~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008 Sun Microsystems

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; version 2 of the License.

 *

 *  This program 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 General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#include <drizzled/server_includes.h>

#include <drizzled/errmsg.h>

#include <drizzled/gettext.h>

#include "drizzled/plugin_registry.h"

#include <vector>

using namespace std;

static vector<Error_message_handler *> all_errmsg_handler;

static bool errmsg_has= false;

void add_errmsg_handler(Error_message_handler *handler)

{

  all_errmsg_handler.push_back(handler);

  errmsg_has= true;

}

void remove_errmsg_handler(Error_message_handler *handler)

{

  all_errmsg_handler.erase(find(all_errmsg_handler.begin(),

                                all_errmsg_handler.end(), handler));

}

class ErrorMessagePrint : public unary_function<Error_message_handler *, bool>

{

  Session *session;

  int priority;

  const char *format;

  va_list ap;

public:

  ErrorMessagePrint(Session *session_arg, int priority_arg,

                    const char *format_arg, va_list ap_arg) :

    unary_function<Error_message_handler *, bool>(), session(session_arg),

    priority(priority_arg), format(format_arg)

    {

      va_copy(ap, ap_arg);

    }

  ~ErrorMessagePrint()  { va_end(ap); }

  inline result_type operator()(argument_type handler)

  {

    if (handler->errmsg(session, priority, format, ap))

    {

      /* we're doing the errmsg plugin api,

         so we can't trust the errmsg api to emit our error messages

         so we will emit error messages to stderr */

      /* TRANSLATORS: The leading word "errmsg" is the name

         of the plugin api, and so should not be translated. */

      fprintf(stderr,

              _("errmsg plugin '%s' errmsg() failed"),

              handler->getName().c_str());

      return true;

    }

    return false;

  }

};

bool errmsg_vprintf (Session *session, int priority,

                     char const *format, va_list ap)

{

  /* check to see if any errmsg plugin has been loaded

     if not, just fall back to emitting the message to stderr */

  if (!errmsg_has)

  {

    /* if it turns out that the vfprintf doesnt do one single write

       (single writes are atomic), then this needs to be rewritten to

       vsprintf into a char buffer, and then write() that char buffer

       to stderr */

    vfprintf(stderr, format, ap);

    return false;

  }

  /* Use find_if instead of foreach so that we can collect return codes */

  vector<Error_message_handler *>::iterator iter=

    find_if(all_errmsg_handler.begin(), all_errmsg_handler.end(),

            ErrorMessagePrint(session, priority, format, ap)); 

  /* If iter is == end() here, that means that all of the plugins returned

   * false, which in this case means they all succeeded. Since we want to 

   * return false on success, we return the value of the two being != 

   */

  return iter != all_errmsg_handler.end();

}