~drizzle-trunk/drizzle/development

851 by Brian Aker
Class rewrite of Session (aka get all of the junk out)
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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
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 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
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 *
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 *  Copyright (C) 2008 Sun Microsystems
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 *
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 *  This program is free software; you can redistribute it and/or modify
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 *  it under the terms of the GNU General Public License as published by
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 *  the Free Software Foundation; version 2 of the License.
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 *
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 *  This program is distributed in the hope that it will be useful,
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 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
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 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 *  GNU General Public License for more details.
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 *
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 *  You should have received a copy of the GNU General Public License
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 *  along with this program; if not, write to the Free Software
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 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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 */
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#ifndef DRIZZLED_INTERNAL_ERROR_HANDLER_H
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#define DRIZZLED_INTERNAL_ERROR_HANDLER_H
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1280.1.10 by Monty Taylor
Put everything in drizzled into drizzled namespace.
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namespace drizzled
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{
851 by Brian Aker
Class rewrite of Session (aka get all of the junk out)
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/**
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  This class represents the interface for internal error handlers.
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  Internal error handlers are exception handlers used by the server
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  implementation.
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*/
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class Internal_error_handler
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{
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protected:
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  Internal_error_handler() {}
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  virtual ~Internal_error_handler() {}
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public:
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  /**
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    Handle an error condition.
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    This method can be implemented by a subclass to achieve any of the
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    following:
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    - mask an error internally, prevent exposing it to the user,
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    - mask an error and throw another one instead.
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    When this method returns true, the error condition is considered
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    'handled', and will not be propagated to upper layers.
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    It is the responsability of the code installing an internal handler
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    to then check for trapped conditions, and implement logic to recover
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    from the anticipated conditions trapped during runtime.
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    This mechanism is similar to C++ try/throw/catch:
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    - 'try' correspond to <code>Session::push_internal_handler()</code>,
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    - 'throw' correspond to <code>my_error()</code>,
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    which invokes <code>my_message_sql()</code>,
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    - 'catch' correspond to checking how/if an internal handler was invoked,
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    before removing it from the exception stack with
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    <code>Session::pop_internal_handler()</code>.
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    @param sql_errno the error number
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    @param level the error level
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    @param session the calling thread
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    @return true if the error is handled
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  */
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  virtual bool handle_error(uint32_t sql_errno,
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                            const char *message,
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                            DRIZZLE_ERROR::enum_warning_level level,
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                            Session *session) = 0;
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};
1280.1.10 by Monty Taylor
Put everything in drizzled into drizzled namespace.
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} /* namespace drizzled */
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851 by Brian Aker
Class rewrite of Session (aka get all of the junk out)
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#endif /* DRIZZLED_INTERNAL_ERROR_HANDLER_H */