// -*- 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>

//

// 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 http_cache_interrupt_handler_h

#define http_cache_interrupt_handler_h

#include <signal.h>

#include <cassert>

#include <iostream>

#include <algorithm>

#include "HTTPCache.h"

#include "EventHandler.h"

#include "debug.h"

namespace libdap

{

static void

unlink_file(const string &f)

{

    unlink(f.c_str());

}

/** Handle SIGINT for HTTPCache. When the cache is in use and the process is

    sent SIGINT, we must make sure that the cache is left in a consistent

    state. This includes removing the lock file, updating the index file and

    making sure no partially written data or meta data files exist.

    @see EventHandler

    @see SignalHandler

    @see HTTPCache

    @author James Gallagher <jgallagher@opendap.org> */

class HTTPCacheInterruptHandler : public EventHandler

{

private:

public:

    ///

    HTTPCacheInterruptHandler()

    {}

    ///

    virtual ~HTTPCacheInterruptHandler()

    {}

    /** Handle SIGINT. This handler first deletes any files opened but not

    added to the cache index files and then calls

    HTTPCache::delete_instance().

    @param signum We know it is SIGINT; included here as a check and only

    when NDEBUG is not defined.

    @return Never returns. */

    virtual void handle_signal(int signum)

    {

        assert(signum == SIGINT);

        DBG(cerr << "Inside the HTTPCacheInterruptHandler." << endl);

        vector<string> *of = &HTTPCache::_instance->d_open_files;

        DBG(copy(of->begin(), of->end(),

                 ostream_iterator<string>(cerr, "\n")));

        for_each(of->begin(), of->end(), unlink_file);

        HTTPCache::delete_instance();

    }

};

} // namespace libdap

#endif // http_cache_interrupt_handler_h