Commit | Line | Data |
---|---|---|
1e4f48d6 | 1 | /* |
0f78b815 WD |
2 | * Block matching used by the file-transfer code. |
3 | * | |
4 | * Copyright (C) 1996 Andrew Tridgell | |
5 | * Copyright (C) 1996 Paul Mackerras | |
ba2133d6 | 6 | * Copyright (C) 2003-2007 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 | */ |
c627d613 AT |
21 | |
22 | #include "rsync.h" | |
23 | ||
24 | extern int verbose; | |
16417f8b | 25 | extern int do_progress; |
ba582f75 | 26 | extern int checksum_seed; |
6cc11982 | 27 | extern int append_mode; |
a36ffd39 WD |
28 | |
29 | int updating_basis_file; | |
c627d613 | 30 | |
c627d613 | 31 | static int false_alarms; |
900cfcb5 | 32 | static int hash_hits; |
c627d613 | 33 | static int matches; |
a800434a | 34 | static int64 data_transfer; |
c627d613 | 35 | |
3a6a366f | 36 | static int total_false_alarms; |
900cfcb5 | 37 | static int total_hash_hits; |
3a6a366f | 38 | static int total_matches; |
c627d613 | 39 | |
a800434a | 40 | extern struct stats stats; |
c627d613 | 41 | |
48cce779 WD |
42 | #define TABLESIZE (1<<16) |
43 | ||
68207537 | 44 | static int32 *hash_table; |
c627d613 | 45 | |
48cce779 WD |
46 | #define SUM2HASH2(s1,s2) (((s1) + (s2)) & 0xFFFF) |
47 | #define SUM2HASH(sum) SUM2HASH2((sum)&0xFFFF,(sum)>>16) | |
c627d613 AT |
48 | |
49 | static void build_hash_table(struct sum_struct *s) | |
50 | { | |
7cacd47e | 51 | int32 i; |
48cce779 WD |
52 | |
53 | if (!hash_table) { | |
54 | hash_table = new_array(int32, TABLESIZE); | |
68207537 | 55 | if (!hash_table) |
d9bca0c3 WD |
56 | out_of_memory("build_hash_table"); |
57 | } | |
c627d613 | 58 | |
48cce779 | 59 | memset(hash_table, 0xFF, TABLESIZE * sizeof hash_table[0]); |
c627d613 | 60 | |
0e36d9da | 61 | for (i = 0; i < s->count; i++) { |
fbbe9a01 | 62 | uint32 t = SUM2HASH(s->sums[i].sum1); |
68207537 WD |
63 | s->sums[i].chain = hash_table[t]; |
64 | hash_table[t] = i; | |
1e4f48d6 | 65 | } |
c627d613 AT |
66 | } |
67 | ||
68 | ||
bcacc18b | 69 | static OFF_T last_match; |
c627d613 AT |
70 | |
71 | ||
f5f95a38 MP |
72 | /** |
73 | * Transmit a literal and/or match token. | |
74 | * | |
75 | * This delightfully-named function is called either when we find a | |
76 | * match and need to transmit all the unmatched data leading up to it, | |
77 | * or when we get bored of accumulating literal data and just need to | |
78 | * transmit it. As a result of this second case, it is called even if | |
79 | * we have not matched at all! | |
80 | * | |
81 | * @param i If >0, the number of a matched token. If 0, indicates we | |
82 | * have only literal data. | |
83 | **/ | |
a06b419d | 84 | static void matched(int f, struct sum_struct *s, struct map_struct *buf, |
37a56445 | 85 | OFF_T offset, int32 i) |
c627d613 | 86 | { |
26404276 | 87 | int32 n = (int32)(offset - last_match); /* max value: block_size (int32) */ |
a06b419d WD |
