libdap-dev 3.12.0-1 / usr / include / libdap / BaseType.h

// -*- 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>
//         Dan Holloway <dan@hollywood.gso.uri.edu>
//         Reza Nekovei <reza@intcomm.net>
//
// 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>
//      dan             Dan Holloway <dan@hollywood.gso.uri.edu>
//      reza            Reza Nekovei <reza@intcomm.net>

// Abstract base class for the variables in a dataset. This is used to store
// the type-invariant information that describes a variable as given in the
// DODS API.
//
// jhrg 9/6/94

#ifndef _basetype_h
#define _basetype_h 1


#include <vector>
#include <stack>
#include <iostream>
#include <string>

// These are instantiated only for DAP4 variables
#if DAP4
#include "D4Dimensions.h"
#include "D4Maps.h"
#endif

#include "AttrTable.h"

#include "InternalErr.h"

#include "dods-datatypes.h"

#include "DapObj.h"

#include "XMLWriter.h"

using namespace std;

namespace libdap
{

class DDS;
class ConstraintEvaluator;
class Marshaller;
class UnMarshaller;

/** <b>Part</b> names the parts of multi-section constructor types.
    For example, the <b>Grid</b> class has an <i>array</i> and
    the array <i>maps</i>. Use the <tt>nil</tt> value for data types that
    don't have separate parts.

    \code
    enum Part {
    nil,
    array,
    maps
    };
    \endcode

    @brief Names the parts of multi-section constructor data types.
    @see Grid
    @see BaseType
*/

enum Part {
    nil,   // nil is for types that don't have parts...
    array,
    maps
};

/** <b>Type</b> identifies the data type stored in a particular type
    class. All the DODS Data Access Protocol (DAP) types inherit from
    the BaseType class.

    \code
    enum Type {
    dods_null_c,
    dods_byte_c,
    dods_int16_c,
    dods_uint16_c,
    dods_int32_c,
    dods_uint32_c,
    dods_float32_c,
    dods_float64_c,
    dods_str_c,
    dods_url_c,
    dods_array_c,
    dods_structure_c,
    dods_sequence_c,
    dods_grid_c,

    dods_int8_c,
    dods_uint8_c,
    dods_int64_c,
    dods_uint64_c,
    dods_url4_c
    dods_enum_c,
    dods_group_c

    };
    \endcode

    @brief Identifies the data type.
    @see BaseType
*/

enum Type {
    dods_null_c,
    dods_byte_c,
    dods_int16_c,
    dods_uint16_c,
    dods_int32_c,  // Added `dods_' to fix clash with IRIX 5.3.
    dods_uint32_c,
    dods_float32_c,
    dods_float64_c,
    dods_str_c,
    dods_url_c,
    dods_array_c,
    dods_structure_c,
    dods_sequence_c,
    dods_grid_c,

    // Added for DAP4
    dods_int8_c,
    dods_uint8_c,

    dods_int64_c,
    dods_uint64_c,

    dods_url4_c,

    dods_enum_c,
    dods_group_c

};

/** This defines the basic data type features for the DODS data access
    protocol (DAP) data types. All the DAP type classes (Float64, Array,
    etc.) subclass it. This class is an abstract one; no variables will ever
    be stored as BaseType instances, only as instances of its child classes.

    These classes and their methods give a user the capacity to set up
    sophisticated data types. They do <i>not</i> provide sophisticated ways to
    access and use this data. On the server side, in many cases, the class
    instances will have no data in them at all until the
    <tt>serialize</tt> function
    is called to send data to the client. On the client side, most DODS
    application programs will unpack the data promptly into whatever local
    data structure the programmer deems the most useful.

    In order to use these classes on the server side of a DODS
    client/server connection, you must write a <tt>read</tt> method
    for each of the data types you expect to encounter in the
    application. This function, whose purpose is to read data from a
    local source into the class instance data buffer, is called in
    <tt>serialize</tt>, when the data is about to be sent to the
    client.  The <tt>read</tt> function may be called earlier, in the
    case of data subset requests (constraint expressions) whose
    evaluation requires it. (For example, the constraint expression
    ``<tt>a,b&b>c</tt>'' requires that <tt>c</tt> be read even though
    it will not be sent.)

