Connect.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>
//         Dan Holloway <dholloway@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 1994-2002
// Please 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 <reza@intcomm.net>

#include "config.h"

//#define DODS_DEBUG
#define FILE_UN_MARSHALLER 1

#include <cstring>
#include <cerrno>

#include <fstream>
#include <algorithm>

#include "debug.h"
#include "DataDDS.h"
#include "Connect.h"
#include "escaping.h"
//#include "RCReader.h"
#include "DDXParserSAX2.h"
#if FILE_UN_MARSHALLER
#include "XDRFileUnMarshaller.h"
#else
#include "fdiostream.h"
#include "XDRStreamUnMarshaller.h"
#endif
#include "mime_util.h"

using std::cerr;
using std::endl;
using std::ifstream;
using std::ofstream;
using std::min;

namespace libdap {

void Connect::process_data(DataDDS &data, Response *rs)
{
    DBG(cerr << "Entering Connect::process_data" << endl);

    data.set_version(rs->get_version());
    data.set_protocol(rs->get_protocol());

    DBG(cerr << "Entering process_data: d_stream = " << rs << endl);
    switch (rs->get_type()) {
        case dods_error: {
            Error e;
            if (!e.parse(rs->get_stream()))
                throw InternalErr(__FILE__, __LINE__, "Could not parse the Error object returned by the server!");
            throw e;
        }

        case web_error:
            // Web errors (those reported in the return document's MIME header)
            // are processed by the WWW library.
            throw InternalErr(__FILE__, __LINE__,
                    "An error was reported by the remote httpd; this should have been processed by HTTPConnect..");

#if 0
            // This code triggers a security warning from Coverity; since it is not used,
            // I have removed it. jhrg 5/5/16
        case dods_data_ddx: {
            // Parse the DDX; throw an exception on error.
            DDXParser ddx_parser(data.get_factory());

            // Read the MPM boundary and then read the subsequent headers
            string boundary = read_multipart_boundary(rs->get_stream());
            DBG(cerr << "MPM Boundary: " << boundary << endl);
            read_multipart_headers(rs->get_stream(), "text/xml", dods_ddx);

            // Parse the DDX, reading up to and including the next boundary.
            // Return the CID for the matching data part
            string data_cid;
            ddx_parser.intern_stream(rs->get_stream(), &data, data_cid, boundary);

            // Munge the CID into something we can work with
            data_cid = cid_to_header_value(data_cid);
            DBG(cerr << "Data CID: " << data_cid << endl);

            // Read the data part's MPM part headers (boundary was read by
            // DDXParse::intern)
            read_multipart_headers(rs->get_stream(), "application/octet-stream", dap4_data, data_cid);

            // Now read the data
#if FILE_UN_MARSHALLER
            XDRFileUnMarshaller um(rs->get_stream());
#else
        fpistream in ( rs->get_stream() );
            XDRStreamUnMarshaller um( in );
#endif
            for (DDS::Vars_iter i = data.var_begin(); i != data.var_end(); i++) {
                (*i)->deserialize(um, &data);
            }
            return;
        }
#endif

        case dods_data:
        default: {
            // Parse the DDS; throw an exception on error.
            data.parse(rs->get_stream());
#if FILE_UN_MARSHALLER
            XDRFileUnMarshaller um(rs->get_stream());
#else
            fpistream in ( rs->get_stream() );
            XDRStreamUnMarshaller um( in );
#endif
            // Load the DDS with data.
            for (DDS::Vars_iter i = data.var_begin(); i != data.var_end(); i++) {
                (*i)->deserialize(um, &data);
            }
            return;
        }
    }
}

void Connect::process_data(DDS &data, Response *rs)
{
    DBG(cerr << "Entering Connect::process_data" << endl);

    data.set_dap_version(rs->get_protocol());

    DBG(cerr << "Entering process_data: d_stream = " << rs << endl);
    switch (rs->get_type()) {
    case dods_error: {
        Error e;
        if (!e.parse(rs->get_stream()))
            throw InternalErr(__FILE__, __LINE__, "Could not parse the Error object returned by the server!");
        throw e;
    }

    case web_error:
        // Web errors (those reported in the return document's MIME header)
        // are processed by the WWW library.
        throw InternalErr(__FILE__, __LINE__,
            "An error was reported by the remote web server; this should have been processed by HTTPConnect.");

