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/* 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;
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