Connect.h

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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) 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 1994-1999,2001,2002
// Please first read the full copyright statement in the file COPYRIGHT_URI.
//
// Authors:
// jhrg,jimg James Gallagher <jgallagher@gso.uri.edu>
// dan  Dan Holloway <dholloway@gso.uri.edu>
// reza  Reza Nekovei <rnekovei@ieee.org>
 
// Connect objects are used as containers for information pertaining to a
// connection that a user program makes to a dataset. The dataset may be
// either local (i.e., a file on the user's own computer) or a remote
// dataset. In the later case a DAP2 URL will be used to reference the
// dataset.
//
// Connect contains methods which can be used to read the DOS DAS and DDS
// objects from the remote dataset as well as reading reading data. The class
// understands in a rudimentary way how DAP2 constraint expressions are
// formed and how to manage the CEs generated by a API to request specific
// variables with the URL initially presented to the class when the object
// was instantiated.
//
// Connect also provides additional services such as error processing.
//
// Connect is not intended for use on the server-side.
//
// jhrg 9/29/94
 
#ifndef _connect_h
#define _connect_h
 
#include <string>
 
#ifndef _das_h
#include "DAS.h"
#endif
 
#ifndef _dds_h
#include "DDS.h"
#endif
 
#ifndef _error_h
#include "Error.h"
#endif
 
#ifndef _util_h
#include "util.h"
#endif
 
#ifndef _datadds_h
#include "DataDDS.h"
#endif
 
#ifndef _httpconnect_h
#include "HTTPConnect.h"
#endif
 
#ifndef response_h
#include "Response.h"
#endif
 
using std::string;
 
namespace libdap {

 
class Connect {
private:
    bool _local; // Is this a local connection?
 
    HTTPConnect *d_http;
    string _URL;  // URL to remote dataset (minus CE)
    string _proj; // Projection part of initial CE.
    string _sel;  // Selection of initial CE
 
    string d_version;  // Server implementation information
    string d_protocol; // DAP protocol from the server
 
    void process_data(DataDDS &data, Response *rs);
    void process_data(DDS &data, Response *rs);
 
    // Use when you cannot use libwww/libcurl. Reads HTTP response.
    void parse_mime(Response *rs);
 
protected:
    Connect();
    Connect(const Connect &);
    Connect &operator=(const Connect &);
 
public:
    Connect(const string &name, string uname = "", string password = "");
 
    virtual ~Connect();
 
    bool is_local();
 
    // *** Add get_* versions of accessors. 02/27/03 jhrg
    virtual string URL(bool CE = true);
    virtual string CE();
 
    void set_credentials(string u, string p);
    void set_accept_deflate(bool deflate);
    void set_xdap_protocol(int major, int minor);
 
    void set_cache_enabled(bool enabled);
    bool is_cache_enabled();
 
    void set_xdap_accept(int major, int minor);

    string get_version() { return d_version; }

    string get_protocol() { return d_protocol; }
 
    virtual string request_version();
    virtual string request_protocol();
 
    virtual void request_das(DAS &das);
    virtual void request_das_url(DAS &das);
 
    virtual void request_dds(DDS &dds, string expr = "");
    virtual void request_dds_url(DDS &dds);
 
    virtual void request_ddx(DDS &dds, string expr = "");
    virtual void request_ddx_url(DDS &dds);
 
    virtual void request_data(DataDDS &data, string expr = "");
    virtual void request_data_url(DataDDS &data);
 
    virtual void request_data_ddx(DataDDS &data, string expr = "");
    virtual void request_data_ddx_url(DataDDS &data);
 
    virtual void read_data(DataDDS &data, Response *rs);
    virtual void read_data_no_mime(DataDDS &data, Response *rs);
    virtual void read_data(DDS &data, Response *rs);
    virtual void read_data_no_mime(DDS &data, Response *rs);
};
 
} // namespace libdap
 
#endif // _connect_h