#if 0
        // FIXME: The following case is never used. There is no such response. jhrg 10/20/15
        // This code triggers a security warning from Coverity; since it is not used,
        // I have removed it. jhrg 5/5/16
    case dods_data_ddx: {
        // Parse the DDX; throw an exception on error.
        DDXParser ddx_parser(data.get_factory());

        // Read the MPM boundary and then read the subsequent headers
        string boundary = read_multipart_boundary(rs->get_stream());
        DBG(cerr << "MPM Boundary: " << boundary << endl);
        read_multipart_headers(rs->get_stream(), "text/xml", dods_ddx);

        // Parse the DDX, reading up to and including the next boundary.
        // Return the CID for the matching data part
        string data_cid;
        ddx_parser.intern_stream(rs->get_stream(), &data, data_cid, boundary);

        // Munge the CID into something we can work with
        data_cid = cid_to_header_value(data_cid);
        DBG(cerr << "Data CID: " << data_cid << endl);

        // Read the data part's MPM part headers (boundary was read by
        // DDXParse::intern)
        read_multipart_headers(rs->get_stream(), "application/octet-stream", dap4_data, data_cid);

        // Now read the data
        XDRFileUnMarshaller um(rs->get_stream());
        for (DDS::Vars_iter i = data.var_begin(); i != data.var_end(); i++) {
            (*i)->deserialize(um, &data);
        }
        return;
    }
#endif

    case dods_data:
    default: {
        // Parse the DDS; throw an exception on error.
        data.parse(rs->get_stream());

        XDRFileUnMarshaller um(rs->get_stream());

        // Load the DDS with data.
        for (DDS::Vars_iter i = data.var_begin(); i != data.var_end(); i++) {
            (*i)->deserialize(um, &data);
        }

        return;
    }
    }
}

// Barely a parser... This is used when reading from local sources of DODS
// Data objects. It simulates the important actions of the libwww MIME header
// parser. Those actions fill in certain fields in the Connect object. jhrg
// 5/20/97
//
// Make sure that this parser reads from data_source without disturbing the
// information in data_source that follows the MIME header. Since the DDS
// (which follows the MIME header) is parsed by a flex/bison scanner/parser,
// make sure to use I/O calls that will mesh with ANSI C I/O calls. In the
// old GNU libg++, the C++ calls were synchronized with the C calls, but that
// may no longer be the case. 5/31/99 jhrg

void Connect::parse_mime(Response *rs)
{
    rs->set_version("dods/0.0"); // initial value; for backward compatibility.
    rs->set_protocol("2.0");

    FILE *data_source = rs->get_stream();
    string mime = get_next_mime_header(data_source);
    while (!mime.empty()) {
        string header, value;
        parse_mime_header(mime, header, value);

        // Note that this is an ordered list
        if (header == "content-description:") {
            DBG(cout << header << ": " << value << endl);
            rs->set_type(get_description_type(value));
        }
        // Use the value of xdods-server only if no other value has been read
        else if (header == "xdods-server:" && rs->get_version() == "dods/0.0") {
            DBG(cout << header << ": " << value << endl);
            rs->set_version(value);
        }
        // This trumps 'xdods-server' and 'server'
        else if (header == "xopendap-server:") {
            DBG(cout << header << ": " << value << endl);
            rs->set_version(value);
        }
        else if (header == "xdap:") {
            DBG(cout << header << ": " << value << endl);
            rs->set_protocol(value);
        }
        // Only look for 'server' if no other header supplies this info.
        else if (rs->get_version() == "dods/0.0" && header == "server:") {
            DBG(cout << header << ": " << value << endl);
            rs->set_version(value);
        }

        mime = get_next_mime_header(data_source);
    }
}

// public mfuncs

Connect::Connect(const string &n, string uname, string password) :
        d_http(0), d_version("unknown"), d_protocol("2.0")
{
    string name = prune_spaces(n);

    // Figure out if the URL starts with 'http', if so, make sure that we
    // talk to an instance of HTTPConnect.
    if (name.find("http") == 0) {
        DBG(cerr << "Connect: The identifier is an http URL" << endl);
        d_http = new HTTPConnect(RCReader::instance());

