AsyncResolverQuery.h

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/*  AsyncResolverQuery.h - asynchronous DNS query encapsulation
    Copyright (C) 2004 Mark Weaver
    Written by Mark Weaver <mark@npsl.co.uk>

    Part of the Open-Win32 library.
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 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
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the
    Free Software Foundation, Inc., 59 Temple Place - Suite 330,
    Boston, MA  02111-1307, USA.
*/

/* Copyright 1998 by the Massachusetts Institute of Technology.
 *
 * Permission to use, copy, modify, and distribute this
 * software and its documentation for any purpose and without
 * fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting
 * documentation, and that the name of M.I.T. not be used in
 * advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.
 * M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 */

#ifndef OW32_AsyncResolverQuery_h
#define OW32_AsyncResolverQuery_h

#include <OW32/IoCompletion.h>
#include <OW32/IoCompletionThreadPool.h>
#include <OW32/auto_buf.h>
#include <OW32/AsyncSocket.h>

#include <vector>

#include <OW32/AsyncResolverError.h>

namespace OW32
{

class OW32_LIB_EXPORT CAsyncResolver;

#ifdef _MSC_VER
#pragma warning(disable: 4251)
#endif

class OW32_LIB_EXPORT CAsyncResolverQueryCallback
{
public: 
    virtual void OnAnswer(AsyncResolverError status, unsigned char *abuf, size_t alen) = 0;
};

class OW32_LIB_EXPORT CAsyncResolverCallback
{
public: 
    virtual void OnAnswer(void *context, AsyncResolverError status, unsigned char *abuf, size_t alen) = 0;
};

class OW32_LIB_EXPORT CAsyncResolverQuery : 
    public CAsyncResolverQueryCallback,
    public CRefCounted
{
public:
    CAsyncResolverQuery(CAsyncResolver *pParent, CAsyncResolverCallback *pCallback, void *callbackContext = 0);

    virtual void OnAnswer(AsyncResolverError status, unsigned char *abuf, size_t alen);

    void query(const char *name, int dnsclass, int type);

    const auto_byte_buf &getQuery() const { return m_query; }

    int getId() const { return m_id; }

    const bool getUsingTCP() const { return m_using_tcp; }

    void setUsingTCP(bool using_tcp) { m_using_tcp = using_tcp; }

private:
    CAsyncResolverQuery(const CAsyncResolverQuery &);
    CAsyncResolverQuery& operator=(const CAsyncResolverQuery &);

    AsyncResolverError mkquery(const char *name, int dnsclass, int type, 
                unsigned short id, int rd);

protected:
    CAsyncResolver              *m_pParent;
    auto_byte_buf               m_query;
    int                         m_try;
    size_t                      m_server;
    int                         m_id;
    bool                        m_using_tcp;
    std::vector<bool>           m_skip_server;
    AsyncResolverError          m_error_status;
    CAsyncResolverCallback      *m_pCallback;
    void                        *m_callbackContext;

    friend class CAsyncResolver;
};

#ifdef _MSC_VER
#pragma warning(default: 4251)
#endif

typedef CAutoRefCountedPtr<CAsyncResolverQuery> CAsyncResolverQueryPtr;

} // namespace OW32

#endif // OW32_AsyncResolverQuery_h

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