    For some data types, the <tt>read</tt> function must be aware of
    the constraints
    to be returned. These cautions are outlined where they occur.

    @brief The basic data type for the DODS DAP types.  */

class BaseType : public DapObj
{
private:
    string d_name;  // name of the instance
    Type d_type;   // instance's type
    string d_dataset; // name of the dataset used to create this BaseType

    bool d_is_read;  // true if the value has been read
    bool d_is_send;  // Is the variable in the projection?
    bool d_in_selection; // Is the variable in the selection?
    bool d_is_synthesized; // true if the variable is synthesized

    // d_parent points to the Constructor or Vector which holds a particular
    // variable. It is null for simple variables. The Vector and Constructor
    // classes must maintain this variable.
    BaseType *d_parent;

    // Attributes for this variable. Added 05/20/03 jhrg
    AttrTable d_attr;

    bool d_is_dap4;         // True if this is a DAP4 variable, false ... DAP2

    // These are non-empty only for DAP4 variables. Added 9/27/12 jhrg

    // FIXME Remove this. This header cannot have compile-time variation
#if DAP4
    D4Dimensions d_dims;   // If non-empty, this BaseType is an DAP4 Array
    D4Maps d_maps;         // if non-empty, this BaseType is a DAP4 'Grid'
#endif

protected:
    void m_duplicate(const BaseType &bt);

public:
    typedef stack<BaseType *> btp_stack;

    // These ctors assume is_dap4 is false
    BaseType(const string &n, const Type &t, bool is_dap4 = false);
    BaseType(const string &n, const string &d, const Type &t, bool is_dap4 = false);
#if 0
    // These provide a way to set is_dap4
    BaseType(const string &n, const Type &t, bool is_dap4);
    BaseType(const string &n, const string &d, const Type &t, bool is_dap4);
#endif
    BaseType(const BaseType &copy_from);
    virtual ~BaseType();

    virtual string toString();

    virtual void dump(ostream &strm) const ;

    BaseType &operator=(const BaseType &rhs);

    bool is_dap4() { return d_is_dap4; }
    void set_is_dap4(const bool v) { d_is_dap4 = v;}

    /** Clone this instance. Allocate a new instance and copy \c *this into
	it. This method must perform a deep copy.

        @note This method should \e not copy data values, but must copy all
        other fields in the object.
	@return A newly allocated copy of \c this. */
    virtual BaseType *ptr_duplicate() = 0;

    string name() const;
    virtual void set_name(const string &n);

    Type type() const;
    void set_type(const Type &t);
    string type_name() const;

    string dataset() const ;

    virtual bool is_simple_type();
    virtual bool is_vector_type();
    virtual bool is_constructor_type();

#if 0
    // Not yet, if ever. Allow 'sloppy' changeover in the handlers
    virtual bool is_dap4_only_type();
    virtual bool is_dap2_only_type();
#endif
    virtual bool synthesized_p();
    virtual void set_synthesized_p(bool state);

    virtual int element_count(bool leaves = false);

    virtual bool read_p();
    virtual void set_read_p(bool state);

    virtual bool send_p();
    virtual void set_send_p(bool state);

    virtual AttrTable &get_attr_table();
    virtual void set_attr_table(const AttrTable &at);

    virtual bool is_in_selection();
    virtual void set_in_selection(bool state);

    virtual void set_parent(BaseType *parent);
    virtual BaseType *get_parent();

    virtual void transfer_attributes(AttrTable *at);

    // I put this comment here because the version in BaseType.cc does not
    // include the exact_match or s variables since they are not used. Doxygen
    // was gaging on the comment.

    /** Returns a pointer to the contained variable in a composite class. The
        composite classes are those made up of aggregated simple data types.
        Array, Grid, and Structure are composite types, while Int and Float are
        simple types. This function is only used by composite classes. The
        BaseType implementation always returns null.

        Several of the subclasses provide alternate access methods
        that make sense for that particular data type. For example,
        the Array class defines a <tt>*var(int i)</tt> method that
        returns the ith entry in the Array data, and the Structure
        provides a <tt>*var(Vars_iter)</tt> function using a
        pseudo-index to access the different members of the structure.

