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3443546f LT |
1 | /* |
2 | * LibXDiff by Davide Libenzi ( File Differential Library ) | |
3 | * Copyright (C) 2003 Davide Libenzi | |
4 | * | |
5 | * This library is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU Lesser General Public | |
7 | * License as published by the Free Software Foundation; either | |
8 | * version 2.1 of the License, or (at your option) any later version. | |
9 | * | |
10 | * This library is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * Lesser General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU Lesser General Public | |
48425792 TZ |
16 | * License along with this library; if not, see |
17 | * <http://www.gnu.org/licenses/>. | |
3443546f LT |
18 | * |
19 | * Davide Libenzi <davidel@xmailserver.org> | |
20 | * | |
21 | */ | |
22 | ||
23 | #include "xinclude.h" | |
24 | ||
25 | ||
3443546f | 26 | #define XDL_KPDIS_RUN 4 |
ca557aff | 27 | #define XDL_MAX_EQLIMIT 1024 |
9b28d554 | 28 | #define XDL_SIMSCAN_WINDOW 100 |
86abba80 TRC |
29 | #define XDL_GUESS_NLINES1 256 |
30 | #define XDL_GUESS_NLINES2 20 | |
3443546f LT |
31 | |
32 | ||
33 | typedef struct s_xdlclass { | |
34 | struct s_xdlclass *next; | |
35 | unsigned long ha; | |
36 | char const *line; | |
37 | long size; | |
38 | long idx; | |
27af01d5 | 39 | long len1, len2; |
3443546f LT |
40 | } xdlclass_t; |
41 | ||
42 | typedef struct s_xdlclassifier { | |
43 | unsigned int hbits; | |
44 | long hsize; | |
45 | xdlclass_t **rchash; | |
46 | chastore_t ncha; | |
27af01d5 TRC |
47 | xdlclass_t **rcrecs; |
48 | long alloc; | |
3443546f | 49 | long count; |
0d21efa5 | 50 | long flags; |
3443546f LT |
51 | } xdlclassifier_t; |
52 | ||
53 | ||
54 | ||
55 | ||
0d21efa5 | 56 | static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags); |
3443546f | 57 | static void xdl_free_classifier(xdlclassifier_t *cf); |
27af01d5 TRC |
58 | static int xdl_classify_record(unsigned int pass, xdlclassifier_t *cf, xrecord_t **rhash, |
59 | unsigned int hbits, xrecord_t *rec); | |
60 | static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_t const *xpp, | |
3443546f LT |
61 | xdlclassifier_t *cf, xdfile_t *xdf); |
62 | static void xdl_free_ctx(xdfile_t *xdf); | |
63 | static int xdl_clean_mmatch(char const *dis, long i, long s, long e); | |
27af01d5 | 64 | static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2); |
3443546f | 65 | static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2); |
27af01d5 | 66 | static int xdl_optimize_ctxs(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2); |
3443546f LT |
67 | |
68 | ||
69 | ||
70 | ||
0d21efa5 | 71 | static int xdl_init_classifier(xdlclassifier_t *cf, long size, long flags) { |
0d21efa5 JS |
72 | cf->flags = flags; |
73 | ||
3443546f LT |
74 | cf->hbits = xdl_hashbits((unsigned int) size); |
75 | cf->hsize = 1 << cf->hbits; | |
76 | ||
77 | if (xdl_cha_init(&cf->ncha, sizeof(xdlclass_t), size / 4 + 1) < 0) { | |
78 | ||
79 | return -1; | |
80 | } | |
848fd5ae | 81 | if (!XDL_CALLOC_ARRAY(cf->rchash, cf->hsize)) { |
3443546f LT |
82 | |
83 | xdl_cha_free(&cf->ncha); | |
84 | return -1; | |
85 | } | |
3443546f | 86 | |
27af01d5 | 87 | cf->alloc = size; |
abf04bda | 88 | if (!XDL_ALLOC_ARRAY(cf->rcrecs, cf->alloc)) { |
27af01d5 TRC |
