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-rw-r--r--mysql/libmariadb/ma_compress.c90
1 files changed, 90 insertions, 0 deletions
diff --git a/mysql/libmariadb/ma_compress.c b/mysql/libmariadb/ma_compress.c
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+/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
+ 2016 MariaDB Corporation AB
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Library General Public
+ License as published by the Free Software Foundation; either
+ version 2 of the License, or (at your option) any later version.
+
+ This library 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
+ Library General Public License for more details.
+
+ You should have received a copy of the GNU Library General Public
+ License along with this library; if not, write to the Free
+ Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ MA 02111-1301, USA */
+
+/* Written by Sinisa Milivojevic <sinisa@coresinc.com> */
+
+#include <ma_global.h>
+#ifdef HAVE_COMPRESS
+#include <ma_sys.h>
+#include <ma_string.h>
+#include <zlib.h>
+
+/*
+** This replaces the packet with a compressed packet
+** Returns 1 on error
+** *complen is 0 if the packet wasn't compressed
+*/
+
+my_bool _mariadb_compress(unsigned char *packet, size_t *len, size_t *complen)
+{
+ if (*len < MIN_COMPRESS_LENGTH)
+ *complen=0;
+ else
+ {
+ unsigned char *compbuf=_mariadb_compress_alloc(packet,len,complen);
+ if (!compbuf)
+ return *complen ? 0 : 1;
+ memcpy(packet,compbuf,*len);
+ free(compbuf);
+ }
+ return 0;
+}
+
+
+unsigned char *_mariadb_compress_alloc(const unsigned char *packet, size_t *len, size_t *complen)
+{
+ unsigned char *compbuf;
+ *complen = *len * 120 / 100 + 12;
+ if (!(compbuf = (unsigned char *) malloc(*complen)))
+ return 0; /* Not enough memory */
+ if (compress((Bytef*) compbuf,(ulong *) complen, (Bytef*) packet,
+ (uLong) *len ) != Z_OK)
+ {
+ free(compbuf);
+ return 0;
+ }
+ if (*complen >= *len)
+ {
+ *complen=0;
+ free(compbuf);
+ return 0;
+ }
+ swap(size_t,*len,*complen); /* *len is now packet length */
+ return compbuf;
+}
+
+my_bool _mariadb_uncompress (unsigned char *packet, size_t *len, size_t *complen)
+{
+ if (*complen) /* If compressed */
+ {
+ unsigned char *compbuf = (unsigned char *) malloc (*complen);
+ if (!compbuf)
+ return 1; /* Not enough memory */
+ if (uncompress((Bytef*) compbuf, (uLongf *)complen, (Bytef*) packet, (uLongf)*len) != Z_OK)
+ { /* Probably wrong packet */
+ free(compbuf);
+ return 1;
+ }
+ *len = *complen;
+ memcpy(packet,compbuf,*len);
+ free(compbuf);
+ }
+ else *complen= *len;
+ return 0;
+}
+#endif /* HAVE_COMPRESS */