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 | |
ba2133d6 | 6 | * Copyright (C) 2004-2007 Wayne Davison |
0f78b815 WD |
7 | * |
8 | * This program is free software; you can redistribute it and/or modify | |
ba2133d6 WD |
9 | * it under the terms of the GNU General Public License version 2 as |
10 | * published by the Free Software Foundation. | |
0f78b815 WD |
11 | * |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
e7c67065 WD |
17 | * You should have received a copy of the GNU General Public License along |
18 | * with this program; if not, write to the Free Software Foundation, Inc., | |
19 | * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. | |
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 AT |
30 | static char last_byte; |
31 | static int last_sparse; | |
4c36ddbe AT |
32 | |
33 | int sparse_end(int f) | |
34 | { | |
35 | if (last_sparse) { | |
36 | do_lseek(f,-1,SEEK_CUR); | |
37 | return (write(f,&last_byte,1) == 1 ? 0 : -1); | |
38 | } | |
39 | last_sparse = 0; | |
40 | return 0; | |
41 | } | |
42 | ||
43 | ||
9dd891bb | 44 | static int write_sparse(int f,char *buf,size_t len) |
4c36ddbe | 45 | { |
a261989c | 46 | size_t l1=0, l2=0; |
4c36ddbe AT |
47 | int ret; |
48 | ||
13aefa13 WD |
49 | for (l1 = 0; l1 < len && buf[l1] == 0; l1++) {} |
50 | for (l2 = 0; l2 < len-l1 && buf[len-(l2+1)] == 0; l2++) {} | |
4c36ddbe AT |
51 | |
52 | last_byte = buf[len-1]; | |
53 | ||
54 | if (l1 == len || l2 > 0) | |
55 | last_sparse=1; | |
56 | ||
4440b8aa | 57 | if (l1 > 0) { |
13aefa13 | 58 | do_lseek(f,l1,SEEK_CUR); |
4440b8aa | 59 | } |
4c36ddbe | 60 | |
13aefa13 | 61 | if (l1 == len) |
4c36ddbe AT |
62 | return len; |
63 | ||
a261989c MP |
64 | ret = write(f, buf + l1, len - (l1+l2)); |
65 | if (ret == -1 || ret == 0) | |
66 | return ret; | |
13aefa13 | 67 | else if (ret != (int) (len - (l1+l2))) |
4c36ddbe | 68 | return (l1+ret); |
4c36ddbe AT |
69 | |
70 | if (l2 > 0) | |
71 | do_lseek(f,l2,SEEK_CUR); | |
13aefa13 | 72 | |
4c36ddbe AT |
73 | return len; |
74 | } | |
75 | ||
76c21947 WD |
76 | |
77 | static char *wf_writeBuf; | |
78 | static size_t wf_writeBufSize; | |
79 | static size_t wf_writeBufCnt; | |
80 | ||
81 | int flush_write_file(int f) | |
82 | { | |
9b9c8aaf WD |
83 | int ret = 0; |
84 | char *bp = wf_writeBuf; | |
13aefa13 | 85 | |
9b9c8aaf WD |
86 | while (wf_writeBufCnt > 0) { |
87 | if ((ret = write(f, bp, wf_writeBufCnt)) < 0) { | |
88 | if (errno == EINTR) | |
89 | continue; | |
90 | return ret; | |
91 | } | |
92 | wf_writeBufCnt -= ret; | |
93 | bp += ret; | |
94 | } | |
76c21947 WD |
95 | return ret; |
96 | } | |
97 | ||
c7e11bfd | 98 | |
9533e15a S |
99 | /* |
100 | * write_file does not allow incomplete writes. It loops internally | |
101 | * until len bytes are written or errno is set. | |
102 | */ | |
9dd891bb | 103 | int write_file(int f,char *buf,size_t len) |
4c36ddbe AT |
104 | { |
105 | int ret = 0; | |
106 | ||
9b9c8aaf | 107 | while (len > 0) { |
9533e15a | 108 | int r1; |
18233a17 | 109 | if (sparse_files > 0) { |
9533e15a S |