88 | int32 j; |
89 | ||
90 | if (verbose > 2 && i >= 0) { | |
91 | rprintf(FINFO, | |
92 | "match at %.0f last_match=%.0f j=%d len=%ld n=%ld\n", | |
93 | (double)offset, (double)last_match, i, | |
94 | (long)s->sums[i].len, (long)n); | |
95 | } | |
c627d613 | 96 | |
a06b419d | 97 | send_token(f, i, buf, last_match, n, i < 0 ? 0 : s->sums[i].len); |
e7ebc36c | 98 | data_transfer += n; |
70d794dc | 99 | |
a800434a AT |
100 | if (i >= 0) { |
101 | stats.matched_data += s->sums[i].len; | |
e7ebc36c | 102 | n += s->sums[i].len; |
a800434a | 103 | } |
1e4f48d6 WD |
104 | |
105 | for (j = 0; j < n; j += CHUNK_SIZE) { | |
a06b419d WD |
106 | int32 n1 = MIN(CHUNK_SIZE, n - j); |
107 | sum_update(map_ptr(buf, last_match + j, n1), n1); | |
e7ebc36c | 108 | } |
9e31c482 | 109 | |
0d0e2e93 | 110 | if (i >= 0) |
e7ebc36c | 111 | last_match = offset + s->sums[i].len; |
0d0e2e93 AT |
112 | else |
113 | last_match = offset; | |
eb86d661 | 114 | |
0394e34a | 115 | if (buf && do_progress) |
4440b8aa | 116 | show_progress(last_match, buf->file_size); |
9e31c482 AT |
117 | } |
118 | ||
119 | ||
c6e7fcb4 | 120 | static void hash_search(int f,struct sum_struct *s, |
da9d12f5 | 121 | struct map_struct *buf, OFF_T len) |
c627d613 | 122 | { |
26404276 WD |
123 | OFF_T offset, end; |
124 | int32 k, want_i, backup; | |
e7ebc36c | 125 | char sum2[SUM_LENGTH]; |
1e4f48d6 | 126 | uint32 s1, s2, sum; |
7560c17a | 127 | int more; |
debb4505 | 128 | schar *map; |
e7ebc36c | 129 | |
a04d77bc WD |
130 | /* want_i is used to encourage adjacent matches, allowing the RLL |
131 | * coding of the output to work more efficiently. */ | |
132 | want_i = 0; | |
923fa978 | 133 | |
0e36d9da | 134 | if (verbose > 2) { |
a06b419d WD |
135 | rprintf(FINFO, "hash search b=%ld len=%.0f\n", |
136 | (long)s->blength, (double)len); | |
0e36d9da | 137 | } |
e7ebc36c | 138 | |
a06b419d | 139 | k = (int32)MIN(len, (OFF_T)s->blength); |
1e4f48d6 | 140 | |
0e36d9da | 141 | map = (schar *)map_ptr(buf, 0, k); |
1e4f48d6 | 142 | |
e7ebc36c AT |
143 | sum = get_checksum1((char *)map, k); |
144 | s1 = sum & 0xFFFF; | |
145 | s2 = sum >> 16; | |
146 | if (verbose > 3) | |
a06b419d | 147 | rprintf(FINFO, "sum=%.8x k=%ld\n", sum, (long)k); |
1e4f48d6 | 148 | |
e7ebc36c | 149 | offset = 0; |
1e4f48d6 | 150 | |
e7ebc36c | 151 | end = len + 1 - s->sums[s->count-1].len; |
1e4f48d6 | 152 | |
0e36d9da | 153 | if (verbose > 3) { |
a06b419d WD |
154 | rprintf(FINFO, "hash search s->blength=%ld len=%.0f count=%.0f\n", |
155 | (long)s->blength, (double)len, (double)s->count); | |
0e36d9da | 156 | } |
1e4f48d6 | 157 | |
e7ebc36c | 158 | do { |
e7ebc36c | 159 | int done_csum2 = 0; |
d9bca0c3 | 160 | int32 i; |
1e4f48d6 | 161 | |
48cce779 WD |
162 | if (verbose > 4) { |
163 | rprintf(FINFO, "offset=%.0f sum=%04x%04x\n", | |
34f961bb | 164 | (double)offset, s2 & 0xFFFF, s1 & 0xFFFF); |