89 | |
90 | xdl_free(cf->rchash); | |
91 | xdl_cha_free(&cf->ncha); | |
92 | return -1; | |
93 | } | |
94 | ||
3443546f LT |
95 | cf->count = 0; |
96 | ||
97 | return 0; | |
98 | } | |
99 | ||
100 | ||
101 | static void xdl_free_classifier(xdlclassifier_t *cf) { | |
102 | ||
27af01d5 | 103 | xdl_free(cf->rcrecs); |
3443546f LT |
104 | xdl_free(cf->rchash); |
105 | xdl_cha_free(&cf->ncha); | |
106 | } | |
107 | ||
108 | ||
27af01d5 TRC |
109 | static int xdl_classify_record(unsigned int pass, xdlclassifier_t *cf, xrecord_t **rhash, |
110 | unsigned int hbits, xrecord_t *rec) { | |
3443546f LT |
111 | long hi; |
112 | char const *line; | |
113 | xdlclass_t *rcrec; | |
114 | ||
115 | line = rec->ptr; | |
116 | hi = (long) XDL_HASHLONG(rec->ha, cf->hbits); | |
117 | for (rcrec = cf->rchash[hi]; rcrec; rcrec = rcrec->next) | |
0d21efa5 JS |
118 | if (rcrec->ha == rec->ha && |
119 | xdl_recmatch(rcrec->line, rcrec->size, | |
120 | rec->ptr, rec->size, cf->flags)) | |
3443546f LT |
121 | break; |
122 | ||
123 | if (!rcrec) { | |
124 | if (!(rcrec = xdl_cha_alloc(&cf->ncha))) { | |
125 | ||
126 | return -1; | |
127 | } | |
128 | rcrec->idx = cf->count++; | |
f7b587bf | 129 | if (XDL_ALLOC_GROW(cf->rcrecs, cf->count, cf->alloc)) |
27af01d5 | 130 | return -1; |
27af01d5 | 131 | cf->rcrecs[rcrec->idx] = rcrec; |
3443546f LT |
132 | rcrec->line = line; |
133 | rcrec->size = rec->size; | |
134 | rcrec->ha = rec->ha; | |
27af01d5 | 135 | rcrec->len1 = rcrec->len2 = 0; |
3443546f LT |
136 | rcrec->next = cf->rchash[hi]; |
137 | cf->rchash[hi] = rcrec; | |
138 | } | |
139 | ||
27af01d5 TRC |
140 | (pass == 1) ? rcrec->len1++ : rcrec->len2++; |
141 | ||
3443546f LT |
142 | rec->ha = (unsigned long) rcrec->idx; |
143 | ||
144 | hi = (long) XDL_HASHLONG(rec->ha, hbits); | |
145 | rec->next = rhash[hi]; | |
146 | rhash[hi] = rec; | |
147 | ||
148 | return 0; | |
149 | } | |
150 | ||
151 | ||
27af01d5 | 152 | static int xdl_prepare_ctx(unsigned int pass, mmfile_t *mf, long narec, xpparam_t const *xpp, |
3443546f LT |
153 | xdlclassifier_t *cf, xdfile_t *xdf) { |
154 | unsigned int hbits; | |
452f4fa5 | 155 | long nrec, hsize, bsize; |
3443546f LT |
156 | unsigned long hav; |
157 | char const *blk, *cur, *top, *prev; | |
158 | xrecord_t *crec; | |
f7b587bf | 159 | xrecord_t **recs; |
3443546f LT |
160 | xrecord_t **rhash; |
161 | unsigned long *ha; | |
162 | char *rchg; | |
163 | long *rindex; | |
164 | ||
159607a8 TRC |
165 | ha = NULL; |
166 | rindex = NULL; | |
167 | rchg = NULL; | |
168 | rhash = NULL; | |
169 | recs = NULL; | |
3443546f | 170 | |
159607a8 TRC |
171 | if (xdl_cha_init(&xdf->rcha, sizeof(xrecord_t), narec / 4 + 1) < 0) |
172 | goto abort; | |
abf04bda | 173 | if (!XDL_ALLOC_ARRAY(recs, narec)) |
159607a8 | 174 | goto abort; |
3443546f | 175 | |
663c5ad0 PW |
176 | hbits = xdl_hashbits((unsigned int) narec); |
177 | hsize = 1 << hbits; | |
848fd5ae | 178 | if (!XDL_CALLOC_ARRAY(rhash, hsize)) |
663c5ad0 | 179 | goto abort; |
3443546f LT |
180 | |
181 | nrec = 0; | |
afe8a907 | 182 | if ((cur = blk = xdl_mmfile_first(mf, &bsize))) { |
739864b1 | 183 | for (top = blk + bsize; cur < top; ) { |
3443546f | 184 | prev = cur; |
0d21efa5 | 185 | hav = xdl_hash_record(&cur, top, xpp->flags); |
f7b587bf PW |
186 | if (XDL_ALLOC_GROW(recs, nrec + 1, narec)) |
