Commit | Line | Data |
---|---|---|
13aefa13 | 1 | /* |
0f78b815 WD |
2 | * File IO utilities used in rsync. |
3 | * | |
4 | * Copyright (C) 1998 Andrew Tridgell | |
5 | * Copyright (C) 2002 Martin Pool | |
d3d07a5e | 6 | * Copyright (C) 2004-2008 Wayne Davison |
0f78b815 WD |
7 | * |
8 | * This program is free software; you can redistribute it and/or modify | |
8e41b68e WD |
9 | * it under the terms of the GNU General Public License as published by |
10 | * the Free Software Foundation; either version 3 of the License, or | |
11 | * (at your option) any later version. | |
0f78b815 WD |
12 | * |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
e7c67065 | 18 | * You should have received a copy of the GNU General Public License along |
4fd842f9 | 19 | * with this program; if not, visit the http://fsf.org website. |
0f78b815 | 20 | */ |
13aefa13 | 21 | |
4c36ddbe AT |
22 | #include "rsync.h" |
23 | ||
13482675 WD |
24 | #ifndef ENODATA |
25 | #define ENODATA EAGAIN | |
26 | #endif | |
27 | ||
c7e11bfd WD |
28 | extern int sparse_files; |
29 | ||
4c36ddbe | 30 | static char last_byte; |
6aa27a7c | 31 | static size_t sparse_seek = 0; |
4c36ddbe AT |
32 | |
33 | int sparse_end(int f) | |
34 | { | |
6aa27a7c WD |
35 | int ret; |
36 | ||
37 | if (!sparse_seek) | |
38 | return 0; | |
39 | ||
40 | do_lseek(f, sparse_seek-1, SEEK_CUR); | |
41 | sparse_seek = 0; | |
42 | ||
43 | do { | |
44 | ret = write(f, "", 1); | |
45 | } while (ret < 0 && errno == EINTR); | |
46 | ||
47 | return ret <= 0 ? -1 : 0; | |
4c36ddbe AT |
48 | } |
49 | ||
50 | ||
6aa27a7c | 51 | static int write_sparse(int f, char *buf, size_t len) |
4c36ddbe | 52 | { |
6aa27a7c | 53 | size_t l1 = 0, l2 = 0; |
4c36ddbe AT |
54 | int ret; |
55 | ||
13aefa13 WD |
56 | for (l1 = 0; l1 < len && buf[l1] == 0; l1++) {} |
57 | for (l2 = 0; l2 < len-l1 && buf[len-(l2+1)] == 0; l2++) {} | |
4c36ddbe | 58 | |
6aa27a7c WD |
59 | /* XXX Riddle me this: why does this function SLOW DOWN when I |
60 | * remove the following (unneeded) line?? Core Duo weirdness? */ | |
4c36ddbe AT |
61 | last_byte = buf[len-1]; |
62 | ||
6aa27a7c | 63 | sparse_seek += l1; |
4c36ddbe | 64 | |
13aefa13 | 65 | if (l1 == len) |
4c36ddbe AT |
66 | return len; |
67 | ||
6aa27a7c WD |
68 | if (sparse_seek) |
69 | do_lseek(f, sparse_seek, SEEK_CUR); | |
70 | sparse_seek = l2; | |
71 | ||
72 | while ((ret = write(f, buf + l1, len - (l1+l2))) <= 0) { | |
73 | if (ret < 0 && errno == EINTR) | |
74 | continue; | |
a261989c | 75 | return ret; |
6aa27a7c | 76 | } |
4c36ddbe | 77 | |
6aa27a7c WD |
78 | if (ret != (int)(len - (l1+l2))) |
79 | return l1+ret; | |
13aefa13 | 80 | |
4c36ddbe AT |
81 | return len; |
82 | } | |
83 | ||
76c21947 WD |
84 | |
85 | static char *wf_writeBuf; | |
86 | static size_t wf_writeBufSize; | |
87 | static size_t wf_writeBufCnt; | |
88 | ||
89 | int flush_write_file(int f) | |
90 | { | |
9b9c8aaf WD |
91 | int ret = 0; |
92 | char *bp = wf_writeBuf; | |
13aefa13 | 93 | |
9b9c8aaf WD |
94 | while (wf_writeBufCnt > 0) { |
95 | if ((ret = write(f, bp, wf_writeBufCnt)) < 0) { | |
96 | if (errno == EINTR) | |
97 | continue; | |
98 | return ret; | |
99 | } | |
100 | wf_writeBufCnt -= ret; | |
101 | bp += ret; | |
102 | } | |
76c21947 WD |
103 | return ret; |
104 | } | |
105 | ||