110 | int len1 = MIN(len, SPARSE_WRITE_SIZE); |
111 | r1 = write_sparse(f, buf, len1); | |
112 | } else { | |
76c21947 | 113 | if (!wf_writeBuf) { |
c7e11bfd | 114 | wf_writeBufSize = WRITE_SIZE * 8; |
76c21947 | 115 | wf_writeBufCnt = 0; |
c7e11bfd | 116 | wf_writeBuf = new_array(char, wf_writeBufSize); |
9b9c8aaf WD |
117 | if (!wf_writeBuf) |
118 | out_of_memory("write_file"); | |
76c21947 WD |
119 | } |
120 | r1 = MIN(len, wf_writeBufSize - wf_writeBufCnt); | |
121 | if (r1) { | |
122 | memcpy(wf_writeBuf + wf_writeBufCnt, buf, r1); | |
123 | wf_writeBufCnt += r1; | |
124 | } | |
125 | if (wf_writeBufCnt == wf_writeBufSize) { | |
9b9c8aaf WD |
126 | if (flush_write_file(f) < 0) |
127 | return -1; | |
76c21947 WD |
128 | if (!r1 && len) |
129 | continue; | |
130 | } | |
9533e15a | 131 | } |
4c36ddbe | 132 | if (r1 <= 0) { |
7f290d5c WD |
133 | if (ret > 0) |
134 | return ret; | |
4c36ddbe AT |
135 | return r1; |
136 | } | |
137 | len -= r1; | |
138 | buf += r1; | |
139 | ret += r1; | |
140 | } | |
141 | return ret; | |
142 | } | |
143 | ||
144 | ||
6e8a1782 WD |
145 | /* This provides functionality somewhat similar to mmap() but using read(). |
146 | * It gives sliding window access to a file. mmap() is not used because of | |
147 | * the possibility of another program (such as a mailer) truncating the | |
148 | * file thus giving us a SIGBUS. */ | |
54281fe7 | 149 | struct map_struct *map_file(int fd, OFF_T len, int32 read_size, |
7aac6604 | 150 | int32 blk_size) |
4c36ddbe | 151 | { |
4440b8aa | 152 | struct map_struct *map; |
4440b8aa | 153 | |
bf2b7ddf WD |
154 | if (!(map = new(struct map_struct))) |
155 | out_of_memory("map_file"); | |
156 | ||
54281fe7 WD |
157 | if (blk_size && (read_size % blk_size)) |
158 | read_size += blk_size - (read_size % blk_size); | |
6e8a1782 | 159 | |
bf2b7ddf | 160 | memset(map, 0, sizeof map[0]); |
4440b8aa AT |
161 | map->fd = fd; |
162 | map->file_size = len; | |
54281fe7 | 163 | map->def_window_size = read_size; |
4440b8aa AT |
164 | |
165 | return map; | |
4c36ddbe AT |
166 | } |
167 | ||
c7e11bfd | 168 | |
4440b8aa | 169 | /* slide the read window in the file */ |
7aac6604 | 170 | char *map_ptr(struct map_struct *map, OFF_T offset, int32 len) |
4c36ddbe | 171 | { |
54281fe7 | 172 | int32 nread; |
4440b8aa | 173 | OFF_T window_start, read_start; |
54281fe7 | 174 | int32 window_size, read_size, read_offset; |
4c36ddbe | 175 | |
7f290d5c | 176 | if (len == 0) |
4c36ddbe | 177 | return NULL; |
54281fe7 WD |
178 | if (len < 0) { |
179 | rprintf(FERROR, "invalid len passed to map_ptr: %ld\n", | |
180 | (long)len); | |
181 | exit_cleanup(RERR_FILEIO); | |
182 | } | |
4c36ddbe | 183 | |
4440b8aa | 184 | /* in most cases the region will already be available */ |
7aac6604 WD |
185 | if (offset >= map->p_offset && offset+len <= map->p_offset+map->p_len) |
186 | return map->p + (offset - map->p_offset); | |
4c36ddbe | 187 | |
4440b8aa | 188 | /* nope, we are going to have to do a read. Work out our desired window */ |
6e8a1782 | 189 | window_start = offset; |
7f290d5c | 190 | window_size = map->def_window_size; |