        // Find and store any CE given with the URL.
        string::size_type dotpos = name.find('?');
        if (dotpos != name.npos) {
            _URL = name.substr(0, dotpos);
            string expr = name.substr(dotpos + 1);

            dotpos = expr.find('&');
            if (dotpos != expr.npos) {
                _proj = expr.substr(0, dotpos);
                _sel = expr.substr(dotpos); // XXX includes '&'
            }
            else {
                _proj = expr;
                _sel = "";
            }
        }
        else {
            _URL = name;
            _proj = "";
            _sel = "";
        }

        _local = false;
    }
    else {
        DBG(cerr << "Connect: The identifier is a local data source." << endl);

        d_http = 0;
        _URL = "";
        _local = true; // local in this case means non-DAP
    }

    set_credentials(uname, password);
}

Connect::~Connect()
{
    DBG2(cerr << "Entering the Connect dtor" << endl);

    if (d_http)
        delete d_http;
    d_http = 0;

    DBG2(cerr << "Leaving the Connect dtor" << endl);
}

string Connect::request_version()
{
    string version_url = _URL + ".ver";
    if (_proj.length() + _sel.length())
        version_url = version_url + "?" + id2www_ce(_proj + _sel);

    Response *rs = 0;
    try {
        rs = d_http->fetch_url(version_url);
    }
    catch (Error &e) {
        delete rs;
        rs = 0;
        throw;
    }

    d_version = rs->get_version();
    d_protocol = rs->get_protocol();

    delete rs;
    rs = 0;

    return d_version;
}

string Connect::request_protocol()
{
    string version_url = _URL + ".ver";
    if (_proj.length() + _sel.length())
        version_url = version_url + "?" + id2www_ce(_proj + _sel);

    Response *rs = 0;
    try {
        rs = d_http->fetch_url(version_url);
    }
    catch (Error &e) {
        delete rs;
        rs = 0;
        throw;
    }

    d_version = rs->get_version();
    d_protocol = rs->get_protocol();

    delete rs;
    rs = 0;

    return d_protocol;
}

void Connect::request_das(DAS &das)
{
    string das_url = _URL + ".das";
    if (_proj.length() + _sel.length())
        das_url = das_url + "?" + id2www_ce(_proj + _sel);

    Response *rs = 0;
    try {
        rs = d_http->fetch_url(das_url);
    }
    catch (Error &e) {
        delete rs;
        rs = 0;
        throw;
    }

    d_version = rs->get_version();
    d_protocol = rs->get_protocol();

    switch (rs->get_type()) {
        case dods_error: {
            Error e;
            if (!e.parse(rs->get_stream())) {
                delete rs;
                rs = 0;
                throw InternalErr(__FILE__, __LINE__, "Could not parse error returned from server.");
            }
            delete rs;
            rs = 0;
            throw e;
        }

        case web_error:
            // We should never get here; a web error should be picked up read_url
            // (called by fetch_url) and result in a thrown Error object.
            break;

        case dods_das:
        default:
            // DAS::parse throws an exception on error.
            try {
                das.parse(rs->get_stream()); // read and parse the das from a file
            }
            catch (Error &e) {
                delete rs;
                rs = 0;
                throw;
            }

            break;
    }

    delete rs;
    rs = 0;
}

void Connect::request_das_url(DAS &das)
{
    string use_url = _URL + "?" + _proj + _sel;
    Response *rs = 0;
    try {
        rs = d_http->fetch_url(use_url);
    }
    catch (Error &e) {
        delete rs;
        rs = 0;
        throw;
    }

    d_version = rs->get_version();
    d_protocol = rs->get_protocol();

    switch (rs->get_type()) {
        case dods_error: {
            Error e;
            if (!e.parse(rs->get_stream())) {
                delete rs;
                rs = 0;
                throw InternalErr(__FILE__, __LINE__, "Could not parse error returned from server.");
            }
            delete rs;
            rs = 0;
            throw e;
        }

        case web_error:
            // We should never get here; a web error should be picked up read_url
            // (called by fetch_url) and result in a thrown Error object.
            break;

        case dods_das:
        default:
            // DAS::parse throws an exception on error.
            try {
                das.parse(rs->get_stream()); // read and parse the das from a file
            }
            catch (Error &e) {
                delete rs;
                rs = 0;
                throw;
            }

            break;
    }

    delete rs;
    rs = 0;
}

void Connect::request_dds(DDS &dds, string expr)
{
    string proj, sel;
    string::size_type dotpos = expr.find('&');
    if (dotpos != expr.npos) {
        proj = expr.substr(0, dotpos);
        sel = expr.substr(dotpos);
    }
    else {
        proj = expr;
        sel = "";
    }

    string dds_url = _URL + ".dds" + "?" + id2www_ce(_proj + proj + _sel + sel);