        @brief Returns a pointer to a member of a constructor class.
        @param name The name of the class member.  Defaults to ""
        @param exact_match True if only interested in variables whose
        full names match \e n exactly. If false, returns the first
        variable whose name matches \e name. For example, if \e name
        is \c x and \c point.x is a variable, then var("x", false)
        would return a BaseType pointer to \c point.x. If \e
        exact_match was <tt>true</tt> then \e name would need to be \c
        "point.x" for var to return that pointer. This feature
        simplifies constraint expressions for datasets which have
        complex, nested, constructor variables. Defaults to true.
        @param s Record the path to \e name. Defaults to null, in
        which case it is not used.
        @return A pointer to the member named in the \e n argument. If
        no name is given, the function returns the first (only)
        variable. For example, an Array has only one variable, while a
        Structure can have many. */
    virtual BaseType *var(const string &name = "", bool exact_match = true, btp_stack *s = 0);
    virtual BaseType *var(const string &name, btp_stack &s);

    virtual void add_var(BaseType *bt, Part part = nil);

    virtual bool read();

    virtual bool check_semantics(string &msg, bool all = false);

    virtual bool ops(BaseType *b, int op);

    virtual void print_decl(FILE *out, string space = "    ",
                            bool print_semi = true,
                            bool constraint_info = false,
                            bool constrained = false);

    virtual void print_xml(FILE *out, string space = "    ",
                           bool constrained = false);

    virtual void print_decl(ostream &out, string space = "    ",
                            bool print_semi = true,
                            bool constraint_info = false,
                            bool constrained = false);

    virtual void print_xml(ostream &out, string space = "    ",
                           bool constrained = false);

    virtual void print_xml_writer(XMLWriter &xml, bool constrained = false);

    /** @name Abstract Methods */
    //@{
#if 0
    /** Return the number of bytes that are required to hold the
	instance's value. In the case of simple types such as Int32,
	this is the size of one Int32 (four bytes). For a String or
	Url type, <tt>width(bool constrained = false)</tt> returns the number of bytes needed
	for a <tt>String *</tt> variable, not the bytes needed for all
	the characters, since that value cannot be determined from
	type information alone. For Structure, and other constructor
	types size() returns the number of bytes needed to store
	pointers to the C++ objects.

	@brief Returns the size of the class instance data. */
    virtual unsigned int width(bool constrained = false) = 0;
#endif
    virtual unsigned int width(bool constrained = false);

    /** Reads the class data into the memory referenced by <i>val</i>.
	The caller should either allocate enough storage to <i>val</i>
	to hold the class data or set \c *val to null. If <i>*val</i>
	is NULL, memory will be allocated by this function with
	<tt>new()</tt>. If the memory is allocated this way, the
	caller is responsible for deallocating that memory. Array and
	values for simple types are stored as C would store an array.

    @deprecated Use value() in the leaf classes.

	@brief Reads the class data.

	@param val A pointer to a pointer to the memory into which the
	class data will be copied. If the value pointed to is NULL,
	memory will be allocated to hold the data, and the pointer
	value modified accordingly. The calling program is responsible
	for deallocating the memory references by this pointer.

	@return The size (in bytes) of the information copied to <i>val</i>.
    */
    virtual unsigned int buf2val(void **val) = 0;

    /** Store the value pointed to by <i>val</i> in the object's
	internal buffer. This function does not perform any checks, so
	users must be sure that the thing pointed to can actually be
	stored in the object's buffer.

	Only simple objects (Int, Float, Byte, and so on) and arrays
	of these simple objects may be stored using this function. To
	put data into more complex constructor types, use the
	functions provided by that class.

    @deprecated Use set_value() in the leaf classes.

	@brief Loads class data.

	@param val A pointer to the data to be inserted into the class
	data buffer.

	@param reuse A boolean value, indicating whether the class
	internal data storage can be reused or not. If this argument
	is TRUE, the class buffer is assumed to be large enough to
	hold the incoming data, and it is <i>not</i> reallocated. If
	FALSE, new storage is allocated. If the internal buffer has
	not been allocated at all, this argument has no effect. This
	is currently used only in the Vector class.