187 | goto abort; | |
159607a8 TRC |
188 | if (!(crec = xdl_cha_alloc(&xdf->rcha))) |
189 | goto abort; | |
3443546f LT |
190 | crec->ptr = prev; |
191 | crec->size = (long) (cur - prev); | |
192 | crec->ha = hav; | |
193 | recs[nrec++] = crec; | |
663c5ad0 | 194 | if (xdl_classify_record(pass, cf, rhash, hbits, crec) < 0) |
159607a8 | 195 | goto abort; |
3443546f LT |
196 | } |
197 | } | |
198 | ||
848fd5ae | 199 | if (!XDL_CALLOC_ARRAY(rchg, nrec + 2)) |
159607a8 | 200 | goto abort; |
3443546f | 201 | |
b82dd3f7 PW |
202 | if ((XDF_DIFF_ALG(xpp->flags) != XDF_PATIENCE_DIFF) && |
203 | (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF)) { | |
abf04bda | 204 | if (!XDL_ALLOC_ARRAY(rindex, nrec + 1)) |
b82dd3f7 | 205 | goto abort; |
abf04bda | 206 | if (!XDL_ALLOC_ARRAY(ha, nrec + 1)) |
b82dd3f7 PW |
207 | goto abort; |
208 | } | |
3443546f LT |
209 | |
210 | xdf->nrec = nrec; | |
211 | xdf->recs = recs; | |
212 | xdf->hbits = hbits; | |
213 | xdf->rhash = rhash; | |
214 | xdf->rchg = rchg + 1; | |
215 | xdf->rindex = rindex; | |
216 | xdf->nreff = 0; | |
217 | xdf->ha = ha; | |
218 | xdf->dstart = 0; | |
219 | xdf->dend = nrec - 1; | |
220 | ||
221 | return 0; | |
159607a8 TRC |
222 | |
223 | abort: | |
224 | xdl_free(ha); | |
225 | xdl_free(rindex); | |
226 | xdl_free(rchg); | |
227 | xdl_free(rhash); | |
228 | xdl_free(recs); | |
229 | xdl_cha_free(&xdf->rcha); | |
230 | return -1; | |
3443546f LT |
231 | } |
232 | ||
233 | ||
234 | static void xdl_free_ctx(xdfile_t *xdf) { | |
235 | ||
236 | xdl_free(xdf->rhash); | |
237 | xdl_free(xdf->rindex); | |
238 | xdl_free(xdf->rchg - 1); | |
239 | xdl_free(xdf->ha); | |
240 | xdl_free(xdf->recs); | |
241 | xdl_cha_free(&xdf->rcha); | |
242 | } | |
243 | ||
244 | ||
245 | int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, | |
246 | xdfenv_t *xe) { | |
86abba80 | 247 | long enl1, enl2, sample; |
3443546f LT |
248 | xdlclassifier_t cf; |
249 | ||
2738bc3f TRC |
250 | memset(&cf, 0, sizeof(cf)); |
251 | ||
86abba80 TRC |
252 | /* |
253 | * For histogram diff, we can afford a smaller sample size and | |
254 | * thus a poorer estimate of the number of lines, as the hash | |
255 | * table (rhash) won't be filled up/grown. The number of lines | |
256 | * (nrecs) will be updated correctly anyway by | |
257 | * xdl_prepare_ctx(). | |
258 | */ | |
307ab20b JH |
259 | sample = (XDF_DIFF_ALG(xpp->flags) == XDF_HISTOGRAM_DIFF |
260 | ? XDL_GUESS_NLINES2 : XDL_GUESS_NLINES1); | |
86abba80 TRC |
261 | |
262 | enl1 = xdl_guess_lines(mf1, sample) + 1; | |
263 | enl2 = xdl_guess_lines(mf2, sample) + 1; | |
3443546f | 264 | |
663c5ad0 | 265 | if (xdl_init_classifier(&cf, enl1 + enl2 + 1, xpp->flags) < 0) |
3443546f | 266 | return -1; |
3443546f | 267 | |
27af01d5 | 268 | if (xdl_prepare_ctx(1, mf1, enl1, xpp, &cf, &xe->xdf1) < 0) { |
3443546f LT |
269 | |
270 | xdl_free_classifier(&cf); | |
271 | return -1; | |
272 | } | |
27af01d5 | 273 | if (xdl_prepare_ctx(2, mf2, enl2, xpp, &cf, &xe->xdf2) < 0) { |
3443546f LT |
274 | |
275 | xdl_free_ctx(&xe->xdf1); | |
276 | xdl_free_classifier(&cf); | |
277 | return -1; | |
278 | } | |
279 | ||
307ab20b JH |
280 | if ((XDF_DIFF_ALG(xpp->flags) != XDF_PATIENCE_DIFF) && |
281 | (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF) && | |
