1 /* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
2 2016 MariaDB Corporation AB
3
4 This library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Library General Public
6 License as published by the Free Software Foundation; either
7 version 2 of the License, or (at your option) any later version.
8
9 This library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Library General Public License for more details.
13
14 You should have received a copy of the GNU Library General Public
15 License along with this library; if not, write to the Free
16 Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
17 MA 02111-1301, USA */
18
19 /* Written by Sinisa Milivojevic <sinisa@coresinc.com> */
20
21 #include <ma_global.h>
22 #ifdef HAVE_COMPRESS
23 #include <ma_sys.h>
24 #include <ma_string.h>
25 #include <zlib.h>
26
27 /*
28 ** This replaces the packet with a compressed packet
29 ** Returns 1 on error
30 ** *complen is 0 if the packet wasn't compressed
31 */
32
_mariadb_compress(unsigned char * packet,size_t * len,size_t * complen)33 my_bool _mariadb_compress(unsigned char *packet, size_t *len, size_t *complen)
34 {
35 if (*len < MIN_COMPRESS_LENGTH)
36 *complen=0;
37 else
38 {
39 unsigned char *compbuf=_mariadb_compress_alloc(packet,len,complen);
40 if (!compbuf)
41 return *complen ? 0 : 1;
42 memcpy(packet,compbuf,*len);
43 free(compbuf);
44 }
45 return 0;
46 }
47
48
_mariadb_compress_alloc(const unsigned char * packet,size_t * len,size_t * complen)49 unsigned char *_mariadb_compress_alloc(const unsigned char *packet, size_t *len, size_t *complen)
50 {
51 unsigned char *compbuf;
52 *complen = *len * 120 / 100 + 12;
53 if (!(compbuf = (unsigned char *) malloc(*complen)))
54 return 0; /* Not enough memory */
55 if (compress((Bytef*) compbuf,(ulong *) complen, (Bytef*) packet,
56 (uLong) *len ) != Z_OK)
57 {
58 free(compbuf);
59 return 0;
60 }
61 if (*complen >= *len)
62 {
63 *complen=0;
64 free(compbuf);
65 return 0;
66 }
67 swap(size_t,*len,*complen); /* *len is now packet length */
68 return compbuf;
69 }
70
_mariadb_uncompress(unsigned char * packet,size_t * len,size_t * complen)71 my_bool _mariadb_uncompress (unsigned char *packet, size_t *len, size_t *complen)
72 {
73 if (*complen) /* If compressed */
74 {
75 unsigned char *compbuf = (unsigned char *) malloc (*complen);
76 if (!compbuf)
77 return 1; /* Not enough memory */
78 if (uncompress((Bytef*) compbuf, (uLongf *)complen, (Bytef*) packet, (uLongf)*len) != Z_OK)
79 { /* Probably wrong packet */
80 free(compbuf);
81 return 1;
82 }
83 *len = *complen;
84 memcpy(packet,compbuf,*len);
85 free(compbuf);
86 }
87 else *complen= *len;
88 return 0;
89 }
90 #endif /* HAVE_COMPRESS */
91