48cce779 | 165 | } |
1e4f48d6 | 166 | |
48cce779 | 167 | i = hash_table[SUM2HASH2(s1,s2)]; |
900cfcb5 WD |
168 | if (i < 0) |
169 | goto null_hash; | |
170 | ||
48cce779 | 171 | sum = (s1 & 0xffff) | (s2 << 16); |
900cfcb5 WD |
172 | hash_hits++; |
173 | do { | |
d9bca0c3 | 174 | int32 l; |
1e4f48d6 | 175 | |
0e36d9da WD |
176 | if (sum != s->sums[i].sum1) |
177 | continue; | |
1e4f48d6 | 178 | |
536541d5 | 179 | /* also make sure the two blocks are the same length */ |
a06b419d | 180 | l = (int32)MIN((OFF_T)s->blength, len-offset); |
0e36d9da WD |
181 | if (l != s->sums[i].len) |
182 | continue; | |
536541d5 | 183 | |
a36ffd39 | 184 | /* in-place: ensure chunk's offset is either >= our |
a3221d2a | 185 | * offset or that the data didn't move. */ |
a36ffd39 | 186 | if (updating_basis_file && s->sums[i].offset < offset |
a3221d2a WD |
187 | && !(s->sums[i].flags & SUMFLG_SAME_OFFSET)) |
188 | continue; | |
189 | ||
d9bca0c3 WD |
190 | if (verbose > 3) { |
191 | rprintf(FINFO, | |
192 | "potential match at %.0f i=%ld sum=%08x\n", | |
193 | (double)offset, (long)i, sum); | |
194 | } | |
1e4f48d6 | 195 | |
e7ebc36c | 196 | if (!done_csum2) { |
debb4505 | 197 | map = (schar *)map_ptr(buf,offset,l); |
e7ebc36c AT |
198 | get_checksum2((char *)map,l,sum2); |
199 | done_csum2 = 1; | |
200 | } | |
1e4f48d6 | 201 | |
fc0257c9 | 202 | if (memcmp(sum2,s->sums[i].sum2,s->s2length) != 0) { |
e7ebc36c AT |
203 | false_alarms++; |
204 | continue; | |
205 | } | |
923fa978 | 206 | |
a36ffd39 | 207 | /* When updating in-place, the best possible match is |
a3221d2a WD |
208 | * one with an identical offset, so we prefer that over |
209 | * the following want_i optimization. */ | |
a36ffd39 | 210 | if (updating_basis_file) { |
d9bca0c3 WD |
211 | int32 i2; |
212 | for (i2 = i; i2 >= 0; i2 = s->sums[i2].chain) { | |
a3221d2a WD |
213 | if (s->sums[i2].offset != offset) |
214 | continue; | |
215 | if (i2 != i) { | |
216 | if (sum != s->sums[i2].sum1) | |
217 | break; | |
218 | if (memcmp(sum2, s->sums[i2].sum2, | |
219 | s->s2length) != 0) | |
220 | break; | |
221 | i = i2; | |
222 | } | |
223 | /* This chunk was at the same offset on | |
224 | * both the sender and the receiver. */ | |
225 | s->sums[i].flags |= SUMFLG_SAME_OFFSET; | |
226 | goto set_want_i; | |
d9bca0c3 | 227 | } |
a3221d2a WD |
228 | } |
229 | ||
923fa978 | 230 | /* we've found a match, but now check to see |
a04d77bc WD |
231 | * if want_i can hint at a better match. */ |
232 | if (i != want_i && want_i < s->count | |
a36ffd39 | 233 | && (!updating_basis_file || s->sums[want_i].offset >= offset |
a3221d2a | 234 | || s->sums[want_i].flags & SUMFLG_SAME_OFFSET) |
a04d77bc WD |
235 | && sum == s->sums[want_i].sum1 |
236 | && memcmp(sum2, s->sums[want_i].sum2, s->s2length) == 0) { | |
5e252dea WD |
237 | /* we've found an adjacent match - the RLL coder |