    Response *rs = 0;
    try {
        rs = d_http->fetch_url(dds_url);
    }
    catch (Error &e) {
        delete rs;
        rs = 0;
        throw;
    }

    d_version = rs->get_version();
    d_protocol = rs->get_protocol();

    switch (rs->get_type()) {
        case dods_error: {
            Error e;
            if (!e.parse(rs->get_stream())) {
                delete rs;
                rs = 0;
                throw InternalErr(__FILE__, __LINE__, "Could not parse error returned from server.");
            }
            delete rs;
            rs = 0;
            throw e;
        }

        case web_error:
            // We should never get here; a web error should be picked up read_url
            // (called by fetch_url) and result in a thrown Error object.
            break;

        case dods_dds:
        default:
            // DDS::prase throws an exception on error.
            try {
                dds.parse(rs->get_stream()); // read and parse the dds from a file
            }
            catch (Error &e) {
                delete rs;
                rs = 0;
                throw;
            }
            break;
    }

    delete rs;
    rs = 0;
}

void Connect::request_dds_url(DDS &dds)
{
    string use_url = _URL + "?" + _proj + _sel;
    Response *rs = 0;
    try {
        rs = d_http->fetch_url(use_url);
    }
    catch (Error &e) {
        delete rs;
        rs = 0;
        throw;
    }

    d_version = rs->get_version();
    d_protocol = rs->get_protocol();

    switch (rs->get_type()) {
        case dods_error: {
            Error e;
            if (!e.parse(rs->get_stream())) {
                delete rs;
                rs = 0;
                throw InternalErr(__FILE__, __LINE__, "Could not parse error returned from server.");
            }
            delete rs;
            rs = 0;
            throw e;
        }

        case web_error:
            // We should never get here; a web error should be picked up read_url
            // (called by fetch_url) and result in a thrown Error object.
            break;

        case dods_dds:
        default:
            // DDS::prase throws an exception on error.
            try {
                dds.parse(rs->get_stream()); // read and parse the dds from a file
            }
            catch (Error &e) {
                delete rs;
                rs = 0;
                throw;
            }
            break;
    }

    delete rs;
    rs = 0;
}

void Connect::request_ddx(DDS &dds, string expr)
{
    string proj, sel;
    string::size_type dotpos = expr.find('&');
    if (dotpos != expr.npos) {
        proj = expr.substr(0, dotpos);
        sel = expr.substr(dotpos);
    }
    else {
        proj = expr;
        sel = "";
    }

    string ddx_url = _URL + ".ddx" + "?" + id2www_ce(_proj + proj + _sel + sel);

    Response *rs = 0;
    try {
        rs = d_http->fetch_url(ddx_url);
    }
    catch (Error &e) {
        delete rs;
        throw;
    }

    d_version = rs->get_version();
    d_protocol = rs->get_protocol();

    switch (rs->get_type()) {
        case dods_error: {
            Error e;
            if (!e.parse(rs->get_stream())) {
                delete rs;
                rs = 0;
                throw InternalErr(__FILE__, __LINE__, "Could not parse error returned from server.");
            }
            delete rs;
            throw e;
        }

        case web_error:
            // We should never get here; a web error should be picked up read_url
            // (called by fetch_url) and result in a thrown Error object.
            break;

        case dods_ddx:
            try {
                string blob;

                DDXParser ddxp(dds.get_factory());
                ddxp.intern_stream(rs->get_stream(), &dds, blob);
            }
            catch (Error &e) {
                delete rs;
                throw;
            }
            break;

        default:
            ObjectType ot = rs->get_type();
            delete rs;
            throw Error("Invalid response type when requesting a DDX response. Response type: " + long_to_string(ot));
    }

    delete rs;
}

void Connect::request_ddx_url(DDS &dds)
{
    string use_url = _URL + "?" + _proj + _sel;

