Mercurial > notdcc

comparison srvrlib/read_rcd.c @ 0:c7f6b056b673

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
First import of vendor version
author Peter Gervai <grin@grin.hu>
date Tue, 10 Mar 2009 13:49:58 +0100
parents
children
comparison
equal deleted inserted replaced
-1:000000000000 0:c7f6b056b673
1 /* Distributed Checksum Clearinghouse
2 *
3 * Copyright (c) 2008 by Rhyolite Software, LLC
4 *
5 * This agreement is not applicable to any entity which sells anti-spam
6 * solutions to others or provides an anti-spam solution as part of a
7 * security solution sold to other entities, or to a private network
8 * which employs the DCC or uses data provided by operation of the DCC
9 * but does not provide corresponding data to other users.
10 *
11 * Permission to use, copy, modify, and distribute this software without
12 * changes for any purpose with or without fee is hereby granted, provided
13 * that the above copyright notice and this permission notice appear in all
14 * copies and any distributed versions or copies are either unchanged
15 * or not called anything similar to "DCC" or "Distributed Checksum
16 * Clearinghouse".
17 *
18 * Parties not eligible to receive a license under this agreement can
19 * obtain a commercial license to use DCC by contacting Rhyolite Software
20 * at sales@rhyolite.com.
21 *
22 * A commercial license would be for Distributed Checksum and Reputation
23 * Clearinghouse software. That software includes additional features. This
24 * free license for Distributed ChecksumClearinghouse Software does not in any
25 * way grant permision to use Distributed Checksum and Reputation Clearinghouse
26 * software
27 *
28 * THE SOFTWARE IS PROVIDED "AS IS" AND RHYOLITE SOFTWARE, LLC DISCLAIMS ALL
29 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
30 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL RHYOLITE SOFTWARE, LLC
31 * BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES
32 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
33 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
34 * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
35 * SOFTWARE.
36 *
37 * Rhyolite Software DCC 1.3.103-1.24 $Revision$
38 */
39
40 #include "srvr_defs.h"
41
42 static int read_rcd_fd = -1;
43 #define BUF_SIZE (64*1024)
44 static u_char read_rcd_buf[BUF_SIZE];
45 static u_int read_rcd_bufsize = BUF_SIZE;
46 static off_t read_rcd_base;
47 static u_int read_rcd_buflen;
48
49 static int system_pagesize;
50
51
52
53 int
54 read_db(DCC_EMSG emsg, void *buf, u_int buf_len,
55 int fd, off_t pos, const char *file_nm)
56 {
57 int i;
58
59 if (-1 == lseek(fd, pos, SEEK_SET)) {
60 dcc_pemsg(EX_IOERR, emsg, "lseek(%s, 0): %s",
61 DB_NM2PATH_ERR(file_nm), ERROR_STR());
62 return -1;
63 }
64
65 i = read(fd, buf, buf_len);
66 if (i >= 0)
67 return i;
68
69 dcc_pemsg(EX_IOERR, emsg, "read(%s): %s",
70 DB_NM2PATH_ERR(file_nm), ERROR_STR());
71 return -1;
72 }
73
74
75
76 u_char
77 read_db_hdr(DCC_EMSG emsg, DB_HDR *hdrp,
78 int fd, const char *file_nm)
79 {
80 return (sizeof(*hdrp) == read_db(emsg, hdrp, sizeof(*hdrp),
81 fd, 0, file_nm));
82 }
83
84
85
86 /* invalidate the read_rcd() read-ahead cache */
87 void
88 read_rcd_invalidate(u_int bufsize)
89 {
90 read_rcd_fd = -1;
91
92 if (system_pagesize == 0)
93 system_pagesize = getpagesize();
94 bufsize = ((bufsize + system_pagesize-1) / system_pagesize
95 * system_pagesize);
96 if (bufsize == 0 || bufsize > BUF_SIZE)
97 bufsize = BUF_SIZE;
98 read_rcd_bufsize = bufsize;
99 }
100
101
102
103 static int
104 read_rcd_sub(DCC_EMSG emsg, void *buf, u_int buflen,
105 int fd, off_t pos, const char *file_nm)
106 {
107 int i;
108
109 if (fd == read_rcd_fd
110 && pos >= read_rcd_base
111 && pos+buflen <= read_rcd_base+read_rcd_buflen) {
112 memcpy(buf, &read_rcd_buf[pos-read_rcd_base], buflen);
113 return buflen;
114 }
115
116 if (system_pagesize == 0)
117 system_pagesize = getpagesize();
118 read_rcd_base = pos - (pos % system_pagesize);
119
120 i = read_db(emsg, read_rcd_buf, read_rcd_bufsize,
121 read_rcd_fd = fd,
122 read_rcd_base, file_nm);
123 if (i <= 0) {
124 read_rcd_fd = -1;
125 return i;
126 }
127 read_rcd_buflen = i;
128 if (buflen > read_rcd_buflen)
129 buflen = read_rcd_buflen;
130 memcpy(buf, &read_rcd_buf[pos-read_rcd_base], buflen);
131 return buflen;
132 }
133
134
135
136 int /* -1=error 0=eof >0=record length */
137 read_rcd(DCC_EMSG emsg, DB_RCD *rcd,
138 int fd, off_t pos, const char *file_nm)
139 {
140 int i, cks_len, num_cks;
141
142 /* read a record, starting with its beginning */
143 i = read_rcd_sub(emsg, rcd, DB_RCD_HDR_LEN,
144 fd, pos, file_nm);
145 if (DB_RCD_HDR_LEN != i) {
146 if (i == 0)
147 return 0;
148 if (i > 0) {
149 dcc_pemsg(EX_DATAERR, emsg,
150 "header of record at "OFF_HPAT" of %s"
151 " truncated by %d bytes",
152 lseek(fd, 0, SEEK_CUR) - i,
153 DB_NM2PATH_ERR(file_nm), DB_RCD_HDR_LEN-i);
154 }
155 return -1;
156 }
157
158 num_cks = DB_NUM_CKS(rcd);
159 if (num_cks > DIM(rcd->cks)) {
160 dcc_pemsg(EX_DATAERR, emsg,
161 "bogus checksum count %#x at "OFF_HPAT" of %s",
162 rcd->fgs_num_cks, lseek(fd, 0, SEEK_CUR),
163 DB_NM2PATH_ERR(file_nm));
164 return -1;
165 }
166 cks_len = num_cks * sizeof(rcd->cks[0]);
167 if (cks_len != 0) {
168 i = read_rcd_sub(emsg, rcd->cks, cks_len,
169 fd, pos+DB_RCD_HDR_LEN, file_nm);
170 if (i != cks_len) {
171 if (i < 0)
172 return -1;
173 if (!i)
174 dcc_pemsg(EX_DATAERR, emsg,
175 "record at "OFF_HPAT" of %s"
176 " truncated after header",
177 lseek(fd, 0, SEEK_CUR),
178 DB_NM2PATH_ERR(file_nm));
179 else
180 dcc_pemsg(EX_DATAERR, emsg,
181 "record at "OFF_HPAT" of %s"
182 " truncated by %d bytes",
183 lseek(fd, 0, SEEK_CUR),
184 DB_NM2PATH_ERR(file_nm), cks_len-i);
185 return 0;
186 }
187 }
188
189 return DB_RCD_HDR_LEN+cks_len;
190 }