1
by brian
clean slate |
1 |
/* Copyright (C) 2000 MySQL AB
|
2 |
||
3 |
This program is free software; you can redistribute it and/or modify
|
|
4 |
it under the terms of the GNU General Public License as published by
|
|
5 |
the Free Software Foundation; version 2 of the License.
|
|
6 |
||
7 |
This program is distributed in the hope that it will be useful,
|
|
8 |
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
9 |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
10 |
GNU General Public License for more details.
|
|
11 |
||
12 |
You should have received a copy of the GNU General Public License
|
|
13 |
along with this program; if not, write to the Free Software
|
|
14 |
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
|
|
15 |
||
16 |
/* Written by Sinisa Milivojevic <sinisa@mysql.com> */
|
|
17 |
||
212.5.39
by Monty Taylor
Phew. Moved my_base and my_global. |
18 |
#include "mysys_priv.h" |
19 |
||
1
by brian
clean slate |
20 |
#include <my_sys.h> |
212.5.18
by Monty Taylor
Moved m_ctype, m_string and my_bitmap. Removed t_ctype. |
21 |
#include <mystrings/m_string.h> |
1
by brian
clean slate |
22 |
#include <zlib.h> |
23 |
||
24 |
/*
|
|
25 |
This replaces the packet with a compressed packet
|
|
26 |
||
27 |
SYNOPSIS
|
|
28 |
my_compress()
|
|
29 |
packet Data to compress. This is is replaced with the compressed data.
|
|
30 |
len Length of data to compress at 'packet'
|
|
31 |
complen out: 0 if packet was not compressed
|
|
32 |
||
33 |
RETURN
|
|
34 |
1 error. 'len' is not changed'
|
|
35 |
0 ok. In this case 'len' contains the size of the compressed packet
|
|
36 |
*/
|
|
37 |
||
146
by Brian Aker
my_bool cleanup. |
38 |
bool my_compress(uchar *packet, size_t *len, size_t *complen) |
1
by brian
clean slate |
39 |
{
|
40 |
if (*len < MIN_COMPRESS_LENGTH) |
|
41 |
{
|
|
42 |
*complen=0; |
|
43 |
}
|
|
44 |
else
|
|
45 |
{
|
|
46 |
uchar *compbuf=my_compress_alloc(packet,len,complen); |
|
47 |
if (!compbuf) |
|
51.3.20
by Jay Pipes
Phase 6 - Remove DBUG from mysys |
48 |
return(*complen ? 0 : 1); |
1
by brian
clean slate |
49 |
memcpy(packet,compbuf,*len); |
50 |
my_free(compbuf,MYF(MY_WME)); |
|
51 |
}
|
|
51.3.20
by Jay Pipes
Phase 6 - Remove DBUG from mysys |
52 |
return(0); |
1
by brian
clean slate |
53 |
}
|
54 |
||
55 |
||
56 |
uchar *my_compress_alloc(const uchar *packet, size_t *len, size_t *complen) |
|
57 |
{
|
|
58 |
uchar *compbuf; |
|
59 |
uLongf tmp_complen; |
|
60 |
int res; |
|
61 |
*complen= *len * 120 / 100 + 12; |
|
62 |
||
63 |
if (!(compbuf= (uchar *) my_malloc(*complen, MYF(MY_WME)))) |
|
64 |
return 0; /* Not enough memory */ |
|
65 |
||
66 |
tmp_complen= *complen; |
|
67 |
res= compress((Bytef*) compbuf, &tmp_complen, (Bytef*) packet, (uLong) *len); |
|
68 |
*complen= tmp_complen; |
|
69 |
||
70 |
if (res != Z_OK) |
|
71 |
{
|
|
72 |
my_free(compbuf, MYF(MY_WME)); |
|
73 |
return 0; |
|
74 |
}
|
|
75 |
||
76 |
if (*complen >= *len) |
|
77 |
{
|
|
78 |
*complen= 0; |
|
79 |
my_free(compbuf, MYF(MY_WME)); |
|
80 |
return 0; |
|
81 |
}
|
|
82 |
/* Store length of compressed packet in *len */
|
|
83 |
swap_variables(size_t, *len, *complen); |
|
84 |
return compbuf; |
|
85 |
}
|
|
86 |
||
87 |
||
88 |
/*
|
|
89 |
Uncompress packet
|
|
90 |
||
91 |
SYNOPSIS
|
|
92 |
my_uncompress()
|
|
93 |
packet Compressed data. This is is replaced with the orignal data.
|
|
94 |
len Length of compressed data
|
|
95 |
complen Length of the packet buffer (must be enough for the original
|
|
96 |
data)
|
|
97 |
||
98 |
RETURN
|
|
99 |
1 error
|
|
100 |
0 ok. In this case 'complen' contains the updated size of the
|
|
101 |
real data.
|
|
102 |
*/
|
|
103 |
||
146
by Brian Aker
my_bool cleanup. |
104 |
bool my_uncompress(uchar *packet, size_t len, size_t *complen) |
1
by brian
clean slate |
105 |
{
|
106 |
uLongf tmp_complen; |
|
107 |
||
108 |
if (*complen) /* If compressed */ |
|
109 |
{
|
|
110 |
uchar *compbuf= (uchar *) my_malloc(*complen,MYF(MY_WME)); |
|
111 |
int error; |
|
112 |
if (!compbuf) |
|
51.3.20
by Jay Pipes
Phase 6 - Remove DBUG from mysys |
113 |
return(1); /* Not enough memory */ |
1
by brian
clean slate |
114 |
|
115 |
tmp_complen= *complen; |
|
116 |
error= uncompress((Bytef*) compbuf, &tmp_complen, (Bytef*) packet, |
|
117 |
(uLong) len); |
|
118 |
*complen= tmp_complen; |
|
119 |
if (error != Z_OK) |
|
120 |
{ /* Probably wrong packet */ |
|
121 |
my_free(compbuf, MYF(MY_WME)); |
|
51.3.20
by Jay Pipes
Phase 6 - Remove DBUG from mysys |
122 |
return(1); |
1
by brian
clean slate |
123 |
}
|
124 |
memcpy(packet, compbuf, *complen); |
|
125 |
my_free(compbuf, MYF(MY_WME)); |
|
126 |
}
|
|
127 |
else
|
|
128 |
*complen= len; |
|
51.3.20
by Jay Pipes
Phase 6 - Remove DBUG from mysys |
129 |
return(0); |
1
by brian
clean slate |
130 |
}
|