    Response *rs = 0;
    try {
        rs = d_http->fetch_url(use_url);
    }
    catch (Error &e) {
        delete rs;
        throw;
    }

    d_version = rs->get_version();
    d_protocol = rs->get_protocol();

    switch (rs->get_type()) {
        case dods_error: {
            Error e;
            if (!e.parse(rs->get_stream())) {
                delete rs;
                throw InternalErr(__FILE__, __LINE__, "Could not parse error returned from server.");
            }
            delete rs;
            throw e;
        }

        case web_error:
            // We should never get here; a web error should be picked up read_url
            // (called by fetch_url) and result in a thrown Error object.
            delete rs;
            throw InternalErr(__FILE__, __LINE__, "Web error.");

        case dods_ddx:
            try {
                string blob;

                DDXParser ddxp(dds.get_factory());
                ddxp.intern_stream(rs->get_stream(), &dds, blob);
            }
            catch (Error &e) {
                delete rs;
                throw;
            }
            break;

        default: {
            ObjectType ot = rs->get_type();
            delete rs;

            throw Error("Invalid response type when requesting a DDX response. Response type: " + long_to_string(ot));
        }
    }

    delete rs;
}

void Connect::request_data(DataDDS &data, string expr)
{
    string proj, sel;
    string::size_type dotpos = expr.find('&');
    if (dotpos != expr.npos) {
        proj = expr.substr(0, dotpos);
        sel = expr.substr(dotpos);
    }
    else {
        proj = expr;
        sel = "";
    }

    string data_url = _URL + ".dods?" + id2www_ce(_proj + proj + _sel + sel);

    Response *rs = 0;
    // We need to catch Error exceptions to ensure calling close_output.
    try {
        rs = d_http->fetch_url(data_url);

        d_version = rs->get_version();
        d_protocol = rs->get_protocol();

        process_data(data, rs);
        delete rs;
        rs = 0;
    }
    catch (Error &e) {
        delete rs;
        rs = 0;
        throw;
    }
}

void Connect::request_data_url(DataDDS &data)
{
    string use_url = _URL + "?" + _proj + _sel;
    Response *rs = 0;
    // We need to catch Error exceptions to ensure calling close_output.
    try {
        rs = d_http->fetch_url(use_url);

        d_version = rs->get_version();
        d_protocol = rs->get_protocol();

        process_data(data, rs);
        delete rs;
        rs = 0;
    }
    catch (Error &e) {
        delete rs;
        rs = 0;
        throw;
    }
}

// FIXME Unused?
void Connect::request_data_ddx(DataDDS &data, string expr)
{
    string proj, sel;
    string::size_type dotpos = expr.find('&');
    if (dotpos != expr.npos) {
        proj = expr.substr(0, dotpos);
        sel = expr.substr(dotpos);
    }
    else {
        proj = expr;
        sel = "";
    }

    string data_url = _URL + ".dap?" + id2www_ce(_proj + proj + _sel + sel);

    Response *rs = 0;
    // We need to catch Error exceptions to ensure calling close_output.
    try {
        rs = d_http->fetch_url(data_url);

        d_version = rs->get_version();
        d_protocol = rs->get_protocol();

        process_data(data, rs);
        delete rs;
        rs = 0;
    }
    catch (Error &e) {
        delete rs;
        rs = 0;
        throw;
    }
}

// FIXME Unused?
void Connect::request_data_ddx_url(DataDDS &data)
{
    string use_url = _URL + "?" + _proj + _sel;
    Response *rs = 0;
    // We need to catch Error exceptions to ensure calling close_output.
    try {
        rs = d_http->fetch_url(use_url);

        d_version = rs->get_version();
        d_protocol = rs->get_protocol();

        process_data(data, rs);
        delete rs;
        rs = 0;
    }
    catch (Error &e) {
        delete rs;
        rs = 0;
        throw;
    }
}

void Connect::read_data(DataDDS &data, Response *rs)
{
    if (!rs)
        throw InternalErr(__FILE__, __LINE__, "Response object is null.");

    // Read from data_source and parse the MIME headers specific to DAP2/4.
    parse_mime(rs);

    read_data_no_mime(data, rs);
}
void
Connect::read_data(DDS &data, Response *rs)
{
    if (!rs)
        throw InternalErr(__FILE__, __LINE__, "Response object is null.");

