~drizzle-trunk/drizzle/development

/* Copyright (C) 2006 MySQL AB

   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 */

#define DRIZZLE_SERVER 1 /* for session variable max_allowed_packet */

#include <drizzled/server_includes.h>

#include <drizzled/drizzled_error_messages.h>

#include <zlib.h>

class Item_func_uncompress: public Item_str_func

{

  String buffer;

public:

  Item_func_uncompress(): Item_str_func(){}

  void fix_length_and_dec(){ maybe_null= 1; max_length= MAX_BLOB_WIDTH; }

  const char *func_name() const{return "uncompress";}

  String *val_str(String *) ;

};

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;

}

Item_func* create_uncompressudf_item(MEM_ROOT* m)

{

  return  new (m) Item_func_uncompress();

}

static struct udf_func uncompressudf = {

  { C_STRING_WITH_LEN("uncompress") },

  create_uncompressudf_item

};

static int uncompressudf_plugin_init(void *p)

{

  udf_func **f = (udf_func**) p;

  *f= &uncompressudf;

  return 0;

}

static int uncompressudf_plugin_deinit(void *p)

{

  udf_func *udff = (udf_func *) p;

  (void)udff;

  return 0;

}

mysql_declare_plugin(uncompress)

{

  DRIZZLE_UDF_PLUGIN,

  "uncompress",

  "1.0",

  "Stewart Smith",

  "UDF for compress()",

  PLUGIN_LICENSE_GPL,

  uncompressudf_plugin_init, /* Plugin Init */

  uncompressudf_plugin_deinit, /* Plugin Deinit */

  NULL,   /* status variables */

  NULL,   /* system variables */

  NULL    /* config options */

}

mysql_declare_plugin_end;