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// -*- mode: c++; c-basic-offset:4 -*-
// This file is part of libdap, A C++ implementation of the OPeNDAP Data
// Access Protocol.
// Copyright (c) 2013 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.
#ifndef D4MAPS_H_
#define D4MAPS_H_
#include <string>
#include <vector>
#include "Array.h"
using namespace std;
namespace libdap {
class Array;
class XMLWriter;
/**
* A 'Map' in DAP4 is an Array in the dataset that is used to provide the
* domain values for a Coverage (aka a DAP2 Grid). These Maps are a more
* general case of the DAP2 'Map vectors' because a DAP4 Map can have N
* dimensions.
*
* Because the Maps can be shared by many of the Arrays in a dataset,
* they also correspond to the NetCDF/CF notion of a Shared Dimension.
*
* In this implementation of the D4Map, each Map has a name and two weak
* pointers, one to the Array that holds the domain values and one to the
* Array that uses the Map. Note that while Maps can be shared by Arrays,
* each Array has it's own collection of these D4Map objects. This makes
* processing constraints possible (because it is possible to write
* different constraints for two arrays that share Maps).
*
* Second try. Including these 'weak' pointers lead to a paradox because
* the pointers don't exist when making deep copies of the Array. In that
* case the parent and source Array (the array that holds the Map's data)
* cannot be found because the Array that holds the Maps _does not yet exist_.
* It's being copied and the source object holds pointers to objects that
* are not reliable - the source Array is being copied because it's maybe
* going to be deleted!
*
* I removed the parent pointer from the D4Map object and added a pathname
* to the source Array. So, now we can set _either_ the weak pointer to
* the source array _or_ the pathname to the source array. The former is
* used when building the Array (as would be done in a handler) and the
* latter is used during a deep copy (where even though the pointer to the
* source Array will soon be invalid, the pathname won't be).
*/
class D4Map {
std::string d_name;
std::string d_array_path; ///< The data source for the Map's values
Array *d_array = nullptr; // the actual map data; cached weak pointer
public:
D4Map() = default;
///@{
/// Special constructors for object creation and deep copy
D4Map(std::string name, Array *array) : d_name(std::move(name)), d_array(array) {}
/// This ctor mimics older behavior - the parent arg is ignored now.
/// @deprecated
D4Map(std::string name, Array *array, BaseType * /*parent*/) : d_name(std::move(name)), d_array(array) {}
D4Map(std::string name, std::string array) : d_name(std::move(name)), d_array_path(std::move(array)) {}
///@}
virtual ~D4Map() = default;
const string &name() const { return d_name; }
void set_name(const string &name) { d_name = name; }
const std::string &get_array_path() const { return d_array_path; }
///@note We can set the path even if the referenced Array does not yet exist!
void set_array_path(const std::string &array) { d_array_path = array; }
///@{
/// Ways to get the Array that holds a Map's values.
///@brief This will always return the correct pointer for a valid data set.
Array *array(D4Group *root);
///@brief Only use this accessor in code that can deal with a nullptr return!
Array *array() const { return d_array; }
///@}
void set_array(Array *array) {
d_array = array;
d_array_path = array->FQN();
}
virtual void print_dap4(XMLWriter &xml);
};
/**
* The D4Maps object holds pointers to all of the Maps used by
* a given Array.
*/
class D4Maps {
public:
typedef vector<D4Map *>::iterator D4MapsIter;
typedef vector<D4Map *>::const_iterator D4MapsCIter;
private:
vector<D4Map *> d_maps;
const Array *d_parent; // Array these Maps belong to; weak pointer
void m_duplicate(const D4Maps &maps, const Array *parent) {
d_parent = parent;
d_maps.reserve(maps.size());
for (auto const map : maps.d_maps) {
d_maps.emplace_back(new D4Map(map->name(), map->get_array_path()));
}
}
public:
D4Maps() = default;
// See comment below at operator=(). jhrg 9/12/23
D4Maps(const D4Maps &maps) = delete;
explicit D4Maps(const Array *parent) : d_parent(parent) {}
D4Maps(const D4Maps &maps, const Array *parent) { m_duplicate(maps, parent); }
virtual ~D4Maps() {
for (D4MapsIter i = d_maps.begin(), e = d_maps.end(); i != e; ++i)
delete *i;
}
// I deleted this because this class needs to set the _parent_ pointer to
// the Array that holds these maps. The one argument assignment operator
// provides no way to include that information. jhrg 9/12/23
D4Maps &operator=(const D4Maps &rhs) = delete;
/**
* Add a map. This does not test for duplicate names or Array pointers.
* It assumes that the caller has done that!
*/
void add_map(D4Map *map) { d_maps.push_back(map); }
void remove_map(D4Map *map) {
// TODO Refactor this to use erase() and find_if(). There is no reason
// to code an explicit loop like this in C++11. jhrg 9/16/22
for (D4MapsIter i = d_maps.begin(), e = d_maps.end(); i != e; ++i) {
/* && (*i)->parent() == map->parent() */
// Don't test if the map->parent() matches - we only care about the name and array.
// This method is intended for processing CE array slices that are edge cases and
// is only called from code where we know map->parent() matches *i->parent().
// jhrg 4/12/16
if ((*i)->name() == map->name()) {
d_maps.erase(i);
break;
}
}
}
D4Map *get_map(int i) { return d_maps.at(i); }
D4MapsIter map_begin() { return d_maps.begin(); }
D4MapsIter map_end() { return d_maps.end(); }
int size() const { return d_maps.size(); }
bool empty() const { return d_maps.empty(); }
virtual void print_dap4(XMLWriter &xml) {
for (D4MapsIter i = d_maps.begin(), e = d_maps.end(); i != e; ++i)
(*i)->print_dap4(xml);
}
};
} /* namespace libdap */
#endif /* D4MAPS_H_ */
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