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f207b33a7b
after Monty's review. - Item_param was rewritten. - it turns out that we can't convert string data to character set of connection on the fly, because they first should be written to the binary log. To support efficient conversion we need to rewrite prepared statements binlogging code first.
98 lines
2.8 KiB
C
98 lines
2.8 KiB
C
/* Copyright (C) 2000 MySQL AB
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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; either version 2 of the License, or
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(at your option) any later version.
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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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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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
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/* Written by Sinisa Milivojevic <sinisa@mysql.com> */
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#include <my_global.h>
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#ifdef HAVE_COMPRESS
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#include <my_sys.h>
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#ifndef SCO
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#include <m_string.h>
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#endif
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#include <zlib.h>
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/*
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** This replaces the packet with a compressed packet
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** Returns 1 on error
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** *complen is 0 if the packet wasn't compressed
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*/
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my_bool my_compress(byte *packet, ulong *len, ulong *complen)
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{
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DBUG_ENTER("my_compress");
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if (*len < MIN_COMPRESS_LENGTH)
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{
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*complen=0;
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DBUG_PRINT("note",("Packet too short: Not compressed"));
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}
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else
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{
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byte *compbuf=my_compress_alloc(packet,len,complen);
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if (!compbuf)
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DBUG_RETURN(*complen ? 0 : 1);
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memcpy(packet,compbuf,*len);
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my_free(compbuf,MYF(MY_WME)); }
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DBUG_RETURN(0);
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}
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byte *my_compress_alloc(const byte *packet, ulong *len, ulong *complen)
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{
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byte *compbuf;
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*complen= *len * 120 / 100 + 12;
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if (!(compbuf= (byte *) my_malloc(*complen,MYF(MY_WME))))
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return 0; /* Not enough memory */
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if (compress((Bytef*) compbuf,(ulong *) complen, (Bytef*) packet,
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(uLong) *len ) != Z_OK)
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{
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my_free(compbuf,MYF(MY_WME));
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return 0;
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}
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if (*complen >= *len)
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{
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*complen= 0;
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my_free(compbuf, MYF(MY_WME));
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DBUG_PRINT("note",("Packet got longer on compression; Not compressed"));
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return 0;
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}
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swap_variables(ulong, *len, *complen); /* *len is now packet length */
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return compbuf;
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}
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my_bool my_uncompress (byte *packet, ulong *len, ulong *complen)
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{
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DBUG_ENTER("my_uncompress");
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if (*complen) /* If compressed */
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{
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byte *compbuf= (byte *) my_malloc(*complen,MYF(MY_WME));
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int error;
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if (!compbuf)
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DBUG_RETURN(1); /* Not enough memory */
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if ((error=uncompress((Bytef*) compbuf, complen, (Bytef*) packet, *len))
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!= Z_OK)
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{ /* Probably wrong packet */
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DBUG_PRINT("error",("Can't uncompress packet, error: %d",error));
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my_free(compbuf, MYF(MY_WME));
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DBUG_RETURN(1);
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}
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*len= *complen;
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memcpy(packet, compbuf, *len);
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my_free(compbuf, MYF(MY_WME));
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}
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DBUG_RETURN(0);
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}
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#endif /* HAVE_COMPRESS */
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