238 | * will be happy */ | |
a04d77bc | 239 | i = want_i; |
923fa978 | 240 | } |
a3221d2a | 241 | set_want_i: |
a04d77bc | 242 | want_i = i + 1; |
1e4f48d6 | 243 | |
e7ebc36c AT |
244 | matched(f,s,buf,offset,i); |
245 | offset += s->sums[i].len - 1; | |
a06b419d | 246 | k = (int32)MIN((OFF_T)s->blength, len-offset); |
0e36d9da | 247 | map = (schar *)map_ptr(buf, offset, k); |
e7ebc36c AT |
248 | sum = get_checksum1((char *)map, k); |
249 | s1 = sum & 0xFFFF; | |
250 | s2 = sum >> 16; | |
251 | matches++; | |
252 | break; | |
900cfcb5 | 253 | } while ((i = s->sums[i].chain) >= 0); |
1e4f48d6 | 254 | |
900cfcb5 | 255 | null_hash: |
26404276 | 256 | backup = (int32)(offset - last_match); |
7560c17a WD |
257 | /* We sometimes read 1 byte prior to last_match... */ |
258 | if (backup < 0) | |
259 | backup = 0; | |
260 | ||
e7ebc36c | 261 | /* Trim off the first byte from the checksum */ |
7560c17a WD |
262 | more = offset + k < len; |
263 | map = (schar *)map_ptr(buf, offset - backup, k + more + backup) | |
264 | + backup; | |
e7ebc36c AT |
265 | s1 -= map[0] + CHAR_OFFSET; |
266 | s2 -= k * (map[0]+CHAR_OFFSET); | |
1e4f48d6 | 267 | |
e7ebc36c | 268 | /* Add on the next byte (if there is one) to the checksum */ |
7560c17a WD |
269 | if (more) { |
270 | s1 += map[k] + CHAR_OFFSET; | |
e7ebc36c | 271 | s2 += s1; |
0e36d9da | 272 | } else |
e7ebc36c | 273 | --k; |
45f133b9 | 274 | |
5914bf15 PM |
275 | /* By matching early we avoid re-reading the |
276 | data 3 times in the case where a token | |
277 | match comes a long way after last | |
278 | match. The 3 reads are caused by the | |
279 | running match, the checksum update and the | |
280 | literal send. */ | |
a06b419d WD |
281 | if (backup >= s->blength+CHUNK_SIZE && end-offset > CHUNK_SIZE) |
282 | matched(f, s, buf, offset - s->blength, -2); | |
e7ebc36c | 283 | } while (++offset < end); |
1e4f48d6 | 284 | |
a06b419d WD |
285 | matched(f, s, buf, len, -1); |
286 | map_ptr(buf, len-1, 1); | |
c627d613 AT |
287 | } |
288 | ||
289 | ||
f5f95a38 MP |
290 | /** |
291 | * Scan through a origin file, looking for sections that match | |
292 | * checksums from the generator, and transmit either literal or token | |
293 | * data. | |
294 | * | |
538ba24f MP |
295 | * Also calculates the MD4 checksum of the whole file, using the md |
296 | * accumulator. This is transmitted with the file as protection | |
297 | * against corruption on the wire. | |
298 | * | |
f5f95a38 MP |
299 | * @param s Checksums received from the generator. If <tt>s->count == |
300 | * 0</tt>, then there are actually no checksums for this file. | |
301 | * | |
302 | * @param len Length of the file to send. | |
303 | **/ | |
304 | void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len) | |
c627d613 | 305 | { |
a0456b9c WD |
306 | char file_sum[MAX_DIGEST_LEN]; |
307 | int sum_len; | |
