~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/session.h>

#include <drizzled/error.h>

#include <drizzled/function/str/strfunc.h>

#include "plugin/compression/uncompress.h"

#include <zlib.h>

#include <string>

using namespace std;

String *Item_func_uncompress::val_str(String *str)

{

  assert(fixed == 1);

  String *res= args[0]->val_str(str);

  ulong new_size;

  int err;

  uint32_t code;

  if (!res)

    goto err;

  null_value= 0;

  if (res->is_empty())

    return res;

  /* If length is less than 4 bytes, data is corrupt */

  if (res->length() <= 4)

  {

    push_warning_printf(current_session, DRIZZLE_ERROR::WARN_LEVEL_ERROR,

                        ER_ZLIB_Z_DATA_ERROR,

                        ER(ER_ZLIB_Z_DATA_ERROR));

    goto err;

  }

  /* Size of uncompressed data is stored as first 4 bytes of field */

  new_size= uint4korr(res->ptr()) & 0x3FFFFFFF;

  if (new_size > current_session->variables.max_allowed_packet)

  {

    push_warning_printf(current_session, DRIZZLE_ERROR::WARN_LEVEL_ERROR,

                        ER_TOO_BIG_FOR_UNCOMPRESS,

                        ER(ER_TOO_BIG_FOR_UNCOMPRESS),

                        current_session->variables.max_allowed_packet);

    goto err;

  }

  if (buffer.realloc((uint32_t)new_size))

    goto err;

  if ((err= uncompress((Byte*)buffer.ptr(), &new_size,

                       ((const Bytef*)res->ptr())+4,res->length())) == Z_OK)

  {

    buffer.length((uint32_t) new_size);

    return &buffer;

  }

  code= ((err == Z_BUF_ERROR) ? ER_ZLIB_Z_BUF_ERROR :

         ((err == Z_MEM_ERROR) ? ER_ZLIB_Z_MEM_ERROR : ER_ZLIB_Z_DATA_ERROR));

  push_warning(current_session, DRIZZLE_ERROR::WARN_LEVEL_ERROR, code, ER(code));

err:

  null_value= 1;

  return 0;

}