AISResources.cc

// -*- mode: c++; c-basic-offset:4 -*-

// This file is part of libdap, A C++ implementation of the OPeNDAP Data
// Access Protocol.

// Copyright (c) 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.

#include "config.h"

#include <iostream>
#include <fstream>
#include <algorithm>
#include <functional>

#include "AISResources.h"
#include "AISDatabaseParser.h"

using namespace std;

namespace libdap {

ostream &
operator<<(ostream &os, const Resource &r)
{
    os << "<ancillary";
    if (r.d_rule != Resource::overwrite) {
        os << " rule=\"";
        (r.d_rule == Resource::fallback) ? os << "fallback\"" : os << "replace\"";
    }
    os << " url=\"" << r.d_url << "\"/>";

    return os;
}

ostream &
operator<<(ostream &os, const AISResources &ais_res)
{
    os << "<?xml version=\"1.0\" encoding=\"US-ASCII\" standalone=\"yes\"?>"
    << endl;
    os << "<!DOCTYPE ais SYSTEM \"http://xml.opendap.org/ais/ais_database.dtd\">" << endl;
    os << "<ais xmlns=\"http://xml.opendap.org/ais\">" << endl;

    for (AISResources::ResourceRegexpsCIter pos = ais_res.d_re.begin();
         pos != ais_res.d_re.end(); ++pos) {
        os << "<entry>" << endl;
        // write primary
        os << "<primary regexp=\"" << pos->first << "\"/>" << endl;
        // write the vector of Resource objects
        for (ResourceVectorCIter i = pos->second.begin();
             i != pos->second.end(); ++i) {
            os << *i << endl;
        }
        os << "</entry>" << endl;
    }

    //  Under VC++ 6.x, 'pos' is twice tagged as twice in the
    //  same scope (this method - not just within for blocks), so
    //  I gave it another name.  ROM - 6/14/03
    for (AISResources::ResourceMapCIter pos2 = ais_res.d_db.begin();
         pos2 != ais_res.d_db.end(); ++pos2) {
        os << "<entry>" << endl;
        // write primary
        os << "<primary url=\"" << pos2->first << "\"/>" << endl;
        // write the vector of Resource objects
        for (ResourceVectorCIter i = pos2->second.begin();
             i != pos2->second.end(); ++i) {
            os << *i << endl;
        }
        os << "</entry>" << endl;
    }

    os << "</ais>" << endl;

    return os;
}

AISResources::AISResources(const string &database) throw(AISDatabaseReadFailed)
{
    read_database(database);
}

void
AISResources::add_url_resource(const string &url, const Resource &ancillary)
{
    add_url_resource(url, ResourceVector(1, ancillary));
}

void
AISResources::add_url_resource(const string &url, const ResourceVector &rv)
{
    ResourceMapIter pos = d_db.find(url);
    if (pos == d_db.end()) {
        d_db.insert(std::make_pair(url, rv));
    }
    else {
        // There's already a ResourceVector, append to it.
        for (ResourceVectorCIter i = rv.begin(); i != rv.end(); ++i)
            pos->second.push_back(*i);
    }
}

void
AISResources::add_regexp_resource(const string &re, const Resource &ancillary)
{
    add_regexp_resource(re, ResourceVector(1, ancillary));
}

void
AISResources::add_regexp_resource(const string &re, const ResourceVector &rv)
{
    ResourceRegexpsIter pos = find_if(d_re.begin(), d_re.end(),
                                      FindRegexp(re));
    if (pos == d_re.end()) {
        d_re.push_back(std::make_pair(re, rv));
    }
    else {
        // There's already a ResourceVector, append to it.
        for (ResourceVectorCIter i = rv.begin(); i != rv.end(); ++i)
            pos->second.push_back(*i);
    }
}

bool
AISResources::has_resource(const string &primary) const
{
    // This code looks for the 'primary' in the AIS database (which is a STL
    // map<> of strings and AIS stuff. As an optimization, it first uses the
    // map<> class' find() method to see if the 'primary' is in there as a
    // literal. If not, then it tries to match each regular expression in the
    // database.
    return ((d_db.find(primary) != d_db.end())
            || (find_if(d_re.begin(), d_re.end(), MatchRegexp(primary))
                != d_re.end()));

}

ResourceVector
AISResources::get_resource(const string &primary)
{
    ResourceVector rv;
    const ResourceMapIter &i = d_db.find(primary);

    if (i != d_db.end())
        rv = i->second;

    // Finds the first matching regular expression and returns a vector of
    // AIS resources.
    const ResourceRegexpsIter &j = find_if(d_re.begin(), d_re.end(),
                                           MatchRegexp(primary));
    if (j != d_re.end())
        copy(j->second.begin(), j->second.end(), inserter(rv, rv.begin()));

    if (rv.size() == 0)
        throw NoSuchPrimaryResource();

    return rv;
}

void
AISResources::read_database(const string &database)
{
    AISDatabaseParser parser;

    parser.intern(database, this);
}

void
AISResources::write_database(const string &filename)
{
    ofstream fos;
    fos.open(filename.c_str());

    if (!fos)
        throw AISDatabaseWriteFailed("Could not open file :" + filename);

    fos << *this << endl;

    if (!fos)
        throw AISDatabaseWriteFailed();
}

} // namespace libdap