282 | xdl_optimize_ctxs(&cf, &xe->xdf1, &xe->xdf2) < 0) { | |
3443546f LT |
283 | |
284 | xdl_free_ctx(&xe->xdf2); | |
285 | xdl_free_ctx(&xe->xdf1); | |
87f16258 | 286 | xdl_free_classifier(&cf); |
3443546f LT |
287 | return -1; |
288 | } | |
289 | ||
663c5ad0 | 290 | xdl_free_classifier(&cf); |
27af01d5 | 291 | |
3443546f LT |
292 | return 0; |
293 | } | |
294 | ||
295 | ||
296 | void xdl_free_env(xdfenv_t *xe) { | |
297 | ||
298 | xdl_free_ctx(&xe->xdf2); | |
299 | xdl_free_ctx(&xe->xdf1); | |
300 | } | |
301 | ||
302 | ||
303 | static int xdl_clean_mmatch(char const *dis, long i, long s, long e) { | |
ca557aff DL |
304 | long r, rdis0, rpdis0, rdis1, rpdis1; |
305 | ||
9b28d554 DL |
306 | /* |
307 | * Limits the window the is examined during the similar-lines | |
308 | * scan. The loops below stops when dis[i - r] == 1 (line that | |
309 | * has no match), but there are corner cases where the loop | |
310 | * proceed all the way to the extremities by causing huge | |
311 | * performance penalties in case of big files. | |
312 | */ | |
313 | if (i - s > XDL_SIMSCAN_WINDOW) | |
314 | s = i - XDL_SIMSCAN_WINDOW; | |
315 | if (e - i > XDL_SIMSCAN_WINDOW) | |
316 | e = i + XDL_SIMSCAN_WINDOW; | |
317 | ||
ca557aff DL |
318 | /* |
319 | * Scans the lines before 'i' to find a run of lines that either | |
320 | * have no match (dis[j] == 0) or have multiple matches (dis[j] > 1). | |
321 | * Note that we always call this function with dis[i] > 1, so the | |
322 | * current line (i) is already a multimatch line. | |
323 | */ | |
324 | for (r = 1, rdis0 = 0, rpdis0 = 1; (i - r) >= s; r++) { | |
3443546f | 325 | if (!dis[i - r]) |
ca557aff | 326 | rdis0++; |
3443546f | 327 | else if (dis[i - r] == 2) |
ca557aff | 328 | rpdis0++; |
3443546f LT |
329 | else |
330 | break; | |
331 | } | |
ca557aff DL |
332 | /* |
333 | * If the run before the line 'i' found only multimatch lines, we | |
334 | * return 0 and hence we don't make the current line (i) discarded. | |
335 | * We want to discard multimatch lines only when they appear in the | |
336 | * middle of runs with nomatch lines (dis[j] == 0). | |
337 | */ | |
338 | if (rdis0 == 0) | |
339 | return 0; | |
340 | for (r = 1, rdis1 = 0, rpdis1 = 1; (i + r) <= e; r++) { | |
3443546f | 341 | if (!dis[i + r]) |
ca557aff | 342 | rdis1++; |
3443546f | 343 | else if (dis[i + r] == 2) |
ca557aff | 344 | rpdis1++; |
3443546f LT |
345 | else |
346 | break; | |
347 | } | |
ca557aff DL |
348 | /* |
349 | * If the run after the line 'i' found only multimatch lines, we | |
350 | * return 0 and hence we don't make the current line (i) discarded. | |
351 | */ | |
352 | if (rdis1 == 0) | |
353 | return 0; | |
354 | rdis1 += rdis0; | |
355 | rpdis1 += rpdis0; | |
356 | ||
357 | return rpdis1 * XDL_KPDIS_RUN < (rpdis1 + rdis1); | |
3443546f LT |
358 | } |
359 | ||
360 | ||
361 | /* | |
362 | * Try to reduce the problem complexity, discard records that have no | |
363 | * matches on the other file. Also, lines that have multiple matches | |
364 | * might be potentially discarded if they happear in a run of discardable. | |
365 | */ | |
27af01d5 | 366 | static int xdl_cleanup_records(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2) { |
c5aa9068 | 367 | long i, nm, nreff, mlim; |
3443546f | 368 | xrecord_t **recs; |
