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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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/**
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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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};
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#endif /* DRIZZLED_INTERNAL_ERROR_HANDLER_H */ |