c7e11bfd | 106 | |
9533e15a S |
107 | /* |
108 | * write_file does not allow incomplete writes. It loops internally | |
109 | * until len bytes are written or errno is set. | |
110 | */ | |
9dd891bb | 111 | int write_file(int f,char *buf,size_t len) |
4c36ddbe AT |
112 | { |
113 | int ret = 0; | |
114 | ||
9b9c8aaf | 115 | while (len > 0) { |
9533e15a | 116 | int r1; |
18233a17 | 117 | if (sparse_files > 0) { |
9533e15a S |
118 | int len1 = MIN(len, SPARSE_WRITE_SIZE); |
119 | r1 = write_sparse(f, buf, len1); | |
120 | } else { | |
76c21947 | 121 | if (!wf_writeBuf) { |
c7e11bfd | 122 | wf_writeBufSize = WRITE_SIZE * 8; |
76c21947 | 123 | wf_writeBufCnt = 0; |
c7e11bfd | 124 | wf_writeBuf = new_array(char, wf_writeBufSize); |
9b9c8aaf WD |
125 | if (!wf_writeBuf) |
126 | out_of_memory("write_file"); | |
76c21947 WD |
127 | } |
128 | r1 = MIN(len, wf_writeBufSize - wf_writeBufCnt); | |
129 | if (r1) { | |
130 | memcpy(wf_writeBuf + wf_writeBufCnt, buf, r1); | |
131 | wf_writeBufCnt += r1; | |
132 | } | |
133 | if (wf_writeBufCnt == wf_writeBufSize) { | |
9b9c8aaf WD |
134 | if (flush_write_file(f) < 0) |
135 | return -1; | |
76c21947 WD |
136 | if (!r1 && len) |
137 | continue; | |
138 | } | |
9533e15a | 139 | } |
4c36ddbe | 140 | if (r1 <= 0) { |
7f290d5c WD |
141 | if (ret > 0) |
142 | return ret; | |
4c36ddbe AT |
143 | return r1; |
144 | } | |
145 | len -= r1; | |
146 | buf += r1; | |
147 | ret += r1; | |
148 | } | |
149 | return ret; | |
150 | } | |
151 | ||
152 | ||
6e8a1782 WD |
153 | /* This provides functionality somewhat similar to mmap() but using read(). |
154 | * It gives sliding window access to a file. mmap() is not used because of | |
155 | * the possibility of another program (such as a mailer) truncating the | |
156 | * file thus giving us a SIGBUS. */ | |
54281fe7 | 157 | struct map_struct *map_file(int fd, OFF_T len, int32 read_size, |
7aac6604 | 158 | int32 blk_size) |
4c36ddbe | 159 | { |
4440b8aa | 160 | struct map_struct *map; |
4440b8aa | 161 | |
7e4b6b7b | 162 | if (!(map = new0(struct map_struct))) |
bf2b7ddf WD |
163 | out_of_memory("map_file"); |
164 | ||
54281fe7 WD |
165 | if (blk_size && (read_size % blk_size)) |
166 | read_size += blk_size - (read_size % blk_size); | |
6e8a1782 | 167 | |
4440b8aa AT |
168 | map->fd = fd; |
169 | map->file_size = len; | |
54281fe7 | 170 | map->def_window_size = read_size; |
4440b8aa AT |
171 | |
172 | return map; | |
4c36ddbe AT |
173 | } |
174 | ||
c7e11bfd | 175 | |
4440b8aa | 176 | /* slide the read window in the file */ |
7aac6604 | 177 | char *map_ptr(struct map_struct *map, OFF_T offset, int32 len) |
4c36ddbe | 178 | { |
54281fe7 | 179 | int32 nread; |
4440b8aa | 180 | OFF_T window_start, read_start; |
54281fe7 | 181 | int32 window_size, read_size, read_offset; |
4c36ddbe | 182 | |
7f290d5c | 183 | if (len == 0) |
4c36ddbe | 184 | return NULL; |
54281fe7 WD |
185 | if (len < 0) { |
186 | rprintf(FERROR, "invalid len passed to map_ptr: %ld\n", | |
187 | (long)len); | |
188 | exit_cleanup(RERR_FILEIO); | |
189 | } | |
4c36ddbe | 190 | |
4440b8aa | 191 | /* in most cases the region will already be available */ |
7aac6604 WD |
192 | if (offset >= map->p_offset && offset+len <= map->p_offset+map->p_len) |
193 | return map->p + (offset - map->p_offset); | |
