint_info, constrained);
        }
 
        out << space << "} " << id2www(name());
    }
 
    if (constraint_info) {
        if (send_p())
            out << ": Send True";
        else
            out << ": Send False";
    }
 
    if (print_semi)
        out << ";\n";
 
    return;
}

void Grid::print_xml(FILE *out, string space, bool constrained) {
    XMLWriter xml(space);
    print_xml_writer(xml, constrained);
    fwrite(xml.get_doc(), sizeof(char), xml.get_doc_size(), out);
}

void Grid::print_xml(ostream &out, string space, bool constrained) {
    XMLWriter xml(space);
    print_xml_writer(xml, constrained);
    out << xml.get_doc();
}
 
class PrintGridFieldXMLWriter : public unary_function<BaseType *, void> {
    XMLWriter &d_xml;
    bool d_constrained;
    string d_tag;
 
public:
    PrintGridFieldXMLWriter(XMLWriter &x, bool c, const string &t = "Map") : d_xml(x), d_constrained(c), d_tag(t) {}
 
    void operator()(BaseType *btp) {
        Array *a = dynamic_cast<Array *>(btp);
        if (!a)
            throw InternalErr(__FILE__, __LINE__, "Expected an Array.");
        a->print_xml_writer_core(d_xml, d_constrained, d_tag);
    }
};
 
void Grid::print_xml_writer(XMLWriter &xml, bool constrained) {
    if (constrained && !send_p())
        return;
 
    if (constrained && !projection_yields_grid()) {
        if (xmlTextWriterStartElement(xml.get_writer(), (const xmlChar *)"Structure") < 0)
            throw InternalErr(__FILE__, __LINE__, "Could not write Structure element");
 
        if (!name().empty())
            if (xmlTextWriterWriteAttribute(xml.get_writer(), (const xmlChar *)"name",
                                            (const xmlChar *)name().c_str()) < 0)
                throw InternalErr(__FILE__, __LINE__, "Could not write attribute for name");
 
        get_attr_table().print_xml_writer(xml);
 
        get_array()->print_xml_writer(xml, constrained);
 
        for_each(map_begin(), map_end(), PrintGridFieldXMLWriter(xml, constrained, "Array"));
 
        if (xmlTextWriterEndElement(xml.get_writer()) < 0)
            throw InternalErr(__FILE__, __LINE__, "Could not end Structure element");
    } else {
        // The number of elements in the (projected) Grid must be such that
        // we have a valid Grid object; send it as such.
        if (xmlTextWriterStartElement(xml.get_writer(), (const xmlChar *)"Grid") < 0)
            throw InternalErr(__FILE__, __LINE__, "Could not write Grid element");
 
        if (!name().empty())
            if (xmlTextWriterWriteAttribute(xml.get_writer(), (const xmlChar *)"name",
                                            (const xmlChar *)name().c_str()) < 0)
                throw InternalErr(__FILE__, __LINE__, "Could not write attribute for name");
 
        get_attr_table().print_xml_writer(xml);
 
        get_array()->print_xml_writer(xml, constrained);
 
        for_each(map_begin(), map_end(), PrintGridFieldXMLWriter(xml, constrained, "Map"));
 
        if (xmlTextWriterEndElement(xml.get_writer()) < 0)
            throw InternalErr(__FILE__, __LINE__, "Could not end Grid element");
    }
}
 
void Grid::print_val(FILE *out, string space, bool print_decl_p) {
    ostringstream oss;
    print_val(oss, space, print_decl_p);
    fwrite(oss.str().data(), sizeof(char), oss.str().length(), out);
}
 
void Grid::print_val(ostream &out, string space, bool print_decl_p) {
    if (print_decl_p) {
        print_decl(out, space, false);
        out << " = ";
    }
 
    // If we are printing a value on the client-side, projection_yields_grid
    // should not be called since we don't *have* a projection without a
    // Constraint. I think that if we are here and send_p() is not true, then
    // the value of this function should be ignored. 4/6/2000 jhrg
    bool pyg = projection_yields_grid(); // hack 12/1/99 jhrg
    if (pyg || !send_p())
        out << "{  Array: ";
    else
        out << "{";
 
    get_array()->print_val(out, "", false);
 
    if (pyg || !send_p())
        out << "  Maps: ";
 
    for (Map_citer i = map_begin(); i != map_end(); i++, (void)(i != map_end() && out << ", ")) {
        (*i)->print_val(out, "", false);
    }
 
    out << " }";
 
    if (print_decl_p)
        out << ";\n";
}
 
// Grids have ugly semantics.

bool Grid::check_semantics(string &msg, bool all) {
    if (!BaseType::check_semantics(msg))
        return false;
 
    msg = "";
 
    if (!get_array()) {
        msg += "Null grid base array in `" + name() + "'\n";
        return false;
    }
 
    // Is it an array?
    if (get_array()->type() != dods_array_c) {
        msg += "Grid `" + name() + "'s' member `" + get_array()->name() + "' must be an array\n";
        return false;
    }
 
    Array *av = (Array *)get_array(); // past test above, must be an array
 
    // Array must be of a simple_type.
    if (!av->var()->is_simple_type()) {
        msg += "The field variable `" + this->name() +
               "' must be an array of simple type elements (e.g., int32, String)\n";
        return false;
    }
 
    // enough maps?
    if ((unsigned)d_vars.size() - 1 != av->dimensions()) {
        msg +=
            "The number of map variables for grid `" + this->name() + "' does not match the number of dimensions of `";
        msg += av->name() + "'\n";
        return false;
    }
 
    const string array_var_name = av->name();
    Array::Dim_iter asi = av->dim_begin();
    for (Map_iter mvi = map_begin(); mvi != map_end(); mvi++, asi++) {
 
        BaseType *mv = *mvi;
 
        // check names
        if (array_var_name == mv->name()) {
            msg +=
                "Grid map variable `" + mv->name() + "' conflicts with the grid array name in grid `" + name() + "'\n";
            return false;
        }
        // check types
        if (mv->type() != dods_array_c) {
            msg += "Grid map variable  `" + mv->name() + "' is not an array\n";
            return false;
        }
 
        Array *mv_a = (Array *)mv; // downcast to (Array *)
 
        // Array must be of a simple_type.
        if (!mv_a->var()->is_simple_type()) {
            msg += "The field variable `" + this->name() +
                   "' must be an array of simple type elements (e.g., int32, String)\n";
            return false;
        }
 
        // check shape
        if (mv_a->dimensions() != 1) { // maps must have one dimension
            msg += "Grid map variable  `" + mv_a->name() + "' must be only one dimension\n";
            return false;
        }
        // size of map must match corresponding array dimension
        Array::Dim_iter mv_asi = mv_a->dim_begin();
        int mv_a_size = mv_a->dimension_size(mv_asi);
        int av_size = av->dimension_size(asi);
        if (mv_a_size != av_size) {
            msg += "Grid map variable  `" + mv_a->name() + "'s' size does not match the size of array variable '";
            msg += get_array()->name() + "'s' cooresponding dimension\n";
            return false;
        }
    }
 
    if (all) {
        if (!get_array()->check_semantics(msg, true))
            return false;
        for (Map_iter mvi = map_begin(); mvi != map_end(); mvi++) {
            if (!(*mvi)->check_semantics(msg, true)) {
                return false;
            }
        }
    }
 
    return true;
}

void Grid::dump(ostream &strm) const {
    strm << DapIndent::LMarg << "Grid::dump - (" << (void *)this << ")" << endl;
    DapIndent::Indent();
    Constructor::dump(strm);
 
    DapIndent::UnIndent();
}
 
} // namespace libdap