e7ebc36c AT |
308 | |
309 | last_match = 0; | |
310 | false_alarms = 0; | |
900cfcb5 | 311 | hash_hits = 0; |
1e4f48d6 WD |
312 | matches = 0; |
313 | data_transfer = 0; | |
e7ebc36c | 314 | |
ba582f75 | 315 | sum_init(checksum_seed); |
e7ebc36c | 316 | |
edb97721 | 317 | if (append_mode > 0) { |
936fa865 WD |
318 | if (append_mode == 2) { |
319 | OFF_T j = 0; | |
320 | for (j = CHUNK_SIZE; j < s->flength; j += CHUNK_SIZE) { | |
321 | if (buf && do_progress) | |
322 | show_progress(last_match, buf->file_size); | |
323 | sum_update(map_ptr(buf, last_match, CHUNK_SIZE), | |
324 | CHUNK_SIZE); | |
325 | last_match = j; | |
326 | } | |
327 | if (last_match < s->flength) { | |
328 | int32 n = (int32)(s->flength - last_match); | |
329 | if (buf && do_progress) | |
330 | show_progress(last_match, buf->file_size); | |
331 | sum_update(map_ptr(buf, last_match, n), n); | |
332 | } | |
6cc11982 | 333 | } |
936fa865 | 334 | last_match = s->flength; |
6cc11982 WD |
335 | s->count = 0; |
336 | } | |
337 | ||
a06b419d | 338 | if (len > 0 && s->count > 0) { |
e7ebc36c | 339 | build_hash_table(s); |
1e4f48d6 WD |
340 | |
341 | if (verbose > 2) | |
9486289c | 342 | rprintf(FINFO,"built hash table\n"); |
1e4f48d6 | 343 | |
a0456b9c | 344 | hash_search(f, s, buf, len); |
1e4f48d6 WD |
345 | |
346 | if (verbose > 2) | |
9486289c | 347 | rprintf(FINFO,"done hash search\n"); |
e7ebc36c | 348 | } else { |
eb86d661 AT |
349 | OFF_T j; |
350 | /* by doing this in pieces we avoid too many seeks */ | |
6cc11982 | 351 | for (j = last_match + CHUNK_SIZE; j < len; j += CHUNK_SIZE) |
a06b419d WD |
352 | matched(f, s, buf, j, -2); |
353 | matched(f, s, buf, len, -1); | |
e7ebc36c | 354 | } |
9e31c482 | 355 | |
a0456b9c | 356 | sum_len = sum_end(file_sum); |
edecdad5 WD |
357 | /* If we had a read error, send a bad checksum. */ |
358 | if (buf && buf->status != 0) | |
359 | file_sum[0]++; | |
c627d613 | 360 | |
bc63ae3f S |
361 | if (verbose > 2) |
362 | rprintf(FINFO,"sending file_sum\n"); | |
a0456b9c | 363 | write_buf(f, file_sum, sum_len); |
c627d613 | 364 | |
e7ebc36c | 365 | if (verbose > 2) |
900cfcb5 WD |
366 | rprintf(FINFO, "false_alarms=%d hash_hits=%d matches=%d\n", |
367 | false_alarms, hash_hits, matches); | |
1e4f48d6 | 368 | |
900cfcb5 | 369 | total_hash_hits += hash_hits; |
e7ebc36c AT |
370 | total_false_alarms += false_alarms; |
371 | total_matches += matches; | |
a800434a | 372 | stats.literal_data += data_transfer; |
c627d613 AT |
373 | } |
374 | ||
375 | void match_report(void) | |
376 | { | |
e7ebc36c AT |
377 | if (verbose <= 1) |
378 | return; | |
c627d613 | 379 | |
9486289c | 380 | rprintf(FINFO, |
900cfcb5 WD |
381 | "total: matches=%d hash_hits=%d false_alarms=%d data=%.0f\n", |
382 | total_matches, total_hash_hits, total_false_alarms, | |
a800434a | 383 | (double)stats.literal_data); |
c627d613 | 384 | } |