4c36ddbe | 194 | |
4440b8aa | 195 | /* nope, we are going to have to do a read. Work out our desired window */ |
6e8a1782 | 196 | window_start = offset; |
7f290d5c | 197 | window_size = map->def_window_size; |
54281fe7 | 198 | if (window_start + window_size > map->file_size) |
26404276 | 199 | window_size = (int32)(map->file_size - window_start); |
54281fe7 WD |
200 | if (len > window_size) |
201 | window_size = len; | |
4c36ddbe | 202 | |
4440b8aa AT |
203 | /* make sure we have allocated enough memory for the window */ |
204 | if (window_size > map->p_size) { | |
58cadc86 | 205 | map->p = realloc_array(map->p, char, window_size); |
7f290d5c WD |
206 | if (!map->p) |
207 | out_of_memory("map_ptr"); | |
4440b8aa AT |
208 | map->p_size = window_size; |
209 | } | |
4c36ddbe | 210 | |
54281fe7 WD |
211 | /* Now try to avoid re-reading any bytes by reusing any bytes |
212 | * from the previous buffer. */ | |
4440b8aa AT |
213 | if (window_start >= map->p_offset && |
214 | window_start < map->p_offset + map->p_len && | |
215 | window_start + window_size >= map->p_offset + map->p_len) { | |
216 | read_start = map->p_offset + map->p_len; | |
26404276 | 217 | read_offset = (int32)(read_start - window_start); |
4440b8aa AT |
218 | read_size = window_size - read_offset; |
219 | memmove(map->p, map->p + (map->p_len - read_offset), read_offset); | |
220 | } else { | |
221 | read_start = window_start; | |
222 | read_size = window_size; | |
223 | read_offset = 0; | |
4c36ddbe AT |
224 | } |
225 | ||
4440b8aa | 226 | if (read_size <= 0) { |
54281fe7 WD |
227 | rprintf(FERROR, "invalid read_size of %ld in map_ptr\n", |
228 | (long)read_size); | |
229 | exit_cleanup(RERR_FILEIO); | |
13482675 | 230 | } |
4440b8aa | 231 | |
13482675 WD |
232 | if (map->p_fd_offset != read_start) { |
233 | OFF_T ret = do_lseek(map->fd, read_start, SEEK_SET); | |
234 | if (ret != read_start) { | |
235 | rsyserr(FERROR, errno, "lseek returned %.0f, not %.0f", | |
236 | (double)ret, (double)read_start); | |
237 | exit_cleanup(RERR_FILEIO); | |
4440b8aa | 238 | } |
13482675 | 239 | map->p_fd_offset = read_start; |
4c36ddbe | 240 | } |
4440b8aa AT |
241 | map->p_offset = window_start; |
242 | map->p_len = window_size; | |
13aefa13 | 243 | |
13482675 WD |
244 | while (read_size > 0) { |
245 | nread = read(map->fd, map->p + read_offset, read_size); | |
246 | if (nread <= 0) { | |
247 | if (!map->status) | |
248 | map->status = nread ? errno : ENODATA; | |
249 | /* The best we can do is zero the buffer -- the file | |
250 | * has changed mid transfer! */ | |
251 | memset(map->p + read_offset, 0, read_size); | |
252 | break; | |
253 | } | |
e3db43ff | 254 | map->p_fd_offset += nread; |
13482675 WD |
255 | read_offset += nread; |
256 | read_size -= nread; | |
257 | } | |
258 | ||
54281fe7 | 259 | return map->p; |
4c36ddbe AT |
260 | } |
261 | ||
262 | ||
6a7cc46c | 263 | int unmap_file(struct map_struct *map) |
4c36ddbe | 264 | { |
6a7cc46c S |
265 | int ret; |
266 | ||
4c36ddbe AT |
267 | if (map->p) { |
268 | free(map->p); | |
269 | map->p = NULL; | |
270 | } | |
6a7cc46c | 271 | ret = map->status; |
bf2b7ddf | 272 | memset(map, 0, sizeof map[0]); |
4c36ddbe | 273 | free(map); |
6a7cc46c S |
274 | |
275 | return ret; | |
4c36ddbe | 276 | } |