54281fe7 | 191 | if (window_start + window_size > map->file_size) |
26404276 | 192 | window_size = (int32)(map->file_size - window_start); |
54281fe7 WD |
193 | if (len > window_size) |
194 | window_size = len; | |
4c36ddbe | 195 | |
4440b8aa AT |
196 | /* make sure we have allocated enough memory for the window */ |
197 | if (window_size > map->p_size) { | |
58cadc86 | 198 | map->p = realloc_array(map->p, char, window_size); |
7f290d5c WD |
199 | if (!map->p) |
200 | out_of_memory("map_ptr"); | |
4440b8aa AT |
201 | map->p_size = window_size; |
202 | } | |
4c36ddbe | 203 | |
54281fe7 WD |
204 | /* Now try to avoid re-reading any bytes by reusing any bytes |
205 | * from the previous buffer. */ | |
4440b8aa AT |
206 | if (window_start >= map->p_offset && |
207 | window_start < map->p_offset + map->p_len && | |
208 | window_start + window_size >= map->p_offset + map->p_len) { | |
209 | read_start = map->p_offset + map->p_len; | |
26404276 | 210 | read_offset = (int32)(read_start - window_start); |
4440b8aa AT |
211 | read_size = window_size - read_offset; |
212 | memmove(map->p, map->p + (map->p_len - read_offset), read_offset); | |
213 | } else { | |
214 | read_start = window_start; | |
215 | read_size = window_size; | |
216 | read_offset = 0; | |
4c36ddbe AT |
217 | } |
218 | ||
4440b8aa | 219 | if (read_size <= 0) { |
54281fe7 WD |
220 | rprintf(FERROR, "invalid read_size of %ld in map_ptr\n", |
221 | (long)read_size); | |
222 | exit_cleanup(RERR_FILEIO); | |
13482675 | 223 | } |
4440b8aa | 224 | |
13482675 WD |
225 | if (map->p_fd_offset != read_start) { |
226 | OFF_T ret = do_lseek(map->fd, read_start, SEEK_SET); | |
227 | if (ret != read_start) { | |
228 | rsyserr(FERROR, errno, "lseek returned %.0f, not %.0f", | |
229 | (double)ret, (double)read_start); | |
230 | exit_cleanup(RERR_FILEIO); | |
4440b8aa | 231 | } |
13482675 | 232 | map->p_fd_offset = read_start; |
4c36ddbe | 233 | } |
4440b8aa AT |
234 | map->p_offset = window_start; |
235 | map->p_len = window_size; | |
13aefa13 | 236 | |
13482675 WD |
237 | while (read_size > 0) { |
238 | nread = read(map->fd, map->p + read_offset, read_size); | |
239 | if (nread <= 0) { | |
240 | if (!map->status) | |
241 | map->status = nread ? errno : ENODATA; | |
242 | /* The best we can do is zero the buffer -- the file | |
243 | * has changed mid transfer! */ | |
244 | memset(map->p + read_offset, 0, read_size); | |
245 | break; | |
246 | } | |
e3db43ff | 247 | map->p_fd_offset += nread; |
13482675 WD |
248 | read_offset += nread; |
249 | read_size -= nread; | |
250 | } | |
251 | ||
54281fe7 | 252 | return map->p; |
4c36ddbe AT |
253 | } |
254 | ||
255 | ||
6a7cc46c | 256 | int unmap_file(struct map_struct *map) |
4c36ddbe | 257 | { |
6a7cc46c S |
258 | int ret; |
259 | ||
4c36ddbe AT |
260 | if (map->p) { |
261 | free(map->p); | |
262 | map->p = NULL; | |
263 | } | |
6a7cc46c | 264 | ret = map->status; |
bf2b7ddf | 265 | memset(map, 0, sizeof map[0]); |
4c36ddbe | 266 | free(map); |
6a7cc46c S |
267 | |
268 | return ret; | |
4c36ddbe | 269 | } |