27af01d5 | 369 | xdlclass_t *rcrec; |
3443546f LT |
370 | char *dis, *dis1, *dis2; |
371 | ||
848fd5ae | 372 | if (!XDL_CALLOC_ARRAY(dis, xdf1->nrec + xdf2->nrec + 2)) |
3443546f | 373 | return -1; |
3443546f LT |
374 | dis1 = dis; |
375 | dis2 = dis1 + xdf1->nrec + 1; | |
376 | ||
c5aa9068 RS |
377 | if ((mlim = xdl_bogosqrt(xdf1->nrec)) > XDL_MAX_EQLIMIT) |
378 | mlim = XDL_MAX_EQLIMIT; | |
3443546f | 379 | for (i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart]; i <= xdf1->dend; i++, recs++) { |
27af01d5 TRC |
380 | rcrec = cf->rcrecs[(*recs)->ha]; |
381 | nm = rcrec ? rcrec->len2 : 0; | |
c5aa9068 | 382 | dis1[i] = (nm == 0) ? 0: (nm >= mlim) ? 2: 1; |
3443546f LT |
383 | } |
384 | ||
c5aa9068 RS |
385 | if ((mlim = xdl_bogosqrt(xdf2->nrec)) > XDL_MAX_EQLIMIT) |
386 | mlim = XDL_MAX_EQLIMIT; | |
3443546f | 387 | for (i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart]; i <= xdf2->dend; i++, recs++) { |
27af01d5 TRC |
388 | rcrec = cf->rcrecs[(*recs)->ha]; |
389 | nm = rcrec ? rcrec->len1 : 0; | |
c5aa9068 | 390 | dis2[i] = (nm == 0) ? 0: (nm >= mlim) ? 2: 1; |
3443546f LT |
391 | } |
392 | ||
393 | for (nreff = 0, i = xdf1->dstart, recs = &xdf1->recs[xdf1->dstart]; | |
394 | i <= xdf1->dend; i++, recs++) { | |
395 | if (dis1[i] == 1 || | |
396 | (dis1[i] == 2 && !xdl_clean_mmatch(dis1, i, xdf1->dstart, xdf1->dend))) { | |
397 | xdf1->rindex[nreff] = i; | |
398 | xdf1->ha[nreff] = (*recs)->ha; | |
399 | nreff++; | |
400 | } else | |
401 | xdf1->rchg[i] = 1; | |
402 | } | |
403 | xdf1->nreff = nreff; | |
404 | ||
405 | for (nreff = 0, i = xdf2->dstart, recs = &xdf2->recs[xdf2->dstart]; | |
406 | i <= xdf2->dend; i++, recs++) { | |
407 | if (dis2[i] == 1 || | |
408 | (dis2[i] == 2 && !xdl_clean_mmatch(dis2, i, xdf2->dstart, xdf2->dend))) { | |
409 | xdf2->rindex[nreff] = i; | |
410 | xdf2->ha[nreff] = (*recs)->ha; | |
411 | nreff++; | |
412 | } else | |
413 | xdf2->rchg[i] = 1; | |
414 | } | |
415 | xdf2->nreff = nreff; | |
416 | ||
417 | xdl_free(dis); | |
418 | ||
419 | return 0; | |
420 | } | |
421 | ||
422 | ||
423 | /* | |
424 | * Early trim initial and terminal matching records. | |
425 | */ | |
426 | static int xdl_trim_ends(xdfile_t *xdf1, xdfile_t *xdf2) { | |
427 | long i, lim; | |
428 | xrecord_t **recs1, **recs2; | |
429 | ||
430 | recs1 = xdf1->recs; | |
431 | recs2 = xdf2->recs; | |
432 | for (i = 0, lim = XDL_MIN(xdf1->nrec, xdf2->nrec); i < lim; | |
433 | i++, recs1++, recs2++) | |
434 | if ((*recs1)->ha != (*recs2)->ha) | |
435 | break; | |
436 | ||
437 | xdf1->dstart = xdf2->dstart = i; | |
438 | ||
439 | recs1 = xdf1->recs + xdf1->nrec - 1; | |
440 | recs2 = xdf2->recs + xdf2->nrec - 1; | |
441 | for (lim -= i, i = 0; i < lim; i++, recs1--, recs2--) | |
442 | if ((*recs1)->ha != (*recs2)->ha) | |
443 | break; | |
444 | ||
445 | xdf1->dend = xdf1->nrec - i - 1; | |
446 | xdf2->dend = xdf2->nrec - i - 1; | |
447 | ||
448 | return 0; | |
449 | } | |
450 | ||
451 | ||
27af01d5 | 452 | static int xdl_optimize_ctxs(xdlclassifier_t *cf, xdfile_t *xdf1, xdfile_t *xdf2) { |
3443546f LT |
453 | |
454 | if (xdl_trim_ends(xdf1, xdf2) < 0 || | |
27af01d5 | 455 | xdl_cleanup_records(cf, xdf1, xdf2) < 0) { |
3443546f LT |
456 | |
457 | return -1; | |
458 | } | |
459 | ||
460 | return 0; | |
461 | } |