    // Read from data_source and parse the MIME headers specific to DAP2/4.
    parse_mime(rs);

    read_data_no_mime(data, rs);
}

// This function looks at the input stream and makes its best guess at what
// lies in store for downstream processing code. Definitely heuristic.
// Assumptions:
// #1 The current file position is past any MIME headers (if they were present).
// #2 We must reset the FILE* position to the start of the DDS or DDX headers
static void divine_type_information(Response *rs)
{
    // Consume whitespace
    int c = getc(rs->get_stream());
    while (!feof(rs->get_stream()) && !ferror(rs->get_stream()) && isspace(c)) {
        c = getc(rs->get_stream());
    }


    if (ferror(rs->get_stream()))
        throw Error("Error reading response type information: " + string(strerror(errno)));
    if (feof(rs->get_stream()))
        throw Error("Error reading response type information: Found EOF");

    // The heuristic here is that a DataDDX is a multipart MIME document and
    // The first non space character found after the headers is the start of
    // the first part which looks like '--<boundary>' while a DataDDS starts
    // with a DDS (;Dataset {' ...). I take into account that our parsers have
    // accepted both 'Dataset' and 'dataset' for a long time.
    switch (c) {
        case '-':
            rs->set_type(dods_data_ddx);
            break;
        case 'D':
        case 'd':
            rs->set_type(dods_data);
            break;
        default:
            throw InternalErr(__FILE__, __LINE__, "Could not determine type of response object in stream.");
    }

    ungetc(c, rs->get_stream());
}

void Connect::read_data_no_mime(DataDDS &data, Response *rs)
{
    if (rs->get_type() == unknown_type)
        divine_type_information(rs);

    switch (rs->get_type()) {
        case dods_data:
            d_version = rs->get_version();
            d_protocol = rs->get_protocol();
            process_data(data, rs);
            break;
        case dods_data_ddx:
            process_data(data, rs);
            d_version = rs->get_version();
            d_protocol = data.get_protocol();
            break;
        default:
            throw InternalErr(__FILE__, __LINE__, "Should have been a DataDDS or DataDDX.");
    }
}
void Connect::read_data_no_mime(DDS &data, Response *rs)
{
    if (rs->get_type() == unknown_type)
        divine_type_information(rs);

    switch (rs->get_type()) {
    case dods_data:
        d_version = rs->get_version();
        d_protocol = rs->get_protocol();
        process_data(data, rs);
        break;
    case dods_data_ddx:
        process_data(data, rs);
        d_version = rs->get_version();
        // TODO should check to see if this hack is a correct replacement
        // for get_protocol from DataDDS
        d_protocol = data.get_dap_version();
        break;
    default:
        throw InternalErr(__FILE__, __LINE__, "Should have been a DataDDS or DataDDX.");
    }
}

bool
Connect::is_local()
{
    return _local;
}

string Connect::URL(bool ce)
{
    if (_local)
        throw InternalErr(__FILE__, __LINE__, "URL(): This call is only valid for a DAP data source.");

    if (ce)
        return _URL + "?" + _proj + _sel;
    else
        return _URL;
}

string Connect::CE()
{
    if (_local)
        throw InternalErr(__FILE__, __LINE__, "CE(): This call is only valid for a DAP data source.");

    return _proj + _sel;
}

void Connect::set_credentials(string u, string p)
{
    if (d_http)
        d_http->set_credentials(u, p);
}

void Connect::set_accept_deflate(bool deflate)
{
    if (d_http)
        d_http->set_accept_deflate(deflate);
}

void Connect::set_xdap_protocol(int major, int minor)
{
    if (d_http)
        d_http->set_xdap_protocol(major, minor);
}

void Connect::set_cache_enabled(bool cache)
{
    if (d_http)
        d_http->set_cache_enabled(cache);
}

bool Connect::is_cache_enabled()
{
    bool status;
    DBG(cerr << "Entering is_cache_enabled (" << hex << d_http << dec
            << ")... ");
    if (d_http)
        status = d_http->is_cache_enabled();
    else
        status = false;
    DBGN(cerr << "exiting" << endl);
    return status;
}

} // namespace libdap