	@return The size (in bytes) of the information copied from
	<i>val</i>.
	@see Grid
	@see Vector::val2buf */
    virtual unsigned int val2buf(void *val, bool reuse = false) = 0;

    /** Similar to using serialize() and deserialize() together in one object.
        Data are read as for serialize and those values are stored in the
        objects as deserialize() does but does not write and then read data
        to/from a stream.

        This method is defined by the various data type classes. It calls the
        read() abstract method.

        @param eval Use this as the constraint expression evaluator.
        @param dds The Data Descriptor Structure object corresponding
        to this dataset. See <i>The DODS User Manual</i> for
        information about this structure. */
    virtual void intern_data(ConstraintEvaluator &eval, DDS &dds);

    /** Sends the data from the indicated (local) dataset through the
	connection identified by the <i>sink</i> parameter. If the
	data is not already incorporated into the DDS object, read the
	data from the dataset.

	This function is only used on the server side of the
	client/server connection, and is generally only called from
	the ResponseBuilder functions. It has no BaseType
	implementation; each datatype child class supplies its own
	implementation.

	@brief Move data to the net.

        @param eval Use this as the constraint expression evaluator.
	@param dds The Data Descriptor Structure object corresponding
	to this dataset. See <i>The DODS User Manual</i> for
	information about this structure.
	@param m A marshaller used to serialize data types
	@param ce_eval A boolean value indicating whether to evaluate
	the DODS constraint expression that may accompany this
	dataset. The constraint expression is stored in <i>dds</i>.
	@return This method always returns true. Older versions used
	the return value to signal success or failure.

	@exception InternalErr.
	@exception Error.
	@see DDS */
    virtual bool serialize(ConstraintEvaluator &eval, DDS &dds,
			   Marshaller &m, bool ce_eval = true) = 0;

    /** Receives data from the network connection identified by the
	<tt>source</tt> parameter. The data is put into the class data
	buffer according to the input <tt>dds</tt>.

	This function is only used on the client side of the DODS
	client/server connection.

	@brief Receive data from the net.

	@param um An UnMarshaller that knows how to deserialize data types
	@param dds The Data Descriptor Structure object corresponding
	to this dataset. See <i>The DODS User Manual</i> for
	information about this structure. This would have been
	received from the server in an earlier transmission.
	@param reuse A boolean value, indicating whether the class
	internal data storage can be reused or not. If this argument
	is TRUE, the class buffer is assumed to be large enough to
	hold the incoming data, and it is <i>not</i> reallocated. If
	FALSE, new storage is allocated. If the internal buffer has
	not been allocated at all, this argument has no effect.
	@return Always returns TRUE.
	@exception Error when a problem reading from the UnMarshaller is
	found.
	@see DDS */
    virtual bool deserialize(UnMarshaller &um, DDS *dds, bool reuse = false) = 0;

    /** Prints the value of the variable, with its declaration. This
	function is primarily intended for debugging DODS
	applications. However, it can be overloaded and used to do
	some useful things. Take a look at the asciival and writeval
	clients, both of which overload this to output the values of
	variables in different ways.

	@brief Prints the value of the variable.

	@param out The output stream on which to print the value.
	@param space This value is passed to the print_decl()
	function, and controls the leading spaces of the output.
	@param print_decl_p A boolean value controlling whether the
	variable declaration is printed as well as the value. */

    virtual void print_val(FILE *out, string space = "",
                           bool print_decl_p = true) = 0;

    /** Prints the value of the variable, with its declaration. This
	function is primarily intended for debugging DODS
	applications. However, it can be overloaded and used to do
	some useful things. Take a look at the asciival and writeval
	clients, both of which overload this to output the values of
	variables in different ways.

	@brief Prints the value of the variable.

	@param out The output ostream on which to print the value.
	@param space This value is passed to the print_decl()
	function, and controls the leading spaces of the output.
	@param print_decl_p A boolean value controlling whether the
	variable declaration is printed as well as the value. */
    virtual void print_val(ostream &out, string space = "",
                           bool print_decl_p = true) = 0;
    //@}
};

} // namespace libdap

#endif // _basetype_h